Abstract
对分布于新疆北部干旱荒漠区的刺山柑Capparisspinosa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 0.05).(3)单花花期为15-16 h,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1.57×104、1.65×104和1.71×104.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18-20 h,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.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
