Insights into the dwarfing mechanism of pear(Pyrus betulaefolia) based on anatomical and structural analysis using X-ray scanning  

作　　者：Lili Dong Chuxuan Yang Jing Wang Jingjing Li Mei Zhao Dingli Li Zhiyun Qiu Chunhui Ma Zhenhua Cui 

机构地区：[1]College of Horticulture,Qingdao Agricultural University,Qingdao,Shandong 266109,China [2]College of Landscape and Forestry,Qingdao Agricultural University,Qingdao,Shandong 266109,China

出　　处：《Horticultural Plant Journal》2024年第2期355-366,共12页园艺学报（英文版）

基　　金：supported by grants from the Agriculture Science and Technology of Shandong Province (Grant No.2019YQ015);the Agricultural Variety Improvement Project of Shandong Province (Grant No.2022LZGC011);the earmarked fund for CARS (Grant No.CARS-28-07)。

摘　　要：The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the present study, the rootstock of the dwarf-type pear (Pyrus betulaefolia)PY-9’ was identified and used as the material for anatomical analysis.PY-9’ grew to half the tree height of the normal cultivar Zhengdu’, along with fewer internodes and shorter length. Significant differences in growth rate betweenPY-9’ andZhengdu’ were detected at approximately 30 days after full bloom, which corresponded with the time of the greatest difference in water potential between the dwarf and normal cultivar.PY-9’ showed a higher photosynthetic rate thanZhengdu’. Anatomical analysis showed thatPY-9’ had higher area ratios of both phloem and xylem and more developed vascular tissues thanZhengdu’. The three-dimensional reconstructed skeleton of the xylem from X-ray computed tomography scanning revealed greater intervessel connectivity inZhengdu’ than inPY-9’, which could contribute to the more vigorous growth ofZhengdu’. This study thus provides the first comparison of the microstructural properties of xylem elements between a dwarfing-type and vigorous-type pear rootstock, providing new insights into the dwarfing mechanism in pear and facilitating breeding of dwarf pear rootstocks to increase crop productivity.

关 键 词：Pyrus betulaefolia Anatomical analysis Dwarfing mechanism Intervessel connectivity ROOTSTOCK 

分 类 号：S661.2[农业科学—果树学]