不同抗旱性甘薯品种叶片生理性状差异及抗旱指标筛选

在人工控水条件下,以15个甘薯品种为试验材料,设置正常灌水和干旱胁迫2个土壤水分处理,研究了干旱胁迫条件下不同甘薯品种叶片生理特性的差异。结果表明,干旱胁迫条件下,叶面积系数均不同程度下降,反映了品种抗旱性的差异。通过抗旱系数聚类分析,将15个甘薯品种分为3个抗旱类型,抗旱品种:济薯21、济薯25、济徐23、济薯15、烟薯25;中等抗旱品种:徐薯18、济薯26、北京553、济紫薯2号、济薯18;不抗旱品种:郑薯20、济紫薯3号、济薯22、济紫薯1号、凌紫。叶面积系数与抗旱系数的相关性分析表明,干旱胁迫条件下抗旱性强的甘薯品种可维持较高的叶面积系数;而正常灌水条件下的叶面积系数不能反映甘薯品种抗旱性。干旱胁迫导致功能叶叶绿素含量和相对含水量下降,叶片相对电导率升高。干旱胁迫条件下,功能叶叶绿素含量和相对含水量与甘薯品种的抗旱性呈显著正相关关系,而功能叶相对电导率则与甘薯品种抗旱性呈显著的负相关关系。因此,叶面积系数以及功能叶叶绿素含量、相对含水量和相对电导率等指标可作为甘薯品种抗旱性鉴定的评价指标。

Screening of leaf physiological characteristics and drought-tolerant indexes of sweetpotato cultivars with drought resistance

Field experiments were conducted under a rain proof shelter using 15 sweetpotato cultivars with well-watered and drought stress treatments.Leaf physiological characteristics of different sweetpotato cultivars under drought stress were studied.The results showed that the leaf area index of all varieties decreased in different degrees under drought stress,which evaluating the difference of drought tolerance in varieties.Cluster analysis of drought resistance coefficient revealed that 15 sweetpotato cultivars were classified into three drought resistant types.The drought-tolerant cultivars were Jishu 21,Jishu 25,Jixu 23,Jishu 15,and Yanshu 25.The moderate drought-tolerant cultivars were Xushu 18,Jishu 26,Beijing 553,Jizishu 2,and Jishu 18.The drought-sensitive cultivars were Zhengshu 20,Jizishu 3,Jishu 22,Jizishu 1,and Ayamaraski.The correlation analysis between leaf area index and drought resistance coefficient demonstrated that the drought-tolerant cultivars could maintain higher leaf area index under drought stress,while the leaf area index under well-watered could not reflect the drought resistance.Drought stress resulted in the decline of chlorophyll content,the relative water content of functional leaves,and the increase of relative electrical conductivity of functional leaves.Under drought stress,the chlorophyll content and relative water content of functional leaves were significantly positively correlated with drought resistance in different cultivars,while the relative electrical conductivity of functional leaves was significantly negatively correlated with the drought resistance of sweetpotato varieties.In summary,leaf area index,chlorophyll content,relative water content,and relative electrical conductivity of functional leaves could be used as comprehensive evaluation indexes for identifying drought resistance of sweetpotato cultivars.