紫花苜蓿资源抗旱性鉴定评价方法研究

Drought Resistant Identification and Evaluation Methods of Alfalfa Germplasm

采用反复干旱法对176份苜蓿(Medicago sativa L)种质资源进行了苗期抗旱性鉴定,开展了鉴定指标与评价方法的研究。结果表明:地上生物量、地下生物量、株高、根长、分枝数和根冠比均与平均抗旱系数、平均抗旱指数呈极显著相关性,均适宜作为苜蓿抗旱性鉴定指标,其中地上生物量、株高相关系数较高;通过对不同评价方法分析比较,明确了DRC适宜种质资源抗旱性评价,IDRI适宜抗旱品种筛选,DRI适宜旱地条件下高产品种的筛选;抗旱性等级划分采用群体逐级分类法;采用DTIg、DRIv、DTIv方法分别对参试材料进行抗旱性分级,一级(抗旱性极强)材料数量分别为30份、25份、21份,对照敖汉苜蓿均处于中等水平。

Drought resistant identification of 176 alfalfa germplasm were conducted at seedling stage using repeated drought method,at the same time,the appropriate identification indexes and evaluation methods were discussed.This experiment examined seven identification indexes including aboveground biomass,underground biomass,plant height,root length,branch number and root-shoot ratio.The results showed that there was a significant correlation between these identification indexes,average drought resistance coefficient and average drought resistance index.They all could be used for drought resistance identification.Among them,correlation coefficients of aboveground biomass and plant height were more prominent than other indexes.By the comparison and analysis of different evaluation methods,we concluded that DRC was suitable for germplasm evaluation of drought resistance,IDRI was suitable for screening of drought resistance varieties and DRI was suitable for screening high-yielding cultivars under upland conditions.Progressive classification method was used as drought resistance classification.The drought resistance of tested alfalfa materials was evaluated by DTIg,DRIv and DTIv methods.The numbers of level 1（the most strong drought resistance）was 30,25,and 21,respectively,and Medicago sativa ‘Aohan＇（as CK）was in the middle level.