The materials used were kindly provided by Dr. C. DASKALOFF of the Institute for Crop and Plant Introduction, Sofia, Bulgaria ; Dr. H. OOHATA Of the Central Agricultural Experiment Station, Konosu, Japan ; Dr. S. RAJKI of the Agricultural Research Institute, Hungary ; and Dr. E. SANCHEZ-MONGE of INIA, Spain. We wish to express deepest appreciation to all of them.
(Received August 15, 1974)