ABSTRACT

Anthracnose fruit rot, caused by Colletotrichum spp. is a major disease of highbush blueberries. The inheritance of fruit rot resistance to C. fioriniae was investigated in crosses of parents with varying levels of susceptibility. Three cultivars with known resistance profiles (Bluecrop, Elliott, and Jersey) and progeny from 16 crosses of parents with varying levels of susceptibility were screened. Fruit of field-grown bushes was inoculated when immature, harvested when ripe, and rated for infection incidence after 5, 8, and 12 days of incubation at 100% RH and 22–23°C. Area under the disease progress curves (AUDPC) values were calculated for 2010 and 2011 and slightly higher disease pressure was observed in 2011. These values were then regressed against actual disease incidences of cultivars and predicted (midparent) values for cross families based on two previous studies in 2010 and 2011 and significant correlations with the proportion of fruit decayed and sporulation capacity were observed. These findings provide strong evidence that anthracnose resistance is heritable in highbush blueberries, which has important implications for anthracnose resistance breeding. Additionally, this research provides benchmark AUDPC values for evaluation of future breeding selections for their resistance to C. fioriniae.

摘要

炭疽病果实腐烂，由炭疽菌属引起。是高丛蓝莓的主要病害。C. fioriniae果实腐烂抗性的遗传在具有不同易感性水平的父母的杂交中进行了调查。筛选了三个具有已知抗性特征的品种（Bluecrop、Elliott 和 Jersey）以及来自 16 个具有不同敏感性水平的亲本杂交的后代。未成熟时接种田间灌木的果实，成熟时收获，并在 100% RH 和 22-23°C 下孵育 5、8 和 12 天后评估感染发生率。计算了 2010 年和 2011 年的疾病进展曲线下面积 (AUDPC) 值，并在 2011 年观察到略高的疾病压力。这些值随后根据栽培品种的实际发病率和基于前两次的跨家族预测（中亲本）值进行回归2010 年和 2011 年的研究，观察到与果实腐烂比例和孢子形成能力显着相关。这些发现提供了强有力的证据，证明炭疽病抗性在高丛蓝莓中是可遗传的，这对炭疽病抗性育种具有重要意义。此外，这项研究提供了基准 AUDPC 值，用于评估未来育种选择的抗性C. fioriniae。