董俊娜 王之欣 于旭东 吴繁花 付影 罗佳佳 蔡泽坪 张涵

摘  要：木本植物维管组织发育对木材形成意义重大。本研究利用石蜡切片法和光学显微技术，研究菠萝蜜（Artocarpus heterophyllus）叶绿素缺失突变体（chlorophyll deficient mutant，CDM）幼苗不同部位的维管组织结构，观察及测量导管分子、筛管分子的孔径和密度等，分析了维管组织和形成层的特点。结果表明，CDM幼苗的根、茎、叶柄和叶主脉维管组织中的木质部和韧皮部的结构均发生改变。与正常苗相比，CDM幼苗中次生木质部导管分子和韧皮部筛管分子的孔径和面积减小，密度增大;根和茎维管组织中形成层厚度减小，层数减少;CDM茎中的维管组织相比于根显示出更强的抑制作用。本研究为进一步探索木本植物维管组织发育提供了新材料。

关键词：菠萝蜜;叶绿素缺失突变体;幼苗;维管组织

中图分类号：S667.8      文献标识码：A

Vascular Tissue Structure Analysis of Chlorophyll Deficient Mutant Seedlings from Artocarpus heterophyllus

DONG Junna1， WANG Zhixin1， YU Xudong1， WU Fanhua2， FU Ying1， LUO Jiajia3， CAI Zeping1*， ZHANG Han1

1. College of Forestry， Hainan University / Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants， Ministry of Education， Haikou， Hainan 570228， China; 2. School of Life and Pharmaceutical Sciences， Hainan University， Haikou， Hainan 570228， China; 3. Tropical Crops Genetic Resources Institute， Chinese Academy of Tropical Agricultural Sciences，  Haikou， Hainan 571101， China

Abstract： The development of the vascular tissue in woody plants is of great significance to wood formation. In this paper， the method of paraffin section and optical microscopy were used to study the vascular tissue structure of different parts of chlorophyll deficient mutant （CDM） from Artocarpus heterophyllus. The pore size and density of vessel elements and sieve tube elements were observed and measured， and the characteristics of vascular tissue and cambium were analyzed. The result showed that the structure of the xylem and phloem in the vascular tissue of CDM seedlings roots， stems， petioles and leaf main vein were changed. Compared with the normal seedlings， the pore size and area of the secondary xylem vessel elements and phloem sieve vessel elements decreased and the density of those increased in CDM seedlings. The thickness of cambium decreased and the number of layers decreased in the vascular tissue of root and stem in CDM. The vascular tissue in the stems of CDM showed stronger inhibition compared with that in the roots. This study would provide new materials for further exploring vascular tissue development of woody plants.

Keywords： Artocarpus heterophyllus; chlorophyll deficient mutant; seedling; vascular tissue

DOI： 10.3969/j.issn.1000-2561.2021.07.018

葉绿素是植物光合作用的核心色素[1]。叶绿素缺失突变体（chlorophyll deficient mutant，CDM）植株无法正常进行光合作用[2]。CDM对揭示植物叶绿素合成与降解途径以及研究光合作用机制有重要意义。目前CDM的研究主要在草本植物中开展[3-7]，在木本植物中的研究较少，如橡木（Quercus petraea）[8]和茶树（Camellia sinensis）[9]等。

维管组织的出现极大地提高了植物体运输水分、矿质元素以及有机物的效率，同时木本植物维管组织发育对木材形成意义重大，一直是科学家们关注的焦点[10]。其发育经历了原分生组织、初生分生组织、初生维管组织以及次生维管组织四个阶段[11]。木质部和韧皮部是维管组织中的重要组成部分，导管分子和筛管分子在植株营养物质的运输上具有重要的意义。……