Livestock Research for Rural Development 19 (6) 2007 Guide for preparation of papers LRRD News

Citation of this paper

Coastal sand dune vegetation: a potential source of food, fodder and pharmaceuticals

K R Sridhar and B Bhagya

Microbiology and Biotechnology, Department of Biosciences, Mangalore University,
Mangalagangotri 574 199, Karnataka, India
sirikr@yahoo.com


Abstract

Coastal sand dune (CSD) flora has a wide range of applications in nutrition, medicine, industry and agriculture. The native people are intimately associated with dune vegetation for a variety of traditional benefits particularly food, fodder, health, soil fertility and recreation. Temperate CSDs comprise of mainly the members of Poaceae, while tropics with Asteraceae, Cyperaceae and Fabaceae and Poaceae. Many CSD legumes meet the protein and energy requirement of rural population and livestock. Canavalia maritima is a major strand legume with pantropical distribution. Tender pods and seeds are edible after boiling or roasting in Northern Australia, while seeds are important source of dietary protein in West Africa and Nigeria. Canavalia cathartica is another wild legume with wide distribution throughout CSDs of tropical Asia and Africa. Seeds of CSD Canavalia serve as potential source of proteins, carbohydrates, amino acids, fatty acids and energy. The CSD legumes of west coast of India are useful as green manure, mulch, cover crop, pasture, fodder, oil and medicinal value. The strand plants possess several bioactive compounds of human, veterinary and industrial importance.

The CSD vegetation is under severe threat mainly due to global warming and human interference and thus needs stringent restoration measures for sustainable use for coastal rural development.

Keywords: bioactive compounds, Canavalia, coastal sand dunes, disturbance, fodder, food, nutrition, restoration, traditional knowledge, vegetation, wild legumes


Introduction

Animal husbandry plays an important role in rural development and economy of developing countries. Nutrition is one of the most critical constraints to increase animal productivity in developing countries (ILRI 1995). Perpetual gap exists between the demand and supply of digestible crude protein and total digestible nutrients to livestock in Asian continent (Singh et al 1997). One of the challenges to uplift the livestock production is to increase the quality of legume-based pasture diets (Poppi and Mclennan 1995). The use of forage legumes as ruminant feed has increased in tropics to meet the protein deficiency. However, supplementation of animal protein for monogastric animals is expensive and not affordable by farmers (Umoren et al 2005). Feed supplementation with wild native legumes is economically viable and provides additional proteins, minerals and energy during dry season. Over the past few decades, research has been directed to evaluate nutritional qualities of underexplored legumes adapted to different habitats (Siddhuraju et al 1995, 2000, Vijayakumari et al 1997, Makkar et al 1998).

Coastal sand dunes (CSD) constitute a variety of habitats and vital ecological and economic importance (Maun and Baye 1989, Martinez et al 1997). Growth, survival and heterogeneity of CSD vegetation spatially and temporally influenced by environmental factors such as temperature, desiccation, low moisture retention, sand erosion, sand accretion, salinity and salt spray (Watkinson and Davy 1985, Maun 1994). Among the dune disturbances, burial is the most important factor followed by salt spray, which influences the distribution of dune plant species (Maun and Perumal 1999). Studies on CSD vegetation, restoration and stabilization confined mainly to temperate regions (Sylvia and Will 1988, Sylvia 1989, Koske and Gemma 1997). Several microflora adapted to strand environment live independently or mutually with vegetation (e.g. rhizobia, Frankia, mycorrhizas). The CSD flora has a wide range of economic value (e.g. nutritional, medicinal, industrial, agricultural) particularly for rural coastal population. The native people intimately associated with dune habitats are dependent on vegetation for a variety of benefits (e.g. food, fodder, health, soil fertility, recreation). The purpose of this review is to project the nature of vegetation on CSDs; nutritional value and bioactive potential of selected dune plants; traditional knowledge of native coastal dwellers on the use of dune plants in human health, veterinary and agriculture; threats to dune vegetation due to human interference and restoration measures with emphasis on Southwest coast of India.

Dune flora

Ammophila(American beach grass) is a major dune building grass adapted to temperate US Atlantic coast has highly influenced the coastal geomorphology and plant community structure (Maun and Baye 1989). Ammophila breviligulata adapted to CSDs becomes senescent on dune stabilization and replaced by other species. Ammophila arenaria (European beach grass or marram grass) is native to European CSDs and deliberately cultivated to stabilize the dunes (Seabloom and Wiedemann 1994). Desmoschoenus spiralis and Scirpoides nodosa are native plants species on the CSDs of New Zealand. The foredune complexes of New Zealand comprise of Calystegia soldanella, is a cosmopolitan prostrate species consists of long rhizomes capable of forming sand mounds. This plant species grow in association with Elymus farctus and Leymus arenarius and tolerate inundation of seawater. Uniola paniculata (sea oats) is a semitropical C4 perennial grass dominates the foredunes of southeastern US Atlantic and Gulf coasts (Hester and Mendelssohn 1987). It is also widely distributed in Bahama Islands and some parts of Cuba. Chamaecrista chamaecristoides is a shrubby legume endemic to Mexico and partly to the Pacific coast (Martinez and Moreno-Casasola 1998). It grows on mobile dunes, increases the biomass significantly on sand covering, fixes nitrogen and facilitates the succession of associated flora.

The dominant tropical coastal sand dune vegetation belongs to the Asteraceae, Cyperaceae, Fabaceae and Poaceae (Moreno-Casasola 1988; Arun et al 1999, Rao and Sherieff 2002). Most tropics and warm temperate shores consist of Ipomoea pes-caprae (Convolvulaceae) (St John 1970). It is a stoloniferous perennial creeping strand species confined to the Indian Ocean establishes along with 73 typical beach plant species in the Gulf of Mexico and tolerates sand erosion, accretion and inundation (Britton and Morton 1989, Devall 1992). Ipomoea brasiliensis is pantropical except for the Indian Ocean (Fosberg and Sachet 1977), while Ipomoea imperati confined to beaches and several islands (Leonard and Judd 1999). In addition to Ipomoea spp., CSDs of east coast of Africa consists of 156 plant species with Gramineae (17 species) and Papilionaceae (16 species) (Musila et al 2001). Stable sand dunes support higher richness and diversity of plant species than disturbed dunes. Dune plants of different microenvironments within the dunes are adapted to exploit nutrient pulses from rain and salt spray and exhibit different growth responses. They have more plasticity in allocation of biomass, wherein significantly high biomass will be allocated to roots than aerial tissues under most unfavourable conditions facilitates dune stabilization.

Indian subcontinent has a coastline of about 7516 km long with 2.1 million km2 exclusive economic zone and 0.13 million km2 continental shelf (Khoshoo 1996).The coastal zone is one among the 10 biogeographically important habitats of the Indian subcontinent (Rodgers and Panwar 1988). The CSD biogeographic regions of the Indian subcontinent have been divided into eight subdivisions (Pakistan, Kutchchh and Northwest Kathiawar, Southern Kathiawar-Gujarat, Konkan, Malabar, Coromandel-Circar, islands between India and Sri Lanka, Utkal and Bengal, Andaman and Nicobar Islands) (Rao and Meher-Homji 1985). A variety of psammophytic strand vegetation exists on the CSDs of the Indian Subcontinent (e.g. mat-forming creepers, prostrate/erect herbs and sedges, climbers, plants with perennating organs, scrubs, trees) (Rao and Meher-Homji 1985). Strand and associated flora of Indian CSDs consist of 154 species belonging to 108 genera and 41 families (Arun et al 1999, Rao and Sherieff 2002). Based on the number of species in each family, Fabaceae stands the highest (24 species) followed by Poaceae (22 species), Asteraceae (15 species) and Cyperaceae (13 species) (Table 1).

