Karyotype analysis of twelve species of Oxalis

Abstract

[ Objective ] This study aims to identify the karyotypic characteristics and genetic relationships of 12 species of Oxalis from a cytologic view , in order to provide a reference for exploring chromosome diver- sity of Oxalis , identifying germplasm resources of Oxalis , and selecting parents for cross-breeding. [ Methods ] The chromosome morphology , number , and karyotype of 12 species of Oxalis plants were ob- served and analyzed by the root-tip compression method. [ Results ] ( 1 ) Chromosome numbers were repor- ted for the first time for 7 species. Of the 5 reported species , O . fabaefolia and O . pes - caprae had chro- mosome numbers consistent with previous reports , while the remaining 3 differed from previous reports , of which 2n=26 was the rarely reported chromosome number in the genus Oxalis . A total of 7 chromo- some bases were found , of which x=13 was rarely reported , and ploidy ranged from 2x to 6x. Actual chromosome sizes ranged from 0.27 μ m to 2.23 μ m. The location of the attachment point was the meta- centric ( m ) and submetacentric ( sm ) chromosomes. There were 4 karyotype types and the karyotype asymmetry coefficients ranged from 56.31% to 65.40%. ( 2 ) O . fabaefolia was the most evolved while O . compressa was the most primitive. ( 3 ) According to the similarity of chromosomal karyotypes , the 12 species of Oxalis can be divided into 4 groups. [ Conclusion ] The 12 species of Oxalis have extensive kary- otypic diversity. Karyotypic classification is not in complete agreement with the morphological classifica- tions of previous reports.

Keywords

• oxalis
• cytology
• karyotype
• chromosome evolution
• relationship