Study on the Source-sink Relationship in Different Types of Weak Spring Wheats during Grain-filling Stage

The source-sink relationship was studie during grain-filling stage in different weak spring wheat varieties Zhengmai 9023(strong gluten),Yanzhan 4110(middle gluten),Yumai 50(weak gluten) under the field experiment conditions.The results showed that: the chlorophyll content,leaf area index and net photosynthetic rate had been maintained at a high level during flowering 0～14 d in different weak spring wheat varieties.These were declined after flowering 14 d with different degrees.Zhengmai 9023 wheat variety had a net photosynthetic rate which was significantly greater than the other two species,with an average 13.1 percent higher.Compared with yanzhan 4110 and Yumai 50,Its 1000-grains were increased by 5.9 g and 12.4 g respectively.Zhengmai 9023 was provided with Leaf strong and grain weight advantage obviously.Yanzhan 4110 showed the averaged leaf area index by 4.16 during filling stage,which was higher than the other two varieties 24.1 percent in the same period;The ear number was higher than Zhengmai 9023 and Yumai 50 by 8.67% and 24.01% respectively.Yanzhan 4110 was provided with Leaf and ear number more advantage obviously.The grain yields of Zhengmai 9023 and yanzhan 4 110 were than 7 500 kg/hm2.The sowing date had obvious regulation effect on the source-sink relationship.