双穗层杂种小麦群体中两种基因型植株光合特性的差异  

Genotypical Difference in Photosynthetic Characteristics in a Hybrid Wheat Population with Semi-dwarf (Rht_3 rht_3) and Tali (rht_3 rht_3) in1:1 Ratio

作　　者：聂毓琦[1] 赵寅槐[1] 邹明烈[1] 芮仁廉[1] 王苏[1] 程光宇[2] 刘静如[2] 

机构地区：[1]江苏省农业科学院 [2]南京师范大学生物系

出　　处：《江苏农业学报》1990年第4期1-8,共8页Jiangsu Journal of Agricultural Sciences

基　　金：自然科学基金(3860648)资助项目

摘　　要：随生育期的推进,群体内半矮秆(MD)与中高秆(H)两种基因型植株的功能叶片的受光量、光合速率与光合组分等均出现显著变化。拔节后,MD株顶端叶片与H株倒2叶处于群体内同一高度。因此,在光竞争上,MD株始终处于劣势地位。MD株叶绿素a/b值与叶绿体类囊体膜组分类似阴生型植物。MD株在抽穗前一段期间内的光合速率(P_n)明显高于H株,可能与MD株的功能叶含何较多的可溶性蛋白和较高的LHCP_s有关。这就表明Rht_3基因在植物光合功能方面能显示出特殊效应。抽穗后,群体顶端增加了穗层的遮荫,MD株与H株在LHCP_s含量上的差异变化,MD株可溶性蛋白含量低于H株,光合作用也低于H株。说明MD株对弱光的适应有一定的限度。本文讨论了利用Rht_3基因提高杂种小麦的光能利用效率和产量的可能性。A hybrid wheat was produced by crossing a male sterile line (Rht_3 rht_3) with T. timopheevii cytoplasm to a restorer line (rht_3rht_3), resulting in an F_1 population with semi-dwarf ( Rht_3rht_3 ) and tall (rht_3rht_3 ) plants in 1 : 1 ratio. To evaluate the efficiency of light utilization, the photosynthetic characteristics of the two genotypes were compared in terms of incident light intensity on the functional leaves at different canopy levels in the population, photosynthetic rate, chlorophyll content, soluble protein content and chlorophyll-protein complexes of the thylakoid membrane during the growth period. At the early stage, almost no difference in the parameters was observed between the two genotypes except that the MD (Semi-dwarf) plants showed higher photosynthetic rate and soluble-protein content than the H (Tall) plants. After jointing the uppermost leaves of the MD plants were positioned at the same level as the second uppermost leaves of the tall plants in such a hybrid wheat population. The photosynthetic rate of MD plants was higher than that of the H plants until heading because MD had higher contents of soluble-protein and LHCP_S, which might be associated with the Rht_3 gene. However, the MD plants were overshadowed to a certain extent by the tall plants after heading, thus leading to a drop in soluble-protein content and photosynthetic rate of the MD plants, which must be unfavourable for high yield formation, although the MD plants showed some advantages over the H plants in photosynthetic performance at the early and middle growth stages. A discussion is given on the potential use of the Rht_3 gene in hybrid wheat breeding to enhance shade tolerance, which is important for the further increase of crop productivity.

关 键 词：小麦 杂种 植株 光合特性 基因型 

分 类 号：S512.103.5[农业科学—作物学]