【作者】 韩丽华；

【导师】 陈贵林； 王建设；

【作者基本信息】 河北农业大学 ， 蔬菜学， 2004， 硕士

【摘要】 将乙烯抑制剂AgNO₃首次应用于厚皮甜瓜离体雌核诱导，获得单倍体。对其胚囊发育途径做切片观察，发现胚囊内卵器继续分裂，形成胚状体，萌发形成单倍体植株。 5月下旬，取开花前14 h的厚皮甜瓜品系2B39未授粉子房，采用剥胚珠的方法，将含有胚珠的三室胎座分开，接种于预培养基A上，35℃恒温箱中黑暗热激4天；而后在25℃光下，含有AgNO₃处理的诱导培养基B上诱导2周，AgNO₃浓度分别为0，5，10，15，20，30，40，60，80，160 mg．L^-1；将胚珠从胎座上剥离下来，转移到胚状体萌发和胚芽伸长培养基C上，结果得到6棵由胚状体萌发的再生植株，AgNO₃浓度为80 mg．L^-1时，出胚率达最高0.74％。再生植株经微繁和继代培养后，共得到12棵小苗。通过保卫细胞叶绿体计数法进行倍性鉴定，1棵为单倍体，1棵为三倍体，1棵为四倍体，其它为混倍体。对胚珠离体雌核发育的不同阶段进行切片观察，发现接种当天，胚囊处于接近成熟的阶段，已经形成了八核结构，两个极核尚未融合；热激4天时，胚囊内出现细胞质浓厚的细胞团；培养18天后，可观察到胚囊内由卵器的发育而来的胚状体产生。8月份，采用剥胚珠法和切片法接种，在同样的培养条件下，未得到再生植株，这说明供体植株的生理状态，接种方式都影响离体雌核的发育。更多还原

【Abstract】 The inhibitor of ethylene AgNOs was first used on in vitro gynogenesis in melon. Haploid was obtained. Cytological analysis on the gynogenesis showed that egg apparatus in embryo sac developed into embryoid.In late May, ovaries of melon (Cucumis melo L. cv. 2B39) excised 14h before anthesis were peeled by hands to make the ovules just out of the ovary. Longitudinally sliced ovaries were surface sterilized, inoculated on pretreatment medium A under 35℃ for 4 days in the dark, then transferred to induction medium B supplemented with different AgNO3 concentration 0, 5, 10, 15, 20, 30, 40, 60, 80, 160 mg.L-1 for two weeks under 25℃ with a 16/8h (light/dark) photoperiod. Following the induction period, the ovules were removed from the placenta, transferred to elongation and regeneration medium C. Six ovules developed into plantlets by direct embryoids., Results from the regeneration test indicated that 80 mg.L-1 AgNO3 was favoured to the efficiency of gynogenesis, the percentage of embryos reaching 0.74%. By micropropagation and subculture, six regenerants were subdivided into 12 plantlets. Through the number of chloroplasts in guard cell for the ploidy level among the plantlets survived, one is haploid, one is triploid, one is tetraploid,others are mixoploid. Cytological observation on gynogenesis showed that at 14h before anthesis, the embryo sacs have formed the eight nuclei structure, the two polar nuclei still separate each other. After 4 days heat treatment, some of the gametophytes have proliferated into multi-celled proembryos. After inoculation for 18 days, the shape of the embryoid can be seen clearly in the embryo sacs, showing the embryoid was initiated directly from egg apparatus. In August, inoculation by peeling the ovaries and cutting the ovary into slice, under the identical culture condition no regenerant was obtained, which indicated that both the physiological condition of the donor plants and the approaches of inoculation affect the gynogenesis.更多还原