小叶桦花序生长物候及其生态适应意义  

Inflorescence Growth Phenology and Ecological Adaptation of Betula microphylla

作　　者：黄刚[1] 阎平[1] 杜珍珠[1] 曹婷[1] 徐文斌[1] 

机构地区：[1]石河子大学生命科学学院,新疆石河子832003

出　　处：《西北植物学报》2014年第12期2569-2575,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家科技基础条件平台建设子项目(2005DKA21006);石河子大学科研启动资金(RCGB201187)

摘　　要：小叶桦(Betula microphylla)是一种典型的荒漠和山地乔木植物,在中国仅分布于新疆。为了明确小叶桦花序生长物候规律及发育特征,该研究对小叶桦进行了花序物候观测,分析其生长规律及果实结籽情况。结果显示:小叶桦雄花序为越年生殖器官,物候周期为345d,其中营养生长期154d、休眠期158d、开花生长期33d;雌花序与果序为当年生殖器官,物候期为105d,其中雌花序生长期24d、果序生长期90d。虽然雄花序比雌花序的生长周期明显较长,但开花授粉均在4月中下旬,雄花序散粉期和雌花序可授粉期之间具有较高的同步性和协调性,表现出集中开花授粉模式,同时这种开花模式在自然条件下,果序的结籽数和结籽率分别为220和76.7%,种子库中具有活力的种子约每平米4万粒,表明小叶桦在荒漠极端环境中能顺利完成有性生殖过程。Betula rnicrophylla is one kind of typical desert and mountain plants trees that CllStrlOute omy in Xinjiang in China. Inflorescence phenological phase,growth rhythm and set seeds were studied to compre- hensively understanding the inflorescence growth phenology and and ecological adaptation of B. microphyl- la. The results are as follows：The staminate inflorescence of 13. rnicrophylla is the two year reproductive organs,whose phenological phase contains 154 days of vegetative growth, 158 days of dormancy and 33 days of flowering growth. The pistillate inflorescence and infructescence are annual reproductive organs, whose phenological phase contains inflorescence growing stage of 24 days and infructescence growing stage of 90 days. In spite of the difference of growth cycle between the staminate and pistillate inflorescence,the staminate and pistillate bud burst time appear same in the late in April,exhibiting a centralized pollination mode and result in more seed number and seed rate and higher seed dynamic. As it mentioned above,in a word,B, rnicrophylla can successfully completion of the process of sexual reproduction in the extreme des ert environment.

关 键 词：小叶桦 雄花序 雌花序 物候期 

分 类 号：Q944.3[生物学—植物学]