不同穗型的两个冬小麦品种冠层结构及光合特性的研究

两个不同穗型的冬小麦品种： 多穗型品种济南16和大穗型品种鲁麦22， 在冠层 结构、 光合特性、 干物质积累运转等方面存在较大的差异， 济南16上部节间相对较长 ， 株高构成指数I值较大。 鲁麦22上三叶面积、 长宽比、 夹角较小。 济南16冠层 光截获大于鲁麦22， 而鲁麦 22 下层相对光强较大。 生育期内小麦群体光合速率的变

Canopy Architecture and Photosynthetic Characteristics in Two Winter Wheat Cultivars with Different Spike Type

Two winter wheat cultivars with different spike type which were larg e spike type cultivar Lumai 22 and small spike type cultivar Jinan 16, were us ed to study their canopy architecture, photosynthetic characteristics and dry matte r production and translocation. Significant cultivar differences were observed fo r all the above characters. Jinan 16 was characterized by shorter plant height,r elatively longer upper internodes,and larger I value. Lumai 22 had smaller leaf areas,length/width,and angle of upper three leaves. Multiple action of above dif ferences and plant population resulted in more light interception for Jinan 16 a nd higher relative light intensity at lower canopy portion for Lumai 22. The dyn amic change of canopy apparent photosynthesis (CAP) rate for two cultivars durin g the growth period appeared to be a single peak curve with Jinan 16 being alwa y s higher. As for apparent photosynthesis rate per stem,Lumai 22 was somewhat sup erior to Jinan 16. The results also indicated that the pattern of dynamic change of canopy respiration rate as well as respiration rate per stem was almost as s ame as photosynthesis,although change curve of respiration rate reached peak val ue a little later than the former. The grain yield of Lumai 22 was mainly depend ent on products of photosynthesis after anthesis, while Jinan 16 showed greater a bility to translocate dry matter produced before anthesis into spike during fill ing stage. The enhancement and maintenance of the CAP rate during the filling st age could lead to increase in grain yield.