用“对话”试验探索植物组织培养机制并建立适用性广的小麦组织培养方法

Researching the Mechanism in Plant in vitro Culture via "Communication" Experiment and to Establish the Methods Widely Used for Tissue Culture of Wheat

以小麦为试材,以揭示培养因素与培养结果之间的对应关系为目标,通过用类似“对话”试验的方法探索了基因型、外植体类型、培养基、培养条件等在植物组织培养中的作用和影响。结果表明,基因型不影响愈伤组织的形成,只影响和决定愈伤组织的质量。外植体既影响愈伤组织的形成,又影响愈伤组织的质量。由外植体类型造成的愈伤组织质量差异并不亚于由基因型所造成的差异,但其作用主要表现在离体培养的早期阶段。培养基除了向培养物提供营养外,不同培养基之间的差别更主要地表现为对愈伤组织质量的不同调控效应。一般情况下,2,4-D和NH4+对细胞分裂、愈伤组织生长表现为促进作用;细胞分裂素和NO3-对细胞分裂、愈伤组织生长表现为抑制作用。光照具有类似细胞分裂素的效应。温度变化对愈伤组织质量也具有调控作用。各培养因素的作用实际上均转化为生理生化效应。借助这种认识,所有培养因素的作用均可在生理生化水平得到解释。据此,植物组织培养的可预见性和可控性得到大幅度增强。通过本研究,为小麦组织培养建立了有较广泛适用意义的方法。

Plant in vitro culture has a history of more than one hundred years, but it is still unable to be predicted and inferred. There are 4 kinds of elements for plant in vitro culture： genotype （genetic elements）, explant-type （physiological elements）, medium （chemical elements）, culture-conditions （physical elements）. In order to find out the effects of these elements and the mechanisms in plant in vitro culture, a series of ＂communication＂ experiments aimed at revealing the relationship between culture-elements and culture-results were conducted. Wheat was used as the main materials （Table 1 ）. Callus induction, subculture and callus quality improvement and evaluation were carried out with mature and immature embryos of different varieties on different media （MS, KS, N6, C 17 etc. ） under different conditions （Table 2, 3）. The effects of genotype, explant-type, medium, culture-conditions to plant tissue culture were studied systematically. The results showed that： Genotype only determined the quality but did not limit the induction of callus. Explants affected both the formation of callus and its quality at early stage. The difference of callus quality originated from explants was no less than that from genotypes. Despite of providing nutrients, medium also played a very important role in regulating the quality of callus. Generally, 2,4-D, NH4^＋ usually accelerated cell division and the growth of callus but cytokinin, NO3^- showed opposite effects. Light had the similar effects to cytokinins. Temperature variation played an influential role to callus too. These results were also improved with corn, rice, millet, cotton and so on. All the functions from these elements in in vitro culture can be considered or imagined as the effects at physiological and biochemical levels and they can be managed as coadjutant factors according to the needs of callus quality improvement. With this idea, plant in vitro culture comes to be more controllable. Through this study, a series of methods wildly used for wheat tissue culture was established.