The Research Of Summer Heat Resistance Of Alfalfa

Many alfalfa varieties can bare high temperature and different area need different varieties .This experiment was conducted to identify some alfalfa varieties which had strong capacity on heat resistance by measuring the activity of Peroxidase(POD) and Superoxide dismutase(SOD) in alfalfa leaf . The results showed that,the Peroxidase(POD) activity of Aohan , Farmer, Algonguin (white) and Vernal were higher , and that of Algonguin (white) was the highest , while that of 8920MF was the lowest . Meanwhile, the Superoxide dismutase(SOD) activity of Flight No.2 , Algonguin (white) , Algonguin (lanpai) were higher , and that of Flight No.2 was the highest, while that of AmeriStand 201 was the lowest in all .In a word, the activity of Peroxidase(POD) and Superoxide dismutase(SOD) differ significantly under high temperature stress in alfalfa varieties . Meanwhile the activity of Peroxidase(POD) has nothing to do with that of Superoxide dismutase (SOD) . Algonguin (white) performance best in high temperature stress, and can be widely used in the high temperature areas, such as torrid zone and subtropics. Alfaking , Golden Empress and Siriver was worse than Algonguin , but can also be plant in temperate zone if rightly used . Heat-resistant of different alfalfa varieties in the summer’s heat stress was studied by using the Spectrophotometer techniques of the proline and malondialdehyde determination . The results showed that the proline content of Emperor in high-temperature stress was the highest of all and the malondialdehyde of Farmers was lower than the others.So these two varieties had the better heat-resistant than the others. According to all of the results that under the condition of high temperature environment in the summer, Emperor and WL-232HQ were the best varieties . they could be plant in high-temperature environment and used to improve capability of the heat-resistant in plant breeding .