Effects Of Water Logging On Physiological Characteristics And Agronomic Traits Of Rapes

Rape is one of the important oil crops. The yield of rapes in china has 11 million per year to 12 million tons, accounting for 40% of domestic oil production. Yangtze River region is the most important rape production area, but Yangtze River region often rains in spring, which is harmful to rapes when they just in critical period of growth. That will lead rapes to reduce yield. In order to study the effects of waterlogging on rapes'Physiological characteristics and agronomic traits, we took the waterlogging treatment experiment at four stages of the rapes growth. Three different waterlogging treatment (3d,5 d and 7d)were carried out at the four stages respectivel, and repeated three times in each treatment. The results are as following:(1)Waterlogging stress in different time has different effects on physiological indicators of rapes. As the Waterlogging time extend, the photosynthetic rate of rapes in each growth period was decreased, especially in flowering stage. The photosynthetic rate has dropped from 18.01 to 8.02 after 7 days of waterlogging treatment. The sensitivity to waterlogging stress in each growth period of rapes was flowering stage, pod maturity, bolting stage, seedling stage.(2)As the Waterlogging time extend, the content of MDA and SOD in each growth period have increased significantly, and the rise in each growth period has no significant difference. But the value of SPDA has decreased.(3)As the Waterlogging time extend, the height of rapes has declined in bolting and seedling stage, the content of oil has declined in flowering and pod maturity stage. The number of pod and the yield of rape have declined significantly in all four growth period. Grain weight also has decreased significantly in pods mature stage. The number of main stem node, branch, fruit all have no changes.