中文摘要：

对分布于新疆北部干旱荒漠区的刺山柑Capparis spinosa性系统进行了研究。结果表明：（1）该物种具有典型的雄全同株性系统。雄花和两性花的雄蕊均正常发育,且有长短之分;两性花的雌蕊发育正常,而雄花的雌蕊败育,只行使雄性功能。（2）居群间每天开放的雄花和两性花比率、两性花的长短雄蕊数及雄花短雄蕊的花丝与花药长等存在极显著差异（P〈0.01）,但花器官生物量没有显著差异（P〉0.05）。（3）单花花期为15-16h,每天18：00时左右开始开放,有强烈的气味和花蜜产生。植株每天产生的雄花和两性花数是随机的,可形成短时的雄花与两性花异株,但居群内雄花数比两性花数多。（4）三个居群两性花的P/O值分别为1.57×10^4、1.65×10^4和1.71×10^4。居群内雄花和两性花的花粉数及长、短雄蕊花药的花粉数均无显著差异（P〉0.05）,居群间雄花和两性花的花粉数、两性花的胚珠数及P/O值差异也不显著（P〉0.05）。（5）各居群雄花和两性花长短雄蕊的花粉活力动态变化曲线相似,花粉寿命为18-20h,两性花雌蕊柱头的可授期为16-18h。（6）访花昆虫为膜翅目Hymenoptera和鳞翅目Lepidoptera昆虫,3个居群共有7种访花昆虫,其活动受天气影响很大。（7）两性花不存在无融合生殖现象,授自花花粉、同株异花花粉和异株异花花粉后均可结实,属于混合交配系统。刺山柑的雄全同株性系统可能是在长期与荒漠环境相适应的过程中由遗传和环境共同作用的结果。雄花的出现不仅增加了花粉数和P/O值,提高了植株的雄性适合度,同时增加了花的数量、对传粉昆虫的吸引力以及两性花柱头接受异花花粉的机会,提高了异交率和雌性适合度,保障其在荒漠极端环境中繁殖成功。

英文摘要：

The sexual system of the perennial shrub Capparis spinosa L. （Capparaceae）, which is distributed in arid deserts of northern Xinjiang, was investigated. The main results can be summarized as follows. （1） The species is andromonoecious, i.e. individuals possess both male and perfect flowers. Stamens of two floral morphs are normal and can be divided into long and short ones in each flower. The perfect flowers have well developed pistils, but male flowers have aborted pistils and only function as males. （2） There were very significant differ- ences among the populations in daily ratio of the two floral morphs, number of long and short stamens of perfect flowers and length of filaments and anthers of short stamens in male flowers （P〈0.01）, but no significant differences occurred in biomass of floral organ （P〉0.05）. （3） Anthesis was nocturnal and lasted 15-16 h. Both male and perfect flowers opened about 18：00 at dusk. The number of two floral morphs produced on each individual was indeterminate every day during flowering, which would make the individual temporally androdioecious. However, the total number of male flowers was more than that of perfect flowers within the population every day. （4） The P/O ratios of perfect flowers in three populations were 1.57×10^4, 1.65×10^4 and 1.71×10^4. There was no significant difference in pollen numbers （P〉0.05） within population between male and perfect flowers or between long and short stamens, and also no significant difference among the populations in pollen numbers of male and perfect flowers, and in ovule numbers and P/O ratios of perfect flowers （P〉0.05）. （5） Dynamic curves of pollen viability of long and short stamens in the two floral morphs were similar in three populations. Pollen longevity of both long and short stamens was about 18-20 h, and duration of stigmatic receptivity was about 16-18 h. （6） Floral visitors were hymenopterous and lepidopterous insects. There was a total of seven species of floral visito