二花蝴蝶草的组织培养及植株再生

摘要

二花蝴蝶草(Torenia biniflora )为玄参科蝴蝶草属一年生植物,分布于广东、广西等亚热带地区,是一种观赏性较高的野生花卉.在自然生长条件下,二花蝴蝶草繁殖速度慢、增殖率低,而且花色和花型种类偏少,无法满足市场多样化的要求.植物组织培养技术为观赏植物的品种改良和新品种选育提供了新途径,目前蓝猪耳、蔓性蝴蝶草和单色蝴蝶草等蝴蝶草属植物的组织培养已获得成功,但二花蝴蝶草的组织培养尚未见有相关报道.该研究以二花蝴蝶草全展叶片为外植体,研究了培养基中添加不同种类和浓度植物生长物质对不定芽诱导和生长的影响,以及离子强度和不同浓度 IBA 对生根的影响.根据不定芽的诱导率和平均芽数筛选出最佳不定芽诱导培养基,并从生根率、平均根数和平均根长等方面筛选出最佳生根培养基.结果表明：不定芽诱导与植物生长物质的浓度和种类有关,以 MS＋6-BA 0．5 mg•L-1＋NAA 0．2 mg•L-1培养基的诱导效果最佳；二花蝴蝶草生根的最佳基本培养基为1/2MS,不同浓度的 IBA 对二花蝴蝶草的生根影响也不相同,其中以 IBA(0．05 mg•L-1)诱导不定芽的生根效果最佳.该研究建立了二花蝴蝶草的高频离体再生体系,为二花蝴蝶草的快速繁殖和遗传转化研究奠定了基础.%Torenia biniflora is a member of Scrophulariaceae Torenia ,and it is an annual flowering plant that widely grows in Chinese subtropical area,such as Guangdong Province and Guangxi Zhuang Autonomous Region.T .bini-flora is a wild flower with high great ornamental value.However,in natural growth condition,the reproduction speed of T .Biniflora is slow,proliferation rate is low,and the kinds of flower colour and type are few,therefore,it is una-ble to meet the diversified need of market.Plant tissue culture technology provides a new way to improve and breed new varieties for ornamental plants.Up to now,a lot of members of Torenia plants have been successfully established in vitro regeration system through tissue culture,such as T .fournieri Linden,T .balllonii Susie Wong and T .con-color Lindl.,etc.While,tissue culture for T .Biniflora has never been reported.The maln objective of this research was to establish in vitro regeneration system of T .Biniflora through tissue culture and study the effects of plant growth substances such as IBA,6-BA and NAA for clonal multiplication.In this study,we created a reliable protocol for regenerating T .biniflora plants in tissue culture by using leaf explants.The effects of different concentrations and combinations of plant growth substances on adventitious bud induction and growth were studied,and the effects of different ionic strengths of media and concentrations of IBA on rooting were analyzed.According to a series of indi-ces,such as average number of buds,frequency of bud induction,frequency of rooting,average number of root and av-erage length of root,the optimal media for inducing adventitious buds and rooting were screened respectively.The re-sults showed that adventitious bud induction was related with the concentrations and combinations of plant growth regulator,and the optimal medium for buds induction was MS+6-BA 0.5 mg•L-1 +NAA 0.2 mg•L-1 .The best medium for rooting was 1/2MS as basal medium with IBA 0.05 mg•L-1 .In this study the in vitro plant reproductive system of T .biniflora with high frequence was completely established,and it would provide an important experiment foundation for the research of rapid propagation and genetic transformation for T .biniflora .