INTRODUCTION Dolichos bean (Lablab purpureus L.), also known as lablab bean or Indian bean, is one of the important indigenous legume vegetables of India, grown for its tender green pods. Besides fresh pods, immature green seeds are also used as vegetable and dry seeds as pulse. Both pods and seeds of dolichos are a rich source of protein, minerals, vitamins and fiber. India is one of the primary centers of origin and diversity of pole-type vegetable dolichos bean (Lablab purpureus var. typicus). The present study was initiated with the objective of understanding extent of variability for pod-yield and pod-colour in the germplasm recently collected from different sources. MATERIAL AND METHODS Fifty seven germplasm lines of dolichos bean collected from different geographical regions of Tamil Nadu, Pondicherry and Karnataka were evaluated during 2006- 08 (between September-February) in the experimental farm at Indian Institute of Horticultural Research, Bangalore. The Evaluation of Dolichos (Lablab purpureus L.) germplasm for pod yield and pod related traits N. Mohan, T.S. Aghora and Devaraju Division of Vegetable Crops Indian Institute of Horticultural Research Hesarghatta Lake Post, Bangalore - 560 089, India E-mail: nmohan@iihr.ernet.in ABSTRACT Fifty seven pole type vegetable dolichos bean (Lablab purpureus var. typicus) germplasm lines collected from Tamil Nadu, Karnataka and Pondicherry were evaluated in a replicated experiment at Indian Institute of Horticultural Research, Bangalore, for pod yield and pod -related traits during 2006-08. Significant differences were recorded for all traits studied. IIHR 177 was the earliest to flower in 43 days and pods matured in 65 days. IIHR 6 recorded maximum pod length (16.5 cm) , and, ten-pod weight was maximum in IIHR 7 (122 g). Pod width was high in IIHR 11 (4.05 cm). Number of pods per plant ranged from 10 to 91, with the maximum in IIHR 159. Maximum pod-yield was recorded in IIHR 150 and IIHR 159 (576.0 g/plant). Six different pod-colors (green, light green, purple, purple green, pink and creamy- white) were recorded. Maximum number of lines (52.63%) had green pod. The present study indicates existence of a wide range of variability for pod characters, namely, pod-maturity, pod -length, ten- pod weight, number of pods per plant and pod- colour. High yielding lines with different pod types can serve as potentially useful parents in further breeding. Key words: Dolichos, germplasm, variability experimental design was RBD with three replications, with each of the lines in a row of three meter length, with a spacing of 15 cm between plants and 1.5 m between rows. The crop was staked and supported and recommended package of practices was followed to raise the crop. Five plants were randomly labeled in each line and data were recorded on seven characters, namely, days to 50% flowering, days to pod maturity, pod-length, pod-width, 10 pod-weight, and, number of pods and pod-yield per plant. The mean value from five plants of each line for each trait in three replications, was computed. The replicated mean data was subjected to statistical