Erath Wiltrud, Bauer Eva, Fowler D Brian, Gordillo Andres, Korzun Viktor, Ponomareva Mira, Schmidt Malthe, Schmiedchen Brigitta, Wilde Peer, Schön Chris-Carolin
TUM School of Life Sciences, Plant Breeding, Technical University of Munich, Liesel-Beckmann-Str. 2, 85354, Freising, Germany.
Department of Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, S7N 5A8, Canada.
Theor Appl Genet. 2017 Oct;130(10):2151-2164. doi: 10.1007/s00122-017-2948-7. Epub 2017 Jul 20.
Rye genetic resources provide a valuable source of new alleles for the improvement of frost tolerance in rye breeding programs. Frost tolerance is a must-have trait for winter cereal production in northern and continental cropping areas. Genetic resources should harbor promising alleles for the improvement of frost tolerance of winter rye elite lines. For frost tolerance breeding, the identification of quantitative trait loci (QTL) and the choice of optimum genome-based selection methods are essential. We identified genomic regions involved in frost tolerance of winter rye by QTL mapping in a biparental population derived from a highly frost tolerant selection from the Canadian cultivar Puma and the European elite line Lo157. Lines per se and their testcrosses were phenotyped in a controlled freeze test and in multi-location field trials in Russia and Canada. Three QTL on chromosomes 4R, 5R, and 7R were consistently detected across environments. The QTL on 5R is congruent with the genomic region harboring the Frost resistance locus 2 (Fr-2) in Triticeae. The Puma allele at the Fr-R2 locus was found to significantly increase frost tolerance. A comparison of predictive ability obtained from the QTL-based model with different whole-genome prediction models revealed that besides a few large, also small QTL effects contribute to the genomic variance of frost tolerance in rye. Genomic prediction models assigning a high weight to the Fr-R2 locus allow increasing the selection intensity for frost tolerance by genome-based pre-selection of promising candidates.
黑麦遗传资源为黑麦育种计划中提高抗冻性提供了宝贵的新等位基因来源。抗冻性是北部和大陆性种植区冬季谷物生产必须具备的性状。遗传资源应含有有望改良冬黑麦优良品系抗冻性的等位基因。对于抗冻性育种而言，鉴定数量性状位点（QTL）以及选择最佳的基于基因组的选择方法至关重要。我们通过在一个双亲群体中进行QTL定位，鉴定了冬黑麦抗冻性相关的基因组区域，该双亲群体源自加拿大品种彪马（Puma）的一个高度抗冻选择系与欧洲优良品系Lo157。这些品系本身及其测交后代在可控冷冻试验以及俄罗斯和加拿大的多点田间试验中进行了表型分析。在不同环境中一致检测到位于4R、5R和7R染色体上的三个QTL。5R染色体上的QTL与小麦族中含有抗霜位点2（Fr-2）的基因组区域一致。发现Fr-R2位点上的彪马等位基因能显著提高抗冻性。将基于QTL的模型与不同的全基因组预测模型所获得的预测能力进行比较，结果表明除了一些大的QTL效应外，小的QTL效应也对黑麦抗冻性的基因组变异有贡献。赋予Fr-R2位点高权重的基因组预测模型能够通过基于基因组的有前景候选材料预选来提高抗冻性的选择强度。
