Department of Plant Breeding and Genetics, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi 46300, Pakistan.
Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences, Umeå 90183, Sweden; Department of Agronomy, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi 46300, Pakistan.
Sci Total Environ. 2020 Aug 10;729:139082. doi: 10.1016/j.scitotenv.2020.139082. Epub 2020 Apr 29.
Drought is one of the most prominent limiting factors that negatively affect crop productivity by manipulating its physiological pathway. One hundred twenty diverse bread wheat genotypes were used in a pot experiment to explore the relationship among their fifteen physio-biochemical traits (PBT) by using multivariate analysis, heatmapping and stress tolerance index (STI) for grain yield as a marker trait to identify high yielding genotype with maximum stress tolerance capability. Increased proline and sugar accumulation were observed from control to moisture deficient environments by 159% and 122%, respectively. Moreover, leaf membrane stability index (LMSI), leaf relative water content (LRWC), relative dry weight (RDW), chlorophyll content, leaf surface area (LSA), Leaf succulence (LS), canopy temperature depression (CTD), relative excised leaf water loss (RELWL) and leaf osmotic potential (LOP) showed significantly decreasing trend in drought stress treatment as compared to well-watered plants by -21%, -21%, -34%, -22%, -38%, -37%, -46%, -18% and -35% respectively. Additionally, principal component analysis and genotype by trait biplot analysis showed that initial 7 principal components (PC1 to PC7) represented 77.27% and 79.02% of total cumulative variation under control and drought stress respectively. Genotypic-Phenotypic correlation revealed that most of the attributes were higher in case of genotypic correlation component (rg) as compared to the phenotypic correlation component (rp) indicating more genetic association between traits. The darker and lighter colour scale produced by heatmap exhibited contrasting nature of genotypes, as positive side with higher values represented drought resistance while values on the negative side with lower values showed susceptible performance of genotypes. Our results concluded that the studied PBT associated with STI for grain yield are the main factors which may contribute in improved productivity of wheat crop and if these traits show appropriate performance under stress condition the crop will show the more productive returns under changing climate.
干旱是影响作物生产力的最主要限制因素之一，它通过操纵作物的生理途径对作物生产力产生负面影响。本研究采用盆栽试验，利用多元分析、热图和以粒重为标记性状的胁迫耐性指数（STI），对 120 个不同的小麦基因型的 15 个生理生化性状（PBT）之间的关系进行了研究，以鉴定具有最大胁迫耐性能力的高产品种。与对照相比，在水分亏缺环境下脯氨酸和糖的积累分别增加了 159%和 122%。此外，叶片膜稳定性指数（LMSI）、叶片相对含水量（LRWC）、相对干重（RDW）、叶绿素含量、叶片表面积（LSA）、叶片多汁性（LS）、冠层温度降低（CTD）、相对离体叶片水分损失（RELWL）和叶片渗透势（LOP）在干旱胁迫处理中较充分供水处理分别显著降低了-21%、-21%、-34%、-22%、-38%、-37%、-46%、-18%和-35%。此外，主成分分析和基于性状的基因型双标图分析表明，在对照和干旱胁迫下，前 7 个主成分（PC1 到 PC7）分别代表了总累积变异的 77.27%和 79.02%。基因型-表型相关分析表明，与表型相关系数（rp）相比，大多数性状的基因型相关系数（rg）更高，表明性状之间存在更多的遗传关联。热图产生的较暗和较亮的颜色尺度反映了基因型的对比性质，正半轴上的较高值表示抗旱性，负半轴上的较低值表示基因型的易感性。研究结果表明，与粒重 STI 相关的研究 PBT 是提高小麦生产力的主要因素，如果这些性状在胁迫条件下表现出适当的性能，那么在气候变化下，作物将获得更高的产量回报。
