薇甘菊组织培养及体细胞胚胎发生的研究

研究了4种外植体、10种不同浓度激素组合对薇甘菊(Mikania micrantha H.B.K.)离体再生的影响,并对胚性愈伤组织中的体细胞胚发生发育过程进行了组织细胞学观察.结果表明,所用不同浓度激素组合的培养基均能诱导薇甘菊外植体产生愈伤,培养基以MS+6BA 1 mg/L为最宜;不同种类的愈伤组织再分化结果有明显差异,生长良好的胚性愈伤组织转入分化培养基后可诱导体细胞胚的发生.薇甘菊体细胞胚胎发生的形式为单细胞内起源.体细胞胚起源于胚性愈伤组织的胚性细胞,胚性细胞经过一次不均等分裂产生两个细胞,即胚细胞和胚柄细胞.然后依次经过具胚柄的多细胞原胚,再经过球形胚、心形胚、鱼雷胚阶段,发育成具有子叶的成熟胚状体,然后长成为再生植株.

Tissue culture and somatic embryogenesis of Mikania micrantha H. B. K.

Using MS as the basal culture medium,the effects of 4 kinds of explants and 10 different combinations of various phytohormone concentrations on callus formation and plantlet regeneration of Mikania micrantha H.B.K.were studied.A high frequency plantlet regeneration system was obtained and all the developmental stages of the somatic embryogenesis were examined by means of histocytological method.The results showed that all the explants and media used successfully induced both callus formation and plantlet regeneration,and the medium containing MS+6BA1 mg/L was testified to be much better than others for inducing callus,but the timing of the callus formation differed with different explants.MS medium containing MS + NAA 2 mg/L + KT 0.1 mg/L + 6BA 2 mg/L was found to be more preferable for inducing somatic embryoid from embryogenic callus for bud sprouting.However,callus redifferentiation occurred only in calli induced from young leaves and flower buds,while no callus redifferentiation were observed in shoot-tips as well as shoot segments with axillary buds.The somatic embryoid was found to originate from some single embryonic cell inside the callus tissue.The first division of the embryonic initial cell resulted in a two-cell proembryo(composed of an embryo cell and a suspensor cell),which ultimately developed into a mature embryoid with cotyledons through the intermediate stages of four-cell proembryo,eight-cell proembryo,sixteen-cell proembryo,multicelluar proembryo,globular embryo,heart-shaped embryo,torpedo-shaped embryo and,finally,cotyledonous embryo,which subsequently grew to form a plantlet.