千年桐嫁接愈合过程解剖结构与内源激素的变化

Changes of Anatomic Structure and Endogenous Hormones in Graft Healing of Vernicia montana

为探索千年桐(Vernicia montana)嫁接愈合机理,以千年桐嫁接口茎段为试材,采用硬组织切片法,观察嫁接愈合进程中的组织结构;采用酶联免疫吸附法测定结合部形成层及韧皮部相关内源激素含量。结果表明,嫁接后第5天,接口处出现隔离层;嫁接后第7天,愈伤组织形成;嫁接后第11天,形成愈伤组织桥;嫁接后第17天,形成形成层;嫁接后第25天,形成层向内分生出木质部。IAA含量在嫁接后第13、17、25、34和43天处于峰值,在嫁接后第17天最高;ABA含量在嫁接后第11、25、34和43天处于峰值;GA3含量在嫁接后第11、17、22、34和46天处于峰值;ZR含量在嫁接后第9、13、25和43天处于峰值。IAA、ABA、GA3和ZR的含量在嫁接后第7、19、28和37天处于谷值,IAA、ABA和GA3的含量均在嫁接后第28天的值最低。愈合过程历经隔离层期(第1~5天)、愈伤组织分化形成期(第5~9天)、愈伤组织连接期(第9~17天)、形成层分化连接期(第17~25天)和维管组织分化连接期(第25~34天)。嫁接后前9天是决定嫁接体能否形成的关键期,前34天是嫁接苗成活的重要时期。

Stems for grafting of Vernicia montana were used as test materials.Tissue structure in graft healing was used to observe by hard tissue section method and contents of endogenous hormones in cambium and phloem of graft junction were determined by enzyme-linked immunosorbent assay(ELISA)in order to explore mechanism of graft healing of V.montana.Results showed that isolation layer appeared at the interface on the 5th day after grafting;callus were formed on the 7th day after grafting;a callus bridge was formed on the 11th day after grafting;cambium was formed on the 17th day after grafting;cambium produced xylem on the 25th day after grafting.IAA content peaked on the 13th,17th,25th,34th and 43th day after grafting,and was the highest on the 17th day after grafting.ABA content peaked on the 11th,25th,34th and 43th day after grafting.GA3 content peaked on the 11th,17th,22th,34th and 46th day after grafting.ZR content peaked on the 9th,13th,25th and 43th after grafting.Contents of IAA,ABA,GA3 and ZR were in the vally value on the 7th,19th,28th and 37th day after grafting,while contents of IAA,ABA and GA3 were the lowest on the 28th day after grafting.The healing process included stage of isolation layer formation(the 1st-5th day),stage of callus differentiation formation(the 5th-9th day),stage of callus connection(the 9th-17th day),stage of cambium differentiation and connection(the 17th-25th day)and stage of vascular tissue differentiation and connection(the 25th-34th day).The first 9 days after grafting is a critical period for grafting formation,while the first 34 days is an important period for the survival of grafting seedlings.