Crested wheatgrass chromosome macrostructure and cross-genome homoeology relative to wheat

Said M., Danilova T., Hřibová E., Friebe B., Gill B. S., Vrána J., Doležel J.
Plant Biotechnology Green for good IV 19-22 June Olomouc Czech Republic : , 2017

Keywords: Agropyron cristatum, single gene fluorescence in situ hybridization, FISH, homoeologous relationships
Abstract: Agropyron cristatum L. (2n=2x=14, PP) commonly known as crested wheatgrass is a wild relative of wheat and an attractive source of novel genes for its improvement. As alien gene transfer by interspecific hybridization is affected by chromosome colinearity, it is important to establish the syntenic relationships between the chromosomes of the donor alien species and wheat. To date, identification of all chromosomes of A. cristatum is not possible and its molecular karyotype has not been developed. With the aim to identify chromosomes of A. cristatum by FISH, its genomic DNA was sequenced and several tandem repeats were discovered. Their location on mitotic chromosomes by FISH revealed specific distribution pattern for six of them. The use of one tandem repeat together with 45S rDNA as probes for FISH enabled identification of all seven chromosomes of A. cristatum. In order to analyze the structure and homoeology of A. cristatum chromosomes, 45 FLcDNA from the seven chromosome groups of wheat were localized by FISH on chromosomes of crested wheatgrass cv. Parkway. Important structural rearrangements were observed for chromosomes 2P, 4P, 6P and 7P, while, no major rearrangements were detected for the remaining three chromosomes. The results of this work provide new insights into the genome evolution within the tribe Triticeae and will facilitate the use of crested wheatgrass in alien introgression breeding of bread wheat.
IEB authors: Mahmoud Said, Jaroslav Doležel, Eva Hřibová, Jan Vrána