Development of interspecific segregating populations of wheat and evaluation of agronomic characteristics and resistance to Fusarium head blight

ABSTRACT. The objective of this study was to develop segregating wheat populations for resistance to gibberella through the introgression of synthetic wheat genes in traditional cultivars and to present the results using the backcross method. In addition, to evaluate these populations in F1RC2, agronomic aspects and type II and III resistance to Fusarium head blight (FHB). The cultivars BRS Guamirim and BRS 179 were used as male parents and three synthetic wheat cultivars (CIGM90.909, CIGM92.1666, and CIGM93.298) as female parents, both previously characterized for the reaction to FHB. Crossing and backcrossing methodological procedures were performed to provide adequate controlled conditions. The F1 (winter 2016), RC1 (summer 2016/2017), and RC2 (winter 2017) populations were developed through emasculation and pollination procedures. In the winter of 2018, segregating populations were evaluated in the field using a randomized block design. In the three generations developed in a greenhouse, it was observed that the best crossbreeding combinations, verified by the number of grains, were obtained with the male parent BRS 179. Under field conditions, all segregating populations were considered moderately susceptible and susceptible to type II resistance. In type III resistance, all segregating populations, except for CIGM90.909/BRS 179 and BRS 179, showed values above 50%. Thus, it was evident that the crossings performed with the male parent BRS 179 generated better resistance to the disease.

摘要。本研究旨在通过将合成小麦基因渗入传统栽培品种，培育抗赤霉病的小麦分离群体，并采用回交法呈现研究结果；此外，还在F₁RC₂群体中评估了农艺性状以及对禾谷镰孢穗腐病（Fusarium head blight，FHB）的Ⅱ型和Ⅲ型抗性。本实验以BRS Guamirim和BRS 179作为父本，以3个均已完成FHB抗性反应鉴定的合成小麦品种（CIGM90.909、CIGM92.1666、CIGM93.298）作为母本。通过去雄与授粉等标准化受控流程开展杂交与回交实验：分别于2016年冬季创制F₁群体、2016/2017年夏季创制RC₁群体、2017年冬季创制RC₂群体。2018年冬季，采用随机区组设计对分离群体进行田间评价。在温室繁育的3个世代中，以籽粒数量为评价指标，父本为BRS 179的杂交组合表现最优。田间试验结果显示，所有分离群体对FHB的Ⅱ型抗性均表现为中感或感病；在Ⅲ型抗性方面，除CIGM90.909/BRS 179组合及亲本BRS 179外，其余分离群体的相关抗性指标值均高于50%。综上，以BRS 179为父本的杂交组合可赋予材料更强的赤霉病抗性。