The effect of light, temperature and bracteoles on germination of polymorphic seeds of Atriplex centralasiatica Iljin under saline conditions

Atriplex centralasiatica, a salt-secreting herb in the family Chenopodiaceae, is one of the most economically important halophytes in China. Seeds were collected from Huanghua City and were separated to get humped-black. humped-brown, flat-black and flat-brown seeds on the basis of the type of bracteoles and seed coat color. The four kinds of seeds were screened for germination with NaCl solutions of different concentration. Results showed that the effects of fruit types were not significant on polymorphic seed germination. Multi-factorial nahsis of variance revealed significant differences in the effects of seed color, temperature, salinity, light and their interactions on seed germination. Maximum germination occurred in distilled water, and an increase in NaCl concentration progressively inhibited germination in all the four types of seeds, A temperature regime of 15/25 degrees C resulted in the maximum germination. Brown seeds had I higher germination percentage than black seeds in mild temperature regime and high salinity; while black seeds had I higher germination percentage than brown seeds in higher temperature and lower salinity. Germination of black seeds was sensitive to light ill NaCl solution but not of brown seeds. Attached bracteoles inhibited the germination of both black and brown seeds. The black seeds were more sensitive to presence of bracteoles than brown ones. In conclusion. the polymorphic seeds showed bet-hedging ecological strategies.