Multiple Near-Isogenic Lines Targeting a QTL Hotspot of Drought Tolerance Showed Contrasting Performance Under Post-anthesis Water Stress

作者：Md Sultan Mia, Hui Liu, Xingyi Wang, Guijun Yan · 发表于：Frontiers in Plant Science · 年份：2019 · DOI：10.3389/fpls.2019.00271 · 被引用次数：35 · 研究领域：Wheat and Barley Genetics and Pathology、Genetic Mapping and Diversity in Plants and Animals、Genetics and Plant Breeding

The complex quantitative nature of drought-related traits is a major constraint to breed tolerant wheat varieties. Pairs of near-isogenic lines (NILs) with a common genetic background but differing in a particular locus could turn quantitative traits into a Mendelian factor facilitating our understanding of genotype and phenotype interactions. In this study, we report our fast track development and evaluation of NILs from C306 × Dharwar Dry targeting a wheat 4BS QTL hotspot in C306, which confers drought tolerance following the Heterogeneous Inbreed Family analysis coupled with immature embryo culture-based fast generation technique. Molecular marker screening and phenotyping for grain yield and related traits under post-anthesis water stress confirmed four isoline pairs, viz. qDSI.4B.1-2, qDSI.4B.1-3, qDSI.4B.1-6 and qDSI.4B.1-8. There were significant contrasts of responses between the NILs with C306 QTL (+NILs) and the NILs without C306 QTL (-NILs). Among the four confirmed NIL pairs, mean grain yield per plant of the +NILs and -NILs showed significant differences ranging from 9.61 to 10.81 g and 6.30 to 7.56 g , respectively, under water stressed condition, whereas a similar grain yield was recorded between the +NILs and -NILs under well-watered condition. Isolines of +NIL and -NIL pairs showed similar chlorophyll content (SPAD), assimilation rate (A) and transpiration rate (Tr) at the beginning of the stress. However, the +NILs showed significantly higher SPAD (12%), A (...