Studies on the occurrence of monoecious variants during vegetative propagation of spinach and asparagus plants by tissue culture techniques

已知植物在通过组织培养进行微繁殖过程中会发生性别表达的变化。为了阐明其可能的作用机制，本研究旨在寻找雌雄异株的性别表达变异体，并对其生长习性、形态特征和座果率进行分析。此外，通过组织培养进行微繁殖，以寻求性别表达的实际变化。此外，从芦笋和菠菜花中提取的蛋白质的分析方法。在实验农场中，我们鉴定了几种芦笋植株，它们具有花药和结实的能力。芦笋的未成熟花通常表现两性形态，在成熟的过程中通过特定阶段的子房组织和胚珠的停滞形成完整的雄花。但能坐果的芦笋雄花的子房较大，花柱较长，柱头正常。子房内的一些胚珠似乎是活的。芦笋植株上的花在子房形态和花柱长度上表现出一定程度的变异。以菠菜根愈伤组织为外植体，在长光周期下培养至开花。根据花的形态对供体植株和再生体的性别进行鉴定。这些结果表明，芦笋和菠菜的性别表达表现为一种灵活的表型，通过组织培养程序从雌雄异株融合为雌雄异株，雄株比雌株更容易发生性别转换。

It has been known that the variation of sex expression in plants occurs during micropropagation through tissue cultures. In order to elucidate the underlying mechanism, the experiments was conducted to find variants that the sex expression had been converted from male or female to monoecious plants and analyze their growth habits, morphological features and the frequency of fruit setting. Moreover, the actual changes in sex expression were pursued by carrying out micropropagation through tissue cultures. In addition, the methods for analysing proteins extracted from asparagus and spinach flowers.In the experimental farm we identified several asparagus plants having anthers and carrying potency to set fruits. Usually immature flowers of asparagus show hermaphroditic morphology, forming complete male flowers by stage-specific arrest of ovary tissue and ovules on the way to maturation. Nevertheless, flowers on male asparagus plants which were able to set fruits had large ovaries and a long style with normal stigma, compared with those of MW 500W male flowers. Some ovules within the ovaries seemed to be alive. The flowers on the asparagus plants showed an extent of variation in the morphology of ovary and the length of styles. Spinach plants regenerated from root calli were grown in vitro under long photoperiod until flowering. The gender of donor plants and regenerants were identified based on the morphology of flowers. The plants derived from root segments of female plants were all female, while those from male donors included monoecy which bears female and male flowers on the same plants.These results suggest that the sex expression of asparagus and spinach is manifested as a flexible phenotype, converged from dioecy to monoecy by the tissue culture procedure and that male plants was susceptible to sex conversion than female plants.