Unveiling the metaxenia effect and its regulatory mechanism in sucrose synthesis through integration of dominant resources in pear.

Breeding efforts have led to numerous superior pear varieties. However, challenges persist in pear cultivation, with limited cultivar diversity and underutilization of local varieties, resulting in an unbalanced industry. Metaxenia offers potential for breeding excellent pear varieties suitable for different ecological conditions. Yet, the precise effects and mechanisms of metaxenia on pear fruit remain unclear. This study examined six pear varieties through artificial pollination with four primary pear varieties ('Cuiguan', 'Chuxialǜ', 'Huangjin', and 'Yuguan'). Eight fruit quality indicators, such as sugar content and sugar-acid ratio, were assessed, and results showed that the choice of pollinating variety significantly affected pear fruit quality. Pollen from 'Huixi' and 'Jinhuazao' resulted in superior fruit quality in 'Cuiguan' pears. Similarly, 'Jinhuazao' and 'Xiyuanbai' outperformed the control group in pollinating 'Chuxialǜ'. Additionally, 'Xiyuanbai' and 'Xipi' improved 'Huangjin' pear quality post-pollination. Cross-pollinating 'Yuguan' with pollen from 'Huixi', 'Xipi', and 'Xiyuanbai' produced hybrid fruits of superior quality. The study also explored metaxenia's impact on sugar metabolism in 'Cuiguan' pears, revealing significant effects on sugar accumulation processes. Further analysis highlighted the regulatory roles of specific genes in sucrose accumulation and degradation within fruits. These findings provide insights into metaxenia's effects on pear fruit appearance, quality, and sucrose content variations, shedding light on underlying mechanisms. The study also offers valuable information for selecting pollinating trees and identifying desirable traits in pear crossbreeding efforts.