不同生长势梨种质矮化预选指标的比较研究

目的]为育种选择、选配亲本及性状的早期鉴定提供理论依据。方法]以S2×山梨（乔化）、S2×山梨（矮化）、S2、山梨、极矮化种质为材料，从叶片气孔密度、枝皮率、叶片厚度、栅栏组织厚度、栅海比、导管密度等指标来判断各种质的矮化性状。结果]5种梨种质中生长势强的山梨枝皮率、叶片厚度、栅栏组织厚度及栅海比最小，而气孔密度和导管密度最大。生长势弱的梨极矮化种质枝皮率、叶片厚度、栅栏组织厚度、栅海比最大，而气孔密度和导管密度最小。各种质在气孔密度、枝皮率、叶片厚度、栅栏组织厚度、栅海比、导管密度之间存在差异。结论]气孔密度、枝皮率、叶片厚度、栅栏组织厚度、栅海比以及导管密度可作为梨树体生长势早期鉴定的指标。

Comparative Study on the Dwarfing Preselected Indices of Pear Germplasm with Different Growth Potential

Objective] The aim was to provide a theoretical basis for breeding selection, matching parents and the identification of traits during early period. Method] With S2×Shanli (Pyrus ussuriensis Maxim) (vigorous), S2×Shanli (dwarfing), S2, Shanli, super-dwarfing germplasm as the materials, the dwarfing traits of each germplasm were identified by indices including leaf stomata density, branch-cortex ratio, leaf thickness, palisade tissue thickness, palsade-spongy ratio and vessel density. Result] Among five kinds of pear germplasms, Shanli with strong growth potential had the smallest branch-cortex ratio, leaf thickness, palisade tissue thickness and palisade-spongy ratio, but the largest stomata density and vessel density. On the contrary, super-dwarfing germplasm with weak growth potential had the largest branch-cortex ratio, leaf thickness, palisade tissue thickness and palisade-spongy ratio, but the smallest stomata density and vessel density. There was a difference in stomata density, branch-cortex ratio, leaf thickness, palisade tissue thickness, palisade-spongy ratio and vessel density for every germplasm. Conclusion] Stomata density, branch-cortex ratio, leaf thickness, palisade tissue thickness, palisade-spongy ratio and vessel density can be used as indices of identification for pear growth potential in early period.