杂种小麦碳同化特性及籽粒产量性状的研究

 在春季小麦返青后的各生育期中，供试化杀型（CHA）杂种麦优4号和T型三系杂种麦优1号与亲本和对照相比，在群体光合速率（CAP）、群体叶源量（CLSC）和叶面积指数（LAI）上都表现明显杂种优势，这些优势随生育进程呈逐渐增强趋势。杂种小麦在返青后各生育期的群体干物重（PDW）均优于亲本。CLSC与PDW呈极显著正相关表明，CLSC可作为反映群体物质生产力大小的可靠指标。供试杂种在籽粒产量上的优势亦较明显，其平均优势（AH）大于超标优势（SH）。麦优4号、麦优1号的穗数、粒数、粒重三产量构成因素的AH均为正值，SH在麦优4号中表现为单位面积穗数和千粒重为正值，穗粒数为负值；在麦优1号中则单位面积穗数和穗粒数为正值，千粒重为负值。麦优4号的籽粒产量优于麦优1号。杂种小麦在CAP、CLSC上的明显优势是其获得PDW优势及籽粒产量优势的重要生理基础。本文还就杂种光合优势和光合作用与产量的关系进行了讨论。

Study on Canopy Carbon Assimilating Characteristics and Grain Yield Traits in Hybrid Wheats

Compared to parents and Yangmai 5 (CK), the tested CHA (Chemical emasculation) hybrid wheat Maiyou 4 and T type hybrid wheat Maiyoul showed obvious heterosis in canopy photosynthetic rate (CAP), canopy leaf source capacity (CLSC) and leaf area index (LAI), and the above heterosis gradually increased with the growth process. During the growth stages in spring, the changes of population dry weight in tested hybrids, parents and CK showed logistic curves. The hybyid wheats displayed obvious heterosis in population dry weight. The significantly positive correlation between CLSC and population dry weight indicated that CLSC could be one accurate index to reflect the potential of canopy productivity. The tested hybrid wheats also showed obvious heterosis on grain yield, but the average heterosis (AH) compared to parents were higher than the super check heterosis (SH) compared to CK. The AH of three yield components (spike number, grain number and grain weight) in Maiyou 4 and Maiyou 1 were all positive values. The SH of spike number per unit area and per 1000 grain weight were positive values and grain number per spike was negative value in Maiyou 4, and the SH of spike number per unit area and grain number per spike were positive values and per 1000 grain weight was negative value in Maiyou 1. The grain yield in Maiyou 4 was higher than that in Maiyou 1. The tested hybrid wheats had obvious heterosis on canopy photosynthetic rate (CAP) and canopy leaf source capacity (CLSC) were important physiological bases on which they acquired obvious heterosis in population dry weight and grain yield. The photosynthetic heterosis and the relationship between photosynthesis and yield were also discussed in this paper.