不同年际间异子蓬种子大小、萌发能力及结实格局

异子蓬(Borszczowia aralocaspica)为中亚荒漠特有种,在我国仅分布于新疆,其果实具有二型性。对同一生长地2006、2007、2008年异子蓬种子的大小、萌发特性及结实格局进行比较,结果表明:(1)年份和种子类型对种子大小和重量均有显著影响(P<0.05)。(2)2种类型种子具有不同的萌发行为,褐色种子萌发率高(>90%),萌发速度快,而黑色种子萌发率低(2006年的萌发率为31%),萌发速度慢;2种类型种子的萌发指数在不同年际间均差异显著。(3)不同年际间,种子总数、褐色种子数、黑色种子数均具有极显著差异(P<0.001),且随个体的增大黑色种子的比例逐渐减小,褐色种子的比例逐渐增大,并且黑色种子数目均高于褐色种子数目。该研究为深入认识异型种子的生态适应对策提供理论基础。

Seed size, germination characteristics, and seed production pattern of Borszczowia aralocaspica in different growth years

Borszczowia aralocaspica is an endemic species in central Asian desert,and only distributes in Xinjiang of China.Its fruit has a property of dichotocarpism.This paper studied the differences in the seed size,germination characteristics,and seed production pattern of B.aralocaspica at the same site in 2006,2007 and 2008.The results showed that growth year and seed type had significant effects on the seed size and seed weight of B.aralocaspica(P<0.05).The two types of the seeds had different germination characteristics.Brown seeds had higher germination rate(>90%),and germinated rapidly.In contrast,black seeds had lower germination rate(31% in 2006),and germinated slowly.The germination index of brown seeds and black seeds had significant differences among different years.There were significant differences in the total amount of seeds and the amounts of brown seeds and black seeds among different years(P<0.001).With the growth of the individuals,the proportion of black seeds decreased while that of brown seeds increased,but the amount of black seeds was larger than that of the brown seeds.Our study could provide theoretical basis for the further understanding on the ecological adaptation strategy of dichotocarpism seeds.