The genus Jatropha is native of tropical America with more than 200 species that are widely distributed in tropics with a promise for use as an oil crop for biodiesel. This investigation was carried out to assess the genetic diversity of 12 Jatropha species based on random amplified polymorphic DNA markers. From 26 random primers used, 18 primers gave reproducible amplification banding patterns of 112 polymorphic bands out of 134 bands scored accounting for 80.2% polymorphism across the genotypes. Three primers viz., OPA 4, OPF 11, and OPD 14 generated 100% polymorphic patterns. The polymorphic information content was highest for the primer OPD 14 (0.50) followed by the primers OPF 11 and OPAD 11 (0.48). Jaccard's coefficient of similarity varied from 0.00 to 0.85, indicative of high level of genetic variation among the genotypes studied. UPGMA cluster analysis indicated three distinct clusters, one comprising all accessions of J. curcas L., while second included six species viz., J. ramanadensis Ramam., J. gossypiifolia L., J. podagrica Hook., J. tanjorensis J. L. Ellis et Saroja J. villosa Wight and J. integerrima Jacq. J. glandulifera Roxb. remained distinct and formed third cluster indicating its higher genetic distinctness from other species. The overall grouping pattern of clustering corresponds well with principal component analysis confirming patterns of genetic diversity observed among the species. The result provides valid guidelines for collection, conservation and characterization of Jatropha genetic resources.

Interspecific hybridization in Jatropha species plays a significant role in crop improvement by transferring useful traits such as yield, high oil content, maximum number of seeds, more femaleness, and hard stems for promoting Jatropha as a biofuel crop. The wide crosses among the species resulted in limited success due to pollen incompatability. Hence, the objective of the study was to assess pre‐ and postzygotic barriers through pollen–pistil interaction between cultivated Jatropha curcas and other three wild Jatropha species. In this study, the cross J. curcas × J. gossypifolia, even though the pollen tubes reached ovaries after pollination, failed to produce seeds, and the cross between J. curcas × J. podagrica indicated incompatibility signs of bulged pollen tubes coupled with reverse direction of pollen tube growth. The interspecific cross of J. curcas with J. villosa showed crossability barriers of crinkled and twisted growth pattern of pollen tubes and failed to reach ovary. In the case of selfing (J. curcas × J. curcas), pollen tubes reached ovary within an hour and produced normal seeds. Reciprocal crosses of these species exhibited successful fertilization of pollen tubes, but seed set was very low or no seed set was noticed.

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Agroforestry has been practicedtraditionally in India in the form of subsistence farming, but is being increasingly recognized from the economic point of view, in addition to its positive contribution to the wood-based industrial sector, which has recent origin. Low forest cover, poor productivity and legal restrictions coupled with an increasing demand for wood and wood products due to increasing population, industries and associated policy changes have ushered in a total mismatch between demand and supply. This has attracted increasing attention towards agroforestry. The National Forest Policy of India 1988 has directed all wood-based industries to generate their own raw material resources by linking farmers and extending technology and market support. However, these directives were not taken seriously, and consequently, the achievements that should have taken place in industrial agroforestry and plantation establishment are dismally modest for want of suitable institutional mechanism to resolve the research gaps that exist in the entire Production to Consumption System (PCS). Against this backdrop, Tamil Nadu Agricultural University (TNAU) has pioneered research by creating a value chain in industrial agroforestry which was initially demonstrated in 200 ha of farmlands through technological, organizational and marketing interventions. Incorporationof high yielding short rotation (HYSR) clones, precision silviculture technology, adoption of multifunctional agroforestry and value addition technology are the major technological interventions that attracted more farmers towards agroforestry development. Conceptualization and successful practice of the contract tree farming model, particularly the quadripartite contract farming model, ensured institutional linkage among the value chain players and facilitated technology transfer, assured buy back, price support system and also institutional credit and insurance. The provision of a market support system for a wide range of pulp wood, plywood, timber, and match wood exerted a significant influence among tree-growing farmers. In order to sustain these value chain innovations and interventions, an institutional mechanism, namely the Consortium of Industrial Agroforestry (CIAF), was established in 2015, which linked all value chain players and aided in resolving the issues in the entire production to consumption system (PCS) of agroforestry on a sustainable basis. Over the years, these innovative interventions have had a significant impact in terms of area increase, productivity and profitability improvement coupled with safeguarding the social and environmental concerns of agroforestry farmers from a holistic perspective. The Consortium-based Value Chain on Industrial Agroforestry model has a very good replication potential not only within India, but also elsewhere across the global landscape.