Seed germination studies of Salvadora persica and Jatropha curcas

Abstract

In nature the seeds of Salvadora persica and Jatropha curcas possess diversity in their size. Based on their weight, the seeds were segregated into seven categories. In S. persica these ranged from 20 to 90 mg per seed while in J. curcas ranged from 100 to 800 mg per seed. When put to germination, there was no germination at all in seeds weighing up to 30 mg per seed in S. persica and up to 300 mg per seed in J. curcas. The germination was found to be 22, 29, 49, 64, 89 and 100% in S. persica in rest of the six categories while in J. curcas it was found to be 20, 30, 60, 85 and 100% in remaining five categories. The seedling development in terms of height and fresh biomass also increased with the increase in seed weight. When treated with salt solution adjusted to different pH levels (2 to 11), the seed germination was found highest in both species at pH 8.0. The germination was faster at pH from 6 to 8 when compared to other levels. The effect of quality of light on seed germination showed maximum germination in natural light in both the species followed by yellow, green, red and blue lights, respectively. The seed germination was initiated after one week when seeds were treated with saline water of electric conductivity of 2 and 4 dS m-1 in both the species while on higher salinity the germination started during second week. The seed germination was lower at higher salinity. After 4th week of germination the shoot length, root length, collar diameter, fresh and dry biomass of shoot and root were decreased with increase in the salinity of irrigation water.