谷子芽期耐盐碱综合鉴定及评价

以全国主推的53个谷子品种为材料,在100 mmol L~(-1)混合盐碱(NaCl∶NaHCO_3=4∶1)胁迫下研究了不同谷子品种的耐盐碱性。结果表明,在盐碱胁迫下, 53个谷子品种的发芽势、发芽率、根长、芽长、根鲜重和芽鲜重均受到不同程度的抑制,以对根长的影响最大;相对发芽势与相对发芽率、相对根长与相对芽长及相对根鲜重与相对芽鲜重均呈显著或极显著正相关。通过主成分分析将14个单项性状指标转化为4个主成分,累积贡献率为90.4%;以4个主成分的得分值通过隶属函数分析获得不同品种耐盐碱的综合得分值,并通过聚类分析将53个谷子品种划分为6种耐盐碱类型,其中强耐盐碱品种2个,耐盐碱品种16个,中间型品种17个,盐碱敏感品种6个,不耐盐碱品种9个和极不耐盐碱的品种3个。同时利用回归分析建立了可用于评价谷子耐盐碱性的回归方程D'=0.298+0.037X_2+0.144X_3+0.018X_6+0.209X_7-0.183X_9+0.115X_(11)-0.201X_(12)+0.112X_(13)-0.101X_(14)+0.284X_(15),相对发芽率、根长盐害率、芽长盐害率和根冠比盐害率可以作为谷子耐盐碱性的评价指标。

Comprehensive identification and evaluation of foxtail millet for saline-alkaline tolerance during germination

In the present study, the evaluation of 53 main foxtail millet cultivars was carried out under saline-alkaline mixed stress (100 mmol L^-1, NaCl : NaHCO₃ = 4 : 1). The results showed that germination potential, germination rate, root length, shoot length, fresh root weight and fresh shoot weight of the 53 cultivars were inhibited, among which with root length most affected by the salt and alkaline condition. Exposed to such a stress condition, significant or extremely significant positive correlations were observed for relative germination potential and relative germination rate, relative root length and relative shoot length, and relative fresh root weight and relative fresh shoot weight. 14 traits were integrated into four principal components with a cumulative contribution rate of 90.4% through principal component analysis (PCA). Composite scores for saline-alkaline tolerance were calculated from membership function with scores of the four principal components. The 53 cultivars were assigned to six different groups of saline-alkaline resistance by using cluster analysis, including 2 highly resistant, 16 moderately resistant, 17 lower resistant, 6 sensitive, 9 susceptible and 3 extremely intolerant foxtail millet cultivars. Meanwhile, a regression equation, D° = 0.298 + 0.037 X₂ + 0.144X₃ + 0.018X₆ + 0.209X₇ - 0.183X₉ + 0.115X₁₁ - 0.201X₁₂ + 0.112X₁₃ - 0.101X₁₄ + 0.284X₁₅, was established to estimate the tolerance of foxtail millet cultivars to saline-alkaline stress. Relative germination rate, salt injury rates for root length and shoot length, and root-shoot ratio could be regarded as the indicators of assessing the resistance of foxtail millet to saline-alkaline mixed stress.