ISOZYME VARIATION IN AVENA-STERILIS L COLLECTED IN TURKEY

The National Small Grains (NSG) collection of Avena sterilis L. is an important germplasm resource for cultivated oat (A. sativa L. and A. b yzantina C. Koch) improvement. Complete evaluation and utilization of the almost 7000 accessions will be protracted. In the interim, new acc essions will he acquired. Previous studies showed that Turkish accessi ons of A. sterilis exhibited a broad array of isozyme phenotypes found in the wild collection and in over 400 cultivated accessions. The obj ectives of this research were (i) to determine if recent Turkish acqui sitions of A. sterilis (Forsberg-Simons collections of 1986) have cont ributed additional isozyme variation to that already in storage and (i i) to illustrate relationships among Turkish A. sterilis and cultivate d germplasm. Zymogram phenotypes of 341 A. sterilis and 405 cultivated samples were recorded for 13 enzyme systems. The 115-plant sample fro m the Forsberg-Simons collection included six phenotypes not previousl y observed in Turkish accessions in the NSG collection. Cluster analys is suggested that approximately 40% of the Forsberg-Simons acquisition s differed from much of the existing NSG Turkish accessions. Both loca l and regional diversity occurred within A. sterilis germplasm. Isozym e patterns in cultivated germplasm were most similar to collections of A. sterilis with a wide geographical distribution.