Study on the roles of plant growth substances in parthenocarpy of fruit vegetables

为明确植物生长物质在黄瓜单性繁殖中的作用，在开花当天分别用苯氨基嘌素（BA）和萘乙酸（NAA）处理和不授粉处理，对两种黄瓜的果实生长模式进行了生理、组织学和化学分析。在果长和鲜重平均值的基础上分析，BA和NAA处理的Mogami果实在不授粉的情况下不诱导生长，但在不授粉的情况下也能促进其生长。未授粉果实的生长与授粉果实的生长基本相同，但无论是否授粉，BA和NAA都不影响其生长。根据果实长度的频率分布对其生长进行分析时，发现秋树的果实长度有两个分离峰。几乎所有已授粉的果实都属于10 cm及以上的峰，未授粉的果实一半属于10 cm及以上的峰，另一半属于与开花当天子房长度相同的4-6 cm的峰。BA和NAA对已授粉果实中4 ~ 6cm的峰位置没有影响，但在未授粉果实中，4 ~ 6cm的峰向6 ~ 10cm区域移动。说明孤雌结实是一种全或无型的触发反应，BA和NAA不作为触发反应，反而促进了未触发果实的生长。用石蜡果切片测定细胞数量和细胞大小，发现授粉和BA处理诱导的果实生长主要是通过细胞分裂进行的。酶联免疫吸附法（ELISA）检测到的吲哚乙酸（IAA）含量是牡丹果实的60倍，经孤雌结实诱导的果实中IAA含量比未经孤雌结实诱导的果实高3个数量级，提示内源生长素可能对孤雌结实有一定的调控作用。

Aimed to clarify the roles of plant growth substances in parthenocarpy of cucumber, var. Chojitsu-ochiai-nigo and Mogami were polinated or not and treated with benzylaminopurine (BA) or naphthaleneacetic acid (NAA) on the day of anthesis, and the mode of fruit growth was analyzed physiologically, histologically and chemically. When the fruit length and fresh weight were analyzed on the basis of their averages, Mogami fruits never induced to grow without polination but its growth was promoted even without polination if treated with BA or NAA. Growth of not-polinated Chojitsu-ochiai-nigo fruits was almost the same as that of polinated ones, but neither BA nor NAA influenced their growth regardless polinated or not. When the growth was analyzed based on frequency distribution of the fruit length, two separated peaks were found in that for Chojitsu-ochiai-nigo. Almost all the polinated fruits belonged to the peak in 10 cm or longer, and half of not-polinated fruits belonged to the peak in 10 cm or longer and other half to the peak in 4-6 cm which was the same as the length of ovary on the day of anthesis. BA and NAA did not influence the positions of the peaks in polinated fruits but the 4-6 cm peak was shifted to 6-10 cm region in not-polinated fruits. These facts suggest that parthenocarpy is all-or-none typed trigger reaction, BA and NAA do not act as the trigger but enhance the growth of not-triggered fruits. Cell number and cell size were measured with the sections cut from paraffined fruits finding that the fruit growth induced by polination and by the treatment with BA was mainly through cell division. The ELISA detected indoleacetic acid (IAA) in Chojitsu-ochiai-nigo at the amount 60 times higher than in Mogami and found the IAA content in the fruits of which growth was induced by parthenocarpy was three orders higher than those not-induced ones suggesting that endogenous auxin may have some roles in regulation of the parthenocarpy.