Table 1.  Families and species of coastal sand dune flora of the Indian  Subcontinent

Family

Number of species

Family

Number of species

Acanthaceae

4

Lythraceae

1

Aizoaceae

1

Malvaceae

3

Amaranthaceae

4

Molluginaceae

1

Anacardiaceae

1

Nyctaginaceae

1

Asclepiadaceae

2

Onagraceae

1

Asteraceae

15

Palmae

2

Boraginaceae

2

Pandanaceae

1

Cactaceae

1

Pedaliaceae

1

Capparaceae

1

Poaceae

22

Caryophyllaceae

1

Portulaceae

1

Casuarinaceae

1

Rhamnaceae

1

Clusiaceae

1

Rubiaceae

7

Commelinaceae

2

Salvadoraceae

1

Convolvulaceae

4

Sapindaceae

1

Cyperaceae

13

Scrophulariaceae

5

Euphorbiaceae

4

Solanaceae

4

Fabaceae

24

Sterculiaceae

1

Goodeniaceae

2

Tiliaceae

2

Lamiaceae

4

Verbenaceae

5

Lauraceae

1

Violaceae

1

Liliaceae

1

 

 

Source: Arun et al 1999, Rao and Sherieff 2002

Among the species of Fabaceae, frequency of occurrence of Canavalia maritima was highest (44.4%) followed by Canavalia cathartica (22.2%), Crotalaria verrucosa (18.1%), Derris triflorum (16.7%), Erythrina indica (15.3%) and Crotalaria retusa (12.5%) (Table 2). Economic value of some nitrogen fixing CSD legumes of Southwest coast of India has been given in Table 2.

Table 2.  Nitrogen fixing coastal sand dune legumes on the Indian Subcontinent, their habit, frequency of occurrence and economic value

Taxon

Habit

Frequency of

occurrence, %

Economic value

Aeschynomene indica

Herb

ND

Cover crop, green manure and mulch

Alysicarpus bupleurifolius

Herb

ND

 

Alysicarpus monilifer

Herb

ND

 

Alysicarpus rugosus

Herb

2.8

Fodder and seeds are edible

Alysicarpus vaginalis

Herb

2.8

Fodder and seeds are edible

Canavalia cathartica

Perennial creeper

22.2

Cover crop, green manure, forage, source of con A and medicinal

Canavalia maritima

Perennial creeper

44.4

Cover crop, green manure, forage, source of con A, medicinal and source of hallucinogen (L-betonicine)

Cassia tora

Herb

ND

Medicinal

Crotalaria nana

Herb

ND

Cover crop and green manure

Crotalaria pallida

Herb

ND

Cover crop and green manure

Crotalaria retusa

Under

shrub

12.5

Cover crop, green manure and pesticide

Crotalaria striata

Herb

9.7

Cover crop, green manure and medicinal

Crotalaria verrucosa

Herb

18.1

Medicinal

Derris triflorum

Woody creeper

16.7

Insecticidal and piscicide

Desmodium triflorum

Herb

ND

Medicinal

Erythrina indica

Small tree

15.3

Medicinal

Erythrina variegata

Small tree

ND

Medicinal

Geissaspis cristata

Herb

ND

 

Mimosa pudica

Herb

5.6

Medicinal

Pongamia pinnata

Tree

5.6

Medicinal and source of biodiesel

Tamarindus indica

Tree

1.4

Pulp and seeds are edible,  medicinal and leaves produce yellow dye 

Tephrosia purpurea

Under

shrub

ND

Cover crop, green manure, vegetable, antifeedant, pesticide, piscicide, cytotoxic and antitumor

Vigna spp.

Creeping

herb

4.2

Seeds edible, cover crop, green manure and mulch

Zornia gibbosa

Herb

ND

 

Source: Arun et al 1999, Rao and Sherieff 2002;   ND not indicated

The CSD vegetation withstand xeric and saline conditions probably due to association with a variety of stress-tolerant bacteria (e.g. nitrogen fixing) (Will and Sylvia 1990, Chen et al 2000, Arun and Sridhar 2004), endophytic fungi (Beena et al 2000, Seena and Sridhar 2004), endo- (Sturmer and Bellei 1994, Koske and Gemma 1997, Kulkarni et al 1997, Beena et al 2000, 2001, Bhagya et al 2005, Arun and Sridhar 2006) and ectomycorrhizae (van der Heijden et al 1999, Ashkannejhad and Horton 2005). These stress-tolerant microbes will be of immense value to domesticate CSD plants having forage and veterinary potential.
 

Food and fodder

Varieties of strand plants are useful as food or fodder. The whole plants of Cakile edentula serve as forage, its powdered roots with other flours used in bread preparation and the leaves are used in salads (Maun et al 1990). Mucuna and Sesbania of west coast of India are useful as fodder (Arun et al 1999, Arun 2002). Pods and seeds of Mucuna pruriens and Sesbania bispinosa are edible (Anonymous 1986, Arun et al 1999). Seed accessions of Sesbania bispinosa collected from Southern India possess adequate quantity of minerals, essential amino acids and essential fatty acids (Pugalenthi et al 2004). Canavalia maritima is one of the major mat-forming creepers of CSDs of southwest India (Arun et al 1999, Beena et al 2001, Seena and Sridhar 2006). The young pods and seeds consumed on boiling or roasting in Northern Australia, while seeds serve as source of dietary protein in West Africa and Nigeria (Abbey and Ibeh 1987). The whole plant is used as feed for rabbits in the southwest coast of India. Similarly, Canavalia cathartica is another wild ancestral form of Canavalia gladiata widely distributed in tropical Asia, Africa (Purseglove 1974) and southwest coast of India (Arun et al 1999, 2003). This legume is also known from Kenya, Seychelles, Tanzania, Japan, Taiwan, Bangladesh, Cambodia, Indonesia, Malaysia, Myanmar, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam, Australia and Hawaiian Islands (http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?310991). In view of economic value, agrobotanical, nutritional, antinutritional properties and bioavailability of proteins of Canavalia maritima and Canavalia cathartica of CSDs of southwest coast of India have been documented.

Canavalia cathartica and Canavalia maritima are perennial, stoloniferous herbaceous plant species withstand dry conditions of tropical CSDs (figure 1 a, b).

a

b

c

d

Figure 1.  Canavalia maritima (a) and Canavalia cathartica (b) grown on the coastal sand dunes of southwest coast of India showing tender and matured pods, dried seeds of Canavalia maritima (c) and Canavalia cathartica (d)

Canavalia cathartica yield larger and heavier pods than Canavalia maritima. The pods of Canavalia spp. are smooth, elongated, thick-walled and green turning yellow on ripening during October-November on the southwest coast of India. Dry seeds of Canavalia maritima are small, oval, bulged, bright orange to maroon with short hilum (figure 1 c), while Canavalia cathartica are large, oval, flattened, brownish black and occasionally striated with long hilum (figure 1 d) (Table 3).

Table 3.  Physical properties of seeds of Canavalia of coastal sand dunes (mean, n=20)

Properties

Canavalia maritimaa,b,c

Canavalia catharticaa,b

Total dry weight, g

0.42-0.5

0.64-0.74

Cotyledon weight, g

0.29-0.35

0.44-0.53

Coat weight, g

0.13-0.15

0.20-0.21

Length, cm

1.3

1.54

Width, cm

0.86

1.17

Thickness, cm

0.76

0.83

Hilum length, cm

0.55

0.97

aArun et al 2003,  bSeena and Sridhar 2006, cSeena et al 2005

Raw seeds of Canavalia cathartica possess highest crude protein (35.5%). Roasting and cooking decreased protein as well as crude fiber, while elevated crude lipids and total carbohydrates (Table 4).

