小麦冷源功能叶片的显微结构和气体交换特性

小麦冷源具有明显降低小麦体温的作用,是培育冷型小麦的优质种质资源。论文通过常规石蜡切片的方法观察比较了冷源、冷型小麦小偃6号和暖型小麦9430功能叶片的显微结构,并在灌浆结实期测定了功能叶片的叶绿素含量、净光合速率、蒸腾速率和气孔导度,旨在揭示冷源功能叶片的结构和生理特性。结果表明,冷源旗叶叶片厚度分别比冷型小麦和暖型小麦高出19.3%和9.0%,倒二叶分别高出19.7%和5.7%,倒三叶分别高出37.2%和2.7%;冷源旗叶叶脉横截面积分别比冷型小麦和暖型小麦高出25.2%和37.7%,倒二叶分别高出5.9%和12.6%,倒三叶分别高出13.1%和33.3%;冷源旗叶、倒二叶和倒三叶中的叶脉间距分别比冷型小麦小偃6号同叶位功能叶片高出17.7%,2.0%和9.2%,分别比暖型小麦9430同叶位功能叶片低3.7%、6.8%和8.3%。随着籽粒灌浆的进行,冷源、冷型小麦和暖型小麦功能叶片的叶绿素含量、净光合速率、蒸腾速率和气孔导度均呈下降趋势,但冷源和冷型小麦在灌浆前、中、后期均较暖型小麦高,功能叶片衰老缓慢,功能期较长。

The Microstructure and Gas Exchange Characteristics of Functional Leaves of Wheat Cold Source.

Wheat cold source could clearly reduce temperature of wheat plant, it is a kind of good germplasm resource which breed cold type wheat. The microstructure of functional leaves of cold source, cold type wheat Xiaoyan6 and warm type wheat 9430 were observed by paraffin slice method, and chlorophyll content, net photosynthesis rate, transpiration rate, stomata conductance of functional leaves were measured during wheat grain filling. The results showed that the flag leaf thickness of cold source was higher by 19.3% and 9.0% than that of cold type wheat and warm type wheat, respectively; the top 2nd leaf was higher by 19.7% and 5.7%, respectively; the top 3rd was higher by 37.2% and 2.7%, respectively. The vein transverse area of flag leaf of cold source was higher by 25.2% and 37.7% than that of cold type wheat and warm type wheat, respectively; the top 2nd leaf was higher by 5.9% and 12.6%, respectively; the top 3rd was higher by13.1% and 33.3%, respectively. The vein interval of flag leaf, the top 2nd leaf and the top 3rd leaf of cold source was higher by 17.7%, 2.0% and 9.2% than that of the same position functional leaf of cold type wheat, respectively, and lower by 3.7%?6.8% and 8.3% than that of the same position functional leaf of warm type wheat, respectively. Chlorophyll content, net photosynthesis rate, transpiration rate and stomata conductance of cold source, cold type wheat and warm type wheat were all downtrend during grain filling, but which of cold source and cold type wheat were higher than that of warm type wheat at grain-filling prophase, metaphase and anaphase.