玉米雌穗离体培养诱导孤雌生殖结实

In vitro Production of Parthenogenetic Seeds from the Unpollinated Ears of Maize

离体条件下，用１６种不同的玉米材料未授粉的雌穗进行整个直插或切段直插培养。培养在２８℃培养箱和室内散射光下，其培养基为：ＭＳ＋０．１ｍｇ／Ｌ２，４－Ｄ＋２ｍｇ／ＬＮＡＡ＋２ｍｇ／ＬＫＴ＋５００ｍｇ／ＬＬＨ＋４％蔗糖＋０．６％琼脂（ｐＨ５．８）和ＭＳ＋０．０５ｍｇ／Ｌ２，４－Ｄ＋２ｍｇ／ＬＮＡＡ＋２ｍｇ／ＬＫＴ＋４％蔗糖＋０．６％琼脂（ｐＨ５．８）。从未授粉的雌穗（成熟胚囊期）获得结实。这些种子萌发的根尖细胞染色体数２ｎ＝２０，其植株花粉母细胞减数分裂终变期染色体构型２ｎ＝１０Ⅱ。Ｐａ１植株形态和生育特征类似母本植株。本文还讨论了影响玉米雌穗离体培养诱导孤雌生殖结实的因素以及二倍体种子产生的可能途径。

We used unpollinated ears of 16 various maize as our experimental materials to induce production of parthenogenetic seeds through the vertical culture of maize whole-ears and part-ears in vitro.In the condition of diffused light(500 1x or so)and 28 culture apparatus,parthenogenetic seeds were obtained from the unpollinated ears at the mature embryo sac stage on the medium A:MS+0.1mg/L2,4-D+2mg/L NAA+2 mg/L KT+500 mg/L LH+4%sucrose+0.6% agar(pH5.8)and on the medium B:MS+0.05 mg/L+2mg/L NAA+2mg/L KT+4% sucrose+0.6%agar(pH5.8).In this study,the chromosome number of the root,tip cells is equal to 20(2n=20)in the obtained parthenogenetic seed3,and the chromosome type is 10 Ⅱ in the meiotic diakinesis of the microsporocytes of the Pal plants.The morphological and generative traits of parthenogenetic first generation(Pa_1)are very similar to those of their parental plants.In this article we also discuss the factors of induction of parthenocarpy from maize unpollinated ears in vitro,and the possible ways of diploid parthenogenetic seeds.