The root characteristics of different alfalfa varieties

The root development characteristics and the correlation with the aboveground biomass of twelve alfalfa varieties introduced from American, Germany and Canada and planted in Qiannan area in Guizhou were studied. The results showed that the root morphological characteristics of different alfalfa varieties had significant difference(P0.05). The aboveground biomass had extremely significantly positive correlation(P0.01) with the root collar diameter, the branch number, the main root length, and the root dry weight. The underground biomass had extremely significantly positive correlation with the root collar diameter, the depth, the number of branches, the bud number, the main root length and the root diameter. Through path analysis, the greatest contribution factors for the root biomass were the root collar diameter, number of branches, length of main root and lateral root number. According to the root morphology characteristics, the twelve alfalfa varieties can be clustered into three categories.