Effects Of Water Condition On The Biomass Allocation And Yield Formation Of Naked Oats

Through the 2-years pot experiment, we studied how the different water conditions affected the oat biomass allocation and yield formation of different varieties of naked oats. And also tracked the oats' non-hydraulic root-sourced signal before and after flowering, discussed the connection between the yield and the threshold of nHRS. All these studied tried to ascertain the composition mode of yield and provide a theoretical basis for the oats breeding. The conclusions were as follows:1. Under well water controls and water stress condition, the total biomass and aboveground biomass of Beishanlaoyoumai were significantly higher than Dingyou series. But the harvest index and water use efficiency of Beishanlaoyoumai were significantly lower than Ding You series. Its yield was lower than Dingyou series. Compared to other varieties of Ding You series, Dingyou 3 had the lowest total biomass and aboveground biomass,but its harvest index was higher than other varieties no matter in what kind of water condition, so it could get a higher yield.2. Under well water controls and water stress condition, the yield and harvest index,water use efficiency showed significant correlation positively (P<0.05). When the water stress became severer,the correlation became higher. In water stress condition, varieties with higher water use efficiency could obtain a higher yield, When the maintenance rate of grain yield was 0.5, the water use efficiency and the MRGY showed significant correlation positively (P<0.05).The reduce of root/shoot ratio and increase of root efficiency didn't show significant correlate with the increase of yield.3.The threshold of non-hydraulic root sourced signal existed in different varieties of naked oats. But whether before or after flowering, the threshold of nHRS didn't show significant correlation relationship with the yield, the yield formation, the maintenance rate of grain yield. These were quite different from the results got from spring wheat. Compared to the spring wheat, the oats' breeding period was shorter, less affected by artificial selection pressure. Their yield potential hasn't yet to fully play, and different varieties has a relatively high similarity These may be the reason why the nHRs threshold of naked oats didn't show the same performance as in spring wheat. It still needs further certification and inspection.