Deblieck Mathieu, Szilagyi Gergely, Andrii Fatiukha, Saranga Yehoshua, Lauterberg Madita, Neumann Kerstin, Krugman Tamar, Perovic Dragan, Pillen Klaus, Ordon Frank
Julius Kühn Institute (JKI), Federal Research Centre for Cultivated Plants, Institute for Resistance Research and Stress Tolerance, Quedlinburg, Germany.
The Hebrew University of Jerusalem, Robert H. Smith Faculty of Agriculture, Food and Environment, Rehovot, Israel.
Front Genet. 2022 Oct 19;13:955295. doi: 10.3389/fgene.2022.955295. eCollection 2022.
Genetic diversity in wheat has been depleted due to domestication and modern breeding. Wild relatives are a valuable source for improving drought tolerance in domesticated wheat. A QTL region on chromosome 2BS of wild emmer wheat ( ssp. ) conferring high grain yield under well-watered and water-limited conditions, was transferred to the elite durum wheat cultivar Uzan ( ssp. ) by a marker-assisted backcross breeding approach. The 2B introgression line turned out to be higher yielding but also exhibited negative traits that likely result from trans-, cis-, or linkage drag effects from the wild emmer parent. In this study, the respective 2BS QTL was subjected to fine-mapping, and a set of 17 homozygote recombinants were phenotyped at BCF generation under water-limited and well-watered conditions at an experimental farm in Israel and at a high-throughput phenotyping platform (LemnaTec-129) in Germany. In general, both experimental setups allowed the identification of sub-QTL intervals related to culm length, kernel number, thousand kernel weight, and harvest index. Sub-QTLs for kernel number and harvest index were detected specifically under either drought stress or well-watered conditions, while QTLs for culm length and thousand-kernel weight were detected in both conditions. Although no direct QTL for grain yield was identified, plants with the sub-QTL for kernel number showed a higher grain yield than the recurrent durum cultivar Uzan under well-watered and mild drought stress conditions. We, therefore, suggest that this sub-QTL might be of interest for future breeding purposes.
由于驯化和现代育种，小麦的遗传多样性已经减少。野生近缘种是提高驯化小麦耐旱性的宝贵资源。通过标记辅助回交育种方法，将野生二粒小麦（亚种）2BS染色体上在水分充足和水分受限条件下均能赋予高产的一个QTL区域转移到了优质硬粒小麦品种乌赞（亚种）中。结果表明，2B导入系产量更高，但也表现出一些负面性状，这些性状可能是由野生二粒小麦亲本的转座、顺式或连锁累赘效应导致的。在本研究中，对相应的2BS QTL进行了精细定位，并在以色列的一个试验农场和德国的一个高通量表型平台（LemnaTec-129）上，在水分受限和水分充足条件下对BCF代的一组17个纯合重组体进行了表型分析。总体而言，两种试验设置都能鉴定出与茎长、粒数、千粒重和收获指数相关的亚QTL区间。粒数和收获指数的亚QTL分别在干旱胁迫或水分充足条件下被检测到，而茎长和千粒重的QTL在两种条件下均被检测到。虽然没有鉴定出直接控制籽粒产量的QTL，但在水分充足和轻度干旱胁迫条件下，具有粒数亚QTL的植株比轮回硬粒品种乌赞的籽粒产量更高。因此，我们认为这个亚QTL可能对未来的育种具有重要意义。
