摘要
多倍化(或全基因组加倍)是植物物种形成的重要途径,现存的被子植物可能都发生过一次甚至多次多倍化事件。多倍化传统的定义是染色体数目相对于祖先类群呈整倍性增加。其中最常用的研究方法是核型分析,核型能够提供物种的基本细胞学参数,包括染色体数目、倍性水平、核型不对称性、核型变异系数等。目前核型研究的趋势表现出从物种基本核型参数分析逐渐演化到多类群、多学科交叉融合的特点:一方面植物核型分析从种群、物种、科属的类群到生命之树,探讨染色体核型在各支系的进化特征、趋势以及驱动植物系统进化的细胞学机制;另一方面探讨和分析区域或生态系统植物区系的染色体谱或倍性等细胞学特征,可以探究区域地质环境变化或生态环境对染色体倍性等的影响,或通过区域染色体谱的构建,分析区域植物区系的形成和进化历史。因而,植物核型研究为系统发育、分子系统进化、生命之树以及植物区系地理的起源和演化研究提供了新思路。越来越多的新方法、新手段在植物核型分析与多倍化研究中得到运用,从而揭示了植物类群或植物区系的染色体进化以及细胞地理特征。今后植物细胞学研究趋势会向多学科交叉融合,整合各研究领域证据,从不同水平角度综合分析植物核型多样性形成的原因及意义,从而更加全面地认识和理解植物物种多样化与物种形成原因。
Polyploidy(or whole-genome doubling) is an important pathway for plant speciation, with existing angiosperms possibly occurring once or even multiple times. The traditional definition of polyploidization is that the number of chromosomes doubles relative to the ancestral group. The most commonly used research method for understanding polyploidy is karyotype analysis, which provides basic cytological parameters of the studied species, including chromosome number, ploidy level, karyotypic asymmetry, and karyotype coefficient of variation. At present, karyotype research has evolved from basic parameter analysis of species to multi-group/multi-disciplinary study, with an associated shift from lower taxonomic level (e. g., population, species, or family/genus) to higher taxonomic level research (e. g., tree of life). In addition, the integration of phylogeny and karyotypes will provide insightful evidence on the potential evolutionary characteristics and tendencies of karyotypes, and the cytological mechanism driving the evolution of plant diversity at the phylogenetic scale. Furthermore, exploring cytological features of the chromosome atlas or polyploidy at the regional or floral scale will help elucidate the influence of geo-ecological environmental shifts on chromosome ploidy. Additionally, constructing a regional chromosome atlas will shed light on the formation and evolutionary history of flora. Plant karyotype research provides new ideas for study on the origin and evolution of systematics, molecular phylogeny, tree of life, and floristic geography. As new methods are used in plant karyotype analysis and polyploidy, results on the effects and mechanisms will reveal the chromosomal evolution and cellular geographic features of plant groups and flora. Future trends in plant cytology research will be multi-disciplinary and integrate evidence from various research fields and will clarify the causes and significance of plant karyotype diversity at different levels to more fully understand plant species diversity and
作者
孙文光
孙航
李志敏
Sun Wen-Guang;Sun Hang;Li Zhi-Min(School of Life Science ,Yunnan Normal University ,Kunming 650500,China;Key Laboratory for Plant Diversity and Biogeography of East Asia ,Kunming Institute of Botany ,Chinese Academy of Sciences ,Kunming 650201,China)
出处
《植物科学学报》
CAS
CSCD
北大核心
2019年第2期260-269,共10页
Plant Science Journal
基金
国家自然科学基金项目(31670206)
中国科学院A类战略性先导科技专项(XDA 20050203)~~
关键词
核型
多倍化
染色体
进化
植物多样性
Karyotype
Polyploidy
Chromosome
Evolution
Plant diversity
