摘心及6－苄基腺嘌呤处理对桑叶缺铁性黄化早衰的延缓作用

当生长在石灰性土壤上的桑树新梢行将缺铁性黄化时，进行叶面追施６－苄基腺嘌呤（６－ＢＡ）和摘心处理。处理枝的早衰症状明显延缓，叶形增大，叶色转绿；各叶位的叶绿素、蛋白质及ＳＯＤ、ＣＡＴ、ＰＯＸ含量或活性水平不同程度地增加；膜脂过氧化作用产物ＭＤＡ含量明显降低，起了延缓早衰的作用。延缓作用摘心比６－ＢＡ处理有效。

RETARDATION OF EARLY-SENESCENCE DUE TO IRON DEFICIENCY IN MULBERRY LEAVES BY BENZYLADENINE AND DECAPITATION

When shoot leaves of mulberry which grows in limy-soil were yellowing due toiron deficiency, an application of 6-benzyladenine solution to shoot leaves or decapita-tion of the shoots profoundly retarded symptoms of early-senescence, made the leavesbigger and green after two weeks of these treatments, In addition ,there was an increasein chlorophyll and protein content as well as SOD,CAT and POX activity levels in leaveson different leave position,while the content of the product of membrane lipid peroxida-tion-malondialdehyde(MDA)obviously decreased which is known to retard senescenceas well.It can be concluded ,therefore ,that the two treatments may play an importantrole in retardation of early-senescence due to iron deficiency.Moreover,decapitation wasmore effective than 6-BA.