analysis. Pod-colour was recorded for all 57 accessions by visual observation. RESULTS AND DISCUSSION Analyzed mean data, and, range for the 57 accessions with respect to seven characters (along with place of collection and pod-colour) are given in Table 1. Significant differences were observed in all the characters studied. Days to 50% flowering ranged from 43 to 83 days. IIHR 177 was the earliest to flower in 43 days, followed by J. Hortl. Sci. Vol. 4 (1): 50-53, 2009 51 Table 1. Source of collection, pod-yield and pod-related traits in 57 germplasm accessions in Dolichos Sl. Line Place from which collected Days to Days to Pod- Pod- 10- No.of Yield Pod colour No. 50% pod- length width pod pods per flowering maturity (cm) (cm) weight (g) per plant plant (g) 1. IIHR-1 Tirchy, Tamil Nadu 61.5 81.5 9.0 3.9 92.0 15.5 141.5 Light green 2. IIHR 2 Dindigul, Tamil Nadu 63.0 82.0 5.9 2.5 93.0 33.5 306.0 Green 3. IIHR 3 Coimbatore, Tamil Nadu 76.0 93.0 5.8 2.2 54.0 41.0 210.5 Green 4. IIHR 4 Trichy, Tamil Nadu 65.5 84.5 5.8 1.8 72.0 21.0 150.6 Green 5. IIHR 5 Dindigul, Tamil Nadu 83.0 100.0 10.0 1.7 62.0 31.5 192.7 Light green 6. IIHR 6 Dindigul, Tamil Nadu 65.0 83.0 16.5 2.9 91.0 30.5 270.5 Green 7. IIHR 7 Dindigul, Tamil Nadu 63.0 83.5 14.5 3.5 122.0 18.5 230.5 Purple 8. IIHR 8 Siva gangai, Tamil Nadu 63.5 84.5 10.5 3.7 92.5 38.5 364.0 Green 9. IIHR 9 Pollachi, Tamil Nadu 54.0 74.5 6.0 2.3 53.0 45.5 236.9 Green 10. IIHR 10 Dindugal, Tamil Nadu 58.5 78.5 16.0 3.2 112.0 25.5 278.0 Green 11. IIHR 11 Kumbakonam, Tamil Nadu 64.0 83.5 11.5 4.1 111.0 13.5 155.0 Green 12. IIHR 12 Trichy, Tamil Nadu 63.5 83.5 11.5 1.5 61.0 27.0 172.5 Purple 13. IIHR 13 Lalgudi, Tamil Nadu 64.0 84.0 11.0 3.4 82.0 20.5 171.5 Green 14. IIHR 14 Madurai, Tamil Nadu 69.5 89.5 11.0 3.5 81.5 20.0 167.0 Green 15. IIHR 15 Madurai, Tamil Nadu 64.0 83.5 12.5 2.5 83.0 22.5 188.5 Purple 16. IIHR 16 Thiruvarur, Tamil Nadu 54.5 75.0 14.5 1.3 65.5 24.0 161.7 Purple green 17. IIHR 17 Madurai, Tamil Nadu 64.0 84.5 10.3 3.8 102.5 18.5 185.5 Green, broad 18. IIHR 18 Sivagangai, Tamil Nadu 61.5 82.5 12.5 2.2 76.0 27.5 199.5 Green 19. IIHR 19 Thiruvarur, Tamil Nadu 55.5 75.0 12.5 1.4 73.0 31.5 320.0 Purple 20. IIHR 139 Vellore, Tamil Nadu 62.5 80.0 11.5 3.0 79.0 25.5 198.3 Green 21. IIHR 140 Kancheepuram, Tamil Nadu 65.0 79.5 6.5 1.9 80.5 23.5 185.2 Green 22. IIHR 141 Kancheepuram, Tamil Nadu 59.5 78.0 12.5 1.5 82.0 18.5 148.4 Green 23. IIHR 142 Pondicherry 64.5 82.0 6.5 1.5 59.0 73.5 429.4 Purple 24. IIHR 143 Pondicherry 53.5 73.5 13.5 1.7 92.5 34.0 308.1 Green 25. IIHR 144 Pondicherry 63.5 82.0 9.8 3.0 83.5 26.5 211.3 Green 26. IIHR 145 Thiruvannamalai, Tamil Nadu 62.5 80.0 10.5 2.0 69.5 34.0 228.2 Green 27. IIHR 146 Thiruvannamalai, Tamil Nadu 61.5 80.0 11.0 1.7 74.5 42.0 241.5 Creamy-white 28. IIHR 147 Kancheepuram, Tamil Nadu 63.5 83.5 11.5 1.9 71.5 25.0 177.5 Creamy-white 29. IIHR 148 Villupuram, Tamil Nadu 61.5 81.0 14.5 1.7 49.5 31.5 153.8 Purple 30. IIHR 149 Kancheepuram, Tamil Nadu 66.5 85.5 9.3 2.0 92.5 41.5 380.5 Purple 31. IIHR 150 Villupauram, Tamil Nadu 66.5 85.0 9.8 2.2 105.0 57.5 576.9 Creamy-white 32. IIHR 151 