ARS | Publication request: PROGRESS IN PRODUCING SCAB-RESISTANT GERMPLASM OF DURUM WHEAT

Submitted to: International Wheat Scab Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 1, 2000
Publication Date: September 15, 2000
Citation: Jauhar, P.P., Peterson, T.S. 2000. Progress in producing scab-resistant germplasm of durum wheat. International Wheat Scab Symposium Proceedings, Nanjing, China, p. 77-81.

Interpretive Summary: Scab or Fusarium head blight (FHB) is a serious fungal disease that causes huge losses in grain yield and quality in the wheat growing regions of the world. By crossing durum wheat cultivar Lloyd with a wheatgrass and after several cycles of backcrossing and selfing, we produced several hybrid derivatives. We report scab screening data on 88 plants in an advanced hybrid generation. Although there was variation from plant to plant, some hybrid derivatives showed as little as 7% infection. Twenty plants (23%) had only 7% infection and 22 plants (25%) fell in the 7% to 15% infection category. Thus, 53% of the total hybrid derivatives had 15% or less infection. Using a sophisticated technique, fluorescent in situ hybridization (FISH), we demonstrated the presence of the wild grass chromosomes (rod-like structures that carry genes for various traits) or chromosome segments in the scab-resistant hybrid derivatives.

Technical Abstract: Tetraploid wheatgrass (Thinopyrum junceiforme) is an excellent source of resistance to scab or Fusarium head blight. We have produced several hybrid derivatives by crossing durum wheat (Triticum turgidum) cv Lloyd with the wheatgrass, followed by several cycles of backcrossing and selfing. We report here scab screening data on an advanced hybrid generation (BC1F4) along with preliminary cytological studies. Although there was variation from plant to plant, some hybrid derivatives showed as little as 7% infection. Twenty (23%) of the 88 plants screened had 7% infection and 22 plants (25%) fell in the 7% to 15% infection category. Thus, 53% of the total hybrid derivatives had 15% or less infection. Fluorescent in situ hybridization on meiotic chromosomes showed the presence of alien chromosomes or chromosome segments in the scab-resistant hybrid derivatives.