Image and visual analyses of G-banding patterns of camomile chromosomes

Karyotypes of three cultivars of Matricaria chamomilla L. were studied using the developed G-like banding technique. The G-banding patterns of chromosomes were reproducible and chromosome-specific. Visual analysis allowed us to reveal from 5 to 10 G-positive bands and/or blocks of adjacent bands on individual chromosomes. In accordance with the G-banding patterns and morphology of chromosomes, all 9 homologous pairs were identified. The G-banding patterns of chromosomes in karyotypes of different Matricaria chamomilla L. cultivars were similar, thus indicating their species-specific character. The description of G-banding patterns of camomile chromosomes was given in accordance with the revealed G-band polymorphism, and the ideogram of M(ch) genome chromosomes was created. Image analysis of G-banding patterns of camomile chromosomes revealed up to 18 G-positive bands per chromosome with different staining intensity. As a result, the quantitative M(ch) genome ideogram reflecting structural peculiarities of chromosomes (band size, position, and staining intensity) was constructed. Comparison of the results of visual and image analyses of G-banding patterns of camomile chromosomes showed that they complemented each other. The first approach allowed us to determine the main peculiarities of G-banding patterns and the second one - to study the quantitative and qualitative characteristics of the G-banded chromosome structure. Our results demonstrate the prospects of the G-like banding technique together with the image chromosome analysis in studying small-chromosome plant species.