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Tropical and Subtropical Agroecosystems Universidad Autónoma de Yucatán ccastrouady.mx ISSN Versión impresa: ISSN Versión en línea: 1870-0462 MÉXICO 2003 P. Gurumoorthi / S. Senthil Kumar / V. Vadivel / K. Janardhanan STUDIES ON AGROBOTANICAL CHARECTERS OF DIFFERENT ACCESSIONS OF VELVET BEAN COLLECTED FROM WESTERN GHATS SOUTH INDIA Tropical and Subtropical Agroecosystems diciembre año/vol. 2 número 003 Universidad Autónoma de Yucatán Yucatán México pp. 105-115 Red de Revistas Científicas de América Latina y el Caribe España y Portugal Universidad Autónoma del Estado de México http://redalyc.uaemex.mx

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Tropical and Subtropical Agroecosystems 2 2003 : 105-115 105 STUDIES ON AGROBOTANICAL CHARECTERS OF DIFFERENT ACCESSIONS OF VELVET BEAN COLLECTED FROM WESTERN GHATS SOUTH INDIA ESTUDIO DE CARACTERES AGROBOTANICOS DE DIFERENTES ACCESIONES DE FRIJOL TERCIOPELO COLECTADOS EN LOS GHATS OCCIDENTALES INDIA P.Gurumoorthi S.Senthil Kumar V.Vadivel and K.Janardhanan Seed Technology Laboratory Botany Department Bharathiar University Coimbatore – 641 046 Tamil Nadu South India. E-mail: karnamjanardhananrediffmail.com corresponding author SUMMARY Seven different accessions of velvet bean Mucuna pruriens var utilis gathered from different agroecological regions of Western Ghats South India are evaluated for agrobotanical traits. They exhibited wide diversity in respect of all the investigated characters especially the traits responsible for the overall biomass of the plant. The accession Thachenmalai black - coloured seed coat exhibited the highest fertility index biomass production and seed yield followed by Valanad accession black – coloured seed coat. Seed recovery percentage ranged between 62.08 ±0.19 and 88.70 ±0.50. Thachenmalai accession registered the highest seed recovery percentage among all the investigated accessions. Besides the leghaemoglobin content of root nodules the mineral profiles of soil before and after cultivation of velvet bean were also studied. Kailasanadu white – coloured seed coat accession showed relatively high content of leghaemoglobin level compared to the other accessions. The genotypic phenotypic and environmental variance and their coefficient variance were also calculated which indicate that variations in agrobotanical traits are more due to impact of both the genotype and phenotype compared to environmental factors. Key words: Velvet bean cover crop agrobotanical traits soil mineral profile Western Ghats. RESUMEN Se evaluaron los caracteres agrobotánicos siete accesiones de frijol terciopelo Mucuna pruriens var utilis colectadas de diferentes regiones agroecológicas de los Ghats occidentales del sur de la India. Las accesiones exhibieron una amplia diversidad en todos los caracteres estudiados especialmente en aquellos responsables de la biomasa total de la planta. La accesión Thachenmalai semilla con pericarpio de color negro presento los índices de fertilidad producción de biomasa y producción de semilla más altos seguido por la accesión Valanad semilla de pericarpio negro. El porcentaje de recuperación de semilla vario entre 62.08 ±0.19 y 88.70 ±0.50. La accession Thachenmalai registró el mayor porcentaje de recuperación de semilla entre todas las accesiones. Adicionalmente se estudió el contenido de leghemoglobina de los nódulos de las raíces y el perfil mineral del suelo antes y después del cultivo de fríjol terciopelo. La accesión Kailasanadu semilla de pericarpio blanco mostró contenidos relativamente altos de leghemoglobina en comparación con las accesiones restantes. La varianza genotípica fenotípica y ambiental y su coeficiente de variación fueron estimados e indicaron que la variación encontrada fue principalmente debida al impacto del genotipo y fenotipo y no debida a factores ambientales. Palabras clave: Frijol terciopelo cultivo de cobertera caracteres agrobotánicos perfil mineral del suelo Ghats occidentales. INTRODUCTION The velvet bean Mucuna pruriens L DC var utilis Wall ex Wight Baker ex Burck is an under utilized tropical legume. It belongs to the family Fabaceae. The plant is a large twining herb leaves are pinnately tri-foliolate terminal leaflet often markedly smaller than laterals flowers are large purple or white in colour the lowest calyx tooth is long and corolla is papilionaceous. Pods are long and linear with hairs seeds are uniseriate and are white or black in colour Wilmot Dear 1987. The velvet bean is widespread in the Southern Southeastern and Asian regions Duke 1981. It is cultivated as a green Tropical and Subtropical Agroecosystems

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Gurumoorthi et al. 2003 106 manure / cover crop Buckles 1995 and is used as a mixed crop with sugarcane and maize and in rotation with sugarcane in Burma. Besides this species can be grown in a wide range of soil types including heavy clay and is tolerant of acid soil. In Southeast Asia the immature pods and leaves of velvet bean are used as vegetables. The seed has high viscosity starch which acts as a thickening agent for food products or as an adhesive in the paper and textile industries Haq 1983. Velvet bean has also been reported to have potential for reducing weed populations partly by smothering weed competition by rapid growth and partly through protective allelochemicals. After conducting crop rotation studies with velvet bean for the management of nematodes Kloepper et al 1991 