Pollen Source Effects on Fruit and Seed Traits of Jatropha curcas L.—A Renewable Biodiesel Feedstock

Abstract

The effects of the pollen source on fruit and seed traits of Jatropha curcas and on potential biodiesel traits were investigated using analysis of breeding system and reciprocal pollination of various genotypes. The field experiments were carried out under Mediterranean conditions in Bet-Dagan, Israel. The breeding system was investigated by comparison of self-pollination with cross, open, and spontaneous self-pollination. Self-pollination, compared with cross-pollination, resulted in significantly lower levels of seed weight, oil concentration, oil content, and linoleic acid concentration in the seed-oil and with higher concentration of oleic acid. These seed traits were measured by near infrared reflectance spectroscopy (NIRS) as previously calibrated for J. curcas. Spontaneous self-pollination resulted in extremely low fruit and seed sets, and apomixis was totally absent. Pollen source effects were investigated by reciprocal pollination of selected genotypes; ‘Ethiopia,’ ‘Niger,’ and ‘Suriname’ both receiving and donating pollen. In addition, the genotype Brazil was used only as pollen source for the above mentioned genotypes. We found that most seed and oil traits were determined by the pollen recipient regardless of the type of pollen source. Additionally, when pollinated with Brazil, Ethiopia resulted in lower seed set, Niger resulted in higher content of seed protein and lower concentration of stearic acid in the seed oil, and Suriname resulted in higher concentration of linoleic acid and lower concentration of oleic acid. We suggest that enhancement of oil yield and oil quality in future plantations should be based either on a single elite genotype with nondetrimental self-pollination traits or on several elite genotypes with improved compatibility both as pollen sources and pollen recipients.