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ThesisItem Open Access Studies on reproductive biology and vegetative propagation in Jatropha curcas L.(CCSHAU, 2006) Aman Kumar; Dhillon, R. S.The present investigation on “Reproductive biology and vegetative propagation in Jatropha curcas L.” was carried out during 2004-2005. The studies on phenology, floral biology and breeding system were carried out on the plants growing in the campus of CCS Haryana Agricultural University, Hisar. The remaining part of the study was conducted by collecting one year old stem/branch cuttings during spring (February-March) and rainy (July-August) seasons. The cuttings were treated with different growth regulators viz. IAA, IBA, NAA and thiamine at 0, 250, 500, 1000, 1500 and 2000 ppm concentration levels for 16 hours and were raised in polythene bags filled with sand, soil and FYM in equal proportion and these poly bags were placed in nursery beds. Observations on sprouting and rooting parameters were recorded after 90 days of planting of cuttings. Defoliation started in first week of October and continued up to end of February, majority of which being completed by mid-February. Leaf primordia started appearing after first fortnight of March. The emerging leaves attained full size in about one month, although emergence of new leaves and their development continued up to end of December. It is monoecious plant i.e. male and female flowers are found separately in the same inflorescence. The male floral bud developed earlier than female ones. The male and female flower buds took 20 to 23 days and 23 to 25 days, respectively, to come to bloom. Maximum flower opening was noticed between 0700 to 0830 h in male flowers and 0730 to 0830 h in female flowers. The female flowers population resulted in sharp decrease with the fall in temperature during winter months and their ratio to male flowers became unfavourable. The flowering pattern showed a low rate initially during November end, gradually increasing to peak during December, followed by cessation from December end to mid-January. The number of days required from anthesis to fruit maturity ranged from 56 to 63 days. Maximum pollen viability (64.1%) was recorded at 1030 h. Dehiscence was observed one hour after anthesis. The receptivity of stigma started with flower opening and continued up to 72 hours after flower opening. The flower visitors included bees, ants, thrips and flies. They played major role in pollination through geitonogamy and xenogamy. Fruit set under natural pollination varied from 60.0 to 100.0 per cent, while 0.0 to 83.3 per cent under selfing with general mean of 34.4 per cent. The high natural fruit set recorded indicates that the plant is capable of producing fruit through geitonogamy and xenogamy. Such a breeding systems represents facultative xenogamy. Spring season was found best for clonal multiplication, even the untreated cuttings showed 100 per cent sprouting during this season. Maximum rooting per cent was recorded in cuttings treated with 2000 ppm IBA in spring as well as rainy season. The average number of roots per cutting and root length were recorded higher in spring season. In spring season, the maximum number of roots per cutting (72.5) and root length (23.6 cm) were recorded in 1500 ppm NAA and IAA treated cuttings, respectively.