Chen W Y, Liu Z M, Deng G B, Pan Z F, Liang J J, Zeng X Q, Tashi N M, Long H, Yu M Q
Chengdu Institute of Biology, Chinese Academy of Sciences, Renmin South Road, Chengdu, China.
Tibet Academy of Agriculture and Animal Sciences, Lhasa, China.
Genet Mol Res. 2014 Mar 17;13(1):1909-25. doi: 10.4238/2014.March.17.19.
Lodging (LD) is a major constraint limiting the yield and forage quality of barley. Detailed analyses of LD component (LDC) traits were conducted using 246 F2 plants generated from a cross between cultivars ZQ320 and 1277. Genetic relationships between LD and LDC were evaluated by unconditional and conditional quantitative trait locus (QTL) mapping with 117 simple sequence repeat markers. Ultimately, 53 unconditional QTL related to LD were identified on seven barley chromosomes. Up to 15 QTL accounted for over 10% of the phenotypic variation, and up to 20 QTL for culm strength were detected. Six QTL with pleiotropic effects showing significant negative correlations with LD were found between markers Bmag353 and GBM1482 on chromosome 4H. These alleles and alleles of QTL for wall thickness, culm strength, plant height, and plant weight originated from ZQ320. Conditional mapping identified 96 additional QTL for LD. Conditional QTL analysis demonstrated that plant height, plant height center of gravity, and length of the sixth internode had the greatest contribution to LD, whereas culm strength and length of the fourth internode, and culm strength of the second internode were the key factors for LD-resistant. Therefore, lodging resistance in barley can be improved based on selection of alleles affecting culm strength, wall thickness, plant height, and plant weight. The conditional QTL mapping method can be used to evaluate possible genetic relationships between LD and LDC while efficiently and precisely determining counteracting QTL, which will help in understanding the genetic basis of LD in barley.
倒伏（LD）是限制大麦产量和饲草品质的主要因素。利用品种ZQ320和1277杂交产生的246个F2植株，对倒伏组成成分（LDC）性状进行了详细分析。通过使用117个简单序列重复标记进行无条件和条件性数量性状位点（QTL）定位，评估了LD与LDC之间的遗传关系。最终，在七条大麦染色体上鉴定出53个与LD相关的无条件QTL。多达15个QTL解释了超过10%的表型变异，检测到多达20个茎秆强度QTL。在4H染色体上的标记Bmag353和GBM1482之间发现了六个具有多效性且与LD呈显著负相关的QTL。这些等位基因以及茎壁厚度、茎秆强度、株高和植株重量QTL的等位基因均来自ZQ320。条件性定位又鉴定出96个LD的QTL。条件性QTL分析表明，株高、株高重心和第六节间长度对LD的贡献最大，而茎秆强度和第四节间长度以及第二节间茎秆强度是抗LD的关键因素。因此，基于对影响茎秆强度、茎壁厚度、株高和植株重量的等位基因的选择，可以提高大麦的抗倒伏性。条件性QTL定位方法可用于评估LD与LDC之间可能的遗传关系，同时高效准确地确定抗性QTL，这将有助于理解大麦LD的遗传基础。
