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接触型化学脱水剂已经被推荐用来模拟扬花后干旱胁迫，并能选择扬花后耐干旱胁迫的小麦品种。本研究的目的是确定早代在组合之间选择化学脱水耐性是否有可能，以及对粒重进行机械混选是否能够改变早代混合群体的化学脱水耐性。１９９１年在科罗拉多州的两个试验点上评价了４个冬小麦单交群体的化学脱水耐性，每个试验点由重复的Ｆ４混合群体试验组成。Ｆ４群体是由在Ｆ２和Ｆ３代进行了化学脱水［２％（ｗ／ｖ）ＮａＣｌＯ３，扬花后１０ｄ喷施］，并对粒重进行了机械混选的群体衍生来的。在两个试验点，耐性亲本间杂交均比敏感亲本间或对照亲本间杂交表现出较低（Ｐ≤０．０１）的化学脱水损害（对籽粒产量、粒重和容重来说）。将Ｆ２群体分成按不同株高和成熟期选择的混合群体，结果表明，来自随机选择和Ｆ２高株的入选混合群体明显地（Ｆ≤０．０１）比来自矮株或花期相近植株的入选混合群体受化学脱水损害轻（只在一个试验点上是这样）。对经过两轮化学脱水处理衍生而来的群体进行机械混选，所产生的Ｆ４混合群体受化学脱水损害明显较轻（Ｐ≤０．０１）。施用脱水剂并机械混选高粒重后所产生的Ｆ４群体，化学脱水损害减轻的几个事例表明，通过选择来改良混合群体的化学脱水耐性是有潜力的。本研究?
Contact chemical dehydration agents have been proposed to simulate post-flowering drought stress and to select drought-tolerant wheat varieties after flowering. The purpose of this study was to determine if the early generation was able to choose chemical dehydration tolerance among combinations, and whether mechanical mixing of grain weights could alter the chemical dehydration resistance of earlier mixed populations. The chemical dehydration resistance of 4 winter wheat cross groups was evaluated at two pilot sites in Colorado in 1991 and each consisted of repeated F4 mixed population experiments. The F4 population was derived from a population that had undergone chemical dehydration [2% (w / v) NaClO3 in F2 and F3 generations, 10 days after flowering], and mechanical mixing of grain weights. At both test sites, hybrids between resistant parents showed lower (P <0.01) chemical dehydration damage (for grain yield, grain weight, and bulk density) than between sensitive or control parents. The F2 population was divided into mixed populations of varying plant height and maturity, and the results showed that the selected mixed populations from the randomly selected and F2 high lines were significantly (F & lt; 0.01) better than the selected mixes from the dwarf or flowering plants The population is harmed by chemical dehydration lightly (only at one test point). Mechanical mixing of populations derived from two rounds of chemical dehydration resulted in significantly less damage to the F4 mixed population by chemical dehydration (P <0.01). Several examples of the application of dehydrating agents and mechanical mixing of high-grain-weight F4 populations resulting in reduced chemical dehydration damage indicate that there is potential for improving the chemical dehydration resistance of mixed populations by selection. this research?