Abstract
To clarify the snow endurance in winter annual forage crops through carbohydrate metabolism, nonstructral carbohydrate (NSC) storage of several species and varieties was investigated in relations to their snow endurance in the present experiment. Twenty-one varieties of oats, barley and rye were used. Concentration and compositon of NSC before the beginning and just after the thawing of snow, and the degrees of damage by snow mold diseases were measured. Results are sumarized as follows. 1) Among the three species, concentration of NSC (NSC%) was the highest in rye, the intermediate in barley and the lowest in oats. The storing capacity of NSC was considered to be higher in the order of oats<barley<rye. 2) NSC% significantly differed among the varieties in each species. The differences was very large in rye, for instance, the NSC% of the highest variety was more than two-fold of that of the lowest one. But the differences were less in barley and very small in oats. Regarding maturity, NSC% of the medium and late maturing varieties were higher than that of the early maturing ones. 3) NSC of the species and varieties were considered to be mainly consisted of low molecular fructosans and lesser amount of sucrose. 4) The species and varieties higher in NSC% before beginning of snow cover were lower in the degrees of snow damage and higher in the NSC% just after the thawing of snow. 5) The storing capacity of NSC seemed to be controlled by genetical factors. The strains having high NSC may be avilable through plant breeding efforts.
