摘要
【目的】通过对核桃芽接愈合过程的组织学观察,研究不同嫁接时期砧穗在愈伤组织形成、增殖和输导组织连接过程中的组织学变化机制,旨在为核桃和其他木本植物嫁接提供理论指导。【方法】以12年生核桃品种‘香玲’半木质化新梢中部芽片为接穗,2年生本地核桃实生苗为砧木,采用方块芽接法分别于砧木萌芽后40~47天和100~107天2个时间进行芽接试验,采用本课题组建立的非均质化材料切片方法对芽接愈合过程进行组织学观察。【结果】核桃萌芽后40~47天的砧穗愈合方式与前人报道一致,即形成层细胞在嫁接体愈合过程中起主导作用,愈合过程中主要组织学变化包括:隔离层的产生(3天)→砧穗形成层细胞分化产生愈伤组织(4天)→愈伤组织连接(6天)→砧穗原有形成层的修复与连接(12天),完成愈合需要12~15天,成活率达95.6%。而在萌芽后100~107天的砧穗愈合过程中,发现了与上述常规愈合不同的嫁接愈合新方式。此过程中木射线细胞起主导作用,愈合过程依次历经隔离层的产生(3天)→木射线细胞分化产生愈伤组织(4天)→砧穗愈伤组织连接(9天)→导管分化形成(15天)→新的形成层产生以及木射线的连接(25天),需要25~30天才能完成愈合,成活率为61.7%;在木射线细胞主导的砧穗愈合过程中砧木一侧的隔离层要先于接穗发生溶解,在砧穗愈伤组织完成连接时消失,而接穗表面隔离层在愈伤组织分化时依然存在,直至新的形成层产生后才完全溶解消失。【结论】核桃芽接过程中,除了常见的由形成层细胞主导的砧穗愈合方式外,还存在由木射线细胞主导的砧穗木质部的愈合新方式,木射线细胞脱分化产生愈伤组织,并进一步分化出导管、形成层和木射线等组织完成最终的砧穗连接;在此过程中愈伤组织主要来自于砧木木射线细胞且砧木隔离层要先于接穗发生溶解。
【Objective】 The mechanism of histological changes between rootstock and scion during callus formation,proliferation and connection of transfusion tissue at different grafting periods was studied through histological observation of the healing process of walnut(Juglans regia) bud grafting,in order to provide theoretical guidance for the practice of grafting walnut and other woody plants.【Method】 The buds of 12-year-old semi-lignified new shoots of J.regia ‘Xiangling’ were used as scions and 2-year-old walnut seedlings were used as rootstocks,bud grafting experiments were carried out on 40-47 days and 100-107 days after bud germination respectively by square bud grafting.Histological observation of healing process was carried out with the method of heterogeneous tissue of woody plants section established by our research group.【Result】 The mode of healing between rootstock and scion 40-47 days after bud germination of walnut was consistent with previous reports.The cambium cells played a dominant role and the main histological changes during healing included:isolation layer formation (3 days)→cambium cell differentiation to produce callus (4 days)→callus connection (6 days)→original cambium repair and connection between scion and rootstock (12 days).It took 12-15 days to complete the healing,and the survival rate of grafting was 95.6%;In the process of healing 100-107 days after bud germination,a new way of grafting healing was found different from the conventional healing.The xylem ray cells played a leading role in this process,and the healing process went through isolation layer generation (3 days)→xylem ray cell differentiation to produce callus (4 days)→callus connection (9 days)→vessel differentiation (15 days)→new cambium formation and connection of xylem rays between scion and rootstock (25 days),it took 25-30 days to complete the healing process,and the survival rate of grafting was 61.7%;During the healing process,the isolation layer on the side of rootstock dissolves before the scion and disappears when the callus was connected,while the isolation layer on the surface of scion still existed when the callus was differentiated,until the new cambium was formed.【Conclusion】 Besides the common mode of healing dominated by cambium cells,there was a new mode of healing dominated by xylem ray cells in the healing process of bud grafting in walnut,xylem ray cells dedifferentiated to produce callus,and further differentiated into vessel,cambium and xylem ray to complete the final connection.During this process,the callus mainly came from the xylem ray cells of the rootstock,and the isolation layer of the rootstock dissolved before the scion.
作者
周乃富
宋晓波
张俊佩
常英英
裴东
Zhou Naifu;Song Xiaobo;Zhang Junpei;Chang Yingying;Pei Dong(State Key Laboratory of Tree Genetics and Breeding,Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration,Research Institute of Forestry,Chinese Academy of Forestry,Beijing 100091)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2019年第6期37-43,共7页
Scientia Silvae Sinicae
基金
中国林业科学研究院基本科研业务费专项“核桃提质增效关键技术研究”(CAFYBB2017ZA004-2)
国家自然科学基金项目“核桃复幼提高生根能力的多基因作用机制解析”(31672126)
关键词
核桃
芽接
木射线
愈合方式
组织学机制
Juglans regia
bud grafting
xylem ray
healing mode
histological mechanism