Karyotype and nuclear DNA content of hexa-, octo-, and duodecaploid lines of Bromus subgen. Ceratochloa

Genetics and Molecular Biology

Joanna Klos²  Elwira Sliwinska¹  Adam Kula²  Hieronim Golczyk¹  Aleksandra Grabowska-joachimiak²  Tomasz Ilnicki¹  Krzysztof Szostek¹  Alan Stewart¹  Andrzej J. Joachimiak¹ 

[1] ,University of Agriculture in Kraków Department of Plant Breeding and Seed Science Cracow,Poland

关键词: karyotype;    C-banding;    heterochromatin;    flow cytometry;    genome size;   

DOI  :  10.1590/S1415-47572009005000046

来源: SciELO

【 摘 要 】

The subgenus Ceratochloa of the genus Bromus includes a number of closely related allopolyploid forms or species that present a difficult taxonomic problem. The present work combines data concerning chromosome length, heterochromatin distribution and nuclear genome size of different 6x, 8x and 12x accessions in this subgenus. Special attention is paid to the karyotype structure and genomic constitution of duodecaploid plants recently found in South America. Hexaploid lineages possess six almost indistinguishable genomes and a nuclear DNA content between 12.72 pg and 15.10 pg (mean 1Cx value = 2.32 pg), whereas octoploid lineages contain the same six genomes (AABBCC) plus two that are characterized by longer chromosomes and a greater DNA content (1Cx = 4.47 pg). Two duodecaploid accessions found in South America resemble each other and apparently differ from the North American duodecaploid B. arizonicus as regards chromosome size and nuclear DNA content (40.00 and 40.50 pg vs. 27.59 pg). These observations suggest that the South American duodecaploids represent a separate evolutionary lineage of the B. subgenus Ceratochloa, unrecognized heretofore.

【 授权许可】

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