Phenotypic variation and heritability of heading date in hexaploid oat

Abstract The onset of flowering is decisive to the reproductive success of plants. The objectives of this study were to characterize the phenotypic variation in heading date and estimate its heritability in segregating populations of oat (Avena sativa L.). F2 and F3 generations of two large populations, derived from crosses ‘URS Taura × Leggett’ and ‘FL0206B-S-B-S1 × UFRGS 078030-1’, were evaluated. A wide phenotypic variation in the number of days to heading was observed in both populations. Heritability coefficients of 0.68 and 0.46 were estimated for the ‘URS Taura × Leggett’ and ‘FL0206B-S-B-S1 × UFRGS 078030-1’ populations. Our results demonstrate that genetic differences derived from parents in response to photoperiod and temperature explain most of the phenotypic variation in heading date of oat populations. Understanding genetic and environmental effects on flowering expression is essential to increase the response to selection for well-adapted and high-yielding oat cultivars.

摘要 开花起始对植物的生殖成功具有决定性作用。本研究旨在表征燕麦（Avena sativa L.）分离群体中抽穗期的表型变异，并估算其遗传力。本研究对两个大型杂交衍生群体的F2和F3代进行了评价，这两个群体分别来自组合‘URS Taura × Leggett’与‘FL0206B-S-B-S1 × UFRGS 078030-1’。两个群体均表现出抽穗天数的广泛表型变异。‘URS Taura × Leggett’与‘FL0206B-S-B-S1 × UFRGS 078030-1’群体的遗传力系数分别为0.68和0.46。本研究结果表明，亲本对光周期和温度响应的遗传差异，可解释燕麦群体抽穗期表型变异的绝大部分。解析遗传与环境因子对开花表现的调控效应，是选育适应性优良且高产燕麦品种、提升选择响应效率的必要前提。