【摘要】 研究了苹果砧木矮化性的评价指标,为苹果矮化砧木预选提供有效的筛选参数。利用石蜡切片法分析叶片的解剖结构,分光光度计法测定多酚氧化酶(PPO)活性、过氧化物酶(POD)活性和总酚含量,酶联免疫吸附测定法(ELISA)测定苹果砧木的内源激素水平,采用欧式聚类法综合评价与砧木矮化相关的各项指标。结果表明:生长势不同的苹果砧木在新梢生长量、叶片栅海比、POD酶活性、PPO酶活性、总酚含量和内源IAA和ABA激素水平在P<0.05差异显著。矮化砧木的新梢年均生长量((19.51±2.03)cm)、春季叶片总酚含量((9.23±0.29)mg/g)及韧皮部PPO酶活性、秋梢韧皮部的IAA含量((22.72±7.62)mg/g)和IAA/ABA的比值(0.18±0.05)均显著低于半矮化砧木和乔化砧木,随砧木矮化性增强而减小;而叶片栅/海比(1.15±0.12)、春季叶片POD酶活性、秋梢韧皮部ABA含量((118.21±13.85)mg/g)均显著高于半矮化砧木和乔化砧木,随砧木矮化性增强而升高。对各指标聚类分析表明:任何单一指标均不能有效地评价砧木的矮化性;苹果矮化砧木预选过程中,以"叶片的栅/海比>1"和"秋梢韧皮部的IAA/ABA值<1"双参数可以有效筛选矮化性强的砧木,再辅以"新梢生长量"和"叶片POD酶活性"指标,可以提高预选的准确性。更多还原

【Abstract】 The goal of this study was to evaluate parameters related to the dwarfing ability in apple rootstocks and to provide some effective parameters for pre-selection of apple dwarfing rootstocks.Paraffin-wax cut-section was used to analyze the anatomical structure of leaves.PPO/POD activity and total phenol content were determined spectrophotometrically.The level of endogenous hormones was measured with ELISA and Hierarchical Clustering Method was used to evaluate these parameters.The result showed that the length of annual shoots,ratio of palisade/spongy of leaves,POD activity and content of endogenous IAA and ABA were significantly different at level P<0.05 among tested rootstocks.The mean length of annual shoots of dwarfing rootstocks((19.51±2.03)cm)was markedly shorter than that of semi-dwarfing rootstocks and of the vigorous rootstock;the same tendency was noted in parameters such as total phenol content of leaves((9.23 ± 0.29) mg/g),PPO activity of phloem in spring,endo-IAA level((22.72 ± 7.62) mg/g)and ratio of IAA to ABA(0.18 ± 0.05),while the ratio of palisade/spongy of leaves from dwarfing rootstocks(1.15± 0.12)was markedly larger than that from semi-dwarfing and vigorous rootstock.The activity of POD in young leaves,content of ABA in phloem((118.21±13.85) mg/g) from dwarfing rootstocks in fall were markedly larger than those of and semi-dwarfing and vigorous rootstocks.From the Hierarchical Clustering Method′,none of the above of palisade to spongy leaves′ and the ratio of IAA to ABA of phloem′ was useful in distinguishing dwarfing rootstocks from parameters could evaluate the dwarfing ability of apple rootstocks.A combination of two parameters: the ratio standard stocks.Therefore,the ratio of palisade to spongy of leaves more than 1 and the ratio of IAA to ABA of phloem less than 1 are combined to exclude the putative standard candidates at first,and adding another parameters will ensure the early selection of dwarfing rootstocks successfully.更多还原