棉花体细胞胚发生过程的组织胞学观察棉花体细胞胚发生过程的组织细胞学观察棉花体细胞胚发生过程的组织细胞学观察棉花体细胞胚发生过程的组织细胞学观察.doc

棉花体细胞胚发生过程的组织细胞学观察 曹景林, 张献龙*, 杨细燕, 邓锋林，谭家福，郝娟 (华中农业大学作物遗传改良国家重点实验室，武汉 430070) 摘 要：以陆地棉品种Coker 201下胚轴为外植体诱导愈伤组织，并以介于30-50目筛之间的胚性愈伤细胞团为材料进行单个细胞团培养，采用石蜡切片法观察棉花愈伤组织诱导和分化过程及体细胞胚发生和发育过程。结果显示棉花胚性愈伤组织有下胚轴两端发生、内发生、非胚性细胞转化、外发生和腺体处发生5种形成途径，其中两端发生和内发生是主要的形成方式；棉花体细胞胚存在单细胞起源，多为表面发生。棉花体细胞胚发育过程中最关键的事件似乎是极性的建立、顶端分生组织的形成以及前形成层的分化和生长轴变化。球形胚时期表皮原层的分化标志着体细胞胚结构分化的开始。初始前形成层的形成是体细胞胚形态转变的第一个信号。球形胚内部等径细胞轴向延长，接着前形成层生长轴发生变化，这些是心形胚或椭圆形体胚中的重要事件。鱼雷形胚基本分生组织中液泡的出现开始了组织分化的过程。对一些停滞发育的球形胚和鱼雷形胚的解剖检查表明，极性建立可能是决定体细胞胚能否萌发的关键因素。 关键词：棉花；体细胞胚胎发生；组织细胞学 基金项目：教育部新世纪人才支持计划(NCET-04-0740) 作者简介：曹景林（1967-），男，博士，遗传育种专业，现在湖北省烟草科研所工作。 *通讯作者（Corresponding author）:张献龙，男，教授，博士生导师。E-mail:xlzhang@mail.hzau.edu.cn Histo-cytological Observation of Somatic Embryogenesis in Cotton (Gossypium hirsutum L.) Cao Jing-lin, Zhang Xian-long, Yang Xi-yan, Deng Feng-lin, Tan Jia-fu, Hao Juan (National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, 430070, Wuhan,Hubei, China) Abstract：Calli were induced from hypocotyl explants of cotton cultivar Coker 201, and individual embryogenic cell clusters with 30–50 mesh sieve, which isolated from embryogenic suspension cultures, were cultured. The development of the calli and single few-celled aggregates was observed through paraffin sections. The results revealed 5 pathways of embryogenic calli origination including origination from both ends of hypocotyls, origination in inner, differentiation from non-embryonic cells, origination from outer cells of calli, and origination in the surrounding of gland. Among these, the origination from both ends of hypocotyls and in inner were the most important pathways. Cotton somatic embryos originated from individual embryogenic cells, which were in exterior of embryogenic calli in most cases. The most critical events appeared to be the establishment of apical-basal patterns of symmetry, formation of apical meristems, and differentiation and axial change of procambium during the d