不同饲草型小黑麦基因型的光合生理差异

为筛选光合性能强的饲草型小黑麦种质及探讨光合性能主要影响因素,采用差异分析和主成分分析法研究了6个饲草型小黑麦基因型在不同生育时期的叶绿素含量及光合生理指标的变化。结果表明,随着生育时期推移,饲草型小黑麦的光合性能指标(除气孔限制值)均为先增加后减少,叶绿素含量、蒸腾速率、光合速率、胞间二氧化碳浓度在抽穗期达到最高值,水分利用效率在开花期达到最高值;随着生育时期推移,饲草型小黑麦的气孔限制值先减少后增加,抽穗期最低。通过生育时期×小黑麦种质间光合性能指标差异分析可知,C31和C19在整个生育时期光合性能都较强,可达到高产的目的,而饲草型小黑麦C19的优势是水分利用效率较高,可进一步作为抗旱种质资源。主成分分析可知,影响饲草型小黑麦光合性能的主要因素有蒸腾速率和与气孔有关的因素。

A study of the photosynthetic physiology of different forage triticale genotypes

The aim of this research was to identify forage triticale genotypes with strong photosynthetic performance and elucidate the main factors influencing photosynthetic performance. The chlorophyll content and photosynthetic physiological index of 6 forage triticale genotypes were studied at different growth stages, and data analysed by analysis of variance and principal component analysis. It was found that parameters related to photosynthesis(except for stomatal limitation value) peaked during early development and then declined with advancing maturity. Values for chlorophyll content, transpiration rate, photosynthetic rate and intercellular CO2 concentration peaked at the heading stage, while water use efficiency peaked at the flowering stage. The time trend for stomatal limitation value was opposite to that of other traits with the lowest value observed at the heading stage. The principal component analysis revealed that transpiration rate and stomatal traits most influenced the photosynthetic performance of forage triticale. Both C31 and C19 had relatively strong photosynthetic performance during the entire development cycle and were high-yielding. However, C19 showed an advantage of relatively high water use efficiency. This line can therefore be further used as a germplasm resource for drought resistance. The principal component analysis showed that transpiration rate and stomatal related factors had significant influence on the photosynthetic performance of forage triticale.