苹果砧木枝条主要输导组织解剖特征与矮化性的关系

Correlation between anatomy feature of main conducting tissue in branch of apple rootstock and dwarfing capacity

[目的]研究苹果砧木枝条主要输导组织解剖特征与矮化性的关系,探讨苹果砧木致矮关键部位.[方法]以不同矮化性的M系苹果砧木植株为试材,以MM106为对照,采用常规石蜡切片法,研究苹果砧木1年生枝各组织尤其是主要输导组织解剖特征与矮化性的关系.[结果]对于苹果砧木1年生枝横截面上不同部位的木质部,导管密度大小顺序均表现为近髓部>中部>近皮部,导管面积均表现为近皮部与中部差异不显著,但二者显著大于近髓部;M系苹果矮化砧木1年生枝的周皮厚度、皮层厚度、髓部半径、筛管面积均小于或显著小于对照,而导管平均密度、木质部厚度/枝条半径、近皮部导管面积/筛管面积、中部导管面积/筛管面积、近髓部导管面积/筛管面积、导管平均面积/筛管面积均大于或显著大于对照.[结论]对于苹果砧木1年生枝的木质部,从近皮部到近髓部,离髓部越近,导管密度越大、面积越小;M系矮化砧木1年生枝木质部发达,韧皮部生长较弱,M系苹果矮化砧木的致矮关键部位可能是韧皮部.

【Objective】This study investigated the correlation of anatomy feature of main conducting issues in apple rootstock and dwarfing capacity for exploring key dwarf position and revealing dwarf mechanism.【Method】Apple dwarf rootstock plants of M series were studied to investigate the correlation of anatomy feature of tissues especially the main conducting tissue of 1-year branch by conventional paraffin section methods.MM106 was used as the control.【Result】The vessel density for xylem of different positions at the cross section of 1-year branch in apple rootstock was in the order of position near phloem>middle position>position near pith.For vessel area,there was no significant difference between position near pith and middle position,but they were significantly bigger than position near phloem.Periderm thickness,cortex thickness,pith radius,and sieve tube area of dwarfing rootstock were smaller or significantly smaller than that of the control,while average vessel density,xylem thickness/branch radius,vessel area near phloem/sieve tube area,central vessel area/sieve tube area,vessel area near pith/sieve tube area,and average vessel area/sieve tube area of dwarfing rootstock were higher or significantly higher than that of the control.【Conclusion】Vessel near pith had larger vessel density and smaller area than that near phloem for xylem of 1-year branch in apple rootstock.Xylem of 1-year branch in dwarfing rootstock was vigorous,while phloem was weak.Thus,the key dwarfing position of M series apple dwarf rootstock was maybe phloem.