山楂种子休眠与萌发生理研究 Ⅴ.山楂种子POD活性及其同工酶的变化与休眠的关系

对不同采收期及层积前后的山楂种子过氧化物酶（ＰＯＤ）活性及其同工酶的变化进行研究，结果表明：８月２５日以前采收的种子种仁中ＰＯＤ活性随成熟度的提高呈增加的趋势，之后趋平稳；而种皮中ＰＯＤ活性８月２５日前基本平稳，以后迅速下降。随成熟度的提高，种仁中ＰＯＤ同工酶条带数有所增加，而种皮中其条带数不变，只是随成熟度的提高酶带颜色变浅。层积后未裂壳的种子种仁和种皮中ＰＯＤ活性与干藏种子差异不显著，而层积后裂壳的种子种仁和种皮中ＰＯＤ活性均显著高于干藏及层积未裂壳的种子；层积后，在ＰＯＤ同工酶谱中，种仁缺少了原有的２条酶带，但增加了４条新的酶带；种皮保留了原有的酶带，并增加了７条新的酶带。

STUDY ON DORMANCY AND GERMINATION PHYSIOLOGY OF HAWTHORN SEED V.THE RELATION AMONG DORMANCY AND POD ACTIVITY AND ITS ISOZYME IN HAWTHORN SEEDS

The activity of peroxidase(POD)and its isozyme were studied in hawthorn seeds collected at different time and before or after stratification.The results showed that:the activity of POD in seed kernels incrcased as the seeds became more mature before August the 25th while it became stable after August the 25th.The activity of POD in seed coats kept stable befor August the 25th and tended to decrease sharply after August the 25th.As the seeds became more mature, the band number of POD isozyme increased in seed kernels and kept unchangeable in seed coats but became lighter in colour.The activity of POD in both seed kernel and seed coat of the uncracked seeds under stratification did not notably differ from that of the dry stored seeds ,while that of cracked seeds under stratification was notably higher than that of uncracked seeds under stratification and dry storing as well.After stratification,2 original bands of POD isozyme in seed kernels disappeared in the pattern,while 4 new bands presented;the original bands in seed coats were still retained, and 7 new bands presented.