ARS | Publication request: Genomic In Situ Hybridization (GISH) as a Tool to Identify Chromosomes of Parental Species in Sunflower Interspecific Hybrids

Submitted to: Meeting Proceedings
Publication Type: Proceedings/Symposium
Publication Acceptance Date: March 12, 2009
Publication Date: March 13, 2009
Reprint URL: http://www.sunflowernsa.com/research/research-workshop/documents/Liu_GISH_09.pdf
Citation: Liu, Z., Feng, J., Jan, C. 2009. Genomic In Situ Hybridization (GISH) as a Tool to Identify Chromosomes of Parental Species in Sunflower Interspecific Hybrids. Proceedings 31st Sunflower Research Workshop, National Sunflower Association, January 13-14, 2009, Fargo, ND. Available: http://www.sunflowernsa.com/research/research-workshop/documents/Liu_GISH_09.pdf

Interpretive Summary: The Helianthus genus is comprised of annual and perennial species. Interspecific hybrids have contributed to the improvement of agronomic traits and oil quality of sunflower. Genomic in situ hybridization (GISH) can detect alien chromosomes or segments in the interspecific or intergeneric hybrids, translocation breakpoints, chromosome pairing activity, and the genome composition of polyploidy plants. This technique has been applied in many crops since its establishment for crops including rye, wheat, barley, beet, rice, potato, tomato, brassica, and cotton. Due to the close relationship between cultivated sunflower and wild Helianthus species, an acceptable GISH technique specific to sunflower is lacking. The objective of the present study was to develop a GISH procedure for identifying the chromosomes or chromosome segments of wild species in the background of cultivated sunflower and to characterize the genome composition of interspecific hybrids.

Technical Abstract: Interspecific hybridization has been widely used to transfer genes from wild species into cultivated sunflower. Fluorescent genomic in situ hybridization (GISH) has been used to identify alien chromosomes or segments in other crops, but an equivalent technique for sunflower is lacking. The objective of this study was to develop a GISH procedure for identifying chromosomes or chromosome segments of wild species in the background of cultivated sunflower. Interspecific hybrids and backcross progenies involving four wild perennial species, H. californicus, H. angustifolius, H. nuttallii and H. maximiliani, were examined. With different blocking/probe ratios and washing stringencies, chromosomes or segments of the four wild species were clearly identified. Our results demonstrated that the GISH procedure is a practical tool for identification of alien chromosomes or chromosome segments during the process of interspecific gene transfer.