吊罗山薹草开花生物学特征及繁育系统研究

Flowering Biological Characteristics and Breeding System of Carex diaoluoshanica

开花生物学特征和繁育系统在生殖生长过程中有着重要的作用。对吊罗山薹草(Carex diaoluoshanica)的开花生物学特征和繁育特性开展定点观测研究,发现吊罗山薹草的小穗呈两性,但顶生小穗的雌花完全退化,而基部侧生小穗的雄花虽高度退化但仍有1~2朵匿藏的雄花发挥自交作用;开花物候和开花动态观测中发现,吊罗山薹草开花同步指数为0.16,顶生雄小穗的花期约5 d,侧生两性小穗的花期约6 d,而群体花期为26 d;在散粉后1 h时花粉活力达到最大,为85%,随后几小时内快速下降;柱头在散粉前1 d已经达到成熟状态,在散粉时依然保持着极高的可授性,到散粉第5天时,柱头不再具有可授性;根据异交指数和花粉/胚珠比检测,吊罗山薹草的繁育系统为兼性自交,进一步的套袋试验验证发现,其繁育系统是以自交为主,兼有异交的混合型交配系统。

The characteristics of flowering biology and breeding system play an important role in plant growth and reproduction.In this paper,the biological characteristics and breeding characteristics of Carex diaoluoshanica were studied based on the population of Diaoluoshan Natural Reserve.It was found that the spikelets were bisexual,but the female flowers of the terminal spikelets were completely degenerated,while the male flowers of the basal lateral spikelets were highly degenerated,but 1~2 male flowers were still remained.According to the observation of flowering phenology and flowering dynamics,the flowering synchronization index of C.diaoluoshanica was 0.16,and the flowering period of male spikelet was about 5 d,while that of lateral pistillate spikes was about 6d,and the flowering period of population was 26 d.The pollen viability reached a maximum of 85% at 1 h after powder dispersal,and then decreased rapidly within a few hours.The stigma had reached the mature state one day before powder dispersal,and remained highly activity in pollinating period,but no longer with activity after 5 days of pollination.According to the OCI and P/O index,the breeding system type of C.diaoluoshanica was facultative autogamy,further bagging experiments showed that the breeding system was mixes with self-pollination and out-crossing,and tended to selfing.