Abstract:
Physic nut (Jatropha curcas L.) is emerging as a sustainable alternative source of bio-fuel for mitigation of global energy crisis. However, profitable exploitation of J. curcas through large scale production schemes is still in its infancy mainly due to unpredictable seed yield traits and seed toxicity. Furthermore, the plant suffers from narrow genetic base. Identification of promising populations of J. curcas from wild habitat or distinct agroclimatic regions is of foremost importance for overcoming this constraints and development of superior varieties in breeding programs. However, in spite of increasing global importance of J. curcas as a bioenergy crop, till date, very little comprehensive studies on estimation of morphological and biochemical characters of J. curcas along with assessment of genetic variation within the germplasm has been conducted for screening and identification of elite and genetically divergent planting materials. With an objective to identify promising J. curcas populations, twenty nine populations were collected systematically from distinct agro-climatic regions of North-East India. Four populations from other parts of India were also included in the study as outgroup. In the present investigation, the morphological variation of J. curcas populations were assessed using agronomically important morphometric traits like plant height, collar diameter, canopy spread, floral sex ratios and yield associated traits like 100 seed weight and total seed yield. Highly significant differences in phenotypic characters were observed among J. curcas populations. The highest broad-sense heritability (%) was recorded for M: F ratio (88.07) and the lowest for canopy spread (66.39). The morphometric characterization of J. curcas populations on the basis of cluster and principal component analyses depicted that association among populations is independent of geographical origin. Seven promising J. curcas populations (IITJC7, IITJC15, IITJC19, IITJC21, IITJC22, IITJC24 and IITJC28) identified from North-East India on the basis of morphological characterization can be used as potential starting material for J. curcas improvement ventures.
