| To provide references for the selection of high-yield and waterlogging-resistant wheat cultivars in the middle and lower reaches of the Yangtze River, Yangmai25, Yangmai24, Ningmai13, and Ningmai9 were selected as materials to study the effects of the 10 days waterlogging treatment at booting stage on grain yield and its components, root dry weight in different soil layers (0 – 100 cm), leaf area, and leaf photosynthetic rate, and aboveground dry matter accumulation. The results showed that the waterlogging treatment significantly decreased grain yield by 12 % – 31 %, mainly due to the reduction of grains per spike and 1000-grain weight. Compared with other cultivars, Yangmai25 showed the lowest reduction in grain yield under the waterlogging treatment. The grain yield components of Yangmai25 were more balanceable and lightly affected by waterlogging. Waterlogging significantly reduced root dry weight in different soil layers at anthesis and maturity stages, and the lower roots were affected more greatly than the upper roots. The green leaf area of the top 3rd leaf and net photosynthetic rate of the top 2nd and 3rd leaf at the milk-ripening stage were decreased significantly by waterlogging. The accumulation of photosynthetic products in shoot organs at maturity and after anthesis was also markedly inhibited. Under the control condition, the root dry weight of Yangmai25 was similar to that of other cultivars at anthesis stage, but it showed significantly higher root dry weight in 0 - 20 cm and 80 - 100 cm soil layers at maturity stage. Compared with other cultivars, Yangmai25 maintained more root biomass in the upper layer after anthesis and showed a significantly higher proportion of 0 - 60 cm root dry weight to total root weight at maturity stage under the waterlogging condition. Besides, Yangmai25 had a larger flag leaf area and higher net photosynthetic rate and maintained a longer duration of the top three green leaf areas, and accumulated more photosynthates after anthesis under different water treatments. Therefore, the stable root growth at post-anthesis, especially for the surface roots, and the large green leaf area with slow decay, especially for the flag leaf, contribute to maintaining a strong post-anthesis photosynthetic accumulation level, ensuring enough grain-filling substances and high and stable spike yield, which can be used as the selection basis of high-yield and waterlogging-tolerance cultivars. |
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