Schnurbusch Thorsten, Langridge Peter, Sutton Tim
Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, PMB 1, Glen Osmond, SA 5064, Australia.
Genome. 2008 Dec;51(12):963-71. doi: 10.1139/G08-084.
High soil boron (B) constitutes a major soil problem in many parts of the world, particularly in low-rainfall areas and land under irrigation. Low accumulation of B in the shoot or grain of cereal crops is correlated with the maintenance of biomass production and grain yield under high B conditions, suggesting that this trait is an important component of field tolerance. A novel screening protocol to measure B accumulation in aerated and supported hydroponics was validated using a set of known and exotic bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) accessions. Furthermore, B accumulation in two Triticum urartu Tumanian ex Gandilyan and 54 Triticum monococcum L. accessions was measured and showed considerable phenotypic variation. However, B accumulation in these lines was higher than that observed in the most tolerant durum or bread wheats. Mapping of high B tolerance in the durum population AUS14010/Yallaroi revealed a locus possibly allelic to Bo1, a major source of B toxicity tolerance previously identified in bread wheat. Here, we show that the Bo1-specific codominant PCR marker AWW5L7 is predictive of B tolerance status among exotic durum and bread wheat accessions. All tolerant durum accessions assayed carried very similar AWW5L7 marker fragments, indicating wide distribution of this allele among tolerant durum wheats. Three bread wheat accessions had tolerance that was independent of Bo1 and is probably located on chromosome 4A. These lines represent a valuable genetic resource for B toxicity tolerance breeding in wheat.
高土壤硼含量是世界许多地区的主要土壤问题，特别是在低降雨地区和灌溉土地上。谷类作物地上部或籽粒中硼的低积累与高硼条件下生物量生产和籽粒产量的维持相关，这表明该性状是田间耐受性的重要组成部分。使用一组已知的和外来的面包小麦（普通小麦）和硬粒小麦（ durum小麦）种质，验证了一种在通气和支撑水培中测量硼积累的新型筛选方案。此外，还测量了两个乌拉尔图小麦（Triticum urartu Tumanian ex Gandilyan）和54个一粒小麦（Triticum monococcum L.）种质中的硼积累，结果显示出相当大的表型变异。然而，这些品系中的硼积累高于在耐受性最强的硬粒小麦或面包小麦中观察到的水平。在硬粒小麦群体AUS14010/Yallaroi中对高硼耐受性进行定位，发现了一个可能与Bo1等位的位点，Bo1是先前在面包小麦中鉴定出的硼毒耐受性的主要来源。在这里，我们表明Bo1特异性共显性PCR标记AWW5L7可预测外来硬粒小麦和面包小麦种质中的硼耐受性状态。所有测定的耐受性硬粒小麦种质都携带非常相似的AWW5L7标记片段，表明该等位基因在耐受性硬粒小麦中广泛分布。三个面包小麦种质具有独立于Bo1的耐受性，可能位于4A染色体上。这些品系代表了小麦硼毒耐受性育种的宝贵遗传资源。
