砧木对伏令夏橙新梢叶片缺锌的生理反应

PHYSIOLOGICAL RESPONSES OF ZINC DEFICIENCY IN THE LEAVES ON NEWLYDEVELOPED SHOOTS OF VALENCIA ORANGE TREES ON DIFFERENT ROOTSTOCKS

在碱性土壤(pH=8.0)上,枳、枳橙、红桔砧伏令夏橙春、夏、秋梢叶中营养元素差异显著,春梢叶无缺锌现象,而夏、秋梢叶含锌量急剧降低.因此,缺素珍断的样本应采秋叶或夏叶,而不宜用春叶。在低磷锌比情况下,磷与锌含量呈正相关.

Analysis of the leaf samples taken from the shoots of 6-year-old Valencia orange(Citrus sinensis Osbeck)trees in an alkaline soil(pH=8)orchard in Jiangan,Sichuanshowed substantial differences in the levels of Zn,Fe,N,P and K among spring,summerand autumn shoots and among trees on trifoliate orange(Poncirus trifoliata Rat.),citrange(P.trifoliata XC.sinensis)and tangerine(C.tangerina Tanaka).Valencia orange trees onthe trifoliatc orange rootstock exhibited Zn deficiency,with the most severe symptom ap-pcaring in autumn cycle leaves.While Zn contents in all spring cycle leaves were within theopti(?) range,they dropped sharply to deficiency levels in summer—and autumn cycle(?) Zn content in autumn cycle leaves,therefore,is recommended to be adopted as a(?)ostic criterion for Zn deficiency.In addition,it was found that P had a positive influ-ence on Zn intake by the tree when the P:Zn ratio was low.