Dormancy and impotency of cocklebur seeds I. CO2, C2H4O2and high temperature

摘要

High O2tensions, CO4, C2H4and high temperatures were effective not only in breaking the dormancy of cocklebur (Xanthium pennsylvanicumWallr.) seeds but also in increasing the germination potential of the nondormant but small seeds. There were few qualitative differences in response to these factors between the dormant and impotent seeds. Unlike CO2, however, enriched O2and C2H4were stimulative even at the low temperature of 13°C.Germination induced by CO2, C2H4and high temperature treatments was lowered when endogenously evolved C2H4or CO2was removed, whereas the effect of O2enrichment was not affected by their removal. CO2and high temperatures remarkably stimulated C2H4production, whereas O2enrichment had no such effect.C2H4productivity was lower in the dormant than non-dormant seeds, suggesting that the after-ripening is characterized by increasing C2H4production