两个杂交棉F1、F2代及亲本冠层结构与物质生产特征

以杂交棉石杂2号和新陆早43的F₁、F₂代及亲本NT2、H2、4-14为试材，通过测定不同生育时期各材料叶面积指数(LAI)、叶倾角(MTA)、冠层光截获率等指标，分析了各指标变化对群体光合物质生产的影响。结果表明，2个杂交棉F₁代LAI具有超亲优势，冠层光截获率具有中亲优势; LAI和冠层光截获率具有明显的母系遗传特性，而MTA受到父本的显著影响。F₂代冠层结构主要受F₁代相关指标和衰退率的影响，LAI中亲优势减小了衰退率; 杂交棉F₁代光合物质积累主要受亲本参数和超亲优势的影响，F₂代主要受F₁代参数的影响。杂交棉光合物质积累最大增长速率和直线增长期开始时间较晚，直线增长期及活跃增长期较长，最终积累量和最大增长速率较高。杂交棉F₁代具有明显的光合生产和产量优势，F₂代具有一定的产量优势。以选择具有优化冠层结构的亲本为基础，组配具有较大MTA的父本和较大LAI的母本，有利于改善杂交棉光合性能，提高群体光能利用率，进一步挖掘产量潜力，为杂交棉高光效组合的选育及提高F₂代应用提供理论依据。

Canopy Structure and Matter Production Characteristics of F1, F2, and Their Parents in Two Cotton Hybrids

A field experiment was conducted using the F₁, F₂ of two cotton hybrids of Shiza 2 and Xinluzao 43 and their parents NT2, H2, and 4-14. After measuring the leaf area index (LAI), leaf inclination angle (MTA) and light interception rate (LIR) at different growing periods, it is clear that the matter production of hybrid cotton was affected directly by the parameter changes of the canopy structure and photosynthetic characteristics of two cotton hybrids parents. The results revealed that the over-parent hereosis of F₁ in two cotton hybrids was observed on LAI and mid-parent heterosis of them was provided with LIR. Both LAI and LIR were observed obviously with matrilineal genetic characteristics, while MTA was influenced by paternal inhentance. The canopy structure of F₂ in two cotton hybrids was mainly influenced by the related parameters of F₁ in hybrid cotton indexes and their decreasing rate. The decreasing rate was deduced by the over-parent hereosis on LAI. The photosynthate accumulation of F₁ in two cotton hybrids was mainly influenced by the numerical value of their parents and over-parent hereosis, and the photosynthate accumulation of F₂ in two cotton hybrids was mainly influenced by the related parameters of F₁. The initial time of the highest increasing velocity of photosynthate accumulation and the linear increasing period was later, the linear increasing period and the active increasing period of photosynthate accumulation were longer, the total photosynthate accumulation and the highest increasing velocity were larger in two cotton hybrids. The photosynthate and yield were very high in F₁ of hybrid cotton, and there was a high yield only in F₂ of hybrid cotton. Based on choosing the parents with the optimizated canopy structure, we should be make a well combination between father plant with larger MTA and mother plant with larger LAI, which will be provides used for improving hybrid cotton photosynthetic performance, increasing light use efficiency for enhancing yield potential further. The study provided come theoretical parameters for breeding high photosynthetic efficiency hybrid line andimproving utilization of F₂ in hybrid cotton.