Effects Of Boron And Phosphorus On Watermelon Seedlings Growth, Nutrient Absorption And Cold Resistance Under Different Temperature

Watermelon seedlings are vulnerable under "Coldness" of early spring on thelower-middle reaches of the Yangtze River. In order to investigate the effect of nutrienton watermelon seedlings growth, nutrient absorption and cold resistance under lowtemperature, the solution culture experiment was conducted on watermelon seedlings,which adopted four treatments: deficiency of Phosphorus, Boron, both and normalnutrient level. When seedlings grew to be the stage of 3 leaves, low and normaltemperature treatments were conducted for 5 days. Then the contents of primary nutrientelements in watermelon were analyzed as well as biological production of watermelonseedlings.The results showed that Boron and Phosphorus had positive effects On increasingseedlings heights, stem heights, diameter and weight as well as real-leaf growth. Inaddition, deficiency of Boron can change the structure of root and lengthened the roots.Phosphorus was more effective than other nutrients under low and normal temperature,but Boron had more effects on increasing seedlings heights, stem heights, diameter andweight. It can be illustrated that Boron and Phosphorus have more obvious effects onseedlings coldness resistance growth.And subsequently, tests were made for POD activation, the contents of Pro, MDAand soluble sugar, and EC. The results showed that application of both Boron andPhosphorus in seedlings stage may effectively reduce the activation of MDA and POD.And meanwhile, the membrane injury percentage (MIP) reduced dramatically.Additionally, it could increase the contents of Pro and soluble sugar.In conclusion, adding Boron and Phosphorus was the key point to increase the coldresistance ability and watermelon seedlings growth.