Breeding and selection of elite lines combining high oil and seed characteristics in nontoxic background of <i>Jatropha curcas</i>

To develop high-yielding, nontoxic Jatropha cultivars suitable for biodiesel production, a study was conducted at Jawaharlal Nehru Krishi Vishwavidyalaya, Jabalpur, India. The background involved interspecific hybridization between Jatropha integerrima and elite lines of J. curcas, followed by backcrossing to eliminate seed toxicity while enhancing yield potential. The material under study comprised four provenances (NBJ-1, JC11, MP55-1, and MP55-2); three spontaneous mutants, Dwarf (Dw), Green foliage (Gf), and Small leaf (Sl); and population crosses, viz., five single crosses (52-2, 52-3, NT-1, 61-3, and B1-11); eight three-way crosses (14-22, 9-1, 12-19, 13-11, 13-17, 13-28, 14-24, and 17-21); four four-way crosses (14-16, 21-8, 34-6, and 34-23); and one multiple cross (A9-1). Plants with a sufficient seed yield (>500 g) were analyzed for oil content and phorbol 12-myristate 13-acetate (PMA) content. The PMA was analyzed in different seed parts to understand the genetics of its nontoxic nature, which revealed its maternal inheritance. The four-way crosses indicated better assembly of genes with three-trait combinations; three-way crosses with three- and two-trait combinations; and single crosses with two combinations of traits. The plants derived from single crosses 52-3×34-6 and 61-3×52-2, as well as a four-way cross (52-2×13-11) × (61-3×52-2), emerged as the most promising through hybridization and require further evaluation in small-scale plantations for development and utilization in future breeding programs.