Table 4.  Proximate composition (%) and energy (kJ/100 g) of seed flours of Canavalia of coastal sand dunes 

Composition

Canavalia  maritima a,b,c

Canavalia cathartica a,b,d

Raw

Roasted

Cooked

Raw

Roasted

Cooked

Crude proteins

34.1

30.0

28.39

35.5

30.5

29.2

Crude lipids

1.65-1.7

1.78

1.7

1.3

1.38

1.36

Total carbohydrates

50.5

60.53

65.8

52.8

65.3

65.42

Starch

ND

ND

ND

32.0

ND

ND

Crude fiber

2.26-10.2

2.14

1.7

1.7-7

1.66

0.96

Total dietary fiber

ND

ND

ND

236.02

ND

ND

Ash

3.5

3.5

3.18

3.08-3.1

3.0

3.1

Energy

1590

1622

1625

1520

1618

1630

aArun et al 2003, b Seena and Sridhar 2006, c Seena et al 2005, d Siddhuraju and Becker 2001, ND Not determined

The dietary guidelines published by USDA/HEW (1980) emphasize on increasing the amounts of dietary fiber in daily diet. As Canavalia seeds are excellent source of dietary fibers, it helps to prevent certain intestinal diseases (Hellendoorn 1979). Crude fiber promotes fast transmission of food through bowel (Van Soest 1975, Cummings 1978). The food containing high dietary fiber protects against atherosclerosis on binding to bile salts (Kritchevsky and Tepper 1968). The energy of raw and thermally processed Canavalia seeds (1520 and 1630 kJ/100 g) is higher than many cultivated legumes (1358.3-1426.2 kJ/100g (Kuzayali et al 1966).

There is a clear gap in our knowledge on vitamins, starch, sugars, dietary fiber, toxins and enzymes of Canavalia seeds. Canavalia seeds are known for several minerals, but it should be considered in conjunction with bioavailability (Table 5).

Table 5.  Mineral composition (mg/100 g) of seed flours of Canavalia of coastal sand dunes compared with NRC/NAS recommended pattern

Mineral

Canavalia  maritima a,b,c

Canavalia cathartica a,b

NRC/NAS

Patternd

Raw

Roasted

Cooked

Raw

Roasted

Cooked

Sodium

47.96-48

41.13

25.53

49.2-49.1

43.8

24.14

120-200

Potassium

974

931

251.49

889-895

821

190

500-700

Calcium

86.16-86.2

69

59.91

83.78-83.8

69.9

44.04

600

Phosphorus

158

124.14

111.62

137

112

99.4

500

Magnesium

23.11-23.13

22.8

17.51

5.14-5.3

4.55

3.58

60

Iron

4.53-4.54

2.57

1.99

2.88

2.45

2.18

10

Copper

0.28

0.18

0.11

0.2-0.35

0.13

0.1

0.6-0.7

Zinc

13.08-13.1

9.70

9.16

11.4

7.44

0.91

5

Manganese

2.02-2.04

2.3

1.13

1.36-1.44

1.22

0.79

0.3-1

aArun et al 2003,  b Seena and Sridhar 2006,  c Seena et al 2005,  d NRC/NAS 1989

Cooking lowered sodium, which is nutritionally advantageous in view of recommended low sodium intake in the diet. High quantity of potassium in Canavalia seeds is beneficial to those who take diuretics to control hypertension and suffer form excessive excretion of potassium through body fluids. Zinc and manganese meet the NRC/NAS (1989) requirements for infants, while phosphorus, magnesium, iron, copper and calcium are inadequate. Fatty acid composition of seeds reveals that palmitic and stearic acids are high in raw seeds of Canavalia maritima, while stearic acid in Canavalia cathartica (Table 6).

Table 6.  Fatty acid composition (mg/g lipid) and P/S ratio of seed flours of Canavalia of coastal sand dunes

Mineral

Canavalia  maritima a,b,c

Canavalia cathartica a,b

Raw

Roasted

Cooked

Raw

Roasted

Cooked

Saturated fatty acids

Palmitic (C16:0)

21.8-23

0.56

0.41

ND

ND

ND

Stearic (C18:0)

209-216

0.37

0.45

281.6

0.02

0.02

Arachidic (C20:0)

ND

ND

ND

ND

ND

ND

Behenic (C22:0)

ND

ND

ND

ND

ND

ND

Polyunsaturated fatty acids

Oleic (C18:1)

630-639

1.48

0.75

714

3.34

0.14

Linoleic (C18:2)

115-119

71

78.36

ND

81.35

76.35

Linolenic (C18:3)

ND

ND

ND

ND

ND

3.36

Total saturated fatty acids

234.9

0.93

0.86

281.6

0.02

0.02

Total unsaturated fatty acids

751.5

72.48

79.11

714

84.69

110.13

P/S ratiod

3.12

78

92

2.5

4234.5

5506.5

aArun et al 2003, bSeena and Sridhar 2006, cSeena et al 2005,
dPolyunsaturated / Saturated fatty acid ratio, ND Not detectable

Raw seeds of Canavalia cathartica possess high quantity of oleic acid, while linoleic acid in Canavalia maritima. Roasting and cooking drastically decreased linoleic acid in Canavalia maritima (115-119 vs. 71-78.4 mg/g lipid). Although raw seeds of Canavalia cathartica were devoid of linoleic acid, roasted and cooked seeds possess linoleic acid (76.4-81.4 mg/g lipid). Similarly, linolenic acid was found only in cooked seeds of Canavalia cathartica. As animals and humans cannot synthesize essential fatty acids, they are required in diets for normal growth and function of all tissues, synthesis of prostaglandin (FAO/WHO 1977) and development and functions of brain (Lamptey and Walker 1976) and retina (Benolken et al 1973). In Canavalia spp. polyunsaturated to saturated fatty acid ratio (P/S ratio) progressively increased from raw, roasted and cooked seeds. High P/S ratio is known to lower the risk of cardiovascular diseases (Ezeagu et al 1998).

Albumins and globulins are the major storage proteins, which constitute about 90% of the total proteins in Canavalia seeds (Table 7).

Table 7.   True protein and fractions (mg/100 mg protein) of seed  flours of Canavalia of coastal sand dunes

Fraction

Canavalia maritimaa,b,c

Canavalia catharticaa,b

True protein

29.3

28.6-28.8

Albumins

7.46-7.6

7.28-7.4

Globulins

18.74-18.8

18.3-18.5

Prolamins

0.28-0.3

0.3

Glutelins

2.86-2.8

2.7

aArun et al 2003, bSeena and Sridhar 2006, cSeena et al 2005

Albumins are rich in sulfur-amino acids and other essential amino acids (EAA) (Baudoin and Maquet 1999). Although many legumes are deficient in sulfur-amino acids, they are rich in lysine (Evans and Bauer 1978, Pusztai et al 1979, Sathe et al 1981). Interestingly, all EAA except for tryptophan and histidine in raw Canavalia seeds surpassed the FAO/WHO (1991) and FAO/WHO/UNU (1985) recommended patterns (Table 8).

