Karyotype Anaylsis And Ploidy Study On Three Species Of Genus Viola

14accessions belong to three species of genus Viola from United States, Germany, Netherlandsand China were taken as the experimental materials in this paper. The morphology of them wereinvestigated and their somatic cell chromosomes were studied by chromosome tabletting, and the ploidywas detected by flow cytometer. The main results were as follows:1. A simple and efficient method was developed to study somatic cell chromosomes of the genusViola, that is, Collecting flourish leaves from7:30to10:30AM in clear days，then pretreating leaves with0.002mol/L8-quinolinol solution for4h, fixing them in freshly Carnoy’s fixed liquid for12~24h，hydrolyzing in the1mol/L HCl at60℃for6~8min; after that, staining chromosome with carbol fuchsin，examinating under microscopic.2.Chromosomes separated and matched by AI Applied Imaging CytoVision showed thechromosome number and ploidy of Viola×wittrockiana Gams. were complicated, the chromosomenumber varied from39to52. Two accessions (‘SRF-Y’、‘XXL-YB’) had the basic number of chromosomex=11, they were both tetraploid; two accessions (‘229.02’、‘PXP-BT’) had the basic number ofchromosome x=12, they were both tetraploid; three accessions had the basic number of chromosome x=13,‘M-BF’、‘229.05’ were triploid diploid,‘M-YC’was diploid; two accessions had the basic number ofchromosome x=24:‘SRA-R’、‘M-YB’ were diploid. The nuclear asymmetric coefficients varied from58.68%to71.82%, the ratio between the longest chromosome and the shortest was1.95~3.47, the variationof the average arm ratios varied from1.49to2.54. The karyotype of ‘SRF-Y’、‘XXL-YB’、‘229.02’、‘229.05’、‘M-YB’ belonged to2B; the karyotype of ‘M-YC’、‘M-YB’ belonged to1A; the karyotype of‘SRA-R’ belonged to3B.3. The chromosome number and ploidy of all the Viola cornuta accessions were consistent(2n=2x=26). The ratio between the longest chromosome and the shortest was2-4, average arm ratio variedfrom1.39to1.96, and the variation of nuclear asymmetric coefficients varied from58.27%to65.78%. Thekaryotype of ‘08H’ belong to1B, the karyotype of ‘E-01’、‘J-P’、‘J-B’ belong to2B. 4. The chromosome number of Viola yedoensis was48, tetraploid, the ratio of the longestchromosome and the shortest was1.82. The average arm ratio was1.38, and the variation of nuclearasymmetric coefficients was58.07%, The karyotype formula was2n=4x=48=48m, the karyotype belong to1B.5.In many pollen mother cells of Viola×wittrockiana Gams., the chromosomal behavior duringmeiosis were normal, but few abnormal as chromosome bridges appearing during meiosis, the conclusionwas that there were homologous chromosomes matched and isolated behaviors were abnormal in somepollen mother cells.6. The flow cytometry instrument was used to detect the ploidies of genus Viola, the Violacornuta accessions was used as the control. The ploidy detection results of four Viola cornuta accessions byflow cytometry instrument were in consistent with the observed results by chromosome tabletting method,they were all diploid; but the ploidy detection results of Viola×wittrockiana Gams. and Viola yedoensiswas inconsistent with the observed results by chromosome tabletting. The flow cytometry to detect theploidy of different accessions in Viola genus should be explored.