大白刺传粉生物学特性研究

Study on pollination biology characteristics of Nitraria roborowskii

以乌兰布和沙漠自然居群的野生大白刺为试验材料,运用定位观察、柱头可授性、花粉/胚珠比率、杂交指数等指标的测定,研究野生大白刺传粉生物学。结果表明：大白刺花粉活力呈现先升高后降低的趋势,开花第3 d,大白刺的花粉活力达到最大值75.24%;雄性不育花和可育花的柱头在开花后第4-5 d可授性均最强。大白刺的P/O值为173 688.9,OCI指数≥4;大白刺在自然条件下能够结实,但结实率不高;存在自花传粉现象,有性生殖中异花传粉起到主要作用,结实受到传粉者限制;不存在无融合生殖现象。大白刺访花昆虫主要有9种类型,主要的传粉昆虫有东方蜜蜂、丽蝇。

Taking the wild Nitraria roborowskii distributed in Ulan Buh desert of Inner Mongolia as experimental material, the flowering habit were observed and the pollen vitality, stigma receptivity, pollen/ovule ratio （P/O）, hybrid index （OCI） and the strong degree of pollination experiment were measured. The results showed that： （1） The pollen viability of Nitraria roborowskii showed a trend from decline to rise. The pollen viability got the highest value （75.24%） at the 4^th day after flowering. The stigma receptivity of male sterile flowers and fertile flowers at 4^th to 5^th d after flowering was the strongest. （2） The P/O value was 173688.9. OCI index was higher than 4. Nitraria roborowskii was able to bear fruit under natural conditions with low setting percentage. （3） There was self-pollinating phenomenon although alienation pollination played a major role in sexual reproduction. Setting percentage was limited by pollinators. There was no apomixis phenomenon. （4） There were 9 types of pollination insects for Nitraria roborowskii, and the main pollinators were Apis cerana Fabricius and Calliphoridae.