demonstrated significantly higher yield for cotton peanut and soyabean which suggest that the soil building and weed suppression effects are important in addition to nematode control. The seed yield reaches 1.5 – 2.0 tonnes/hec and the yield of fresh leaves and stems is 20-30 t/hec thus it is considered to be one of the most productive legumes of the world Fujii et al. 1991. Interest in developing Mucuna’s food and feed uses originates in the efforts of many national and international organizations during the 1980s and 1990s. Mucuna has repeatedly impressed farmers and researchers due to its high biomass production weed suppression and consequent beneficial impacts on many crop yields. It has proved to be less impressive in providing more direct benefits to farmers despite its track record as a food and feed crop. Although detailed information is available on the nutritional and anti-nutritional properties of velvet bean Mucuna pruriens var utilis Janardhanan and Lakshmanan 1985 Ravindran and Ravindran 1988 Udedibe and Carlini 1998 Vadivel and Janardhanan 2000 Siddhuraju et al. 2000 there has been relatively few reports on the systematic collection and evaluation of diverse Mucuna been accessions. Despite of the potential of this species as a source of food and fodder to our knowledge meager information is available on the germplasm collection from South India and their evaluation for agrobotanical traits Vadivel and Janardhanan 2000 Siddhuraju et al. 2000. In short selection of elite germplasm among all available accessions should be the objective for purpose of conventional breeding and/or genetic engineering. In view of this in the present study seven accessions of Mucuna bean were collected from five different agroecological regions of Western Ghats Tamil Nadu and Kerala states South India and their agrobotanical traits evaluated. MATERIALS AND METHODS Seven different accessions of velvet bean Mucuna pruriens var utilis L. DC were collected as mature pods from the natural stands of five different agroecological regions of Tamil Nadu and Kerela. Table 1. After drying thoroughly in the sunlight for 2-3 days the pods were thrashed to remove seeds. The seeds after thorough cleaning and removal of broken seeds and foreign materials were stored in plastic containers until further use. Evaluation of agrobotanical traits. The agrobotanical characters are the ideal tools for the analysis and evaluation of elite germplasm. For evaluation of agrobotanical traits of collected seven different accessions the dry and mature seeds were sown in a Randomised Blocks with three replications in the experimental plots of the Botanical Garden Bharathiar University Coimbatore Tamil Nadu India. Approximate plots of 15m by 7m 105m 2 were constructed at Botanical Garden Bharathiar University latitude 11.02’N and longitude 76.58’E located at foothills of Marudhamalai Palakkad gap of Western Ghats and situated at an altitude of 409m above the sea level. The total plot area 105m 2 was equally divided into 21 small sub - plots each measuring an area of 5m 2 7m X 0.71m. Seeds were sown on 18 th September 2002 at 50cm regular intervals along rows of each sub - plot. The plants were raised in open sunlight and watered regularly twice a week. In the agroclimatic of Coimbatore the average annual rainfall is 61.22cm the temperature is maximum 34.7 o C and minimum 22.1 o C in general and the Bharathiar University campus in particular is semi-arid and the soils are alfisols. At the onset of germination seed germination percentage was recorded. Subsequently the day of plumule emergence and day of first leaf formation were also recorded. On 90 th day to study the variation in the size of leaflets among the different accessions twenty five leaves were selected at random their petiole length cm leaf area of both lateral and terminal leaflets cm 2 were measured with a Portable leaf Area Meter LI-COR Model Li-3000. Their mean values were calculated and recorded. The yield based characters such as day of flower initiation number of clusters per plant number of flowers per cluster and number of pods per cluster of all plants were recorded. Pods were harvested between 160 and 170 days from planting as leaves began to turn yellow from green. The following data were also collected: number of branches per

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Tropical and Subtropical Agroecosystems 2 2003 : 105-115 107 plant pod length cm pod weight g and the number of seeds per pod. The fertility index was calculated as Number of pods per cluster ------------------------------------- X 100 Number of flowers per cluster The seed recovery percentage was calculated as Weight of seeds per pod -------------------------------- X 100 Weight of pods with seeds The average100 -seed –weight g from three estimates per plot were also recorded. The harvest index tonnes/hec was calculated and recorded. Table 1. Agroecological regions of the seven collected accessions of velvet bean. S.No Name of the accession Month year of collection Place of Collection Ecological region 1 Thachenmalai white– coloured seed coat March 2001 Kanyakumari district Tamil Nadu Deciduous forest slightly elevated sandy soil near river side 2 Thachenmalai black– coloured seed coat March 2001 Kanyakumari district Tamil Nadu Deciduous forest slightly elevated sandy soil near river side 3 Mundanthurai white – coloured seed coat March 2001 Tirunelveli district Tamil Nadu Evergreen forest red soil altitude 500m 4 Kailasanadu