Pondicherry 62.0 81.5 7.5 2.3 66.0 23.5 147.5 Green 33. IIHR 152 Salem, Tamil Nadu 60.0 80.0 13.5 1.4 73.0 29.5 207.7 Purple green 34. IIHR 153 Thiruvannamalai, Tamil Nadu 62.5 82.0 14.5 1.9 69.5 34.5 232.4 Purple 35. IIHR 154 Thiruvannamalai, Tamil Nadu 60.5 80.5 16.0 1.9 108.0 36.5 387.1 Purple 36. IIHR 155 Chidambaram, Tamil Nadu 63.0 82.0 16.0 2.5 109.5 37.5 398.8 Green 37. IIHR 156 Chidambaram, Tamil Nadu 67.5 86.5 11.5 2.7 82.5 57.5 471.2 Green 38. IIHR 157 Chennai, Tamil Nadu 62.5 82.5 12.5 2.7 104.0 51.0 515.2 Green 39. IIHR 158 Villupuram, Tamil Nadu 58.5 87.5 13.5 1.6 73.0 37.5 269.4 Green 40. IIHR 159 Pondicherry 60.0 80.5 9.5 1.8 64.0 91.0 576.2 Green 41. IIHR 160 Kancheepuram, Tamil Nadu 62.0 80.0 9.0 4.0 83.5 26.5 211.3 Green 42. IIHR 161 Chidambaram, Tamil Nadu 64.0 84.5 10.0 3.1 83.0 24.5 194.2 Pink 43. IIHR 162 Chidambaram, Tamil Nadu 55.5 75.5 8.5 1.6 54.5 44.5 239.9 Green 44. IIHR 163 Nelamangala, Kanataka 64.0 83.5 15.5 2.3 73.0 51.5 370.5 Green 45. IIHR 164 Dobbsspet, Karnataka 61.5 81.0 11.0 2.0 72.5 25.5 183.1 Purple 46. IIHR 165 Tumkur, Karnataka 62.0 82.0 14.5 2.0 64.0 25.5 156.6 Purple 47. IIHR 167 Tumkur, Karnataka 58.5 78.5 10.0 1.9 52.5 53.0 275.5 Light green 48. IIHR 168 Tumkur, Karnataka 64.5 84.0 8.5 3.3 92.0 18.0 160.3 Light green 49. IIHR 169 Nelamangala, Karnataka 58.5 78.5 7.0 1.2 64.0 10.0 69.5 Light green| 50. IIHR 170 Nelamangala, Karnataka 65.5 83.5 7.5 1.8 62.0 82.5 501.0 Creamy-white 51. IIHR 171 Nelamangala, Karnataka 62.0 81.5 7.5 1.8 54.5 67.5 365.5 Creamy-white 52. IIHR 172 Nelamangala, Karnataka 64.5 83.0 14.5 2.4 92.5 43.5 397.5 Creamy-white 53. IIHR 173 Nelamangala, Karnataka 65.5 83.5 7.5 2.1 57.0 38.5 210.0 Light green 54. IIHR 174 Tumkur, Karnataka 63.0 83.5 15.8 2.5 111.0 32.5 355.5 Creamy-white 55. IIHR 175 Tumkur, Karnataka 63.5 83.5 8.2 2.4 62.0 25.5 151.5 Green 56. IIHR 176 Tumkur, Karnataka 57.0 76.0 10.5 2.0 63.5 76.5 486.5 Green 57. IIHR 177 Tumkur, Karnataka 43.0 65.0 9.0 1.8 71.5 75.0 535.0 Green Mean - 62.4 81.9 11.0 2.3 78.6 36.1 270.4 - Range - 43.0 65.0 5.75 1.15 49.5 10.0 69.5 - –83.0 -100 -16.5 - 4.1 -122.0 -91.0 -576.9 CD (P=0.05) - 2.2 2.57 1.32 0.59 5.19 3.21 34.08 - CV % - 1.8 1.6 6.19 13.07 3.37 4.54 6.45 - Germplasm evaluation in Dolichos J. Hortl. Sci. Vol. 4 (1): 50-53, 2009 52 IIHR 143 (53.5 days). Pod-maturity ranged from 65 to 100 days. IIHR 177 was early to pod maturity in 65.0 days, followed by IIHR 143 (73.5 days). Pod-length ranged from 5.75 to 16.5 cm and IIHR 6 recorded maximum pod length. Pod-width ranged from 1.15 to 4.05 cm with maximum pod-width recorded in IIHR 11. Pods were narrow in IIHR 169. Ten pod weight ranged from 49.5 -122 g and maximum ten-pod weight was recorded in IIHR 7. Number of pods per plant ranged from 10 to 91, with maximum pod number in IIHR 159. Pod-yield per plant ranged from 69 to 576.9 g and maximum pod-yield was recorded in IIHR 150 and IIHR 159 with 576.9 and 576.2 g/plant, respectively (Fig.1 and 2). The results indicated existence of wide variability for each of the seven traits studied. Similar findings were reported (Baswana et al, 1980; Desai et al, 1996; Anon. 