Rapid and Nondestructive Method for Detecting Composition Changes in Wheat Germplasm Accessions
- Kar-ling J. Tao ,
- Pietro Perrino and
- Pierluigi L. Spagnoletti Zeuli
Gene banks around the world have had difficulty detecting changes in the genetic composition of germplasm accessions after seed storage and regeneration. The large number of accessions requires a rapid and easy test. This study was conducted to develop such a test for wheat (Triticum spp.) accessions. A phenol test modified by soaking seeds in 40 °C water for 30 rain and then exposing them to 130 mM phenol solution vapor on a wire screen can differentiate among genetic types by staining in up to five colors: dark brown, brown, light brown, fawn, and ivory. The test is nondestructive. Phenol test results from gene-bank accessions indicate that there was no significant change in the population composition after regeneration in homogeneous accessions such as bread wheat (T. aestivum L.) cultivars Sprint Aquileja, and Adria, and durum cultivars (T. turgidum L., durum group) Appulo, Capeiti, and Creso. Several heterogeneous durum wheat accessions showed significant changes, however. In the Italian durum wheat accession MG 8001, the dark brown phenol-stained seeds increased from 11% to 95% after eight regeneration cycles. Gliadin polyacrylamide gel electrophoresis and root tip chromosome counting, conducted on the same seed, indicated that the dark-brown phenol-stained seeds were bread wheat instead of durum wheat. Thus, the modified phenol test could be a useful test for gene banks to detect changes in the composition of heterogeneous germplasm accessions after regeneration and storag.
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