Advances in Classification and Reproduction Studies of Medicinal Plants Atractylodes

DUAN Yuan-sheng;WANG Mo;Institute of Medicinal Plants , Huazhong Agricultural University;College of Biological and Chemical Engineering,Huanggang Polytechnic;

Atractylodes;;plant classification;;cytology;;reproduction;;meiosis

The medicinal plant Atrac tylodeswhich belongs to the Asteraceae family. These perennial herbal plants are distributed in eastern Asia and are cultivated in many regions of China,fortheir dry atractylodes rhizome is used as medicines.They can be reproduced and cultivated by seeds, division propagation and rhizome.The classifications of Atractylodesplants are based on theirlimited variations in leaves and flowers. All plants studied have 2 n =24,including two pairs of satellited chromosomes except for one pair of the Luotian type from Hubei Province. The satellites of small size occur at low frequency.The chromosomes types(meta-/submeta-/subtelo-centromeric chromosomes) and their numbers varies in different plants.A single locus of 5S r DNA and two loci of 45 S r DNA loci were identified and separated on different chromosomes for the Luotian type.Furthermore,the Luotian type keeps the more symmetric karyotype than all others. Its karyotype differentiation supports its taxonomic uint of subspecies.DNA sequences and molecular markers provide some new clues for the genetic variations and evolution of these plants.During the meiotic divisions of pollen mother cells for the Luotian type,thenormal chromosome pairing and segregation were performed and thus no laggards and micronuclei were formed. The pollen grains with high stainability were produced, which provided the cytological explanations for the high seed-sets and good seed viability of this plant type.The normal meiosis also ensured the stable chromosome number(2n=24) for different types of this plant which reproduced sexually and asexually.