Developmental Evidence of Male and Female Gametophytes of Jatropha curcas L.: Pollen Capability and Stigma Receptivity

Physic nut (Jatropha curcas L.), a promising alternative resource for biodiesel production, produces restrictively a seed yield and has a low level of genetic variation, causing a barrier to improve the oil performance. Therefore, better understanding of reproductive biology is crucially important for breeding programs to achieve commercial viability in the future. The developmental features related to floral bud diameter and floral morphology of male and female gametophytes, by means of light and scanning electron microscopes, and their capability were investigated. It was found that bud diameter could be used as criteria for identification of pollen and embryo sac stages. Pollen capability and stigma receptivity showed an inverse S-shape with time after flowering. The highest pollen viability assessed by FCR (93.20 - 98.60 %), TTC (78.80 - 87.00 %), and germination test (43.40 %) were obtained at 0 - 8, 0 - 12, and 0 HAF, respectively. Moderately linear correlations were exhibited between viability and germination test (R2 = 0.57 - 0.62). Stigma receptivity was the highest (97.22 - 100 %) on the first three days.