Adaptability and stability of reproductive and vegetative phases of peach trees in subtropical climate

ABSTRACT. The peach tree (Prunus persica) is a fruit species native to temperate climates that requires a chill during its hibernal period to overcome dormancy. However, due to genetic breeding, varieties are currently grown in subtropical and tropical regions where there are low occurrences of chill during this phenological stage. This study evaluated the adaptability and stability of the reproductive and vegetative phases of peach tree cultivars in a subtropical climate. An experiment was designed in randomized blocks with split time plots, with 23 peach tree cultivars and four replications, with each replication consisting of one plant and four shoots. The years of evaluated (plots) and the cultivars (subplots) were considered to be treatments. The relative rates of budburst (RRB), flowering (RRF), shoot formation (SF) and fruit set (FS), average time of budburst (ATB) and flowering (ATF), duration of budburst (DB) and flowering (DF) and number of hours with temperatures below 7.20°C were evaluated during the experimental period. The cultivars ‘Bonão’, ‘Ouromel-4’, ‘Libra’ and ‘Maciel’ demonstrated greater adaptability during the vegetative phase, whereas‘Ouromel-4’ and ‘Libra’ demonstrated greater adaptability and stability during the reproductive phase of peach trees in a subtropical climate.摘要：桃树（Prunus persica）是一类原产于温带气候的果树，其在越冬休眠期需满足一定低温积累量以打破休眠。然而，借助遗传育种技术，目前已有多个桃树品种可在亚热带与热带区域种植，而这些区域在桃树的该物候期内低温积累事件相对不足。本研究针对亚热带气候下桃树品种的营养生长与生殖生长阶段的适应性及稳定性展开评价。试验采用随机区组-时间裂区试验设计，共设置23个桃树品种，4次重复，每次重复包含1株植株与4个枝条。本试验以试验年份（大区处理）与品种（副区处理）作为试验因子。试验期间测定的指标包括：芽萌发相对速率（budburst relative rate, RRB）、开花相对速率（flowering relative rate, RRF）、新梢形成量（shoot formation, SF）、坐果率（fruit set, FS）、芽萌发平均时间（average time of budburst, ATB）、开花平均时间（average time of flowering, ATF）、芽萌发持续时长（duration of budburst, DB）、开花持续时长（duration of flowering, DF），以及试验期间环境温度低于7.20℃的累积小时数。结果表明，品种‘Bonão’、‘Ouromel-4’、‘Libra’与‘Maciel’在亚热带气候下的桃树营养生长阶段表现出更优的适应性；而‘Ouromel-4’与‘Libra’则在生殖生长阶段兼具更优异的适应性与稳定性。