Abstract:

Xiaoyan 54 is a wheat cultivar created by crossing Triticum aestivum L. with Thinopyrum ponticum，and has special features of inherent higher cyclic photophosphorylation activity during photosynthesis and its higher tolerance to stresses. In this paper, we studied the photosynthetic characteristics of the lines selected from crosses between Xiaoyan 54 and wheat cultivar Jing 411 or wheat line 8602 during heading and grain filling stages in two experimental fields at suburb of Beijing. In one experiment, it was found that the net photosynthetic rates of the two selected offspring bred from cross between Xiaoyan 54 and the other two lines were a little higher than those of their parents during the heading and grain filling stages. This is an interesting phenomenon, as these two offspring are good enough to be new varieties, although they were selected without using photosynthetic rate as a criterion previously. It means that the higher photosynthetic rate is often closely related to high yield of crops. In the other experiment, three recombinant inbred lines which were selected from the cross between Xiaoyan 54 and Jing 411 by the single seed descent method with special features respectively showed similar levels of net photosynthetic rates and chlorophyll contents compared to their parents. However, the adenosine triphosphate (ATP) content in the leaves of Xiaoyan 54 and its offspring was generally higher than that in Jing 411, and was more than two-fold higher in one of the offspring than in its parents during heading and grain filling stages. This phenomenon may be related to the inherence of higher cyclic photophosphorylation activity from Xiaoyan 54.

Key words: Wheat, Hybrid offspring, Photosynthesis, Adenosine triphosphate(ATP)