Impact of chilling accumulation and hydrogen cyanamide on floral organ development of sweet cherry in a warm region

The microscopic investigation of the floral development of sweet cherry（Prunus avium L. cv. Hongdeng） from a warm winter climate（Shanghai） and cold winter climate（Tai＇an, Shandong Province, China） was conducted to explore the reason of low fruit set. The effect of hydrogen cyanamide（HCN） on floral development under warm winter conditions was also investigated. Trees grown in Shanghai with insufficient chilling accumulation exhibited little difference in the progression of microspore development compared to trees in Tai＇an that accumulated adequate chilling, but showed substantial delays in ovule and embryo sac development. The growth of nucelli did not proceed beyond the macrospore mother cell and macrospore stages with abortion rates of 13, 15 and 45% by 6, 3 and 0 d before full bloom, respectively. These abnormalities in the ovule and embryo sac in the Shanghai-grown trees were eliminated by HCN application. These results suggest that chilling regulates the development of female floral organs in winter dormancy; therefore, insufficient chilling accumulation, causing abnormality of the female floral organs, restricts the cultivation of sweet cherry in warm winter regions. Interestingly, HCN application, which decreased the chilling requirements for Hongdeng, may be a potential strategy for sweet cherry cultivation in warm winter regions.

单氰胺对甜樱桃休眠解除及开花过程树体碳氮营养的影响

【目的】探讨单氰胺对甜樱桃休眠解除与开花的影响。【方法】以甜樱桃‘萨米脱’为试材,对喷施单氰胺后‘萨米脱’的物候期、碳水化合物含量、氮素营养等变化进行研究。【结果】单氰胺的施用引起‘萨米脱’休眠解除提早约半个月,萌芽提早11 d,花期提前5 d,且花期持续缩短2 d,更重要的是坐果率增加了11.6%。单氰胺的施用促进了甜樱桃‘萨米脱’休眠解除过程中淀粉、蔗糖和山梨糖醇等含量的降低,葡萄糖、果糖和总氮的含量升高,抑制蛋白态氮的含量降低。【结论】单氰胺可以作为甜樱桃‘萨米脱’在冬季低温累积较低区域商业生产的一个重要手段。

上海地区使用单氰胺打破甜樱桃休眠的效果

通过对上海栽培的"早红宝石"甜樱桃进行喷施2%单氰胺、遮阴和2%单氰胺+遮阴等3种打破休眠措施比较,发现喷施2%单氰胺对打破休眠和提高着果率最有效,与对照(空白)相比能提前萌芽5天,花期持续时间明显缩短,着果率达到20%。对"早红宝石"进行单氰胺处理后,单叶面积增大,单位新梢叶面积相应增加,着果率提高了18.8个百分点,发育正常子房的比例由12%提高到58%。单氰胺处理"先锋"品种,显著增加了果实可溶性固形物含量,提高了糖酸比,明显改善了品质,但对果实硬度和大小无显著影响。

单氰胺对设施大樱桃萌芽的促进作用

为了探讨单氰胺对大樱桃萌芽和成熟期的影响,萌芽前,在平度、泰安两地的“红灯”樱桃树上喷洒单氰胺1.5%和2.5%溶液。平度保护地的施药时间为2003年12月24日,泰安保护地和露地的施药时间分别为2004年1月12日和2月10日。试验结果表明,单氰胺能有效促进大樱桃萌芽和开花。平度试验点:经单氰胺处理的樱桃萌芽、开花、成熟期分别比对照提前13d、8d、7d,单果重略小于对照。泰安试验点:经单氰胺处理的萌芽期比对照提前7d,但果实成熟期与对照差异不明显。因此,单氰胺在大樱桃上的作用效果与施药时期有关。