苹果施用PP333后分配控长及GA缓解效应研究

DISTRIBUTION OF PP333 IN YOUNG APPLE TREES, ITS INHIBITION EFFECT AND INHIBITION-RELIEVING WITH GA_3

利用３Ｈ－ＰＰ３３３示踪法研究了土施ＰＰ３３３在辽伏苹果幼树体内的分配规律。结果表明，ＰＰ３３３由木质部运输，在韧皮部积累，并向叶片扩散，以短梢中含量最高，长梢叶片中由基向上含量渐多，而中梢叶由基向上渐少，网状吸收根含量少于豆芽状延伸根。上施ＰＰ３３３发挥抑制作用，自施入时起约需１个月，而喷施仅需１周，两者结合抑制效应最佳。当ＰＰ３３３施用过量时，于花后２周喷施１００～３００ＰＰｍＧＡ３，可有效地解除ＰＰ３３３的抑制作用，新梢生长量和叶面积增大，蛋白质合成增强，气孔阻力变小，蒸腾强度变大，微量元素的叶含量发生变化，对果实品质无不良影响。经综合性状比较，以２００ＰＰｍＧＡ。喷施效果较佳。

H--PP333 was used to' trace distribution of soil--applied PP333 in young apple trees (cv. Liaofu). The results showed that PP333 transported through xylem and accumulated in phloem, then distributed to leaves, in leaves on long shoots increased from base to tip of the shoot and in leaves on mid--long shoots decreased in the same manner, and there was more amount in netted roots than in absorbing roots. PP333 brought into play about one month after soil application and one week after foliage spray. The inhibition effect of excessive PP333 on apple trees was relieved by spraying 100--300 ppm GA3 2 weeks after blooming.GA3 increased shoot growth and leaf area, promoted protein synthesis, lowered stomatal resistance and strengthened transpiration. The treatment brought into change of contents of mineral elements in leaves but did not harm fruit quality. Considering the comprehensive effect, it was better to give GA3 at 200 ppm by foliage spray.