Ogbonnaya F C, Imtiaz M, Ye G, Hearnden P R, Hernandez E, Eastwood R F, van Ginkel M, Shorter S C, Winchester J M
Department of Primary Industries, Primary Industries Research Victoria, VIC 3401, Australia.
Theor Appl Genet. 2008 May;116(7):891-902. doi: 10.1007/s00122-008-0712-8. Epub 2008 Mar 27.
The inheritance and genetic linkage analysis for seed dormancy and preharvest sprouting (PHS) resistance were carried out in an F8 recombinant inbred lines (RILs) derived from the cross between "CN19055" (white-grained, PHS-resistant) with locally adapted Australian cultivar "Annuello" (white-grained, PHS-susceptible). Seed dormancy was assessed as germination index (GI7) while assessment for preharvest sprouting resistance was based on whole head assay (sprouting index, SI) and visibly sprouted seeds (VI). Segregation analysis of the F2, F3 data from the glasshouse and the RIL population in 2004 and 2005 field data sets indicated that seed dormancy and PHS resistance in CN19055 is controlled by at least two genes. Heritabilities for GI7 and VI were high and moderate for SI. The most accurate method for assessing PHS resistance was achieved using VI and GI7 while SI exhibited large genotype by environment interaction. Two quantitative trait loci (QTLs) QPhs.dpivic.4A.1 and QPhs.dpivic.4A.2 were identified. On pooled data across four environments, the major QTL, QPhs.dpivic.4A.2, explained 45% of phenotypic variation for GI7, 43% for VI and 20% for SI, respectively. On the other hand, QPhs.dpivic.4A.1 which accounted for 31% of the phenotypic variation in GI7 in 2004 Horsham field trial, was not stable across environments. Physical mapping of two SSR markers, Xgwm937 and Xgwm894 linked to the major QTL for PHS resistance, using Chinese Spring deletions lines for chromosome 4AS and 4AL revealed that the markers were located in the deletion bins 4AL-12 and 4AL-13. The newly identified SSR markers (Xgwm937/Xgwm894) showed strong association with seed dormancy and PHS resistance in a range of wheat lines reputed to possess PHS resistance. The results suggest that Xgwm937/Xgwm894 could be used in marker-assisted selection (MAS) for incorporating preharvest sprouting resistance into elite wheat cultivars susceptible to PHS.
以“CN19055”（白粒，抗穗发芽）与澳大利亚当地适应性品种“Annuello”（白粒，感穗发芽）杂交衍生的F8重组自交系（RIL）群体为材料，开展了种子休眠和抗穗发芽（PHS）的遗传及遗传连锁分析。种子休眠以发芽指数（GI7）进行评估，而抗穗发芽性评估则基于整穗测定（发芽指数，SI）和明显发芽种子（VI）展开。对温室中F2、F3数据以及2004年和2005年田间数据集的RIL群体进行分离分析表明，CN19055中的种子休眠和抗穗发芽性受至少两个基因控制。GI7和VI的遗传力较高，SI的遗传力中等。使用VI和GI7评估抗穗发芽性最为准确，而SI表现出较大的基因型与环境互作效应。鉴定出两个数量性状位点（QTL），即QPhs.dpivic.4A.1和QPhs.dpivic.4A.2。在四个环境的汇总数据中，主效QTL QPhs.dpivic.4A.2分别解释了GI7表型变异的45%、VI表型变异的43%和SI表型变异的20%。另一方面，在2004年霍舍姆田间试验中占GI7表型变异31%的QPhs.dpivic.4A.1在不同环境下不稳定。利用中国春4AS和4AL染色体缺失系对与抗穗发芽主效QTL连锁的两个SSR标记Xgwm937和Xgwm894进行物理定位，结果表明这些标记位于4AL - 12和4AL - 13缺失区间内。新鉴定的SSR标记（Xgwm937/Xgwm894）在一系列已知具有抗穗发芽性的小麦品系中与种子休眠和抗穗发芽性表现出强关联。结果表明，Xgwm937/Xgwm894可用于标记辅助选择（MAS）将抗穗发芽性导入易穗发芽优质小麦品种中。
