濒危植物长柄双花木开花物候与生殖特性  

The flowering phenology and reproductive features of the endangered plant Disanthus cercidifolius var. longipes H. T. Chang (Hamamelidaceae)

作　　者：肖宜安[1] 何平[1] 李晓红[2] 

机构地区：[1]西南师范大学生命科学学院,重庆400715 [2]井冈山师范学院生命科学系,吉安江西343009

出　　处：《生态学报》2004年第1期14-21,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目 (3 0 0 70 0 80 )~~

摘　　要：研究了长柄双花木开花过程中花部表型的变化 ,连续 4 a对其野生种群、1a对人工种群的开花物候进行了观察 ,并运用相对开花强度和同步性等开花物候指数分析了开花物候对其生殖的影响。结果如下 :长柄双花木开花时间为 9月上、中旬至 11月中、下旬 ;单花花期一般为 6～ 7d,单花依其形态和散粉特征可以分为 4个时期 :散粉前期、散粉初期、散粉盛期和凋谢期。个体开花持续时间 4 9～ 5 5 d,种群花期历时 6 3～ 71d。种群内不同年度间开花物候指数没有显著差异 ,而种群间则存在显著差异 ,野生种群开花进程为渐进式单峰曲线 ,人工种群则为“钟”形曲线 ,二者均属于“集中开花模式”。长柄双花木具有 2个相对开花强度的分异趋势 ,这种分异趋势具有进化意义。开花物候指数与生殖间的相关分析表明 ,始花时间与开花数量、座果率及花期长度之间均具显著负相关关系 ,而开花数量与花期长度之间则呈显著正相关 ,但均为线性相关。长柄双花木开花物候在种群间的差异和种群内年度间的相似性说明 ,其开花时间可能是由与其相关的复杂的微生境特征和 (或 )由其遗传因子决定的 ,同时也反映了种群间的遗传分异和种群内个体间的遗传一致性。作为一种濒危物种 ,长柄双花木在这种环境的选择压力之下 ,形成了“大量、集中开放的花?The flowering phenology of a plant population is the sum of the individual phenologies. These individual phenologies can be subdivided into variables such as the starting date of flowering, the date of the flowering peak, and flowering duration. Various characteristics of phenology may have an important effect on reproductive success, including the starting date of flowering and flowering synchrony. However, different flowering indices may affect different aspects of phenology, and may be constrained by other plant characteristics. Disanthus cercidifolius var. longipes H.T.Chang, a plant species that only occurs in a few counties in Hunan, Jiangxi Province and Zhejiang Province and with relatively small numbers of individuals, is recorded as a 2^(nd) Class endangered species for conservation in China. The variations in morphological traits, flowering phenology and reproductive success of this species were studied. The study sites were located at Mt. Jinggang, Jiangxi Province. 50 individuals with more or less the same heights and crown diameters, in the wild population in Caijiatian, were marked and observed from 1999 to 2002. Another 50 individuals in the artificial population of Ciping, planted in 1990, and originating from Mt. Guanshan in Jiangxi Province, were also marked and observed in 2002. The flowering course of each individual was observed and the data on flowering onset, duration, mean flowering amplitude (flowers/plant/day) and end of flowering were registered. Then the relative flowering intensity and synchrony indices were calculated. The relationships between onset, duration, flower and fruit set, the correlation matrix between starting date and duration, flowering and duration, the phenology index, and fruit set in the wild population were analyzed. The results are as follows:In Disanthus cercidifolius var. longipes H.T.Chang, two axillary inflorescences are often placed opposite each other at the same node. Each inflorescence has two opposite bisexual flowers without pedicels. Each flower is ca.

关 键 词：开花物候 开花同步性 相对开花强度 座果率 长柄双花木 

分 类 号：Q945[生物学—植物学]