Studies on the remaining of astringency in relation to decreased capability of seed formation in Japanese persimmon fruits (cv."Nishimura wase")

日本柿子果实（cv.“Nishimura wase”）中残留涩味与种子形成能力下降相关的研究

• 批准号: 61560030
• 负责人: NAKAMURA Mitsuo
• 金额: $ 1.28万
• 依托单位: Gifu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61560030/
• 关键词: Embryosac development; Tissue culture of Japanese persimmon; 花粉の発芽; カキ; 授精; 胚嚢の発育; 組織培養

Japanese persimmon (cv."Nishimura wase") is a pollination variant non-astringent (PVNA) type, and de-astringency has not been achived along with decreased capability of seed formation. This decreased capability has been researched from the point of view of male gamete sterility, germination percentage and germination rate of pollen. The development of embryosac from the mother cell to complete formation was investigated in order to understand the relationship between capability of seed formation and female sterility. Embryosac mother cells and tetrasporangii were formed 18 and 12 days before bloom. The embryosac reached maturity 4 days before bloom. There were 3 phases in the development: the first phase, characterized by extension and no enlargement, extended from embryosac mother cell to tetrasporangium, the second phase, characterized by rapid enlargement, extended to the nuclear division of embryosac cells, and the third phase, characterizedby rapid extension, extended to completion of the embryosac. Embryosac abortion and degeneration were observed, at rates reaching 22.5%, after the tetrasporangium or embrvosac cell formation phases. There might be only six fertile embryosacs in a "Nishimura wase" fruit judging from the percentage of embryosac abortions and degenerations.In order to establish thebasic conditions of tissues culture, aseptic shoot cultures were initiated from shoot tips of "Nishimura wase". Shoot tips were excised from dormant axillary buds and cultured in vitro. The best shoot growth was obtained on MS medium containing half strength nitrogen supplemented with Zeatin at 10^<-5> M: BAP or 2ip was ineffective. A five-fold proliferation rate was obtained by single node cutting of elongated shoot.Anther culture, leaf culture and rooting of new shoots cultured using aseptic shoot were also carried out.

日本柿（cv.“Nishimura wase”）是一种授粉变异体非涩（PVNA）类型，沿着种子形成能力的降低，没有实现去涩。从雄配子育性、花粉萌发率和花粉萌发率等方面对这种能力下降进行了研究。通过对胚囊从母细胞到胚囊形成过程的研究，探讨了种子形成能力与雌性不育的关系。胚囊母细胞和四孢子囊在开花前18和12天形成。胚囊在开花前4d达到成熟。其发育过程可分为3个阶段：第一阶段以胚囊母细胞向四孢子囊延伸为特征，但不膨大;第二阶段以胚囊细胞核分裂为特征，迅速膨大;在四孢子囊或胚囊细胞形成期后，胚囊败育和退化率达22.5%。从胚囊败育率和退化率判断，西村早实果实中可能只有6个可育胚囊，为了建立组织培养的基本条件，以西村早实茎尖为外植体，进行了无菌茎段培养。从休眠腋芽上切取茎尖进行离体培养。在含氮量减半的MS培养基上，添加10 μ M玉米素，芽生长最好<-5>，BAP或2 ip无效。采用单节扦插法获得了5倍的增殖率，并对无菌苗进行了花药培养、叶片培养和新梢生根培养。