摘要
地生兰的类原球茎体(PLB)在不加激素的1/2 MS培养基上驯化培养,获得“无需外源激素仍能增殖的无性系(PLB-O)”,已继代5年,不分化芽和根。连续光照有利于PLB-O分生区的增殖,8h光照的次之,黑暗中增殖速度最低。PLB培养在含10％椰乳的1/2 BMS液体培养基中,随继代培养进程,形成分枝更多的丛生型PLB,约4个月后,在PLB顶端开始形成植株。兰花离体培养中,在同一个培养物中,同时存在着处于不同发育时期的分生区、原球茎、芽和小植株。PLB培养在含1/2BMS+6BA 2mg/L+NAA 0.2 mg/L的培养基中,同一个丛生型PLB上,因分生区和PLB的发育年龄的不同,形成不同发育年龄的幼芽。
Shoot meristem and axillary buds of Cymbidium ensifolium (L.) Sw were cultured on revised Murashige and Skoog medium (1/2 MS) supplemented with 10% coconut milk (CM) and 5 mg/L naphthalene acetic acid (NAA) under continuous illumination. The explants formed protocorm-like bodies (PLB) within 3～4 months. When PLBs were cultured on 1/2 MS without any growth regulators and illuminated continuously, a 'habituated mericlone (PLB-0)' was established, which could be multiplied and subculturcd without any exogenous plant growth substances. They have been subcultured for more than 5 years without differentiation of buds or roots. The multiplication of PLBs cultured in continuous light was greater than that illuminated 8 h/day, and almost no multiplication was shown in darkness (Table 1). When PLBs were cultured on 1/2 MS supplemented with 10% CM liquid medium, they not only differentiated into plantlets, but also formed a large number of PLBs (Fig. 2). It was shown that the meristematic regions on rosette PLBs multiplied, and the tips of PLB gradully differentiated into buds, and then formed roots (Fig. 2). It took about 4 months or longer to form perfect plantlets. When PLBs were cultured on 1/2MS supplemented with 6BA 2 mg/L+NAA 0.2 mg/L, they developed buds with varied leaflets, according to position of the meristematic region and the developmental stage of the protocorms. The youngest meristematic regions became brown and no longer multiplied. The results show that cell division, protocorm initiation and development, multiplication, and organogenesis, form a whole continuous process. These stages of process occurred on the same PLB and developed into the young buds different ages on the basis of the ages of of meristematic regions and PLB (Plate Ⅰ,Ⅱ).
关键词
兰花
组织培养
原球茎
个体发生
Cymbidium, tissue culture, protocormlike body, ontogenesis