Table 8.   Essential amino acid composition of seed flours of Canavalia of coastal sand dunes (mg/100 mg protein) compared with FAO/WHO/UNU recommended patterns

Amino acid

Canavalia maritima a,b,c

Canavalia maritimaa,b

FAO/WHO

Patternd

FAO/WHO/

UNU patterne

Raw

Roasted

Cooked

Raw

Roasted

Cooked

Threonine

5.2

2.4

1.34

3.8-4.7

2.0

1.82

3.4

0.9

Valine

6.8

2.7

2.18

4.8-5.95

2.9

2.23

3.5

1.3

Cystine + Methionine

6.08-8.0

6.6

3.32

6.39-6.8

5.6

4.11

2.5

1.7f

Isoleucine

5.4

2.3

2.0

4.1-5.14

2.6

1.9

2.8

1.9

Leucine

10.3

4.9

4.20

9.4-11.65

5.1

3.9

6.6

1.3

Tyrosine + Phenylalanine

11.5

7.5

6.62

9.2-11.4

6.1

5.89

6.3

1.9g

Tryptophan

ND

ND

ND

ND

ND

ND

1.1

0.5

Lysine

13

7.5

3.72

12-14.7

6.1

4.58

5.8

1.6

Histidine

ND

ND

ND

ND

ND

ND

1.9

1.6

aArun et al 2003, b Seena and Sridhar 2006, c Seena et al 2005, d FAO/WHO 1991, eFAO/WHO/UNU 1985,
f
Cystine + Methionine,  gTyrosine + Phenylalanine, ND Not detectable

The EAA of seeds reduced on thermal processing (e.g. pressure-cooking), however most EAA meets the required standard. As in other legumes, seeds of Canavalia are also known to possess antinutritional factors (ANFs) such as phenolics and phytohemagglutinins. Elimination or reduction of ANFs is desirable to improve the nutritional quality and acceptability. Total phenolics in Canavalia seeds were low, while tannins and trypsin inhibition activity are absent (Table 9).

Table 9.  Antinutritional components of seed flours of Canavalia of coastal sand dunes

 

Canavalia maritimaa,b,c

Canavalia catharticaa,b

Raw

Roasted

Cooked

Raw

Roasted

Cooked

Total phenolics, mg/100 mg

1.37

1.42

1.1

1.5

1.53

1.29

Tannins

NP

NP

NP

NP

NP

NP

Trypsin inhibition activity

NP

NP

NP

NP

NP

NP

Phytohemagglutinin activity

Rabbit RBC

+++

++

++

+++

++

++

aArun et al 2003, bSeena and Sridhar 2006,  cSeena et al 2005,
NP Not present,  ++ RBC showed clumpy patches,  +++ Grainy

In vivo growth and nitrogen balance studies of Canavalia seeds with rat model revealed that roasting and pressure-cooking partially effective in detoxifying the undesirable components (Table 10).

Table 10.   In vivo protein bioavailability of seed flours of Canavalia of coastal sand dunes

 

Canavalia maritimaa,b

Raw

Roasted

Cooked

Protein efficiency ratio (PER)

0.1

0.38

0.48

True digestibility (TD), %

42.26

51.29

53.71

Biological value (BV), %

37.55

43.34

47.83

Net protein utilization (NPU), %

16.88

22.23

25.72

 a Seena and Sridhar 2006, b Seena et al 2005

The biological indices analysed for raw Canavalia seed proteins significantly different with casein-fed rats. However, the bioavailability studies proved that pressure-cooked seeds have better biological indices than roasted seeds. Low performance of rats fed with raw seed diet may be due to the presence of ANFs. Single method of processing cannot eliminate all the ANFs of Canavalia seeds and combination of methods warranted. Several methods of seed processing (e.g. soaking, cooking, germination, dehusking, fermentation, roasting or frying) are available to overcome the problems posed by ANFs.

Bioactive compounds and medicinal value

The strand plants possess many useful bioactive compounds of pharmaceutical and veterinary importance. Extracts of Ipomoea pes-caprae serve as ingredient in indigenous medicines (hot water extract used to treat strain, fatigue and physical weakness) (Halberstein and Saunders 1978). Ipomoea pes-caprae is useful as diuretic in French Guyana, in treatment of rheumatism in India and arthritis in Nigeria (Luu 1975, Iwu and Anyanwu 1982). Cakile edentula is diuretic, antiscorbutic and purgative agent (Maun et al 1990). Some legumes of CSDs of southwest coast of India yield oil and possess many medicinal uses (Arun et al 1999, Arun 2002). Monocrotaline of Crotalaria retusa is antileukemic, antitumor, cardio-depressant and hypotensive, while retusin is antineoplastic. Indigotin derived form Indigofera tinctoria has antiseptic and astringent properties, whereas indirubin of I. tinctoria is antileukemic. Various phytochemicals derived from Mucuna pruriens are pharmacologically valuable. Bufotenine is a cholinesterase inhibitor, 3,4-dihydroxy phenylalanine (L-DOPA) is anti-Parkinsonian, mucunain is antihelminthic and serotonin is antiaggregant, antigastric, cholinesterase inhibitor, coagulant, myorelaxant and myostimulant. Lupeol derived from Tephrosia purpurea fights against tumors and rheumatic problems. Derris triflorum stem consists of rotenone, which serve as antitumor compound (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15229812) as well as potential bioinsecticide. Trigonelline of Canavalia maritima fights against cervical and liver cancers and lowers blood sugar level.

Concanavalin A (con A) of Canavalia ensiformis is known for a wide range of uses (e.g. antiviral, mutagenic, isolation of immunoglobulin, tumor therapy by immunomodulation, blood group substances, glycoprotein hormones) (Surolia et al 1973, Ruediger and Gabius 2001). Con A can be used as spermatogenic and epididymal-specific cell markers. Histological observations of normal and pathologically altered human peripheral nerves through fluorescein isothiocyanate labeled con A provides baseline information on the reaction pattern of lectins with human peripheral nerves and thereby a tool to study peripheral nerve pathology (Estruch and Damjanov 1986). Histochemistry using con A is a reliable tool to understand the structural and secretary glycoconjugates of jejunal mucosa related diseases of cell maturation cycle of small bowel (Vecchi et al 1987). Con A also serves as a marker of structural changes in various stages of normal and abnormal epidermal cell differentiation (Reano et al 1982). Carcinomas from different colonic regions have uniform distribution of carbohydrates than normal mucosa was traced using con A of C. ensiformis (Caldero et al 1989). Rodrigues and Torne (1990) suggested that seed lectins of C. gladiata can be used as an anti A, anti B, while lectins of Canavalia cathartica as anti O and anti Oh (Bombay group) blood grouping reagents. As mannose-binding lectin, con A is useful in creating transgenic plants resistant to insect herbivory (Sauvion et al 2004). The L-amino-4-(guanidinooxy) butyric acid or L-canavanine (also known as cav) of Canavalia possesses antitumor activity against Walker carcinoma, human melanoma, pancreatic cancer (Kruse and McCoy 1958, Mattei et al 1992, Swaffar et al 1994), in vivo murine leukemia and rat colon tumor (Green et al 1980, Thomas et al 1986). The Cav is also suitable for pancreatic cancer study due to lack of considerable amount of arginase in pancreas (Swaffar and Ang 1999). Seeds of C. ensiformis are commercial source of urease and it catalyzes hydrolysis of urea to ammonia, carbon dioxide and water (Rosenthal 1974, Staples and Reithel 1976, Dixon et al 1980). Saponins are recently shown to have hypocholesterolemic as well as anticarcinogenic effects (Koratkar and Rao 1997), thus exploration of nutraceutical properties of CSD Canavalia is important.

