苹果对土施^(10)B的吸收、分配与利用

ABSORPTION,DISTRIBUTION AND UTILIZATION OF SOILAPPLED10B IN APPLE TREES

盆栽辽伏／海棠新梢迅速生长期，土施１０Ｂ肥１个月后，硼肥利用率为７０％。１０Ｂ在根系、多年生枝干及地上部新生器官的分配率依次为：２４４％，４６６％，２９０％；新生器官中，长梢及其叶片对１０Ｂ的竞争能力强，具Ｂｄｆ％值高于其它梢类及叶片。施硼初期，叶片的全硼及Ｂｄｆ％值上升较快，但生长季末期，叶片的全硼含量下降，Ｂｄｆ％值上升缓慢，而枝梢皮部及木质部全硼、Ｂｄｆ％值持续升高，表明１０Ｂ的分配中心随生长季而变化。根部及枝干部积累的硼，对新生器官中硼的供应有调节作用，对根系停止供硼，能加速植株体为积累的硼向新生器官输送。秋季土壤中施浓度为２μｇ·ｇ－１１０Ｂ肥，第３年春季土壤中Ｂｄｆ％值在５％以下，新生器官中Ｂｄｆ％值仍达２０％～３０％，表明植株内贮藏的部分１０Ｂ能继续被新生器官利用。

オ┆?0B utilization rate was 7.0% and 10B distribution rate in roots,trunks and newly emerged organs of pot cultured apple tree(cv.`liao fu'/Malus ptunifolia Borkh.)was 24.4%,46.6% and 29.0%,respectively,in one month after soilapplicatoin of 10B during shoot rapid growth period.As the aerial newly emerged organs were concerned,Bdff% in long shoots and its lesves were higher than that in other shoots and leaves, suggesting that long shoots and its leaves had stronger ability of uptaking 10B.At beginning of boron application,total boron amount and Bdff% in leaves increased fast,but 10B accumulating speed in shoot,particularly in its cortex,was higher than that in leaves in the later growing season, indicating that distribution center changed with growing period.The reserved boron in root and trunk played a mediaive role in boron supply to newly emerged organs,a part of reserved mobile boron could transport to newly emerged organs when roots could not absorb any boron.With soilapplied 10B of 2μg·g-1 in autumn,Bdff% in soil was found less than 5%in the spring of the third year,but Bdff% in newly emerged organs was still 20%～30%,which suggested that a part of reserved 10B could be reused.