不同小麦进化材料生育后期的光合特性及其对环境因子响应的比较

为了解不同小麦近缘材料光合特性,以二倍体节节麦、四倍体硬粒小麦、六倍体普通小麦、八倍体小黑麦为材料,在生育后期测定了其光合气体交换参数、叶绿素含量、叶面积指数等光合相关性状,并对净光合速率在不同光照、CO_2浓度、温度、湿度条件下的变化进行了分析。结果表明,八倍体小黑麦的光合气体交换参数和叶绿素含量比其他三个材料高,六倍体小麦在叶面积上具有明显优势;四倍体和六倍体小麦具有较高的光能利用效率,而二倍体小麦和八倍体小黑麦对强光的抗性较强;六倍体小麦和八倍体小黑麦对CO_2的利用率和抗逆性都较强;八倍体小黑麦的光合速率受温度的影响较小,而二倍体和四倍体小麦的光合速率受温度的影响比较大;二倍体小麦的光合速率受湿度的影响较大,四倍体小麦的光合速率受湿度的影响较小,六倍体小麦和八倍体小黑麦光合速率在高湿条件下变化较小。这说明不同小麦近缘种具有不同的光合特性,是小麦进行小麦高光合育种的重要基因资源。

Comparison of Photosynthetic Characteristics of Different Wheat Evolution Materials at Late Growth Stage and Their Response to Environmental Factors

In this study, diploid species Aegilops tauschii, tetraploid species T .durum, hexaploid species T.aestivum and octoploid species Triticale were used as materials and photosynthetic gas exchange parameters, such as chlorophyll concentration, leaf area index etc. were determined at the late developmental stage. The changes of net photosynthetic rate under different illumination, CO₂ concentration, temperature and humidity conditions were investigated. Results showed that, the photosynthetic gas exchange parameters and chlorophyll concentration of octoploid material were higher than those of the other three materials and hexaploid material had obvious advantages in leaf area; tetraploid and hexaploid materials had higher light utilization efficiency, while diploid and octoploid materials had stronger resistance to light; hexaploid and octoploid materials had higher utilization efficiency of CO₂ and stronger resistance to CO₂; the photosynthetic rate of octoploid material was less affected by temperature while diploid and tetraploid materials were more affected by temperature; diploid material had greater influence on humidity, but tetraploid material had less influence on humidity. The changes of hexaploid and octoploid materials on photosynthesis were less under high humidity conditions. Therefore, the growth environment of wheat and related species could be changed according to the change rules of net photosynthetic rate under environmental impact in order to improve the photosynthesis of different wheat evolution materials.