white – coloured seed coat March 2001 Idukki district Kerala Semi evergreen forest red soil altitude 500-700m 5 Valanad black – coloured seed coat March 2001 Thiruvananthapuram district Kerala Moist deciduous forest black clay soil altitude 600-800m 6 Mundanthurai black –coloured seed coat March 2002 Tirunelveli district Tamil Nadu Evergreen forest red soil altitude 500m 7 Mylaru white – coloured seed coat March 2002 Tirunelveli district Tamil Nadu Evergreen forest red soil altitude 500m Estimation of chlorophyll content Arnon 1949. The chlorophyll content was estimated following the method of Arnon 1949 from leaves collected at random at regular intervals of 30 th 60 th 90 th 120 th and 150 th day after sowing. Extraction and estimation of leghaemoglobin content Appleby and Bergersen 1980. Like most legumes velvet bean has the potential to fix atmospheric nitrogen through symbiotic relationship with soil microorganisms Sanginga et al. 1996 Stefan and Christian 2002. The nitrogen is converted by the Rhizobia on the root nodules of the plant to an available form by leghaemoglobin and making the plant an efficient source of nitrogen. Thus to find out capacity of this plant to fix atmospheric nitrogen the leghamoglobin content was determined from fresh root nodules from 90 – day-old plants Extraction: Fresh nodules were mixed with 3 volumes of phosphate buffer and macerated. The contents were filtered

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Gurumoorthi et al. 2003 108 through two layers of cheesecloth. Nodule debris was discarded and remaining brown filtrate was centrifuged and diluted. To an equal volume of extract alkaline pyridine reagent was added and mixed. The resulting hemochrome was equally divided into two portions. To one portion few crystals of sodium dithionite was added to reduce the hemochrome and stirred without aeration. To the other portion few crystals of potassium hexacyanoferrate were added to oxidize the hemochrome and the contents of both of the test tubes were measured at 556nm and 539nm respectively. Leghaemoglobin content was calculated using the following formula A 556 --- A 539 x 2D Lb concentration mM 23.4 where D is initial dilution. pH Ten gram of dry soil was taken in a beaker and 100 ml of double distilled water added to make a suspension of 1:10 w/v dilution and the pH was determined with a digital pH meter. Electrical conductivity Ten gram of dry soil was taken in a beaker and 100 ml of double distilled water was added to make a suspension of 1:10 W/V dilution and the electrical conductivity was measured with a digital electric conductivity meter. Estimation of mineral profiles of the soil: The soil samples were collected from study area before and after raising the velvet bean. For analysis of micro and macronutrients 25 cores or sub samples were collected randomly by traversing in a zig – zag manner along with different sections of area until the whole area is covered on random basis. Before collecting the soil samples for analysis the surface area / top soil was removed for about 1 inch thickness and then with soil auger ‘V’ shaped depth was made for about 20cm and removing the slice about 2.5cm thickness from the sides of the depth. The soil aggregates are broken down and dried at 25 o C. All the sub samples / cores are mixed to provide composite sample and passed through sieve to provide 50g of air dry sample. The total nitrogen N and available phosphorus P were determined respectively by micro-Kjeldahl and molybdenum blue methods of Jackson 1973. Exchangeable K was extracted from the soil in ammonium acetate solution pH 7 and measured with a digital flame photometer Jackson 1973. The micronutrients are estimated by following the method of Lindsay and Norvell 1978 using DTPA diethylene triamine penta aceticacid. Statistical analysis All the values were estimated in triplicate determinations except soil samples. The statistical values: range mean standard error standard deviation were computed for agronomic traits. An analysis of variance ANOVA such as genotyic phenotypic and environmental and coefficient variance such as GCV PCV ECV were also calculated using the software package Genres Agres D square / Path D square analysis. RESULTS AND DISCUSSION The evaluated agrobotanical characters of seven different accessions of velvet bean are presented in Tables 2-5. Range of variation displays wide diversity among the different accessions in respect of all the characters studied especially leaf area 90- day-old-plant number of pods per cluster number of clusters per plant seed weight per pod seed yield per plant and 100-seed-weight. IBPGR adopted a germination percentage of 85 as the preferred standard Frankel et al. 1995. The latter four characters may have an impact on the over all biomass of the plant which can affect the plant yield. Among the investigated seven accessions Mundanthurai black-coloured seed coat registers the highest germination percentage 99.75 ±0.29 while in others germination percentage ranges between 79.75 ±0.25 and 96.00 ± 0.00 and these values seem to be higher when compared with the other wild pulses like Vigna aconitifolia V. sublobata and V.glabrascens Rajaram 1990 V.trilobata Siddhuraju 1990 and Bauhinia malabarica Vijayakumari 1990. Thus it is inferred that the Mundanthurai black – coloured seed coat accession undoubtedly is an elite accession when compared to the various accession of different species of Vigna/ Bauhinia evaluated in our Laboratory.

