白刺属植物的繁育系统与开花结实特征

Breeding System Characteristics,Blooming and Fruiting Habits of Nitraria L.

对乌兰布和沙漠地区白刺属4种植物在花期、果期的样株调查观测及室内外实验分析,系统研究了唐古特白刺、西伯利亚白刺、大白刺和泡泡刺4种白刺属植物的繁育系统和开花结实习性。结果表明:不同白刺属植物在花序花数、花冠直径、柱头高度、雄蕊长度等花部特征方面均有显著差异;4种白刺属植物的花粉胚珠比(P/O比)在400～2 000之间,杂交指数(I OC)都大于4,繁育系统属于兼性异交类型,部分自交亲和,需传粉者。除泡泡刺外,其它3种白刺植物的理论现时生殖值和实际现时生殖值之间差异不显著,但是白刺属不同植物种间的2种生殖值均有较大差异。4种白刺属植物果实、种子纵径、横径和果、种形指数差异均达到显著水平。

With the sample plants in the plot during the blooming and fruiting stages, we studied the breeding systems and flow- ering and fruiting characteristics of four plant species of Nitraria L. in Ulan Buh Desert including Nitraria tangutorum, Ni- traria sibirica, Nitraria roborowskii and Nitraria sphaerocarpa. There are significant differences in the floral characteristics of four plant species, such as the number of flowers per cyme, corolla diameter, stigma height and stamen length. Their pollen-ovule ratios （P/O） are about 400-2 000, and the outerossing index （/oc ） values are above 4. Their breeding sys- tems belong to the xenogamy chiefly and self-compatible partly, and the pollinators are required during the pollination process. There are not significant differences between the theoretical present reproductive value and actual present repro- ductive value for Nitraria species excluding N. sphaerocarpa, but there is the difference in two present reproductive values among four species. The morphological characteristics of their fruit and seed, vertical, lateral diameter and shape index are in the significant difference level.