Genebank Department, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), 06466 Gatersleben, Germany.
Department of Genetics, Faculty of Agriculture, Assiut University, Assiut 71526, Egypt.
Genes (Basel). 2024 Aug 24;15(9):1119. doi: 10.3390/genes15091119.
Drought stress, which significantly affects growth and reduces grain yield, is one of the main problems for wheat crops. Producing promising drought-tolerant wheat cultivars with high yields is one of the main targets for wheat breeders. In this study, a total of seven drought-tolerant wheat genotypes were screened for the presence of 19 specific drought tolerance genes. The genotypes were tested under normal and drought conditions for two growing seasons. Four spike traits, namely, spike length (SPL), grain number per spike (GNPS), number of spikelets per spike (NSPS), and grain yield per spike (GYPS), were scored. The results revealed that drought stress decreased the SPL, GNPS, NSPS, and GYPS, with ranges ranging from 2.14 (NSPS) to 13.92% (GNPS) and from 2.40 (NSPS) to 11.09% (GYPS) in the first and second seasons, respectively. ANOVA revealed high genetic variation among the genotypes for each trait under each treatment. According to the drought tolerance indices, Omara 007 presented the highest level of drought tolerance (average of sum ranks = 3), whereas both Giza-36 genotypes presented the lowest level of drought tolerance (average of sum ranks = 4.8) among the genotypes tested. Among the 19 genes tested, 11 were polymorphic among the selected genotypes. Omara 007 and Omara 002 presented the greatest number of specific drought tolerance genes (nine) tested in this study, whereas Sohag-5, Giza-36, and PI469072 presented the lowest number of drought tolerance genes (four). The number of different genes between each pair of genotypes was calculated. Seven different genes were found between Omara 007 and Giza-36, Omara 007 and Sohag-5, and Omara 002 and PI469072. The results of this study may help to identify the best genotypes for crossing candidate genotypes, and not merely to genetically improve drought tolerance in wheat.
干旱胁迫严重影响小麦的生长并降低其产量，是小麦生产面临的主要问题之一。培育高产、耐旱的小麦品种是小麦育种工作者的主要目标之一。本研究共筛选了 7 个耐旱小麦基因型，以鉴定其是否携带 19 个特定的耐旱基因。在两个生长季中，对这些基因型在正常和干旱条件下进行了测试。对四个穗部性状（穗长、每穗粒数、每穗小穗数和穗粒产量）进行了评分。结果表明，干旱胁迫降低了穗长、每穗粒数、每穗小穗数和穗粒产量，降幅分别在两个生长季中为 2.14%（每穗小穗数）至 13.92%（每穗粒数）和 2.40%（每穗小穗数）至 11.09%（穗粒产量）。方差分析显示，每个处理下各基因型的每个性状均存在较高的遗传变异。根据耐旱性指数，Omara 007 的耐旱性最强（平均总分排名 = 3），而两个 Giza-36 基因型的耐旱性最弱（平均总分排名 = 4.8）。在所测试的基因型中，有 11 个基因型在 19 个测试基因中存在多态性。Omara 007 和 Omara 002 携带了本研究中最多的 9 个特定耐旱基因，而 Sohag-5、Giza-36 和 PI469072 携带了最少的 4 个耐旱基因。计算了每对基因型之间的不同基因数量。在 Omara 007 和 Giza-36、Omara 007 和 Sohag-5 以及 Omara 002 和 PI469072 之间发现了 7 个不同的基因。本研究结果有助于鉴定最佳的杂交候选基因型，而不仅仅是提高小麦的耐旱性。
