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Karyotype analysis of the Calligonum mongolicum complex (Polygonaceae) from Northwest China

Shi, Wei, Pan, Borong
Caryologia 2015 v.68 no.2 pp. 125-131
Calligonum, chromosome number, chromosomes, karyotyping, metaphase, mitosis, monoploidy, satellites, China
This study focused on the karyotype characters, mitotic metaphase chromosomes, monoploid idiograms and karyograms of the Calligonum mongolicum Turcz. (Polygonaceae) complex which includes Calligonum chinense A. Los., Calligonum gobicum A. Los., Calligonum pumilum A. Los., and Calligonum zaidamense A. Los., which were investigated for the first time. Analysis of somatic metaphases showed that the chromosome numbers and the formulae of the taxa were 2 n = 2 x = 18 = 8m + 10sm and 2 n = 3 x = 27 = 8m + 8sm + 2st for C. mongolicum in Qingtongxia, Ninxia Erlianhot, Inner Mongolia; 2 n = 2 x = 18 = 8m + 8sm + 2st for C. mongolicum in Erjina, Inner Mongolia;, 2 n = 2 x = 18 = 6m + 12sm for C. mongolicum in Yumen, Gansu; 2 n = 2 x = 18 = 8m + 8sm + 2st for C. chinense in Zhangye, Gansu; 2 n = 2 x = 18 = 6m + 12sm for C. gobicum in Ejina, Inner Mongolia; 2 n = 2 x = 18 = 4m + 14sm for C. pumilum in Hami, Xinjiang; and 2 n = 2 x = 18 = 10m + 8sm for C. zaidamense in Zhangye, Gansu. No satellites were observed in the karyotypes of these taxa. Karyotype asymmetry was estimated by Stebbins classification, karyotype asymmetry index (As.K %), total form per cent (TF %), Rec and Syi indices, intrachromosomal asymmetry index (A1) and interchromosomal asymmetry index (A2), dispersion index (DI), degree of asymmetry of karyotype (A index), asymmetry index (AI), coefficient of variation of centromeric index (CV CI), mean centromeric asymmetry (M CA), and coefficient of variation of chromosome length (CV CL).