Abstract:

In order to investigate the characteristics of grain filling and dehydration rate and their relationships with yield of different wheat varieties, five new wheat varieties bred by Luohe Academy of Agricultural Sciences from 2020 to 2023 were used as experimental materials, along with two control varieties. The dynamic changes of grain filling and moisture content of these varieties were examined. This could potentially serve as a theoretical foundation for breeding wheat varieties with quick filling and dehydration rates and do not require drying processes at harvest time. The results showed that there were significant differences among these varieties in the grain-filling rate at different stages after anthesis; the average grain-filling rate and grain-filling time in fast increase period were the key factors during the whole filling period; the initial grain-filling rates of Luomai 49, Luomai 50 and Zhoumai 18 were relatively large, mean grain-filling rate, grain-filling rate in incremental period and fast increase period were higher, the 1000-grain weight at 29 days after anthesis was more than 42 g, the filling was completed quickly, and the 1000-grain weight 41 days after anthesis and yield were higher; the 1000-grain weight of Luomai 26 was significantly lower at different filling stages over the three years; the performance of 1000-grain weight of Luomai 36 was inconsistent in different years; mean grain-filling rate, grain-filling time in incremental period, grain-filling rate in fast increase period were significantly positively correlated with 1000-grain weight. From physiological maturity to harvest, the average grain moisture content followed a slow-fast-slow pattern and decreased most rapidly around 39 days after anthesis; there were significant differences in grain moisture content and average dehydration rate among different wheat varieties; the average dehydration rate of Luomai 49, Luomai 50 and Zhoumai 18 were fast after physiological maturity and Luomai 26 was slow; grain moisture content at harvest was positively correlated with grain moisture content at physiological maturity, and was significantly negatively correlated with average dehydration rate and average dehydration rate at two to four days after physiological maturity. In summary, Luomai 49, Luomai 50 and Zhoumai 18 demonstrate well-synchronized grain-filling and dehydration process. The 1000-grain weight greater than 42 g at 29 days after anthesis could be used as the criterion for measuring the grain-filling rate. The average grain moisture content of 39 days after anthesis was used as an index to evaluate the dehydration rate of wheat.

Key words: Wheat, Grain filling characteristic, Grain moisture content, Dehydration characteristic, 1000-grain weight