Extractant Influence on the Relationship between Extractable Proteins and Cold Tolerance of Alfalfa.

The influence of ionic composition and pH of extractant on the relationship between the extracted proteins and the cold tolerance of Vernal and Arizona Common alfalfa (Medicago sativa L.) was examined. Five environments were used to induce different tolerance levels. The quantity of protein extracted from plants was influenced by the hardening environment, cultivar, and ionic composition and pH of 29 extractants. Extractants with a pH below 6 generally extracted less protein.The measured cold tolerance of the plants was correlated with the quantity of protein detected in many of the 14 regions of the electrophoresis gel columns regardless of extractant but was most closely associated with the protein in either region 7 or 8 with nine of ten extractants.The magnitudes of cultivar and hardening effects on quantities of protein detected on various column regions were influenced by choice of extractant. This suggests that proper extractant selection may be vital for study of isozymes by electrophoresis.