15份燕麦材料苗期抗旱性综合评价

Comprehensive evaluation of drought resistance of 15 oat varieties at the seedling stage

为了研究干旱胁迫对不同燕麦材料苗期生理特性的影响以及评价不同材料的抗旱性,采用营养液砂培法,于两叶一心期对15份燕麦材料施加15%PEG胁迫,分别于胁迫0、7和14 d测定供试材料的抗氧化酶活性、丙二醛含量、渗透调节物质含量、叶绿素含量、水分利用率和相对电导率。利用相关性和主成分分析筛选燕麦抗旱性鉴定指标,通过聚类分析和隶属函数法对15份材料进行抗旱性综合评价。结果表明:干旱胁迫下,供试燕麦的抗氧化酶活性随胁迫时间的延长呈现"先升后降"的趋势;丙二醛含量、渗透调节物质含量和相对电导率均随胁迫时间的延长而增加,水分利用率及叶绿素含量显著下降(P<0.05)。10个抗旱性指标之间具有较好的相关性,相关系数最高达0.97。主成分分析结果表明,干旱胁迫下燕麦的质膜系统因子、光合因子、渗透调节因子可作为抗旱性评价的综合指标,通过第一主成分可将15份燕麦材料清晰地划分为抗旱性不同的两个独立类群;聚类分析进一步将供试材料划分为抗旱性不同的4个亚组,其中6份材料(蒙燕1号、青引1号、定燕2号、DA92-2F4、青燕1号、巴燕5号)属于抗旱种质。抗旱隶属函数综合评价值(D)显示,抗旱性较强的燕麦材料有青燕1号(0.829)、青引1号(0.744)和DA92-2F4(0.728),而陇燕3号(0.208)、坝燕6号(0.240)和张燕4号(0.241)抗旱性相对较弱。利用多方法关联分析的综合评价方法所得结果更加准确,可靠性较高。研究结果为燕麦抗旱性评价及抗旱种质筛选提供了参考。

This research evaluated the physiological response to drought stress of 15 different oat varieties at the seedling stage and used multivariate analyses of data for multiple traits to develop drought resistance indexes. Oat seedlings at the two-leaf growth stage in sand culture were stressed with nutrient solution containing 15% PEG.Antioxidant enzyme activity,malondialdehyde concentration,osmolyte levels,chlorophyll content,water use efficiency and relative conductivity of oat seedlings were measured at 0,7 and 14 days of stress. Correlation analysis and principal component analysis were used to develop drought resistance indexes of the oat varieties,and cluster analysis and the membership function method were used to evaluate their drought resistance. It was found that:with increasing duration of drought stress,the antioxidant enzyme activity of the oat seedlings initially increased and then decreased;malondialdehyde content,osmolyte content and relative conductivity increased with increasing stress duration,while water use efficiency and chlorophyll content decreased significantly(P<0. 05). There was a good correlation between the 10 drought resistance indexes,with the correlation coefficient as high as 0. 97. Principal component analysis showed that under drought stress,measures indicating the status of the plasma membrane system,photosynthetic factors and osmotic adjustment of the oat seedlings could be used as multivariate indexes to evaluate drought resistance,and the 15 tested oat varieties could be clearly separated into two distinct groups of differing drought resistance through scores for the first principal component. Cluster analysis further divided the tested varieties into four subgroups with different drought resistance. In particular,six varieties(Mengyan No. 1,Qingyin No. 1,Dingyan No. 2,DA92-2 F4,Qingyan No. 1,Bayan No. 5)displayed strong drought resistance. The cluster results also showed that the drought resistance of oat accessions from Northwest China(Gansu and Qinghai)was stronger than those from Northeast China(Jilin)and North China(Hebei). Based on the multivariate score(D)for drought resistance from subordinate function analysis,the oat materials with the strongest drought resistance were Qingyan No. 1(0. 829),Qingyin No. 1(0. 744)and DA92-2 F4(0. 728),while Longyan No. 3(0. 208),Bayan No. 6(0. 240)and Zhangyan No. 4(0. 241)had relatively weak drought resistance. The results of each evaluation method were consistent,but the multivariate evaluation system based on multi method correlation analysis was the most accurate and reliable. The results provide data on oat drought resistance to support selection and breeding decisions,and a methodology for generating a drought resistance index.