The use of flow cytometry to characterize nuclear genome of Agropyron cristatum, a wild relative of wheat

Said M., Vrána J., Karafiátová M., Čížková J., Cabrera A., Kopecký D., Bartoš J., Doležel J.
XXXV CONFERENZA NAZIONALE DI CITOMETRIA 3-6 October Paestum (Salerno) Italy : , 2017

Klíčová slova:
Abstrakt: Crested wheat grass (Agropyron cristatum) is a wild relative of wheat which exhibits large genetic variation and offers a pool of alleles and genes for wheat improvement. The species comprises a complex of diploid (2n=2x=14, PP), tetraploid (2n=4x=28, PPPP) and hexaploid (2n=6x=42, PPPPPP) forms. In the first part of this work, we characterized 80 accessions from different parts of the world. Flow cytometric analysis classified 26 accessions as diploid, 51 accessions as tetraploid and 3 accessions as hexaploid. These results were confirmed by chromosome counting. Mean nuclear 2C DNA content of diploid plants was estimated as 12.83 pg DNA (1C genome size = 6.27 Gbp). Some diploid genotypes exhibited slightly higher DNA content, and were identified as B-chromosome carriers. With the aim to facilitate genome mapping and sequencing, we explored a possibility of developing flow cytogenetics for the species. Flow karyotypes obtained after the analysis of DAPI-stained suspensions of mitotic metaphase chromosomes of diploid A. cristatum consisted of three peaks representing seven chromosomes of the species and the chromosomes could only be sorted in groups of 2 or 3. However, chromosomes 1P - 6P could be sorted individually from wheat-A. cristatum addition lines at purities ranging from 81 to 98 %. B chromosomes could be easily discriminated and sorted at purities higher than 95%. These results provide an attractive opportunity to investigate the structure and evolution of the P genome of A. cristatum and to develop molecular tools to facilitate the exploitation of this wild species and support alien introgression breeding of bread wheat. This work has been supported by the Grant Agency of the Czech Republic (award 315160-2015).
Autoři z ÚEB: Mahmoud Said, Jan Bartoš, Jana Čížková, Jaroslav Doležel, Miroslava Karafiá..., David Kopecky, Jan Vrána