苹果不同植株类型和不同势力枝条碳素同化物分配习性研究

以盆栽4年生苹果和大树4年生枝组为处理单位,分三个时期标记不同的植株类型和枝类。通过测定碳素同化物的分配动向,了解分配习性。结果表明:壮树分配到多年生枝和根系的碳素同化物,周年稳定,呈逐期增加的趋势。各期都有明显的两极分配。相对比强,叶>枝,上位枝叶>下位枝叶,短枝叶>长枝叶,近距根>远距根,细根>母根>粗根;而弱树和多果树分配到多年生枝和地下部根的同化物,周年被动大,并且少而不稳;壮长枝的碳素同化物在向外输出上比弱长枝常年多而稳,是与地下根营养交换的主要来源;短枝前期(新梢旺长期)养分输出的多,后两期输出的较少,主要供木枝的花芽分化和后期的进一步充实。

STUDIES ON THE DISTRIBUTIONS OF CARBONASSIMILATES IN THE DIFFERENT PARTS OF APPLE TREES

Four-year-old apple trees planted in pots and four-year-old branches of mature apple trees which had different growth patterns were used to study the distribution of carbon-assimilates during three growth periods. The results showed that the carbonassimilates in vigorous plants were steadily distributed to the branches and roots during a year and the amount of assimilates distributed to the branches and roots during a year and the amount of assimilate distributed increased as the season progressed. The polarization of transportation (downward and upward)of carbon-assimilates was observed during all the periods.The distribution sequences calculated in relative specific intensity were as following: within a plant, leaves>stems,upper shoots lower shoots, leaves on short-shoots>ones on long-shoots, adaxial roots abaxial roots, fine roots>main roots>thick roots. The carbon-assimilates in weak or fruitful plants were fluctuately distributed to the branches and roots during a year and the amount was less and more unsteady than in vigour plants.The strong long-shoots were the main organs for exchanging food materials with the roots, and their export rate of the carbon-assimilates was higher and more steady than that of weak-short-shoots.The export rate by the short-shoots was higher periods the vigorous growth period and then decreased in the last two in while a large number of the assimilates remained in the labelled short-shoots to promote the flower bud differentiation and development.