The emergence of flowering disorder, specifically the bud break disorder observed in flower buds, has become a serious problem for Japanese pear ‘Kosui’ greenhouse production in southern Japan. To understand the mechanism behind this problem, the expression of genes related to endodormancy and flowering were investigated in “flowering disorder trees” (FDTs). In 2017 and 2019, remarkably warm temperatures were recorded during the winter season, and the degree of flowering disorder in FDTs was severe. Forced cultivation experiments suggested that endodormancy of “normal trees” (NTs) was released well before fulfilling the chilling requirement (CR), suggesting that ‘Kosui’ trees grown in greenhouses had a short endodormancy period. We also found that the dormancy depth of FDTs was shallower than that of NTs before and after fulfilling the CR, whereas FDTs entered a deeper dormancy when the greenhouse was covered by a plastic film during the ecodormancy period, suggesting that FDTs’ dormancy progression was significantly different from that of NTs during endodormancy and ecodormancy. Gene expression analysis showed that the expression level of the endodormancy-related gene, MADS13-3, was correlated with dormancy depth in NTs, but not in FDTs. Additionally, the expression levels of the putative flowering regulator, PpFLC3-like gene, were significantly lower in FDTs than in NTs in December, before fulfilling the CR. Additionally, the flowering promoter, PpFT, was also significantly lower in FDTs than in NTs in March after fulfilling the CR. The survey years 2017 and 2019 were warm winters with a high mean temperature difference from the climatological normal in December. These results suggest that the flowering disorder of greenhouse-cultivated ‘Kosui’ is related to the shallow dormancy depth and/or inappropriate dormancy and flowering progression during endodormancy and ecodormancy, especially when flower buds encounter high temperatures during dormancy.

开花障碍的出现，特别是在花蕾中观察到的芽折断障碍的出现，已经成为日本南部日本梨“ Kosui”温室生产的一个严重问题。为了了解此问题的机理，在“开花无序树”（FDT）中研究了与气味和开花相关的基因的表达。在2017年和2019年，冬季录得明显温暖的温度，而FDT中的开花异常程度很严重。强制耕种实验表明，在满足冷藏要求之前，“普通树”（NTs）的内在香气已经释放，这表明在温室中种植的“ Kosui”树的内在香气期短。我们还发现，在满足CR要求之前和之后，FDT的休眠深度要比NT的休眠深度浅，而在生态休眠期间，当温室被塑料薄膜覆盖时，FDTs进入更深的休眠状态，这表明在气味休眠和生态休眠期间，FDTs的休眠进程与NTs的休眠进程显着不同。基因表达分析表明，内嗅相关基因的表达水平高，MADS13-3与NT中的休眠深度相关，但与FDT中的休眠深度无关。此外，在实现CR之前，12月FDTs中假定的开花调节因子PpFLC3样基因的表达水平显着低于NTs。此外，开花促进剂PpFT达到CR后，3月FDT的汇率也明显低于新台币。2017年和2019年的调查年份是温暖的冬天，与12月的气候正常值相比，平均气温差高。这些结果表明，温室栽培的“ Kosui”的开花障碍与浅休眠深度和/或内在休眠和生态休眠期间不适当的休眠和开花进程有关，尤其是在休眠期间花蕾遇到高温时。