温度、pH对马铃薯多酚氧化酶活性的影响

对加工型马铃薯试管苗、茎段愈伤组织、块茎及块茎芽在不同温度、不同 pH条件下PPO活性的检测结果表明 :pH对马铃薯PPO活性具有明显的影响 ,块茎芽以及愈伤组织PPO活性均在 pH 5～ 5 5之间最高 ,分别为 94 2 0及 2 0 4 0 (0 0 1ΔOD/min) ,而试管苗在培养基 pH为 8时PPO活性最高 (19 80 (0 0 1ΔOD/min) )。不同温度下不同品种PPO活性表现不同 ,甘农薯 1号、Atlantic试管苗PPO活性在 18～ 2 5℃之间达到高峰 ,分别为 16 80和 37 2 0 (0 0 1ΔOD/min) ;Shep ody、Snowden试管苗在 5℃下PPO活性较高 ;除此之外 ,不同品种贮藏块茎PPO活性均在 2 5℃表现最高。

THE EFFECTS OF TEMPERATURE AND PH ON THE POLYPHENOL OXIDASE ACTIVITY OF POTATOES

The plants in vitro, calluses, tubers and buds on tuber of processing potatoes were used to test the polyphenol oxidase (PPO) activity. The PPO activities of tuber, tuber bud and callus were highest at pH 5 to 5.5, but the PPO activity of plants in vitro was not high until the pH was 8. The PPO activities varied with different varieties. The PPO activities in the plants in vitro from cvs Gannong No.1 and Atlantic were highest (16.80 0.01ΔOD/min and 37.20 0.01ΔOD/min, respectively) when the temperature was 18 to 25 ℃ ; whereas the PPO activities in plants in vitro from cvs Shepody and Snowden were higher at 5 ℃.The PPO activities in all of the tubers tested were highest at 25 ℃.