Study On Establishment Of Regeneration System And Karyotype Analysis Of Artemisia Selengensis

Artemisia selengensis.,a perennial herbaceous plant of the Asteraceae.Presl family,is native to Asia and is now distributed throughout China,as well as in Mongolia,North Korea,and Russia.This plant has high medicinal value.This study explored the establishment of a regeneration system and karyotype analysis of 10 Artemisia selengensis germplasm resources distributed within and outside of Hubei Province from the perspective of cell biology.The study classified these 10 germplasm resources at the cellular level and discussed their genetic diversity,providing preliminary cell biology data and reference for the evolutionary trend,hybrid breeding,and systematic classification of Artemisia selengensis.The main results of this study are as follows:(1)Multi-factorial 3-level experiments were conducted using orthogonal experimental method to explore the most suitable system for regeneration and tissue culture of Artemisia selengensis.The best disinfection effect was obtained with 75 % ethanol treatment for 40 seconds followed by 0.1 % mercuric chloride treatment for 8 minutes.The optimal hormone combination for inducing callus tissue was MS + 0.5 mg/L 6-BA + 1.0 mg/L 2,4-D,the optimal hormone rationing scheme for value-added guava tissue induction was a combination of 1.0mg/L 6-BA + 0.1 mg/L NAA and the optimal hormone combination for inducing root formation was MS + 1.0 mg/L IAA + 0.6 mg/L NAA.The best hormone combination for inducing adventitious shoots from callus tissue was MS + 4.0 mg/L 6-BA + 1.0 mg/L IAA.(2)The changes in the karyotype at the chromosomal level were compared among Artemisia selengensis germplasm resources distributed in different geographic locations.All10 germplasm resources were with a chromosome number of 2x=36,and exhibited genetic stability.The chromosomes of these 10 Artemisia selengensis germplasm resources were mainly composed of metacentric chromosomes(m)and submetacentric chromosomes(Sm),except for ’Xiangsha Yihao’ and ’Qichun Artemisia selengensis’,which also had submedian chromosomes(M).(3)The karyotype types of the 10 Artemisia selengensis germplasm resources were divided into four types: 1A,2A,1B,and 2B.Based on their karyotype parameters,the germplasm resources were classified into four categories.The first category was ’Baishazhou2’,the second category was ’Baishazhou 5’ and ’Baishazhou 7’,the third category was’ Baishazhou 8’ and ’Caidian Artemisia selengensis’,and the fourth category was ’Xiangli Yihao’,’Xiangsha Yihao’,’Nanjing Artemisia selengensis’,’Suqian Artemisia selengensis’,and ’Qichun Artemisia selengensis’.From another perspective,’Baishazhou 2’ could also be clustered with’Qichun Artemisia selengensis’ into one category,and the other eight germplasm resources could be clustered into the same category.The genetic distances between ’Baishazhou 5’ and’Baishazhou 7’,’Baishazhou 8’ and ’Caidian Artemisia selengensis’,’Xiangsha Yihao’ and’Nanjing Artemisia selengensis’,and ’Suqian Artemisia selengensis’ and ’Qichun Artemisia selengensis’ were relatively close,indicating that the genetic distances between these germplasm are relatively close.The genetic distances of the first two pairs of germplasms correspond to their geographical distances,while the latter two pairs do not match their geographical distribution very well.After discussion and analysis,it may be related to their own genetic variation and external environmental influences.