【作者】 刘瑞峰；

【导师】 张新全；

【作者基本信息】 四川农业大学 ， 草业科学， 2006， 硕士

【摘要】 川西南地区缺乏高产优质的紫花苜蓿品种，引入和选育适应该区气候和土壤条件的紫花苜蓿品种成为急需解决的问题。试验以‘拉丁诺白三叶’为对照，通过田间试验和盆栽试验，研究比较了14个紫花苜蓿品种在该区的生产性能、根系形态、持久性和适应性。结果如下： (1)12个紫花苜蓿品种的干草产量依次为‘海盗’＞‘游客’＞‘四季绿’＞‘超级7’＞‘威可’＞‘塞特’＞‘昆德拉’＞‘三得利’＞‘盛世’＞‘特瑞’＞‘山锐’＞‘阿尔刚金’。干草产量达32-43t·DM/hm~2，所有供试紫花苜蓿品种的干草产量均高于对照‘拉丁诺白三叶’的产量(20-25t·DM/hm~2)。 (2)紫花苜蓿的越夏率和产量在第二年度显著降低，该年度降雨量多且降雨在时间上的分布不均衡是导致各紫花苜蓿品种产量和持久性降低的主要原因。持久性较好且产量较高的紫花苜蓿品种是‘游客’(越夏率75.34％，产量40987.61kg·DM/hm.2)、‘四季绿’(越夏率63.70％，产量40912.81 kg·DM/hm~2)和‘威可’(越夏率72.31％，产量40130.45 kg·DM/hm~2)。‘海盗’(越夏率41.67％，产量42522.53 kg·DM/hm~2)和‘超级7’(越夏率38.41％，产量40355.49 kg·DM/hm~2，)生产性能好，条件适宜情况下，产量优势突出，但在当地环境条件下耐湿性差，持久性低。 (3)土壤条件影响紫花苜蓿的生产性能。紫色黏土中以‘WL525’和‘四季绿’表现最好，单株地上干物质量为6.342g和6.192g；紫色砂壤中以‘WL414’和‘四季绿’表现最好，单株地上干物质量为7.178g和6.693g；紫色黏壤中以‘WL414’和‘盛世’表现最好，单株地上干物量为8.057g和7.631g。三种土壤中以紫色黏壤最为适宜紫花苜蓿的生长。 (4)根系形态与地上部干重相关性大小依次为侧根干重((?)=0.5316)＞总侧根长度((?)=0.4112)＞侧根数目((?)=0.3174)＞主根干重((?)=0.3006)＞主根长度((?)=0.0286)。侧根的发达程度对紫花苜蓿的产量有重要作用，且这种作用在紫花苜蓿受到环境胁迫时表现更为突出。根系形态能够更好地反映紫花苜蓿对气候土壤的适应性，可作为紫花苜蓿引种选育的有效指标。 (5)湿热因素为紫花苜蓿的主要限制因素，湿为主导因素。对根系形态和抗更多还原

【Abstract】 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更多还原