MUTATION STUDIES OF AN OILSEED SPURGE RICH IN VERNOLIC ACID

Euphorbia lagascae Spreng., a wild spurge native to southeastern Spain, is being evaluated as a potential new oilseed crop. It has high seed oil content, with 58 to 62% vernolic acid, a long-chain unsaturated fatty acid with several applications for the chemical industry. Seed dehiscence is a common problem of all 62 accessions collected to date. The objective of this work was to use chemically induced mutagenesis to develop nonshattering lines. Self-pollinated M2, M3, and M4 plants were observed in the field in Spain. Three indehiscent mutants were found in the M2 and M3 generations of ethyl methanesulfonate-treated seed, together with four quatricarpellate mutants containing capsules with > 3 seeds capsule-1. The M3 and M4 progenies of mutant plants were studied and the following results were observed: (i) indehiscent plants transferred the character to almost-equal-to 3.5 and 5% of their M3 and M4 progenies, respectively; (ii) indehiscent plants had on the average 2 seeds capsule-1, one-third less than normal plants; (iii) M3 quatricarpellate mutants transferred this character, on average, to 40 to 60% of their M4 progeny and produced 10 to 30% more seeds per plant with the same number of capsules.