Laboratory of Mycology, Pathologies and Biomarkers LR16ES05, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis, 2092, Tunisia.
Agricultural Applied Biotechnology Laboratory (LR16INRAT06), Institut National de la Recherche Agronomique de Tunisie (INRAT), University of Carthage, Tunis, Tunisia.
Mol Biol Rep. 2024 Mar 23;51(1):432. doi: 10.1007/s11033-024-09340-9.
The future predictions for frequent and severe droughts will represent a significant threat to wheat yield and food security. In this context, breeding has proven to be the most efficient approach to enhance wheat productivity in dry environments.
In this study, both agronomic and molecular-based approaches were used to evaluate the response of twenty-eight Tunisian wheat varieties to drought stress. The primary objective was to screen these varieties for drought tolerance using molecular and agro-morphological markers. All varieties were significantly affected by drought stress regarding various traits including total dry matter, straw length, flag leaf area, number of senescent leaves, SPAD value, grain yield and grain number. Furthermore, substantial variability in drought-stress tolerance was observed among wheat genotypes. The cluster analysis and principal component analyses confirmed the existence of genotypic variation in growth and yield impairments induced by drought. The stress susceptibility index (SSI) and tolerance index (TOL) proved to be the most effective indices and were strongly correlated with the varying levels of genotypic tolerance. The genotyping evaluation resulted in the amplification of 101 alleles using highly polymorphic 12 SSR markers, showed an average polymorphism of 74%.
Taken together, the combination of agronomic and molecular approaches revealed that Karim, Td7, D117 and Utique are the most drought-tolerant wheat varieties. These varieties are particularly promising candidates for genetic improvements and can be utilized as potential genitors for future breeding programs in arid and semi-arid regions.
未来频繁且严重的干旱预测将对小麦产量和粮食安全构成重大威胁。在这种情况下，培育已被证明是提高旱地小麦生产力的最有效方法。
本研究采用农艺和分子方法评估了 28 个突尼斯小麦品种对干旱胁迫的响应。主要目的是使用分子和农艺形态标记筛选这些品种的耐旱性。所有品种在总干物质、秸秆长度、旗叶面积、衰老叶片数、SPAD 值、籽粒产量和粒数等多个性状上均受到干旱胁迫的显著影响。此外，小麦基因型之间存在显著的耐旱性差异。聚类分析和主成分分析证实了存在由干旱引起的生长和产量受损的基因型变异。胁迫敏感指数（SSI）和耐受指数（TOL）被证明是最有效的指数，与基因型的耐受水平有很强的相关性。基因型评估使用高度多态性的 12 个 SSR 标记对 101 个等位基因进行了扩增，平均多态性为 74%。
综合农艺和分子方法的结果表明，Karim、Td7、D117 和 Utique 是最耐旱的小麦品种。这些品种是遗传改良的有前途的候选品种，可作为干旱和半干旱地区未来育种计划的潜在供体。