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Table : 2. Agrobotanical traits of seven different accessions of velvet bean a Trait Accessions TW TB MW KW VB MB MYW Germination 84.25 ±0.25 79.75 ±0.25 95.75 ±0.25 96.00 ±.0.00 95.50 ±0.29 99.75 ±.0.25 91.75 ±0.25 Day of plumule emergence 9.75 ±0.48 10.50 ±0.28 11.50 ±0.25 10.75 ±0.25 9.00 ±.000 9.50 ±0.28 9.25 ±0.25 Day of first leaf formation 11.75 ±0.25 11.00 ±0.58 13.75 ±0.25 14.00 ±0.00 10.75 ±0.25 11.50 ±0.50 12.75 ±0.25 Leaf Area cm 2 90 day– old plant 109.02 ±0.21 108.76 ±0.61 84.40 ±1.56 117.00 ±0.41 78.70 ±0.69 96.02 ±0.39 123.40 ±0.72 Day to flower initiation 59.75 ±0.48 59.75 ±0.25 61.50 ±0.29 66.50 ±0.25 61.75 ±0.48 60.50 ±0.29 60.25 ±0.25 No.of branches per plant 6.50 ±0.65 5.50 ±0.65 5.25 ±0.25 5.05 ±0.75 4.25 ±0.63 5.50±0.29 4.50±0.50 No. of clusters per plant 8.75±1.11 13.0±0.91 11.25±2.39 6.50±0.64 11.50±1.94 12.25±2.29 6.50±0.65 No. of flowers per cluster 12.5±2.96 7.50±0.65 8.00 ±0.91 9.50 ±1.32 5.75 ±0.25 9.25 ±0.25 15.5 ±1.32 Fertility index 66.28 ±0.57 81.54 ±0.60 66.01 ±0.51 72.54 ±0.75 76.23 ±1.61 80.55 ±1.54 79.45 ±2.18 No. of pods per cluster 9.25 ±2.56 7.00 ±0.70 5.25 ±0.25 7.75 ±1.65 5.75 ±0.48 7.52 ±0.85 10.00 ±2.35 Pod length cm 2 10.34 ±1.31 9.57 ±0.16 11.45 ±1.31 9.20 ±0.90 11.18 ±0.10 10.34 ±0.10 12.41 ±0.14 Pod weightg 9.50 ±0.36 10.41 ±0.32 12.20 ±0.80 8.42 ±0.23 9.80 ±0.16 10.83 ±0.26 12.30 ±0.22 No. of seeds per pod 5.25 ±0.25 4.25 ±0.63 5.25 ±0.25 4.75 ±0.48 5.25 ±0.25 5.50 ±0.50 6.50 ±0.65 Seed weight per pod g 6.11 ±0.80 9.49 ±0.16 8.16 ±0.40 6.43 ±0.60 7.05 ±0.70 7.79 ±0.17 8.90 ±0.11 Seed recovery 62.08 ±0.19 88.70 ±0.50 66.06 ±0.37 75.33 ±0.24 71.83 ±0.33 70.33 ±0.32 71.30 ±0.17 100 – seed weightg 113.84 ±1.61 104.60 ±1.67 120.52 ±0.77 106.03 ±0.90 100.59 ±1.35 101.89 ±1.11 120.76 ±0.89 Leghaemoglobin content mM 0.29 ±0.06 0.27 ±0.04 0.18 ±0.04 0.52 ±0.03 0.18 ±0.08 0.20 ±0.04 0.42 ±0.03 Life span 152 152 150 156 150 148 156 Harvest index t/hec 1.307 1.181 0.934 1.164 1.528 2.995 3.128 a. All the values are mean of tripilicate determinations ± Standard Error TW: Thachenmalai white- cloured seed coat TB: Thachenmalai black- coloured seed coat MW: Mundanthurai white – coloured seed coatKW: Kailasanadu white – coloured seed coatVB: Valanad black – coloured seed coatMB: Mundanthurai black – coloured seed coat MYW: Mylaru white–coloured seed coat

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Table 3: RangeMeanStandard deviationvariance and coefficient variance of 17 traits in different accessions of velvet bean Variance Coefficient variance Trait Range Mean S.D Genotypic Phenotypic Environmental Genotypic Phenotypic Environmental Germination 79.75 - 99.75 91.82 7.22 52.00 52.23 0.23 7.85 7.87 0.52 Day of plumule emergence 9.00 - 11.50 10.04 0.91 0.72 1.12 0.40 8.47 10.54 6.28 Day of first leaf formation 10.75 -14.00 12.21 1.30 1.59 2.01 0.42 10.33 11.61 5.31 Leaf Area cm 2 90 day– old plant 78.70 – 123.40 102.47 16.66 276.87 279.27 2.39 16.24 16.31 1.51 Day to flower initiation 59.75 - 66.50 61.43 2.37 5.26 6.70 1.43 3.73 4.21 1.95 No.of branches per plant 4.25 - 6.50 5.29 0.74 0.23 1.51 1.28 9.08 23.26 21.42 No. of clusters per plant 6.50 - 13.00 9.96 2.71 4.50 15.77 11.27 21.30 39.86 33.69 No. of flowers per cluster 5.75 - 15.50 9.71 3.29 9.50 14.86 5.35 31.74 39.68 23.82 