Study On Fall Dormancy And Production Performance Of Different Alfalfa Cultivars

According to the methods of Teuber and Mc Caslin and using the 11 different American fall dormancy and 6 winter survival standard alfalfa cultivars as contrast we assessed the practical fall dormancy rating of 41 alfalfa cultivars in the central western regions of Inner Mongolia. In Wuyuan area we compared the production performance and nutritional quality among 45 alfalfa cultivars. The main results are as follows.1. We have established three linear regression equations between the fall dormancy class and the natural plant height after final clipping of the 11 compared alfalfas. The R2 are 0.9867, 0.9884 and 0.9805. Using the NPH substituted into the regression equations we calculated the actual fall dormancy rate of the different test alfalfas. Correlation analysis showed that the correlation between the actual FDR and the original FDR which gave by California university of the 11 standard alfalfas are significant(P<0.01). The correlation coefficient is 0.9969. The correlation between actual and original FDR of the 13 alfalfas which have known the original FDR also have significant difference(P<0.01). The correlation coefficient is 0.9716.2. Clustering analysis showed that all testing varieties can be divided into 6 major categories. Then, we divided the testing alfalfas into 11 groups corresponding with the 11 different standard alfalfas. Among the 20 national alfalfa cultivars the Yumu NO.1, Gannong NO.5 and Liangmu NO.1 are the no-dormant type, the actual FDR of other alfalfas are lower than the control 4 variety, belong to very dormant, dormant and mid-dormant type. The fall dormant type of the imported cultivars is various and distribute in different fall dormant type.3. Cold resistance index evaluation study showed that the average wintering rate of all cultivars in Wuchuan is 17%. It is not meet the requirements of cold resistance evaluation. That rate in Wuyuan and Tuzuo are 86% and 66.8%. The correlation between cold resistance score and winter hardiness index(WHI) of the 6 winter survival standard cultivars are significant(P<0.01). The correlation coefficients are 0.9836 and 0.9839. Clustering analysis showed that all varieties were divided into 4 major categories. 14 national and 5 imported varieties with the winter survival control NO.1 and NO.2 variety were divided into the first category. Huaiyin alfalfa and 12 imported varieties with winter survival control varieties rang 3and 4 were divided into the second category. Control variety NO.5 and three introduced varieties divided into third category. Yumu NO.1, Gannong NO.5, Liangmu NO.1 and 8 imported varieties with the winter survival control NO.6 variety were divided into the fourth category.4. 45 alfalfas can be divided into 3 groups according to the production of two years. The first group had 5 cultivars which winter survival rates were below to 50% and have no yield in the second year. The second group had 6 cultivars which two years output were range 25189.7kg/hm2 to 29074.3kg/hm2. The third group has 34 cultivars. There productions of two years were range 30862.0kg/hm2 to 36686.4kg/hm2. The top three cultivars of the third group are Xinmu NO.2, Rambler and SR4030.5. Nutritional quality correlation analysis showed that the correlation between RFV and ADF and NDF was negative significant. In contrast, the correlation between RFV and CP was positive significant. Clustering showed that the 40 alfalfas in the second year were divided into 5 categories. The first one was only Xinjiang daye which had the highest RFV(135.27). The RFV of the second category was range 129.68 to 132.15 and the marked cultivar was Knight-2(2010). The RFV of the third group was range 120.86 to 123.23 and the marked cultivars was Power 4.2. The last one RFV was 116.35 to 120.13 and the marked alfalfa was 55V48.6. The comprehensive cluster analysis of production performance and nutritional quality showed the same results of the production cluster. The top three varieties in the comprehensive evaluation are WL440 HQ, MF4020 and SK3010.The values of them are 0.579, 0.571 and 0.565.