极危植物多脉含笑的花部变异研究

对昆明树木园栽培的7株多脉含笑56朵花花部的数量、形态及大小变异的观察分析,结果表明:花部的数量、形态和大小性状均有变异。从花部数量变异来看,花枝节间数、花被片总数、花被片轮数等12类数量性状的变异系数为6.17%～219.33%,其中第三轮花被片数发生的变异最大;从花部形态变异来看,梗毛被颜色、花被片形状、花被片颜色等11类花部形态性状的变异也主要发生在株间,并且大部分表现为变异极显著。从花部大小变异来看,花枝节间长、花枝节间径、花序梗长等31类花部大小性状变异系数为9.13%～229.35%,其中花梗的大小变异最大;故花被片和雄蕊2个花部结构是该种的主要变异器官。其花部也存在异步演化的现象,原始性状和进化性状是交织出现的,是一种较进化的物种。多脉含笑花部变异主要发生在株间,为优良单株存在的可能性及其选择提供了科学依据。

Floral variation of Michelia coriacea, a critically endangered species

The floral variation of 56 flowers from 7 plants of Michelia coriacea H.T.Chang et B.L.Chen in Kunming Arboretum was observed.The results show that the numerical,morphological and size characters of their floral parts are varied.There are 12 floral parts such as the internode of floral brachyblast,the whorl,the tepal and so on,in numerical variation.Their coefficients of variance are from 6.17% to 219.33%,of which the biggest one is in the third-whorled tepals.There are 11 floral characters such as the indumentum on peduncle,the shapes of the tepal,the colors of the tepal and so on,in morphological variation.Their variations among different individuals are more than those in a same single plant and most of their differences are very significant.Their coefficients of variance are from 9.13% to 229.35%,of which the biggest one is in the length of the pedicle.Summarized all above,the variations of two floral parts including tepal and stamen are the biggest.The two floral parts are main varied organs of the species.There are more variations among the individuals than those in a same single plant in this species so that it will present a scientific basis for the occurrence possibility and the breeding selection of excellent individuals.The phenomenon of heterobathmy also occurs in Michelia coriacea.This species is a more evolutional species in Magnoliaceae although there are many primitive and evolutional characters in it.