Fertility index 66.01 - 81.54 74.66 1.72 41.75 46.12 4.38 8.65 9.09 2.80 No. of pods per cluster 5.25 - 10.00 7.46 6.55 1.35 7.83 6.49 15.54 37.50 34.12 Pod length cm 2 9.20 - 12.41 10.64 1.12 1.24 1.29 0.05 10.46 10.66 2.05 Pod weightg 8.35 - 12.31 10.49 1.44 2.04 2.16 0.12 13.62 14.03 3.34 No. of seeds per pod 4.25 - 6.50 5.25 0.69 0.25 1.16 0.90 9.60 20.47 18.08 Seed weight per pod g 6.11 - 9.49 7.71 1.25 1.56 1.59 0.03 16.21 16.37 2.21 Seed recovery 62.08 - 88.70 72.23 8.43 70.96 71.52 0.56 11.66 11.71 1.03 100 – seed weightg 100.59 -120.63 109.74 8.53 72.62 73.78 1.16 7.77 7.83 0.98 Leghaemoglobin content mM 0.18 - 0.52 0.29 0.13 0.02 0.02 0.001 44.06 44.98 9.03

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Table 4: Variation in chlorophyll content level in different accessions of velvet bean in 306090120 and 150 - day old plants Accessions Chlorophyll content mg / g fresh weight 30 day 60 day 90 day 120 day 150 day chl a chl b total chl chl a chl b Total chl chl a chl b Total chl chl a chl b total chl chl a chl b Total Chl TW 0.21 0.17 0.38 0.30 0.23 0.53 0.26 0.20 0.46 0.13 0.10 0.23 0.07 0.01 0.08 TB 0.25 0.20 0.45 0.30 0.24 0.54 0.27 0.21 0.48 0.19 0.14 0.33 0.11 0.01 0.12 MW 0.23 0.19 0.42 0.27 0.21 0.48 0.26 0.21 0.47 0.12 0.09 0.21 0.01 0.04 0.05 KW 0.20 0.16 0.37 0.27 0.22 0.49 0.24 0.18 0.42 0.09 0.07 0.16 0.10 0.04 0.14 VB 0.18 0.14 0.32 0.25 0.19 0.44 0.23 0.18 0.41 0.22 0.16 0.38 0.05 0.01 0.06 MB 0.18 0.14 0.32 0.30 0.23 0.53 0.26 0.19 0.45 0.13 0.09 0.22 0.13 0.04 0.17 MY-W 0.27 0.21 0.48 0.31 0.24 0.55 0.29 0.23 0.52 0.13 0.09 0.22 0.06 0.005 0.065 TW: Thachenmalai white- cloured seed coat TB: Thachenmalai black- coloured seed coat MW: Mundanthurai white – coloured seed coat KW: Kailasanadu white – coloured seed coatVB: Valanad black – coloured seed coatMB: Mundanthurai black – coloured seed coatMYW: Mylaru white – coloured seed coat

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112 The data on the day of plumule emergence indicate that in the accessions Valanad black-coloured seed coat and Mylaru white-coloured seed coat the plumule emerges earlier i.e. on the 9 th day after sowing while in other investigated accessions plumule emerges either on 10 th or 11 th day after sowing. In respect of the formation of the first leaf all the accessions exhibit more or less similar trend which is in good agreement with an earlier investigation on the same species collected from some other agroclimatic regions Vadivel and Janardhanan 1997. Regarding the amount of chlorophyll pigments their contents keep on increasing with the age of the plant and slightly decrease when the plants enter reproductive phase with 90-day – old plants registering the maximum chlorophyll content in all the investigated accessions. Among the seven accessions studied Mylaru white- coloured seed coat registers the highest number of flowers per cluster pods per cluster compared to the other accessions. Nonetheless Thachenmalai black-coloured seed coat shows higher number of clusters per plant 13.00 ± 0.91 and the highest fertility index and this value seems to be closer to that of certain Vigna species such as Vigna calcaratus V. sublobata Rajaram 1990 V. trilobata Siddhuraju 1990. From this it is inferred that accession Mylaru white – coloured seed coat and Thachenmalai black – coloured seed coat are at least on par with several accessions of different species of Vigna evaluated earlier in our Lab. Both the accessions of Thachenmalai black-coloured seed coat and Mylaru white-coloured seed coat come to flowering on 60 th day after sowing earlier than others. Early flowering is an important trait because it reduces the incidence of pest and disease thereby improving yield and quality of pods and seeds Vadivel et al. 1998. Other accessions come to flowering on 61 st 62 nd 63 rd and 67 th day after sowing. In the present study flower initiation appears to be earlier when compared to an earlier report from our Lab for some other accessions of velvet bean collected from Kanyakumari Tirunelveli and Thiruvananthapuram districts in Tamil Nadu and Kerala Vadivel and Janardhanan 1997. In the present study the seed recovery percentage ranges between 62.08 ± 0.19 and 88.70 ± 0.50 and 100- seed- weight ranges from 100.59 ± 1.35 to 120.52 ± 0.77g. These values seem to be higher when compared with that of other little known pulses such as Vigna aconitifolia V.radiata and V. trilobata reported by Rao et al 1978 Tawer et al 1988 Rajaram 1990 and Siddhuraju 1990. Earlier Bennett – Lartey 1998 has studied the agrobotanical traits of 8 accessions of velvet bean M. pruriens var utilis Wall collected from the Ashanti Eastern and Upper West Regions of Ghana which include pods per plant pod length and 100 – seed – weight. The leghaemoglobin content of the presently investigated accession of velvet bean ranged from 0.18 ±0.04 to 0.52 ±0.03mM. Kailasanadu white-coloured seed coat shows the maximum value compared to the other investigated accessions. Higher the content of legheamoglobin more the efficiency of a particular accession in terms of its capacity for atmospheric nitrogen fixation. Quick growing legumes are valuable green manure for many low input systems and have the potential to meet much if not all of the nitrogen requirements of succeeding non-legume crops. The equivalent amount of nitrogen fertilizer required to match the green manure can be 80- 200kg/hec. One of the most remarkable features of the velvet bean is it can fix large amounts of nitrogen and can annually produce 50 – 100 tonnes/hec of organic matter. The present study brings to light a significant increase in the soil nutrient status as a result of cultivation of Kailasanadu white – coloured seed coat accession Table 6. Not only the contents of soil macronutrients such as N P K increase from 175.2 to 194.4 13.4 to 16.8 211.2 to 480 kg/hec respectively but also the contents of micronutrients such as Fe Zn Cu and Mn also are found to increase 1.92 to 20.2 0.72 to 2.01 1.15 to 1.63 4.37 to 9.65 kg/hec. In recent years it has been reported that of the various types of green manure legumes introduced into farming systems to improve soil fertility and replenish soil nutrients Mucuna exhibits the greatest potential to improve soil fertility Mureithi et al. 2000 It is known to effectively control a wide range of diverse pests. Among the seven accessions investigated in the present study Mylaru white-coloured seed coat accession exhibits maximum production of biomass and gives relatively a high harvest index i.e. 3.128 tonnes/hec while in others the harvest index ranges between 0.934 and 2.955 tonnes/h.