Intense studies should be focused on the bioactive compounds of CSD vegetation to meet the specific veterinary requirements of coastal rural dwellers. The rural traditional veterinary healers use several dune plant species for healing ailments of livestock. Following are some examples of use of CSD plant species of Southwest coast of India for veterinary purpose. The leaf juice of Cassia alata useful in preventing hair fall of cattle skin, while ground leaves of Cassia tora with salt is useful in prevention of cattle skin diseases. The ground Crotalaria seeds are also useful in treating cattle skin diseases. Pongamia seed oil and stem juice are useful to treat a vaeiety of cattle skin diseases. For cattle indigestion or constipation, bark of Erythrina ground into paste and administered orally, likewise the juice made out of ground Tamarindus bark is also given orally. The paste of ground leaves of Indigofera will be applied to prevent swelling of udder, while the roots of Indigofera are useful in treatment for diarrhea of calves. The whole plant of Mimosa administered orally after delivery of calf to control bleeding. Similarly, juice of the whole plant of Mimosa is useful in prevention of slipping of uterus after delivery. The specific knowledge on the veterinary uses of CSD plant species have been gained through inherent traditional means and practice by the coastal dwellers. More information has been given in the following section about the traditional knowledge of coastal dwellers. Assessment of plant parts in different seasons may provide more insight to use specific part of plants to meet the nutritional or pharmaceutical or veterinary requirement. Production of value-added metabolites by CSD vegetation under xeric and stressed habitats needs further exploration. In view of pharmaceutical as well as veterinary potential, specific dune plant species besides in situ conservation deserves ex situ conservation and domestication in coastal farms.
 

Traditional knowledge

Several direct and indirect uses of CSD plant species are unnoticed as they are traditional practices. Many legumes of CSDs of west coast of India are useful as green manure, mulch, cover crops, fodder, pasture legumes, oil and medicinal value (Arun et al 1999, Arun 2002). Canavalia seeds are important source of dietary protein in West Africa and Nigeria for humans and livestock (Abbey and Ibeh 1987). Boiled or roasted tender pods and seeds of Canavalia are edible in Northern Australia, while fishermen occasionally consume processed tender pods and ripened beans in southwest coast of India. Pandanus fruits are used as insect repellent and leaf fibers are useful to preserve paddy (packed paddy called 'Mudi') in coastal India. Canavalia maritima is a common cover crop in arid lands of Australia and Africa. It checks soil erosion in dry and sandy areas of southwest coast of India and grown by farmers in agricultural fields as cover crops after harvest of main crops (e.g. paddy, sugarcane) to improve the soil nitrogen budget. Australian aboriginals use Canavalia maritima for medicinal purposes. In South America, Africa and Gulf of Mexico its beans are ingested or smoked with dried leaves, which has an active principle L-betonicine and suspected to be similar to marijuana. Roots of Canavalia maritima are also useful in curing skin diseases in southwest coast of India. Derris triflorum leaves are crushed and used to stun or kill fish and shrimp for easy catch, while leaves and roots are also used as laxative (Bhandaranayake 1998). Stem of Derris triflorum is highly fibrous and serves as cordage for coastal dwellers. Documentation of traditional knowledge and uses of CSD vegetation for nutritional and health purposes is utmost important in view of intellectual property rights of specific geographical region. No systematic efforts have been focused on the traditional uses of CSD vegetation by the coastal dwellers (e.g. fisherman community), such efforts facilitates to develop strategies for effective use as well as appropriate conservation measures. Exploration and implementation of traditional knowledge of coastal dwellers in preservation and sustainable use of xeric CSD vegetation for the benefit of livestock and veterinary uses needs utmost importance.

Threats and restoration

Various natural forces influencing CSD vegetation include sea level changes, wind regime, movement of dunes, storms and climatic changes. Global warming and climatic changes (e.g. increase in sea level) has direct impact on CSD vegetation. Several human interferences (industrialization, pollution, waste disposal, harbours, roads, sand mining, sea-fencing, commercial or social forestry, construction of resorts and beach tourism) cause destabilization of CSDs and severely influence the dune ecosystem. According to Oosting and Billings (1942), disturbances such as fire, grazing and foot and vehicular traffic cause migrating dunes. Migration of sand dunes enhanced when the vegetation on stabilized dunes is seriously damaged or destroyed. As sea erosion is a major problem in temperate and tropical regions, extensive projects have been implemented to avoid beach erosion in US Atlantic coast (Sylvia and Will 1988, Sylvia 1989, Read 1989, Koske and Gemma 1997).

Grasses have been planted along the beaches to initiate dune-building processes to prevent erosion losses in the Atlantic coast. Intermediate scale of disturbance of CSDs facilitates the insulation of seedling roots from high temperature and desiccation, access to soil moisture, high nutrient resulting in increased plant species richness and diversity (Connell 1978, Maun 1994, Beena et al 2000). Burial of seeds, seedlings and plants in CSDs increase the abundance of tolerant plant species (Maun 1998). Burial of six tropical sand dune plant species resulted increased plant vigor and allocation of more biomass to aerial parts (Martinez and Moreno-Casasola 1996). Severe disturbance of CSDs reduces or destroys the obligate plant symbiotic fungi (arbuscular mycorrhizae), which results in the reduction or elimination of plant species (Reeves et al 1979). Such disturbances are fatal and require long-term for re-establishment of mycorrhizal vegetation, natural plant succession and dune stabilization. A variety of human interferences affect CSD biota (e.g. fishing activities, recreation activities, dredging, shell mining, sand mining, gravel harvesting, shoreline modification, oil spills, waste dumping, stone fencing and road construction). Stone fencing cannot replace vegetation of CSDs, but reduce the input of nutrients to dunes. These activities besides affecting dune microflora and vegetation, interferes the biogeochemical cycles (e.g. nitrogen, phosphorus). Deficiency of organic carbon reduce the N, S and P storage capacity of soil, thus decrease soil fertility (Hartenstein 1986). Turnover of organic matter by soil invertebrates helps biogeochemical cycling of elements (Krivolutzky and Pokarzhevsky 1977). For instance, calcium assimilation takes place in invertebrates through fungi as calcium oxalate. Microbial transformation of calcium oxalate and oxaloacetic acid into ionic calcium in the digestive system influences the calcium cycle in soil.

Garcia-Mora et al (2000) monitored plant diversity of 30 coastal dunes of Portugal and Spain and concluded that the dune vulnerability is mainly due to human disturbance. Large dune areas have been reclaimed for forest and farmland in New Zealand to implement traditional principles and knowledge to restore dunes for future needs (Gadgil and Ede 1998). Among the methods employed to stabilize the CSDs, revegetation is the best alternative because as it is least expensive, long lasting and self-sustaining (Woodhouse 1978). In the absence of such vegetation, the wind action on the exposed sand leads to migrating dunes that move back and forth with the wind (Chapman 1976). In an effort to stabilize the dunes, extensive plantations of exotic tree species (e.g. Casuarina, Acacia) has been planted at about 50 m away from the low tide line (Nordstorm and Lotstein 1989, Kutiel et al 2000). However, unless the site is well vegetated, the dune will not last long against wind erosion and storm tides. Several measures have been implemented to prevent erosion in Atlantic Coast of the US (Read 1989, Sylvia 1989, Koske and Gemma 1997). Planting grasses along the beaches to initiate dune building is one of the important measures. Native plant species withstand environmental perturbations of dunes and support stabilization. In Pacific Coast, establishing grass stands with perennial legume purple beachpea (Lathyrus maitimus) was effective in nourishment of dunes (Brown 1948). Fertilizing the American beachgrass with N, P, K and limestone showed success in Atlantic Coast (Seliskar 1995). A few pioneer perennial dune grasses are effective to stabilize CSDs of the US: American beachgrass (Ammophila breviligulata) (North Pacific, North Atlantic and Great Lakes), European beachgrass (Ammophila arenaria) (North and South Pacific), bitter panicum (Panicum amarum) (South Atlantic and Gulf Coasts), sea oats (Uniola peniculata) (South Atlantic and Gulf Coasts) and salt-meadow cordgrass (Apartina patens) (South Atlantic Gulf Coasts) (Woodhouse 1978). Inoculation of arbuscular mycorrhizal fungi (e.g. Gigaspora gigantea) enhanced the success of transplant of Ammophila (Maun and Baye 1989, Gemma and Koske 1997). In Southern US, A. berviligulata, I. pes-caprae and Uniola paniculata have been used for dune stabilization (Woodhouse et al 1968).

