黍稷芽、苗期抗旱性评价及抗旱资源鉴定

为了全面了解中国现存黍稷种质资源的抗旱性,研究黍稷在PEG6000模拟干旱胁迫下的抗旱表现,挖掘优异抗旱种质并筛选抗旱鉴定指标,本研究以前期构建的包含230份资源的黍稷微核心种质为试验对象,开展室内PEG6000模拟干旱胁迫处理下的芽、苗期抗旱性研究。通过对芽期和苗期抗旱性指标的测定发现:干旱胁迫下,芽期和苗期各指标较对照组均有下降趋势;芽期指标变异系数较苗期偏大,苗期根鲜重变异系数最大,根干重、苗鲜重、苗干重其次(变化范围在0.35~0.50之间)。相关性分析显示多数指标间相关性都达到了显著或极显著水平,其中相对根鲜重与相对根干重的相关性最高,而相对叶绿素含量与相对根长、相对苗长、相对根鲜重及相对苗干重的相关性均较低。采用平均值-标准差逐级分级法和分层聚类分析综合鉴定参试黍稷芽期和苗期抗旱性,发现芽期极强抗旱、强抗旱材料分别为3份和10份,苗期极强抗旱、强抗旱材料分别为24份和23份;其中紫秆黍(00003289)、乌克兰黍(00006438)和白糜子(00000101)三个品种在芽期和苗期均有很好的抗旱性,可作为后续全生育期抗旱研究和抗旱品种选育的优良资源。对芽期及苗期各抗旱鉴定指标进行相关性分析,结果表明芽期与苗期抗旱性没有显著相关性;主成分分析表明,相对苗长、相对苗鲜重以及相对叶绿素含量可作为评价黍稷苗期抗旱性鉴定的主要指标。

Evaluation and Identification of Broomcorn Millet Resources for Drought Resistance at Germination and Seedling Stages

To completely assessment the drought resistance of broomcorn millet(Panicum miliaceum)germplasm resources in China and study the drought resistance performance of broomcorn millet resources under PEG6000 simulated drought stress,and then to select the excellent drought resistance germplasm as well as the proper drought resistance identification indexes.In this study,the pre-constructed broomcorn millet microcore germplasm containing 230 resources was taken to analyse the drought resistance of germination stage and seedling stage under drought stress simulated by PEG6000 in the laboratory.Through the test of drought resistance indexes of germination stage and seedling stage,it was found that under drought stress,the indexes of germination stage and seedling stage had a decreasing trend compared with the control group.The coefficient of variation in germination stage was relatively larger than seedling stage,and for seedling stage,the coefficient of variation in root fresh weight was the largest,followed by dry weight of roots,fresh weight of seedlings and dry weight of seedlings(the variation range from 0.35 to 0.50).Correlation analysis showed that the correlation between most indexes has reached a significant or extremely significant level,among which the correlation between relative root fresh weight and relative root dry weight is the highest.The correlation between relative chlorophyll content and relative root length,relative seedling length,relative root fresh weight and relative seedling dry weight was low.The drought resistance of broomcorn millet at germination stage and seedling stage was comprehensively identified by means of gradation of mean-standard deviation and hierarchical cluster analysis,there were 3 super strong drought resistance and 10 strong drought resistance in germination stage and 24 super strong drought resistance and 23 strong drought resistance in seedling stage.Among them,three varieties of Zigan Shu(00003289),Ukraine Shu(00006438)and Bai Mizi(00000101)have good drought resistance in germination and seedling stage,which can be used as an excellent resource for drought resistance research and drought resistance breeding in the whole growth period.The correlation analysis of drought resistance identification indexes at germination stage and seedling stage showed that there was no significant correlation between the germination stage and the seedling stage in drought resistance.Principal component analysis showed that relative seedling length,relative seedling fresh weight and relative chlorophyll content could be used as main identification indictors to evaluate drought resistance in seedling stage of broomcorn millet.