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Tropical and Subtropical Agroecosystems 2 2003 : 105-115 113 Table 5.Variation in leaf size in different accessions of Mucuna pruriens var utilis in 90 - day – old plants a S.No Name of the accession Petiole length cm Lateral leaflet area cm 2 Terminal leaflet area cm 2 1 Thachenmalai white -coloured seed coat 15.9 ± 1.20 102.32 ±1.29 97.15 ± 2.52 2 Thachenmalai black -coloured seed coat 10.3 ± 0.80 95.46 ±1.38 89.22 ± 1.63 3 Mundanthurai white-coloured seed coat 7.2 ± 1.70 94.17 ± 3.46 88.04 ±1.18 4 Kailasanadu white -coloured seed coat 20.3 ± 0.90 173.35 ± 1.71 142.08 ± 3.69 5 Valanad black -coloured seed coat 18.0 ± 1.30 93.85 ± 1.97 62.58 ± 1.78 6 Mundanthurai black-coloured seed coat 18.5 ± 0.60 143.65 ± 2.58 102.45 ± 3.35 7 Mylaru white-coloured seed coat 24.1 ± 0.80 128.22 ± 1.85 105.87 ± 1.77 a. All the values are mean of triplicate determinations ± Standard Error Table: 6 Profiles of macro and micronutrients of soil samples before and after raising Kailasanadu white - coloured seed coat accession Macronutrients kg/hec Micronutrients kg/hec Soil test pH EC N P K Fe Zn Cu Mn Before cultivation 7 . 9 0 0.10 175 . 2 13 . 4 211 . 2 1.92 0.72 1.15 4.37 After cultivation 8 . 2 9 0.10 194 . 4 16 . 8 480 . 0 20.2 2.01 1.63 9.65 The genotypic phenotypic and environmental variance and coefficient variance GCV PCV and ECV are shown in Table –3. In general magnitude of the PCV is higher than that of both GCVand ECV in almost all traits. Nonetheless GCV seems to be more or less equal for traits such as germination percentage day to flower iniation fertility index seed weight per pod g seed recovery percentage 100- seed weight and leghaemoglobin content. Thus it is inferred that the diversity in all the investigated traits is mainly due to phenotypic and partly by genotypic factors. ECV is less pronounced for a majority of the traits. The life span of all the accessions is found to be more or less similar i.e.152 days after sowing. This value seems to be lower than an earlier investigation in the same species Vadivel and Janardhanan 1997. The results of the present study go to suggest that Mucuna definitely can act as an effective green manure crop. CONCLUSIONS The evaluation of agrobotanical traits of seven different accessions of velvet bean collected from five different agroecological regions in the present study reveals the existence of diversity in all the investigated. The accession Thachenmalai black - coloured seed coat exhibited the highest fertility index biomass production and seed yield followed by Valanad accession black – coloured seed coat. Kailasanadu white – coloured seed coat accession showed relatively high content of leghaemoglobin level compared to the other accessions. Seed recovery percentage ranged between 62.08 ±0.19 and 88.70 ±0.50. Taking into account the versatile nature of this plant it can be recommended as a successful green

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114 manure crop in addition to its track record as food and feed crop. Though all the seven accessions are collected from different agroecological zones of South India the evaluated agrobotanical traits are not markedly affected by environment. From this it is inferred that there exists genetic diversity among the evaluated accessions of velvet bean which does not seem to be influenced by the environment. Attempts to decipher the gene diversity and phenetic relationship among all the available accessions of velvet bean from Western Ghats South India by employing modern biotechnological techniques such as AFLP and RAPD are in progress. ACKNOWLEDGEMENT Thanks are due to Mr.P.Muthsamy Assistant Soil Chemist Soil Testing Laboratory Govt.of Tamil Nadu Coimbatore India for his help in soil analysis. Thanks are also due to Dr.M.Pugalenthi Lecturer Dept. Biotech Karpagam Arts Science College and Mr. A.Nanjukutti Field Assistant for their help in collection of velvet bean accessions. REFERENCES Appleby CA and Bergersen FJ. 1980. In: Methods for Evaluating Biological Nitrogen fixation Ed. Bergersen F.J. John Wiley and Sons New York. pp. 315. Arnon DE. 1949.Copper enzymes in isolated chloroplasts. Plant Physiology 24: 1- 5. Bennett – Lartey SO. 1998. Characterization and preliminary evaluation of some accessions of local germplasm of velvet bean Mucuna pruriens Dc var utilis Wall of Ghana. Ghana Journal of Agricultural Science. 