Photosynthetic and Fluorescence Characteristics in Non-leaf Organs of Wheat Cultivars with Different Quality

Net photosynthetic rates,chlorophyll fluorescence characteristic and their contribution to grains of winter wheat (Triticum aestivum L.) cultivars with different quality type,'Zhengmai 9023','Xinmai 13' and 'Yumai 50',were measured to study the differences in photosynthetic and fluorescence characteristics of non-leaf organs.The chlorophyll contents of non-leaf photosynthetic organs in all three different quality wheat cultivars showed the order of sheath in flag leafinternode under spikeawnglume in spike.The order of the chlorophyll contents in the same organs of different cultivars were 'Yumai 50''Xinmai 13''Zhengmai 9023' after anthesis 18 days;Fv/Fm and ΦPSⅡ of non-leaf photosynthetic organ of 'Yumai 50' were higher than that of another two cultivars at early grain filling stage and the decline extent of Fv/Fm and ΦPSⅡ at later grain filling stage was significantly less than that of 'Zhengmai 9023','Yumai 50' also had higher net photosynthetic rate at the same time.The result indicated that non-leaf photosynthetic organ of 'Yumai 50' was able to maintain higher photosynthesis capability and produce more photosynthesis output.The relative contribution rate to grain for different photosynthesis organ showed the order of spikeflag leafinternode and sheath.The same rule was found that contribution to grain of 'Yumai 50' was higher than that of another two cultivars in non-leaf photosynthetic organ.The relative contribution rate of spike and sheath of 'Yumai 50' to grains was 15.7% and 35.4%,respectively.The results indicated that non-leaf photosynthetic organ of cultivar 'Yumai 50' had higher photosynthetic ability and photosynthetic output.They played important role for increasing grain weight.