1. National Agricultural Research Foundation (N.AG.RE.F.); Fodder Crops and Pastures Institute; 413 35 Larissa Greece
2. Dep. of Agronomy; Aristotle Univ. Farm of Thessaloniki; 570 01 Thermi Greece
3. Dep. of Genetics and Plant Breeding; School of Agriculture; Aristotle Univ. of Thessaloniki; 541 24 Thessaloniki Greece