311: 247 - 251. Buckles D. 1995. Velvetbean: A new plant with a history. Economic Botany. 49:13-25. Duke JA. 1981. Handbook of legumes of world economic importance. Plenum Press New York USA Frankel OH Brown and Burdon J.J.1995. The conservation of plant biodiversity. Cambridge Univ. Press. Cambridge. UK. pp. 29-33. Fujii Y Shibuya T and Yasudha T. 1991. L-3 4 – Dihydroxy phenylalanine as an allelo chemical candidate from Mucuna pruriens L. DC. var. utilis. Agricultural Biological Chemistry. 5: 617 - 618. Haq N. 1983. New food legume crops for the tropics In: Better crops for food. Eds. Nugent J. and Connor MO. Pitman Books London Cuba Foundation Symposium 97. pp. 144-160. Janardhanan K and Lakshmanan K.K. 1985. Studies on the pulse Mucuna utilis: Chemical composition and antinutritional factors. Journal Food Science and Technology. 22: 369-371. Jackson C. 1973. Determination of soil nutrients. In: Methods of analysis of soilsplantswaters and fertilizers.Ed..TandonHLA.Fertliser.Developme nt and consultation organisationNew Delhi.pp.81- 94. Kloepper JW Rodriguez–Kabana.R McInroy Collins. DJ.1991. Analysis of populations and physiological characterization of microorganisms in rhizospheres of plant with antagonistic properties to phytopathogenic nematodes. Plant and soil.136: 95 – 102. Lindsay R and Norvell WA. 1978.Development of DTPA soil test for zinc iron manganese and copper. American Journal of Soil Science Society .42: 421 – 428. Mureithi JG Mwaura P and Nekesa C. 2000. Introduction of legume cover crops to small holder farms in Gatanga Central Kenya. Presented at the 2 nd scientific conference of the Soil Management and Legume Research Network projects. Kenya. Rajaram N. 1990. Studies on the pulses of tribal utility and their wild related species in India. Ph.D. Thesis Bharathiar University. Coimbatore India. Rao SK Gupta AK and Tiwari AS. 1978. Nutrient composition and protein quality in mung bean Vigna radiata L. Wilczek Legume Research. 2 : 11 -18. Ravindran V and Ravindran G. 1988. Nutritional and anti- nutritional characteristics of Mucuna Mucuna utilis bean seeds. Journal of Science Food Agriculture. 46: 71-79. Sanginga NB Ibewiro P Houngnandan B Vanlauwe JA Okogun IO Akobundu and Versteeg M.1996. Evaluation of symbiotic properties and nitrogen contribution of Mucuna to maize grown in the derived savanna of West Africa. Plant and Soil. 179: 119 – 129.

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Tropical and Subtropical Agroecosystems 2 2003 : 105-115 115 Siddhuraju P. 1990. Studies on the tribal pulses Vigna aconitifolia Jacq. Marechal and V.trilobata L. Verd C. M.Phil. Dissertation Bharathiar University. Coimbatore. Siddhuraju P Becker K Harinder P and Makkar S. 2000. Studies on the nutritional composition and antinutritional factors of three different germplasm seed material of an underutilized tropical legumes Mucuna pruriens var. utilis. Journal of Agricultural Food Chemistry. 48: 6048 – 6060. StefanH Christian N. 2002. Biomass production and N fixation of five Mucuna pruriens varieties and their effect on maize yield in the forest zone of Cameroon. Journal of Plant Nutrition and Soil Science.165: 101 – 109. Tawar ML Mishra AK Rao SK and Sharma SK. 1988. Genetic divergence in mungbean. Legume Research.11: 109-113. Udedibe ABI and Carlini CR. 1998. Brazilian Mucuna pruriens seeds velvet bean lack haemagglulinating activity. Journal of Agricultural Food Chemistry. 46: 1450 – 1452. Vadivel V and Janardhanan K. 1997. Agrobotanical characters of different germplasm of velvet bean Mucuna pruriens var utilis Wall ex. Wight. Journal of Swamy Botanic Club. 14: 37-40. Vadivel V Janardhanan K and Vijayakumari K. 1998. Diversity in swordbean Canavalia gladiata Jacq. DC. collected from Tamil Nadu India. Genetic Resources Crop Evolution. 45:63-68. Vadivel V and Janardhanan K. 2000. Nutritional and antinutritional composition of velvet bean: an under –utilized food legume in South India. International. Journal of Food Science and Nutrition. 51: 279- 287. Vijayakumari K. 1990. Studies on the tribal pulse Bauhinia malabarica Roxb. M.Phil. Dissertation Bharathiar University Coimbatore. Wilmot-Dear CM. 1987. A revision of Mucuna Leguminogae Phaseolae in the India sub- continent and Burma. Kew Bulletin. 42: 23-46. Submitted May 16 2003 - Accepted July 21 2003

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