紫茉莉不定芽诱导和植株再生

紫茉莉(Mirabilis jalapa)观赏价值较高,是一种重要的污染修复植物.组织培养技术为植物品种改良和选育的重要途径,但紫茉莉离体快繁方面的研究尚未见有相关报道.该研究以紫茉莉叶片和茎段为外植体,通过观察和统计外植体愈伤组织和不定芽的诱导情况,分析不同植物生长物质对紫茉莉植株再生的影响.结果表明:紫茉莉带芽茎段比较适合丛生芽的诱导,当带芽茎段在MS+1.0 mg·L-16-BA+1.5 mg·L-1 KT+1.0 mg·L-1 NAA+0.05 mg·L-1 TDZ培养基中培养时,不定芽的增殖系数较高.无论是MS或1/2MS培养基,都可诱导不定根的产生,其中生根效果较好的培养基为1/2 MS+0.5 mg·L-1 NAA.该研究结果探索了紫茉莉组织培养的最适条件,根据愈伤组织诱导率和不定芽的增殖系数筛选出了适宜不定芽诱导的培养基类型,根据不定芽生根情况确定了最佳的生根诱导培养基,为建立紫茉莉高效稳定的再生和遗传转化体系奠定了基础.

Adventitious shoot induction and plant regeneration of Mirabilis jalapa

Mirabilis jalapa is a perennial herb of Nyctaginaceae, native to South America. It grows faster and can reproduce itself. Not only is it a high-value ornamental flowering and greening plant, but also can be used as medicine. In addition, the recent studies show that Mirabilis jalapa has good bioremediation function. Plant tissue culture technology provides an important way to improve and breed new varieties for horticultural plants. However, the research related to M. jalapa is still relatively little, and there are no reports on plant regeneration of M. jalapa at present. In this study, the achenes of M. jalapa were sterilized and inoculated into basal MS medium containing 0.1 mg·L^-1 NAA for the sterile seedlings obtained. Then the leaves and stems of the sterile seedlings were as explants to study the effects of different plant regulators on the buds induction and plant regeneration. According to frequency of callus induction, average number of buds and roots, the optimal media for inducing adventitious buds and rooting were screened respectively. The results showed that most of leaf explants did not produce calli, none of which formed adventitious buds. Moreover, with the prolongation of culture time, leaves began to produce adventitious roots, and gradually became more and more. The nodal stem segments of vegetative branches of sterile seedlings were more suitable for the induction of buds. Micropropogated shoots were quickly induced from axillary buds of nodes on an induction medium consisting of basal MS medium supplemented with different concentrations of 2,4-D, NAA, KT, 6-BA, and TDZ. Among them, the optimal medium for the explant culture in vitro of M. jalapa was MS + 1.0 mg·L^-1 6-BA + 1.5 mg·L^-1 KT + 1.0 mg·L^-1 NAA + 0.05 mg·L^-1 TDZ, the number of adventitious shoots were more and growth robust. For rooting induction, either MS or 1/2MS medium could induce the adventitious buds to produce roots, and the optimal medium was 1/2MS + 0.5 mg·L^-1 NAA. This study was designed to explore the optimal conditions for tissue culture of M. jalapa, which provides the information for the future establishment of an efficient regeneration system of M. jalapa tissue culture and genetic transformation system.