Study On The Genetic Diversity Of Xinjiang Garlics And Their Wild Relatives

Allium plants are important germplasm resources of vegetables, medicinal, ornamental and forage.About69kinds of wild Allium plants in xinjiang, which have certain resistance to cold, drought, barren,diseases and insect pests, and provide valuable genetic material to stress tolerance breeding of cultivatedonion, garlic, leek. In this study, Xinjiang garlics and its wild relatives were used as the research materials.Under the condition of introduction, the phenological biological characteristics of wild species were studied.And the genetic diversity of Xinjiang garlics and its wild relatives were studied based on the karyotype,Giemsa C-banding characteristics and ISSR molecular markers. The main results were as follows:In early march, the wild relatives’s underground bud unearthed, being into the nutrition growth period,completed the reproductive growth as temperatures rising, and went into dormancy just before summer heatarrived. There was no secondary growth in the same year, and formed drought and cold escaping year lifecycle. And the year life cycle is60to106days. A. spp (Qitai)’s, A. spp (Hong)’s and A. spp (Hongqi)’s lifecycle were shorter. The life cycle of A. roborowskianum and A. spp (Yuan) were longer.The flowering amplitude reached to the highest on5to11days of flowering phase, and floweringnumbers presented the trend of increasing or decreasing before or after the highest flowering. The maincharacteristics were6tepals,6stamens, and1pistil, and on the ventral suture of ovary base, had shadehoney hole or not. All single flowers bloom process can be divided into9stages as tepals cracking, insideanther powdering, inside anthers completely powdering, outside anther powdering, anthers completelypowdered, tepals eversioned completely, filaments completely wilting, tepals wilted completely and stylarcompletely wilting. The single flower blooming time ranged from5to15days.Karyotypes of Xinjiang garlics and its wild relatives were analyzed by squash method. Ice and waterwas the best preprocessing method. A. fetisowii had karyotype differentiation, and has2types as2n=2x and2n=3x. The rest of the materials were diploid. The chromosomes base of A. fetisowii and A. spp (Yuan)were x=10, the others were all x=8. All materials had m and sm chromosome, A. fetisowii, A. spp (Yuan)ans garlics also had st chromosomes, garlic from Zhongmu had1M chromosome. The karyotype of A. fetisowii and A. spp (Yuan) were2B, and the others were all2A. Intermediary satellite appeared on theshort arm of m and sm chromosomes in garlics, which had a certain relationship with cultivation seasonand ecological environments of garlic. Satellite appeared on the end of short arm of A. robustum and A.roborowskianum (RQ). And it also appeared on the end of long arm in A. spp (Hong). Chromosomestructure and composition were interspecific different and presented diversity characteristics.HBSG method was the optimal Giemsa C-banding studying method. The number of bands,incomplete bands and content of heterochromatin of garlics and its wild relatives were different. And theheterochromatin content were mainly concentrated in Loci P and Loci C. Garlics and its wild relatives hadhyperchromatic T band, I band and C band, and their number and location were different. The wild relativeshad P band except A. spp (Hongqi). A. robustum and A. roborowskianum (RQ) had S and N band on theshort arm. A. spp (Hongqi) had N band on the long arm. A. fetisowii and A. spp (Yuan) had differentnumbers of D bands. Garlics from Zhongmu garlic and Jimusaer contains all types of bands. Garlics fromZhaosu had no D banding, and had no N bands from Aheqi. There was range difference in geneticstructures of Xinjiang garlics and wild relatives, and there were more or less introgress.Genetic diversity of garlics and wild relatives were analyzed by using ISSR molecular markers.Improved SDS method is more suitable for DNA extraction. By combination of orthogonal experimentdesign and single factor screening method, the best ISSR-PCR reaction system was15μL, including: DNA75ng, dNTP0.3mmol/L, Taq DNA polymerase0.09U/L and primer0.5μmol/L.18ISSR primers wereselected from34primers, amplified254loci totally,244loci were polymorphic, and polymorphism ratewas96.06%. Nei’s gene diversity index was0.1849~0.4697, with a mean of0.3873. Nei’s genetic identitywas0.4606~0.9094. Nei’s genetic distance was0.0949~0.7752. Shannon information index was0.2815~0.6617, with a mean of0.5642. The polymorphism information content (PIC) was0.1511~0.3583,with a mean of0.3047. Based on DICE coefficient method, the genetic similarity coefficient was0.45~0.91,Xinjiang garlics and its wild relatives were gathered into4groups,11groups by UPGMA clustering.