大豆种质发芽期耐盐碱性鉴定及指标筛选

Identification of Mixed Saline-alkali Tolerance and Screening of Indicators in Soybean at Germination Stage

旨在比较不同大豆种质发芽期对盐碱胁迫的耐受性,以确定鉴定指标。试验材料为18份大豆种质,在种子发芽期以60 mmol/L混合盐碱溶液对其进行胁迫处理,并以蒸馏水为对照。分别调查发芽势、发芽率、幼苗长、根长、苗鲜质量、根鲜质量和根干质量等指标,计算耐逆系数,并利用主成分分析、隶属函数和逐步回归等统计方法对大豆种质发芽期的耐盐碱性进行综合评价。结果表明,混合盐碱胁迫能够抑制种子发芽和幼苗的早期生长;通过综合评价可知18份大豆种质发芽期的耐盐碱性存在差异,按照耐逆性强弱可划分为5类;进一步利用逐步回归的方法构建大豆发芽期耐盐碱性评价模型:D=-0.365+0.808X7+0.772X1+0.364X4(X1、X4和X7分别代表幼苗长、根鲜质量和发芽率的耐盐碱系数),筛选出发芽率、幼苗长和根鲜质量3个耐盐碱性鉴定指标。

In order to compare the tolerance of different soybean germplasms to mixed saline-alkali stress and identify the important indicators.18 soybean germplasms were treated with 60 mmol/L mixed saline-alkali solution at seed germination stage.Meanwhile,distilled water was used as control treatment.7 indicators namely germination energy,germination rate,seedling length,root length,seedling fresh mass,root fresh mass and root dry mass were evaluated.Based on the saline-alkali tolerance coefficient of each indicator,the principal component analysis and subordinate function value method were jointly applied to comprehensively evaluate the tolerance of the tested germplasms to mixed saline-alkali stress.The results showed that mixed saline-alkali stress inhibited seed germination and growth of early seedling.Tolerances of 18 soybean germplasms to mixed saline-alkali stress were different and divided into five categories.The mathematical evaluation model of D=-0.365+0.808X7+0.772X1+0.364X4,was established by stepwise multiple regression analysis.Where D,X7,X1 and X4 represented the comprehensive evaluation value,the saline-alkali tolerance coefficient of seedling length,the saline-alkali tolerance coefficient of germination rate and the saline-alkali tolerance coefficient of root fresh mass,respectively.Using this mathematical evaluation model,the germination rate,seedling length and root fresh mass were screened,which could be regarded as important identification indicators of mixed saline-alkali tolerance in soybean at germination stage.The results provide useful information for rapidly identifying the tolerance to mixed saline-alkali stress and resistance breeding of soybean.