Karyotypes of six populations of Lycoris radiata and discovery of the tetraploid

Chromosomes and karyotypes are important aspects of plant phylogeny and evolution. The chromosome numbers and karyotypes of Lycoris radiata display great variability among and within different populations. By studying different populations of L. radiata we acquired some basic data on karyotype evolution and evolutionary mechanisms in L. radiata and the genus Lycoris. Six populations of L. radiata from Anhui and Zhejiang provinces in China were investigated cytologically. The chromosome numbers and karyotype formulae are as follows: Huoshan populations, 2n=44=28st+8t+8T, 2n=22=6st+12t+4T; Huangshan populations, 2n=22=22t, 2n=22=18st+4t, 2n=21=12st+7t+2T; Chuzhou population, 2n=33=33t; Ma'anshan populations, 2n=33=18st+15T, 2n=25=1m+20st+2t+2T; Xuancheng populations, 2n=22=20st+2T, 2n=21=1m+20st; and Hangzhou populations 2n=22=12st+4t+6T, 2n=21=18st+3t. The chromosome numbers and karyotypes of some populations are reported here for the first time and the wild tetraploid population of L. radiata was found for the first time. In addition, karyotype evolution among populations and the origin of polyploids are discussed.