The Compositive Appraising About The Ecological Adaptation And Production Performance Of Twelve Introduced Alfalfa Varieties In The Heat-humid Areas Of Southwest In Sichuan Province

Alfalfa varieties adapted to the climate and soil of southwest of Sichuan province were needed in dire. Based on that, the productivity, the root morphology and adaptability of 14 alfalfa varieties introduced from different counties were studied and compared through the field and pot experiments in this paper, the white clover was as the control. The results as follows:(1 )The dry matters of 12 alfalfa varieties were sorted as'Super7'>'Verko'>'Sitel'>'Qquadrella'>'Sanditi'>'Millennium'>'Trifecta'>'Paramount '>'Algonquin'. The yield of 12 alfalfa varieties between the 32-32-43t DM/hm~2 which was better to the control of white clove (the yield was between the 20-25 t DM/hm~2.).(2)The over-summering rate and dry biomass of alfalfa varieties debased during the 2004～2005 because the abundant rainfall and the rainfall distributing disequilibrium at time. 'Eureka', 'Millennium' and 'Verko had the higher yield and better persistence with the yields and the over-summering rate being 40987.61kg DM/ hm~2 and 75.34%, 40912.81 kg.DM/ hm~2 and 63.70%, 40130.45 kg · DM/ hm~2 and 72.31%. 'Pirate' and 'Super7'had the higher productivity (the yields were 42522.53 kg.DM/ hm~2 and 40355.49 kg.DM/ hm~2) and the lower ability to resistance the waterlogging, so their persistence in the field environment was very low .(3)The soil condition affected the productivity performance of alfalfa varieties. 'WL525'and 'Millennium' performed best in the purple clay soil with the dry biomass of single plant was 6.342g, and 6.192g, 'WL414'and 'Millennium' performed best in purple sandy loam with the dry biomass of single plant was 7.178g and 6.693g, 'WL414'and Millennium performed best in the clay loam with the dry biomass of single plant was 8.057g and 7.631g.. The purple clay loam was the best choice to the alfalfa varieties in the tested soils.(4) The correlated coefficient of root morphology and dry biomass of up-ground were sorted as the dry weight of lateral root ( r|- =0.5316) >the length of lateral roots( 7 =0.4112) > the number of lateral roots (r|- =0.3174) > the dry weight of tap root(r|- =0.3006) > the length of tap root. The developing degree of lateral roots...