陆地棉愈伤组织产生及胚胎发生的细胞学研究

CAT CYTOLOGICAL OBSERVATION ON CALLUS PRODUCTION AND EMBRYOGENESIS OF Gossypium hirsutum L.

对陆地棉5个栽培品种的下胚轴进行了培养、观察。5个品种均获得了生长旺盛且性质不同的两类愈伤组织,第一类愈伤组织呈淡绿色或灰色,疏松易脆可分化产生胚状体;第二类愈伤组织呈白色或绿色,紧密坚实且未能分化成胚状体。经分离培养及细胞学检查表明:第一类愈伤组织来源于皮层细胞;第二类愈伤组织则来自于中柱部分。对胚状体的分化发育过程进行了观察,发现胚状体具有结构完整和独立的维管束系统,其发育的主要过程由原胚到球胚、心形胚和子叶胚,整个发育过程与合子胚相似。

Five Chinese cultivars of GossyPium hirsutum L.were cultured and observed.Two kinds of calli formed in all cultivars when the hypocotyls were cultured on the MS or LS medium supplemened with IAA 2mg/l and KT 1mg/L. One is fragile and light green or grey colored, while the other is hard and white or dark green colored. The former grew rapidly and eventually developed into embryogenic callus and produced embryoids. On the contrary, the latter grew solowly and never formed embryoid at al. The cytological observation and longitudinal section of the explant cultured shows that the former is developed from the cortex tissue, while the latter is from the stele tissue. It is confirmed this result through the cortex tissue and stele tissue were excised from the hypocotyl and cultured seperately. The process of embryogenesis and somatic embryo development, was described which was similar to that of zygotic embryo.