Genetic susceptibility to late maturity alpha-amylase (LMA) in wheat (Triticum aestivum L.) results in increased alpha-amylase activity in mature grain when cool conditions occur during late grain maturation. Farmers are forced to sell wheat grain with elevated alpha-amylase at a discount because it has an increased risk of poor end-product quality. This problem can result from either LMA or preharvest sprouting, grain germination on the mother plant when rain occurs before harvest. Whereas preharvest sprouting is a well-understood problem, little is known about the risk LMA poses to North American wheat crops. To examine this, LMA susceptibility was characterized in a panel of 251 North American hard spring wheat lines, representing ten geographical areas. It appears that there is substantial LMA susceptibility in North American wheat since only 27% of the lines showed reproducible LMA resistance following cold-induction experiments. A preliminary genome-wide association study detected six significant marker-trait associations. LMA in North American wheat may result from genetic mechanisms similar to those previously observed in Australian and International Maize and Wheat Improvement Center (CIMMYT) germplasm since two of the detected QTLs, QLMA.wsu.7B and QLMA.wsu.6B, co-localized with previously reported loci. The Reduced height (Rht) loci also influenced LMA. Elevated alpha-amylase levels were significantly associated with the presence of both wild-type and tall height, rht-B1a and rht-D1a, loci in both cold-treated and untreated samples.

中文翻译：

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北美春小麦 (Triticum aestivum L.) 晚熟 α-淀粉酶 (LMA) 的遗传学

小麦对晚熟α-淀粉酶（LMA）的遗传易感性（小麦L.) 在谷物成熟后期出现凉爽条件时，导致成熟谷物中的 α-淀粉酶活性增加。农民被迫以折扣价出售α-淀粉酶升高的小麦谷物，因为它增加了最终产品质量差的风险。这个问题可能是由于 LMA 或收获前发芽、收获前下雨时母株上的谷物萌发造成的。尽管收获前发芽是一个众所周知的问题，但人们对 LMA 对北美小麦作物构成的风险知之甚少。为了检验这一点，LMA 易感性在代表 10 个地理区域的 251 个北美硬春小麦品系中进行了表征。北美小麦似乎对 LMA 有很大的敏感性，因为只有 27% 的品系在冷诱导实验后表现出可重复的 LMA 抗性。一项初步的全基因组关联研究检测到了六个重要的标记-性状关联。北美小麦中的 LMA 可能源于与之前在澳大利亚和国际玉米和小麦改良中心 (CIMMYT) 种质中观察到的相似的遗传机制，因为检测到的两个 QTL，QLMA.wsu.7B和QLMA.wsu.6B，与先前报道的基因座共定位。这降低高度(RHT) 基因座也影响了 LMA。升高的α-淀粉酶水平与野生型和高身高的存在显着相关，右转B1a和右旋D1a, 冷处理和未处理样品中的基因座。