冬小麦品种更替过程中旗叶结构与光合作用的关系研究

为研究冬小麦品种更替过程中旗叶结构与光合作用的关系,以60a来广泛种植的10个冬小麦品种为材料,对株高,收获指数,旗叶的厚度、面积、叶肉细胞形态、叶绿体数目、光合速率、叶绿素含量等进行观察和测定比较。结果显示,随着品种更替,从BM1到LX998株高降低了37.25%,旗叶厚度、面积和收获指数均呈上升趋势;4环叶肉细胞面积由2 546.12μm2减小到2 285.92μm2,6环以上叶肉细胞的比例逐渐增大。灌浆期4环叶肉细胞中叶绿体个数增加了48.68%,叶绿素含量逐渐增大,光合速率高值持续期延长。上述结果说明,旗叶结构在小麦品种更替过程中有明显改变,可为小麦品种改良提供微观结构方面的依据。

Relationship between Flag Leaf Structure and Photosynthesis of Winter Wheat Cultivars

Ten winter wheat cultivars(Triticun aestivum L.)widely used in past six decades were selected to study the relationship between flag leaf structure and photosynthesis.The plant height,harvest index,leaf thickness and area,morphological features of mesophyll cells,chloroplast number,photosynthetic capacity and chlorophyll content of flag leaf were investigated.The results showed that the plant height decreased by 37.25% from BM1 to LX998.The area and thickness of flag leaf,harvest index,percentage of mesophyll cells more than 6 branches and chloroplast number in mesophyll cells with 4 branches were larger in modern cultivars than in old ones.It were further found that the area of mesophyll cells with 4 branches decreased from 2 546.12 μm2 to 2 285.92 μm2,while chlorophyll content increased in modern cultivars than in old ones during grain filling stage.The chloroplast number in mesophyll cells with 4 branches increased 48.68% in modern cultivars as compared with old cultivars at grain filling stage.The period of photosynthesis was longer in modern cultivars than in other cultivars.The results demonstrated that there were remarkable changes in flag leaf characteristics along with the wheat cultivar renewing,which might provide evidence for the changes of microscopic structure in wheat improvement.