Tree species adapted to coastal habitats immensely useful in dune stabilization and habitat restoration. Tree fencing is an effective means in trapping sand and reduces the wind velocity in their immediate vicinity (Woodhouse 1978). Barron and Dalton (1996) attempted direct seeding of Acacia sophorae and Eucalyptus diversifolia on CSDs of southern Australia. Success of seedling survival and growth of shrub plant species (Myrica cerifera) in Virginia Barrier Island was dependent on nitrogen fixing symbiont (Frankia) (Wijnholds and Young 2000). Multistoried cropping using mat-forming creepers, grasses, sedges, xerophytes, scrubs, herbs and tree species may effectively withstand wind and wave action, build the dunes and restore landscapes of CSDs. There is ample scope to restore the tropical CSDs as they consist of diverse stress-tolerant plant species. The ecological services derived from CSDs are of immense value than currently considered as benefits (e.g. shell mining, sand mining, gravel harvesting, waste dumping). Strategies have to be implemented for protection and sustainable use of CSD vegetation in coastal areas for the benefit of farmers particularly for food, fodder and health promotion.

Conclusions

Acknowledgements

The authors are grateful to Mangalore University for granting permission to carry out this study at the Department of Biosciences. We are indebted to the editor as well as referee for comments and constructive suggestions for improvement of manuscript.
 

References

Abbey B W and Ibeh G O 1987 Functional properties of raw and heat processed brown bean (Canavalia rosea DC.) flour. Journal of Food Science 52: 406-408.

Ashkannejhad S and Horton T R 2005 Ectomycorrhizal ecology under primary succession on coastal sand dunes: interactions involving Pinus contorta, suilloid fungi and deer. New Phytologist 169: 345-354.

Anonymous 1986 The Useful Plants of India. Publications and Information Directorate, Council of Scientific and Industrial Research, New Delhi, India.

Arun A B 2002 Studies on Coastal Sand Dune Legumes of Karnataka (India). Ph.D. Thesis, Mangalore University, Mangalore, Karnataka, India.

Arun A B, Beena K R, Raviraja N S and Sridhar K R 1999 Coastal sand dunes - A neglected ecosystem. Current Science 77: 19-21.

Arun A B and Sridhar K R 2004 Symbiotic performance of fast-growing rhizobia isolated from the coastal sand dune legumes of west coast of India. Biology and Fertility of Soils 40: 435-439.

Arun A B and Sridhar K R 2006 Arbuscular mycorrhizal association with coastal sand dune legumes of southwest coast of India. Mycorrhiza News 18: 13-17.

Arun A B, Sridhar K R, Raviraja N S, Schmidt E and Jung K 2003 Nutritional and antinutritional components of Canavalia spp. seeds from the west coast sand dunes of India. Plant Foods for Human Nutrition 58: 1-13.

Barron P and Dalton G 1996 Direct seeding of native trees and shrubs in coastal environments. Journal of Coastal Research 12: 1006-1008.

Baudoin J P and Maquet A 1999 Improvement of protein and amino acid content in seeds of food legumes - A case study in Phaseolus. Biotechnology and Agronomical Society of Environment 3: 220-224.

Beena K R, Arun A B, Raviraja N S and Sridhar K R 2001 Association of arbuscular mycorrhizal fungi with plants of coastal sand dunes of west coast of India. Tropical Ecology 42: 213-222.

Beena K R, Raviraja N S, Arun A B and Sridhar K R 2000 Diversity of arbuscular mycorrhizal fungi on the coastal sand dunes of the west coast of India. Current Science 79: 1459-1466.

Benolken R M, Anderson R E and Wheeler T G 1973 Membrane fatty acids associated with the electrical response in visual excitation. Science 182: 1253-1254.

Bhagya B, Sridhar K R and Arun A B 2005 Diversity of legumes and arbuscular mycorrhizal fungi in the coastal sand dunes of southwest coast of India. International Journal of Forest Usufructs Management 6: 1-18.

Bhandaranayake W M 1998 Traditional and medicinal uses of mangroves. Mangroves and Salt Marshes 2: 133-148.

Britton J C and Morton B 1989 Shore Ecology of the Gulf of Mexico. University of Texas Press, Texas.

Brown R L 1948 Permanent coastal dune stabilization with grasses and legumes. Journal of Soil and Water Conservation 3: 69-74.

Caldero J, Campo E, Ascaso C, Ramos J, Panades M J and Rene J M 1989 Regional distribution of glycoconjugates in normal, transitional and neoplastic human colonic mucosa: A histochemical study using lectins. Vircghows Archiv A Patholgoical Anatomy and Histopathology 415: 347-356.

Chapman V J 1976 Coastal Vegetation. 2nd Edition, Pergamon Press, Oxford.

Chen W M, Lee T M, Lam C C and Cheng C P 2000 Characterization of halotolerant rhizobia isolated from root nodules of Canavalia rosea from seaside areas. FEMS Microbiology Ecology 34: 9-16.

Connell J H 1978 Diversity in tropical rain forests and coral reefs. Science 199: 1302-1310.

Cummings J H 1978 Nutritional implications of dietary fiber. American Journal of Nutrition 31: 521-529.

Devall M S 1992 The biological flora of coastal sand dunes and wetlands. 2. Ipomoea pes-caprae (L.) Roth. Journal of Coastal Research 8: 442-456.

Dixon N E, Riddles P W, Gazzola C, Blakeley R L and Zerner B 1980 Jack bean urease (EC 3.5.1.5) on the mechanism of action of urease and urea, formamide, acetamide, n-methyl urea and related compounds. Canadian Journal of Biochemistry 58: 1534-1535.

Estruch R and Damjanov I 1986 Lectin histochemistry applied to human nerves.Archives of Pathology and Laboratory Medicine 110:730-735.

Evans R J and Bauer D H 1978 Studies of the poor utilization by the rat of methionine and cystine in heated dry bean seed (Phaseolus vulgaris), Journal of Agricultural and Food Chemistry 26: 779-784.

Ezeagu I E, Petzke K J, Lange E and Metgea C C 1998 Fat content and fatty acid composition of oils extracted from selected wild gathered tropical plant seeds from Nigeria. Journal of the American Oil Chemists' Society 75: 1031-1035.

FAO/WHO 1977 Dietary Fats and Oils in Human Nutrition. Food and Agriculture Organization, Rome.

FAO/WHO 1991 Protein quality evaluation. Reports of a joint FAO/WHO Expert Consultation, Food and Agriculture Organization of the United Nations, FAO, Rome, Food and Nutrition Paper # 51, 1-66.

FAO/WHO/UNU 1985 Energy and protein requirements. WHO Tech Rep Ser # 724, Geneva.

Fosberg F R and Sachet M H 1977 Flora of Micronesia 3. Convolvulaceae. Smithsonian Contributions to Botany 36: 1-34.

Gadgil R L and Ede F J 1998 Application of scientific principles to sand dune stabilization in New Zealand: past progress and future needs. Land Degradation and Development 9: 131-142.

