从156个随机引物中筛选出30个引物，对来自国内外的31个烤烟品种进行了遗传多样性和亲缘关系的RAPD分析。在检测的246个位点中，127个位点为多态位点（52%）。聚类分析表明，不同烤烟品种之司存在明显差异，31个品种基本上可分为4大类，品种最多的第一大类（19个）主要由来自美国的Orinoco烤烟选育而成，反映了我国现在推广的烤烟品种遗传基础比较狭窄。研究结果表明，RAPD技术可用于烤烟品种的鉴别和纯度测定。研究为烤烟杂种育种中亲本的选配提供了一定的理论依据。

对葱属根茎组Allium sect. Rhiziridium的8种21个地方居群的核型进行研究，以期为解决该组的种间亲缘关系和物种进化机制提供依据。贺兰韭A. eduardii和阿拉善韭A. flavovirens 2个种的核型以及辉韭A. strictum的六倍体核型均属首次报道。研究结果表明：贺兰韭A. eduardii、阿拉善韭A. flavovirens、北韭A. lineare、蒙古韭A. mongolicum和滩地韭A. oreoprasum的各居群均为二倍体，核型类型为Stebbins的2A型；韭A. tuberosum和野韭A. ramosum的各个居群均为四倍体，核型类型为2A型；辉韭A. strictum的4个居群均为六倍体，核型类型为2B型。通过研究可以得出如下推论：（1）该组植物中存在着大量的多倍体或多倍体系列，染色体数目变化与物种进化具有密切相关性，多倍化可能是根茎组植物核型进化的重要机制之一；（2）随体染色体多为st或t染色体，均位于短臂末端；（3）可以认为辉韭是以增加倍性来克服该物种扩大新的生存空间所带来的困难；（4）现今栽培的韭可能是由野生的二倍体韭和四倍体韭经过长期人工驯化而来的，现今栽培的三倍体韭可能是二倍体韭和四倍体韭杂交而来，并且以无性繁殖方式保存三倍体类群的存在。

对国产大戟科Euphorbiaceae大戟属Euphorbia的13种15个地方居群的核型进行研究，以期为解决该属的种间亲缘关系和物种进化机制提供依据。结果如下：地锦E-humifusa （望江居群），2n=2x=22=20m（2SAT）+2sm；地锦E-humifusa （红旗村居群），2n=2x=22=18m+4sm；千根草E-thymifolia，2n=4x=40=40m；斑地锦E-maculata，2n=4x=40=36m+4sm；银边翠E-marginata，2n=8x=56=40m+ 8sm+8st；铁海棠E-milii，2n=4x=40=32m+8sm；金刚纂E-neriifolia，2n=6x=60=6m+36sm+12st+6t；火殃勒E-antiquorum，2n=6x=60=24m+24sm+12st；一品红E-pulcherrima，2n=4x=28=24m（3SAT）+4sm；猩猩草E-cyathophora，2n=4x=28=16m+12sm；齿裂大戟E-dentata，2n=4x=28=28m；续随子E-lathyris，2n=2x=20=12m+8sm；泽漆E-helioscopia，2n=6x=42=36m+6sm；乳浆大戟E-esula （陈家沟居群），2n=2x=20=14m+6sm；乳浆大戟E-esula （樱桃沟居群），2n=4x=40=32m+8sm。千根草和斑地锦两个种的核型以及乳浆大戟的四倍体居群核型均为首次报道。

Hengduan Mountains are the diversity center for the genus Bupleurum of Apiaceae in China. This paper reports chromosome numbers of six species and two varieties of Bupleurum, and for four species and two varieties their chromosome numbers are reported for the first time. The phylogeny of Bupleurum was investigated based on the ITS region of the nuclear ribosomal DNA (nrDNA) of 14 taxa from the Hengduan Mountains, 3 taxa from the North China (Hebei and Heilongjiang), and 16 taxa from Africa and the Mediterranean region. Variations in chromosome numbers and the ITS sequences were used to infer phylogenetic relationships between Bupleurum species in Hengduan Mountains. The results showed that the Hengduan Mountains might represent one of the frequency and diversity centers for Bupleurum. The ancestors of Bupleurum species in the Hengduan Mountains may be related to the woody B. fruticosum in North Africa, or the species in the western Mediterranean region. It is postulated that the ancestral population migrated into Hengduan Mountains through the Middle East and the Caucasus. Furthermore, the neo-endemic B. mundtii in South Africa appeared to be a close relative of the species in the Hengduan Mountains. In the trend of basic chromosome number evolution, x=8 should be regarded as the ancestral basic number, while x= 6, 7 as the derived ones. The Bupleurum species in the Hengduan Mountains have been undergoing changes in the basic chromosome numbers or the ploidy level. The ITS phylogenetic tree showed that the Chinese species were divided into two clades: one with the basic chromosome number x = 8, and the other with x=6, 7. The results rejected the previous infrageneric classification of Bupleurum in China. We further suggested to raise B. marginatum var. stenophyllum to species rank based on the combined evidence from morphology, karyology, pollen morphology, and the ITS phylogenetic tree.

Separate and combined analyses of nuclear ribosomal DNA internal transcribed spacer (ITS) and cpDNA rps16 provided phylogenetic hypotheses and molecular data for the taxonomy of Chinese Bupleurum species. The phylogenetic results derived from Bayesian and maximum parsimony analyses supported the monophyly of the Bupleurum with strong evidence. The origin of Chinese Bupleurum is likely to be through the Middle East and the Caucasus from the Mediterranean region with the basic chromosome number (8→7→6), and polyploidization. Our molecular data are not consistent with other earlier Chinese Bupleurum classifications and are consistent with the molecular classification proposed by Neves and Watson. The analyses also provide molecular data to elucidate the taxonomic treatments for Bupleurum falcatum from China and Europe.