The Adaptive Assessment Of16Alfalfa Materials In Yangzhou Region

The planting and research of alfalfa in north China has been performed for many years. The research of alfalfa was mostly focused on the resistance to cold, drought and salt, etc. While, the planting and research of alfalfa in south China, south to Huaihe River and Qinling Mountains, are much less, which mainly due to the rainy and heat climate in summer and acidic soil, which are not suitable for alfalfa growth. If we can develop alfalfa planting in large-scale in these region, the problem of lacking of animal husbandry diet and the irrational planting structure in the Southern Region will be solved effectively. In view of these reasons,16alfalfa varieties (strains), which are graded into low, medium and high degree of fall dormancy (FD) were collected at home and abroad, and compared in Yangzi River region in this study. The varieties were assigned in a randomized block field experiment. The production of features, quality properties and heat resistance were conducted to evaluate the adaptability and productivity of these16alfalfa varieties, so that we can screen out the high yield, high quality, strong resistance and good adaptability of alfalfa varieties.The results showed that in seedling period the16alfalfa varieties all grew slow, the growth rate were0.11-0.27cm/d. After alfalfa turning green, the growth rate was faster, which were0.95-1.20cm/d. The fastest growth period was in their regeneration, which were1.86-2.42cm/d. In the seedling period, Hunter River (FD=7) grew fastest, which was significantly faster than other varieties (P<0.05). In regeneration period, Derby (FD=5) and Sitel (FD=5) grew significantly faster than the other varieties, plant height was significantly higher than other varieties (P﹤0.05). The growth rate of Algonquin (FD=3) was the slowest, which was significantly lower than the others (P <0.05). The above results suggested that the semi-dormancy varieties had higher growth rate in the experimental location.The fresh yield of these alfalfa varieties was18074-39630kg/hm2, and the hay yield was4140-9072kg/hm2. And the yield of renewable hastily of all the varieties was about30%less than the first harvest. Both fresh and hay yield of Affinity (FD=4) and Leafy King (FD=4) were significantly higher than those of Algonquin (P﹤0.05). In addition, both fresh and hay yield of Sanditi (FD=5) and GL0602were significantly higher than those of CUF101(FD=9) and WL612(FD=9)(P﹤0.05). Both the fresh and the hay yield order were semi-dormancy varieties> non-fall dormancy varieties> fall dormancy varieties.The ratio of stem and leaf of the regrowth was0.5%lower than that of the first cut. The stem leaf ratio of Algonquin and Affinity were significantly higer than Sanditi and Derby. While the CP content of Algonquin and Affinity were22.08%and20.88%, which were significantly higher than other varieties. And the ADF. NDF content of Algonquin and Affinity was lower than the most other varieties. Comprehensively compared, the quality of Algonquin and Affinity were the best, then followed by Golden Empress(FD=3) and CUF101.The summering rate of all species were below60%. High temperature in summer season lead to the decreasing of12.04-34.87%in chlorophyll content of alfalfa varieties. While MDA content, POD and SOD activity were increasing with the temperature increasing, and the activity of POD and SOD showed a exactly similar change trend. With the temperature increasing, the decreasing degree of chlorophyll content of Leafy King, GL0602, Ameri Graze (FD=4) and Algonquin were significantly higher than Victoria, WL612, Flourish Age (FD=8) and Affinity(P<0.05). While the MDA content of Ameri graze, Sitel and Flourish Age were significantly higher than other varieties(P<0.05), and the MDA content of WL612, Derby and Sidel (FD=8) were significantly higher than that of Leafy King, Sanditi, GL0602and Victoria(P<0.05). The antioxidant enzyme activity of Victoria (FD=6) was significantly higher than Hunter River(P<0.05). The POD activity of Sidel was significantly higher than that of GL0602, Gold Empress, Derby and Hunter River(P<0.05).The relative conductivity rate and cell damage rate of16alfalfa varieties were tested to get the membrane permeability and the lethal temperature. In the range of45-55℃, the relative conductivity of Derby, Algonquin, Victoria and Affinity showed a sharp rise, and significantly higher than that of the other varieties, which showed their cell membrane were severely injured. This result suggested that Derby, Algonquin, Victoria and Affinity were poor in heat resistance. However, Sidel, Alfalfa King and CUF101showed the opposite situation, the lethal temperature of them were much higher than other varieties. So we can see the different varieties showed big differences in heat tolerance.The yield characteristics, quality properties and heat resistance of16alfalfa varieties were analyzed by method of Euclidean Distance. The resulted showed that Affinity clustered separately, which was characterized with the highest fresh yield, hay yield and CP content, showed the best comprehensive performance. Ameri Graze, Leafy King, Sanditi and GL0602clustered together, their performance just followed Affinity, but their plants was higher. Other varieties(strains) performanted common or even poor.In summary, the results suggested that semi-dormancy cultivar Affinity was suitable for cultivation in the experiment region, followed by Ameri graze, Leafy King, Sanditi and GL0602. Other varieties had such a poor performance in the region so that promoting planting of these varieties should be carefully considered.