Heterosis and genetic parameters for grain quality in oat segregating populations

ABSTRACT Improvement of quality-related traits of grains is a constant concern in white oat breeding programs, which challenges breeders to understand their dynamics. The performance of different genetic combinations must be thoroughly evaluated to make high nutritional quality cultivars available. This study aimed to estimate the heterosis on F1 and F2 generations, vigor loss, due to inbreeding, and correlation between the grain chemical components to understand the dynamics of these traits, considering two segregating oat progenies. The populations Albasul × UPF 15 (population 1) and IAC 7 × UFRGS 19 (population 2) were developed. Both populations showed transgressive segregant individuals. The combination Albasul × UPF 15 provided significant heterosis for traits β-glucan total and soluble fiber contents, while the population obtained by crossing IAC 7 × UFRGS 19 generated significant gain by heterosis for total fiber, insoluble fibers and non-structural carbohydrate contents. Considering the F2 average for each population, one can observe that population 1 presents higher β-glucan and lipid contents than population 2. On the other hand, population 2 has higher protein content than population 1. In both populations, the non-structural carbohydrate content is strongly and negatively correlated whith protein, total and insoluble fibers. Correlations between total fibers and lipids and between total fibers and insoluble fibers were both positive and high in both populations.

摘要：籽粒品质相关性状的改良始终是白燕麦育种项目的核心关切，这要求育种者深入解析其性状动态变化规律。为选育出兼具高营养品质的栽培品种，需对不同遗传组合的表现开展全面评估。本研究以2个燕麦分离后代群体为材料，旨在估算子一代（F₁）与子二代（F₂）的杂种优势、近交衰退导致的活力损失，以及籽粒化学成分间的相关性，以解析上述性状的动态变化规律。本研究构建了Albasul × UPF 15（群体1）与IAC 7 × UFRGS 19（群体2）两个燕麦群体，两个群体均出现了超亲分离个体。Albasul × UPF 15组合的总β-葡聚糖与可溶性膳食纤维含量表现出显著的杂种优势；而IAC 7 × UFRGS 19组合构建的群体，其总膳食纤维、不溶性膳食纤维及非结构性碳水化合物含量均通过杂种优势获得了显著提升。以各群体的子二代平均性状值为参照，群体1的β-葡聚糖与脂质含量均高于群体2；而群体2的蛋白质含量则显著高于群体1。在两个群体中，非结构性碳水化合物含量与蛋白质、总膳食纤维及不溶性膳食纤维含量均呈显著负相关。两个群体中，总膳食纤维与脂质含量、总膳食纤维与不溶性膳食纤维含量之间均呈显著正相关。