不同产地紫花苜蓿品种在东北地区的抗寒性评价及与根部贮藏性碳水化合物关系分析

Evaluation of cold resistance of alfalfa varieties from different areas in northeast China and analysis of the relationship between cold resistance and root storage carbohydrate

为了研究不同产地紫花苜蓿(Medicagosativa L.)品种的抗寒性,并分析其与根部贮藏性碳水化合物含量的关系,试验选择在吉林省西部松嫩平原开展,选取38个国内与国外紫花苜蓿品种进行对比研究,依据不同品种越冬后的存活植株评分进行抗寒等级分类,并分析根部的贮藏性碳水化合物(可溶性糖、蔗糖、淀粉)含量与存活植株评分相关性。结果表明:38个品种的抗寒性分为极不抗寒(Ⅰ)、不抗寒(Ⅱ)、较抗寒(Ⅲ)和抗寒(Ⅳ)4类,其中美国、澳大利亚和加拿大引进的品种抗寒性较差,在东北地区基本无法越冬,而以东北地区选育为主的部分国内北方品种抗寒性表现较好,适宜在本地种植。不同抗寒类别的紫花苜蓿可溶性糖含量无显著性差异;极不抗寒(Ⅰ)的蔗糖含量与抗寒(Ⅳ)之间差异不显著,但是显著高于极不抗寒(Ⅱ)和较抗寒(Ⅲ);淀粉含量在极不抗寒(Ⅰ)和不抗寒(Ⅱ)中极显著高于较抗寒(Ⅲ)和抗寒(Ⅳ)。相关性分析表明,存活植株评分与可溶性糖含量呈显著的负相关(P<0.05),与淀粉含量呈现极显著的正相关(P<0.01)。说明具有较高抗寒能力的紫花苜蓿品种入冬前的根系中具有较高可溶性糖和较低淀粉含量,二者可视为衡量抗寒性的指标,而蔗糖与苜蓿抗寒性的关系并不明确,不能成为衡量抗寒性的指标。

In order to study the cold resistance of alfalfa(Medicagosativa L.)varieties from different regions,and to analyze the relationship between cold resistance and root storage carbohydrates,38 domestic and foreignalfalfa cultivars were compared in the western Songnen Plain of Jilin Province.The cold resistance grade was evaluated based on the scores of surviving plants of different varieties after overwintering,and the correlation between the root storage carbohydrates(soluble suqar,sucrose,starch)and the score of surviving plantswas analyzed.The results showed that the cold hardiness of 38 varieties was divided into 4 types:extremely sensitive to cold(Ⅰ),sensitive to cold(Ⅱ),resistant to cold(Ⅲ)and extremely resistant to cold(Ⅳ).The varieties introduced from America,Australia and Canada exhibited low cold resistance and could not survive the winter in northeast China,but some varieties from north China,which were mainly bred in northeast China,had good cold resistance and were suitable for local planting.There was no significant difference in the soluble sugar content among different varieties;and no significant difference in the sucrose content between extremely sensitive to cold(Ⅰ)and extremely resistant to cold(Ⅳ),but it was significantly higher than that in sensitive to cold(Ⅱ)and resistant to cold(Ⅲ)groups;the starch content in extremely sensitive to cold(Ⅰ)and sensitive to cold(Ⅱ)groups was significantly higher than that in resistant to cold(Ⅲ)and extremely resistant to cold(Ⅳ)groups.The correlation analysis showed that there was a significant negative correlation(P<0.05)between the score of surviving plants and the content of soluble sugar,but a very significant positive correlation(P<0.01)between the score of surviving plants and the content of starch.These results indicated that alfalfa varieties with higher cold resistance exhibited higher soluble sugar and lower starch contentin their roots before winter,which could be considered as the indicators to evaluate cold resistance;however,the relationship between sucrose content and cold resistance of alfalfa was not clear and could not be used as an index of cold resistance.