枝梢环剥对荔枝新梢生长和叶片矿质营养的影响

环剥处理中断韧皮部光合产物向下运输及抑制枝梢生长的效应已经明确,但对不同矿质营养运输的影响则有待进一步揭示。研究以妃子笑荔枝为试材,揭示了枝梢环剥处理对新梢生长和叶片矿质营养的影响。结果表明,枝梢环剥处理可强烈抑制枝梢上的新梢发生;环剥17 d后,叶片叶绿素指数明显下降;同时,环剥口上端的叶片不同的矿质营养发生不同的变化。其中对钾和镁影响微弱,而氮、磷、钙、铁、锰、铜、锌等矿质营养含量发生不同程度降低,其中微量元素铁、铜、锰的含量下降较为明显,这表明,中断韧皮部运输也会导致叶片摄取这些矿质元素的减少。

Effects of branch girdling on shoot growth and mineral nutrients in Litchi

It is known that girdling inhibits shoot growth as well as downward translocation of photosynthates via phloem.However,effect of girdling on the translocation of various mineral nutrients is still unclear and awaits further study.In this study,trees of litchi(Litchi chinensis Sonn.) cv.Feizixiao were used to examine the effects of branch girdling on shoot growth and mineral nutrients.The results showed that girdling significantly inhibited the growth of new sprouts.The chloro-phyll index in leaves above the girdle decreased significantly about 17 days after girdling.Girdling treatment caused differen-tial changes in different mineral nutrients.The treatment hardly affected K and Mg levels in the leaves.N,P,Ca,Fe,Mn,Cu and Zn in both young and old leaves were reduced to various extents,and the reduction in Fe,Mn and Cu concentrations was more significant;it is suggested that the uptake of these nutrients by leaves was inhibited by girdling treatment,which breaks the phloem transport pathway.