离体培养下白杜木质部的形态发生研究

白杜(Euonymus bungeanus Maxim.)的离体木质部经过组织培养,成功地诱导出小植株,诱导率为8%。诱导过程经过3个阶段:1.诱导愈伤组织形成,以 H 培养基效果最好,但需附加不同浓度的2,4-D、NAA 或 BA。2.分化阶段,诱导小植株的形成,以 H 或 MS BA2mg/1 KT0.5—1mg/1 NAA0.2mg/1分化培养基为宜。3.小植株的成长,以 White NAA0.1mg/1 IAA0.1mg/1培养基最适。愈伤组织主要起源于木射线细胞。在愈伤组织中可以产生连续的或不连续的、呈带状排列的分生组织,其中有些分生组织最后可形成象茎中的形成层那样连成一圈,但它们不能产生正常的维管组织,只能向一侧分化出木质部的管状分子,而不能向另一侧分化出韧皮部的筛状分子。另外,在愈伤组织中还出现了一些鸟巢状管胞团。不定根发生在愈伤组织深处,为内起源;不定芽起源于愈伤组织表面,为外起源。

STUDIES ON THE MORPHOGENESIS OF THE XYLEM OF EUONYMUS BUNGEANUS CULTURED IN VITRO

The isolated xylem of Euonymus bungeonus Maxim.has been successfully induced into plantlets for the first time under culture in vitro.The percentage of plantlet formation was about 8%.The process of cultivation was able to be devided into three stages:I.To induce the formation of callus,for which the medium H showed the best effect,but it was necessary to supply with the different concentration of 2,4-D,NAA or BA.2.The differentiation of the callus into plantlets,for which the medium H or MS BA 2mg/l KT 0.5-1.0 mg/l NAA. 0.2mg/l was most promising and 3.The growth of plantlets,for which the medium White(?) NAA 0.1mg/l IAA 0.1/1 was most suitable.Further observations based on the histology showed that callus was produced from the ray cells.Meristematic tissue appeared as a discontinuo(?)s and more or less regularly arranged bands.Later,some of them were arranged in a cirle like in the normal stem.However,the newly formed meristematic tissu(?) did not produce nor- mal vascular tissues.They could only differentiate into tracheid-like (?)lements on one side and no sieve-like elements differentiatedon the opposite side.In addition,there might be ap- peared nest-like tracheid mass in groups.The adventitious buds and roots derived from the excised xylem which followed the normal process of ontogenesis i.e.the buds were from exo- genous origin and the roots,endogenous origin.