Garcia-Mora M R, Gallego-Fernandez J B and Garcia-Novo F 2000 Plant diversity as a suitable tool for coastal dune vulnerability assessment. Journal of Coastal Research 16: 990-995.

Gemma J N and Koske R E 1997 Arbuscular mycorrhizae in sand dune plants of the North Atlantic coast of the US: field and greenhouse inoculation and presence of mycorrhizae in planting stock. Journal of Environmental Management 50: 251-264

Green M H, Brooks T L, Mendelsohn L and Howell S B 1980 Antitumor activity of L. canavanine against L1210 murine leukemia. Cancer Research 40: 535-537.

Halberstein R A and Saunders A B 1978 Traditional medicinal practices and medicinal plant usage on a Bahamanian Island. Cultural and Medical Psychiatry 2: 177-203.

Hartenstein R 1986 Earthworm biotechnology and global biogeochemistry. Advances Ecological Research 15: 379-409.

Hellendoorn E W 1979 Beneficial physiological activity of leguminous seeds. Plant Foods Human Nutrition 29: 227- 244.

Hester M W and Mendelssohn I A 1987 Seed production and germination response of four Louisiana populations of Uniola paniculata (Gramineae). American Journal of Botany 74: 1093-1101.

ILRI 1995 (International Livestock Research Institute) Global agenda for livestock research. In: Proceedings of a Consultation. (Editors, Gardiner P R and Devendra C), Nairobi, Kenya.

Iwu M M and Anyanwu B N 1982 Phytotherapatic profile of Nigerian herbs. 1. Anti-inflammatory and anti-arthritic agents. Journal of Phytotherapy 9: 125.

Khoshoo T N 1996 Vesicular-arbuscular mycorrhizae of Hawaiian dune plants. Current Science 71: 506-513.

Koratkar R and Rao A V 1997 Effect of soya bean saponins on azoxymethane-induced preneoplastic lesions in the colon of mice. Nutrition and Cancer 27: 206-209.

Koske R E and Gemma J N 1997 Mycorrhizae and succession in plantings of beachgrass in sand dunes. American Journal of Botany 84: 118-130.

Kritchevsky D and Tepper S A 1968 Experimental atherosclerosis in rabbits fed cholesterol-free diets: Influence of chow components, Journal of Atherosclerosis Research 8: 357- 369.

Krivolutzky D A and Pokarzhevsky A D 1977 The role of soil animals in nutrient cycling in forest and steppe. Ecological Bulletin 25: 253-260.

Kruse P R, McCoy T A 1958 The competitive effect of canavanine on utilization of arginine in growth of Walker carcinosarcoma 256 cells in vitro. Cancer Research 18: 279-282.

Kulkarni S S, Raviraja N S and Sridhar K R 1997 Arbuscular mycorrhizal fungi of tropical sand dunes of west coast of India. Journal of Coastal Research 13: 931-936.

Kutiel P, Peled Y and Geffen E 2000 The effect of removing shrub cover on annual plants and small mammals in a coastal sand dune ecosystem. Biological Conservation 94: 235-242.

Kuzayali M V, Cowan J W and Sabry Z I 1966 Nutritive value of Middle Eastern foodstuffs - II. Composition of pulses, seeds, nuts and cereal products of Lebanon. Journal of Science of Food and Agriculture 17: 82-84.

Lamptey M S and Walker B L 1976 A possible essential role of dietary linolenic acid in the development of the young rat. Journal of Nutrition 106: 86-93.

Leonard R I and Judd F W 1999 The biological flora of coastal dunes and wetlands Impomoea imperati (Vahl.) Griseb. Journal of Coastal Research 15: 645-652.

Luu C 1975 Notes on the traditional pharmacopoeia of French Guyana. Plant Medicinal Phytotherapy 9: 125.

Makkar H P S, Aderibige A O, Becker K 1998 Comparative evaluation of non toxic and toxic varieties of Jatropha curcas for chemical composition, digestibility, protein degradability and toxic factors. Food Chemistry 62: 207-215.

Martinez M L and Moreno-Casasola P 1996 Effects of burial by sand on seedling growth and survival in six tropical sand dune species from the Gulf of Mexico. Journal of Coastal Research 12: 406-419.

Martinez L M and Moreno-Casasola P 1998 The biological flora of coastal dunes and wetlands: Chamaecrista chamaecristoides (Colladon) I. & B. Journal of Coastal Research 14: 162-174.

Martinez M L, Moreno-Casasola P and Vazquez G 1997 Effects of disturbance by sand movement and inundation by water on tropical dune vegetation dynamics. Canadian Journal of Botany 75: 2005-2014.

Mattei E, Damasi D, Mileo A M, Delpino A and Ferrini U 1992 Stress response, survival and enhancement of heat sensitivity in a human melanoma cell line treated with L-canavanine. Anticancer Research 12: 757-762.

Maun M A 1994 Adaptations enhancing survival and establishment of seedling on coastal dune systems. Vegetatio 111: 59-70.

Maun M A 1998 Adaptations of plants to burial in coastal sand dunes. Canadian Journal of Botany 76: 713-738.

Maun M A and Baye P R 1989 The ecology of Ammophila breviligulata Fern. On coastal dune ecosystem. CRC Critical Reviews in Aquatic Science 1: 661-681.

Maun M A, Boyd R S and Olson L 1990 The biological flora of coastal dunes and wetlands 1. Cakile edentula (Bigel.) Hook. Journal of Coastal Research 6: 137-156.

Maun M A and Perumal J 1999 Zonation of vegetation on lacustrine coastal dunes: effect of burial by sand. Ecology Letters 2: 14-18.

Moreno-Casasola P 1988 Patterns of plant species distribution on coastal dunes along the Gulf of Mexico. Journal of Biogeography 15: 787-806.

Musila W M, Kinyamario J I and Jungerius P D 2001 Vegetation dynamics of coastal sand dunes near Malindi, Kenya. African Journal of Ecology 39: 170-177.

Nordstorm K F and Lotstein E L 1989 Perspectives on resource use of dynamic coastal dunes. The Geographical Review 79: 1-12.

NRC/NAS 1989 Recommended Dietary Allowances. 10th Edition, National Academy Press, Washington DC.

Oosting H J and Billings W D 1942 Factors affecting vegetational zonation on coastal dunes. Ecology 23: 131-142.

Poppi D P and Mclennan S R 1995 Protein and energy utilization by ruminants at pasture. Journal of Animal Science 73: 278-290.

Pugalenthi M, Vadivel V, Gurumoorthi P and Janardhanan K 2004 Comparative nutritional evaluation of little known legumes, Tamarindus indica, Erythirna indica and Sesbania bispinosa. Tropical and Subtropical Agroecosystems 2: 107-123.

Purseglove J W 1974 Tropical crops: Dicotyledons. Longman, London, pp 242-246.

Pusztai A, Clarke E M W, King T P and Stewart J C 1979 Nutritional evaluation of kidney beans (Phaseolus vulgaris): Chemical composition, lectin content and nutritional value of selected cultivars. Journal of Science of Food and Agriculture 30: 843-848.

Rao T A and Meher-Homji V M 1985 Strand plant communities of the Indian sub-continent. Proceedings of Indian Academy of Science (Plant Science) 94: 505-523.

Rao T A and Sherieff A N 2002 Coastal Ecosystem of the Karnataka State, India II - Beaches. Karnataka Association for the Advancement of Science, Bangalore, India.

Read D J 1989 Mycorrhizas and nutrient cycling in sand dune ecosystem. Proceedings of Royal Society of Edinburgh 96: 89-100.