2000; Singh et al, 2004; Bendale et al, 2004; Nahar and Newaz, 2005). Lines found promising for six of the characters are shown in Table 2. There are five lines for earliness; six lines for pod-length; 12 for pod-width; nine for high pod- weight; six for high pod-number and eight lines for high pod-yield. Wide variations were recorded for pod-colour with six types, namely, green, light-green, purple, purple- Table 2. Grouping of dolichos germplasm for pod maturity, yield and pod related traits Traits Germplasm No. of Lines Early maturity (65-75 days) IIHR 9, IIHR 16, IIHR 19, IIHR 143, IIHR 177 5 Pod length (>15 cm) IIHR 6, IIHR 10, IIHR 154, IIHR 155, IIHR 163, IIHR 174 6 Pod width (> 3.0 cm) IIHR 1, IIHR 7, IIHR 8, IIHR 10, IIHR 11, IIHR 13, IIHR 14, IIHR 17, IIHR 144, IIHR 160, IIHR 161, IIHR 168 12 Ten pod weight (> 100 g) IIHR 7, IIHR 10, IIHR 11, IIHR 17, IIHR 150, IIHR 154, IIHR 155, IIHR 157, IIHR 174 9 Pod number /plant ( >65) IIHR 142, IIHR 159, IIHR 170, IIHR 171, IIHR 176, IIHR 177 6 Pod yield per plant (>400 g) IIHR 142, IIHR150, IIHR 156, IIHR 157, IIHR 159, IIHR 170, IIHR 176, IIHR 177 8 Table 3. Grouping of Dolichos germplasm based on pod-colour Pod colour Green Light- Purple Purple- Deep Creamy- green green pink white No. of germplasm lines 30 6 11 2 1 7 Per cent 52.63 10.53 19.30 3.51 1.75 12.28 Fig 1. IIHR-150 (pod-yield 576.9 g /plant) Fig 2. IIHR-159 (pod-yield 576.2 g/plant) Fig 3.Variation in podin some germplasm lines of dolichos green, pink and creamy-white. Details for pod-colour are presented in Table 3. In 30 lines (52.63%), pod colour was green. 11 lines (19.3%) had purple pods, seven lines cream- white pods and six lines had light-green pod-colour (Fig. 3). Two lines had purple- green pods and one line with deep pink pods, indicating wide variation for pod-colour. Similar variation in pod-colour was observed in dolichos germplasm collected by AVRDC in Bangladesh (Anon, 2000). The present study on 57 lines of dolichos revealed occurrence of wide variability for pod-yield, pod-maturity, pod- length, ten-pod weight, number of pods per plant and pod- colour. High-yielding germplasm lines and lines with different pod-types can be utilized further in breeding programmes. Lines with colour variation can be used as phenotypic markers in genetic and hybridization studies. J. Hortl. Sci. Vol. 4 (1): 50-53, 2009 Mohan et al 53 REFERENCES Anonymous, 2000. Annual Report, AVRDC, World Vegetable Center, Tainan, Taiwan, p. 82 Baswana, K.S., Pandita, M. L., Dhankhar, B.S. and Partap, P. S. 1980. Genetic variability and heritability studies on Indian bean (Dolichos lablab var. lignosus L.) Haryana J. Hortl. Sci., 9:52-55 Bendale, V.W., Topare, S.S., Bhave, S.G., Mehta, J.K. and Madav, R.R. 2004. Genetic analysis of yield and yield components in lablab bean [Lablab purpureus (L.) Sweet]. Orissa. J. Hort., 32:99-101 Desai, N.C., Tikka, S.B.S and Chauhan, R.M. 1996. Genetic variability and correlation studies in Indian beans (Dolichos lablab. var. lignosus). New Botanist, 23:197-204 Nahar, K and Newaz, M.A. 2005. 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