林木植物组织培养及存在问题的研究进展

从外植体选择及分化途径、影响增殖、生根的主要因素三方面,概述了近年来林木植物组培的研究进展,外植体3种分化途径(腋芽萌发途径、间接器官发生途径、体细胞发生途径)有其相应的最适外植体类型,林木组培首选腋芽萌发途径。培养基和植物生长调节剂是影响增殖的两大因素,对培养基的探索已从对林木植物组培常用培养基的筛选发展到无糖培养基的探索,出现了光自养、开放组培等概念;植物生长调节剂是生根的关键因素,外源激素与内源激素的相互作用对增殖有较大影响。阐述了组培中褐化、玻璃化、污染三大难题的起因和解决措施,对褐化和玻璃化的研究主要集中在外植体的生理状态和培养环境方面,提出无糖组培通过对培养环境进行改善,有望改善褐化、玻璃化问题;传统组培希望从无菌技术层面解决污染难题,这也造成了组培成本偏高的问题,进而对开放组培和无糖组培的探索,通过抑菌剂的添加及糖的剔除有望降低组培对无菌操作的要求。随着组培技术的发展,在抑菌剂加入的条件下,不进行高温高压灭菌,进行开放式的组培;利用植物自生的光合能力,剔除培养基中的蔗糖,同时改变光照条件、培养环境中的CO_2浓度、湿度,以促进外植体光自养微繁殖生长;二者均着眼于降低组培成本,简化组培程序,有望使组培技术得到革新。本文对林木组织培养研究进展进行综述,为今后开展林木植物组织培养技术的研究提供重要参考。

Advances in Tissue Culture Techniques of Trees and the Problems Existed

The advances in forest plant tissue culture in recent years are reviewed from the aspects of explant selection, explant differentiation pathway, and the factors that have effects on proliferation and rooting in the process of tissue culture. There are three differentiation pathways (axillary bud germination, indirect organogenesis and somatic enbryogenesis), in which the axillary bud germination is popularity. It is necessary to choose different kind of explant according to the differentiation pathway. The culture medium and plant growth regulator are the main factors influencing the proliferate. The study on culture medium has shifted from the selection of general medium to culture medium without sucrose, and the concepts of photoautotrophic culture and open tissue culture emerged. Plant growth regulator is the critical factor for rooting. The interaction of endogenous hormone and exogenous hormones has great influence on proliferation. The causes and solutions of vitrification, browning and pollution in tissue culture were explained. Studying on vitrification and browning focused on the physiological state and culture environment of explant. It is suggested that tissue culture without sucrose could less the vitrification and browning by improvement of culture environment. Traditional culture focuses on solving the pollution problem by aseptic technique, resulting in high cost. The new tissue culture could lower the requirement of aseptic technique by adding bacteriostats and taking out sucrose. Open culture without high temperature and pressure sterilization under the adding of bacteriostats. Photoautotrophic culture which making use of the photosynthetic capacity of cultured explants, reducing the concentration of sucrose, and adjusting the light conditions, concentration of CO₂, and moisture is another method for tissue culture. Both focus on reducing cost and simplifying culture procedure.