Reano A, Faure M, Jacques Y, Reichert U, Schaefer H and Thivolet J 1982 Lectins as markers of human epidermal cell differentiation. Differentiation 22: 205-210.

Reeves F B, Wagner D, Moorman T and Kiel J 1979 The role of endomycorrhizae in revegetation practices in the semi-arid west. I. A comparison of incidence of mycorrhizae in severely disturbed vs. natural environments. American Journal of Botany 66: 6-13.

Rodgers W A and Panwar H S 1988 Planning a Wildlife Protected Area Network in India. Volume 1 and 2, Wildlife Institute of India, Dehra Dun, India.

Rodrigues B F and Torne S G 1990 Lectin activity in the seeds of three Canavalia species. Comparative Physiology and Ecology 15: 123-124.

Rosenthal G A 1974 The interrelationship of canavanine and urease in seeds of the lotoidee. Journal of Experimental Botany 25: 609-613.

Ruediger H and Gabius H J 2001Plant lectins: Occurrence, biochemistry, functions and applications. Glycoconjugate Journal 18: 589-613.

Sathe S K, Iyer V and Salunkhe D K 1981 Functional properties of Great Northern bean (Phaseolus vulgaris L.) proteins: Amino acid composition, in vitro digestibility, and application to cookies. Journal of Food Science 47: 8-11.

Sauvion N, Charles H, Febvay G and Rahbe Y 2004 Effects of jackbean lectin (Con A) on the feeding behaviour and kinetics of intoxication of the pea aphid, Acyrthosiphon pisum. Entomologia Experimentalis et Applicata 110: 31-44.

Seabloom E W and Wiedermann A M 1994 Distribution and effects of Ammophila breviligulata Fern. (American beachgrass) on the foredunes of the Washington Coast. Journal of Coastal Research 10: 178-188.

Seena S and Sridhar K R 2004 Endophytic fungal diversity of 2 sand dune wild legumes from the southwest coast of India. Canadian Journal of Microbiology 50: 1015-1021.

Seena S and Sridhar K R 2006 Nutritional and microbiological features of little known legumes, Canavalia cathartica Thouars and Canavalia maritimaThouarsof the southwest coast of India. Current Science 90: 1638-1650.

Seena S, Sridhar K R and Bhagya B 2005 Biochemical and Biological evaluation of an unconventional legume Canavalia maritima of coastal sand dunes of India. Tropical and subtropical Agroecosystems 5: 1-14.

Seliskar D M 1995 Coastal dune restoration: A strategy for alleviating the dieout of Ammophila breviligulata. Restoration Ecology 3: 54-60.

Siddhuraju P and Becker K 2001 Species/variety differences in biochemical composition and nutritional value of Indian tribal legumes of the genus Canavalia. Nahrung 45: 224-233.

Siddhuraju P, Becker K and Makkar H P S 2000 Studies on the nutritional composition and antinutritional factors in three different germplasm seed materials of an under-utilized tropical legume, Mucuna pruriens var. utilis. Journal of Agricultural and Food Chemistry 48: 6048-6060.

Siddhuraju P, Vijayakumari K and Janardhanan K 1995 Nutritional and antinutritional properties of the underexploited legumes Cassia laevigata Willd. and Tamarindus indica L. Journal of Food Composition and Analysis 8: 351-362.

Singh K, Habib G, Siddiqui M M and Ibrahim M N M 1997 Dynamics of feed resources in mixed farming systems of south Asia. In: Crop Residues in Sustainable Mixed Crop/Livestock Farming Systems. (Editor, Renard C), CAB International, Wallingford, pp 113-130.

Staples S J and Reithel F J 1976 Evidence for an active-inactive subunit complex in jack bean urease. Archives of Biochemistry and Biophysics 174: 651-657.

St John H 1970 Classification and distribution of the Ipomoea pes-caprae group (Convluvulaceae). Botanische Jahrbucher Systematik 89: 563-583.

Sturmer S L and Bellei M M 1994 Composition and seasonal variation of spore population of arbuscular mycorrhizal fungi in dune soils on the island of Santa Catarina, Brazil. Canadian Journal of Botany 72: 359-363.

Surolia A, Prakash N, Bishayee S and Bachhawat B K 1973 Isolation and comparative physicochemical studies of concanavalin A from Canavalia ensiformis and Canavalia gladiata. Indian Journal of Biochemistry Biophysics 10: 145-148.

Swaffar D S and Ang C Y 1999 Growth inhibitory effect of L-canavanine against MIA PaCa-2 Pancreatic cancer cells is not due to conversion to its toxic metabolite canaline. Anti Cancer Drugs 10: 113-118.

Swaffar D S, Ang C Y, Desai P B and Rosenthal G A 1994 Inhibition of the growth of human pancreatic cancer cells by the arginine antimetabolite L-canavanine. Cancer Research 54: 6045-6048.

Sylvia D M 1989 Nursery inoculation of sea oats with vesicular-arbuscular mycorrhizal fungi and outplanting performance of Florida beaches. Journal of Coastal Research 5: 747-754.

Sylvia D M and Will M E 1988 Establishment of vesicular-arbuscular mycorrhizal fungi and other microorganisms on a beach replenishment site in Florida. Applied and Environmental Microbiology 54: 348-352.

Thomas F A, Rosenthal G A, Gold D V and Dickey K 1986 Growth inhibition of a rat colon tumor by L-canavanine. Cancer Research 46: 2898-2903.

Umoren U E, Essien A I, Ukorebi B A and Essien E B 2005 Chemical evaluation of the seeds of Milletia obanensis. Food Chemistry 91: 195-201.

USDA/HEW 1980 Nutrition and Your Health: Dietary Guidelines for Americans. U.S. Department of Health, Education and Welfare, Washington DC.

van der Heijden E W, de Vries F W and Kuyper Th W 1999 Mycorrhizal associations of Salix repens L. communities in succession of dune ecosystems. I. Above-ground and below-ground views of ectomycorrhizal fungi in relation to soil chemistry. Canadian Journal of Botany 77: 1821-1832.

Van Soest P J 1975 Physicochemical aspects of fiber digestion, Proceedings of 4th International Ruminant Congress 351-365.

Vecchi M, Torgano G, Monti M, Berti E, Agape A, Primignani M, Ronchi G and De Franchis R 1987 Evaluation of structural and secretory glycoconjugates in normal human jejunum by means of lectin histochemistry. Histochemistry 86: 359-364.

Vijayakumari K, Siddhuraju P and Janardhanan K 1997 Chemical composition, amino acid content and protein quality of the little-known legume Bauhinia purpurea L. Journal of Science of Food and Agriculture 73: 279-286.

Watkinson A R and Davy A J 1985 Population of salt marsh and sand dune annuals. Vegetatio 62: 487-497.

Wijnholds A E and Young D R 2000 Interdependence of Myrica cerifera seedlings and the nodule forming actinomycete, Frankia, in a coastal environment. Journal of Coastal Research 16: 139-144.

Will M E and Sylvia D M 1990 Interaction of rhizosphere bacteria, fertilizer and vesicular-arbuscular mycorrhizal fungi with sea oats. Applied and Environmental Microbiology 56: 2073-2079.

Woodhouse W W Jr 1978 Dune Building and Stabilization with Vegetation. US Army Corp of Engineers 3: 9-104.

Woodhouse W W Jr, Seeneca E D and Cooper A W 1968 Use of sea oats for dune stabilization in the southeast. Shore and Beach 35: 15-21.



Received 11 February 2007; Accepted 23 March 2007; Published 4 June 2007

Go to top