InDel Markers for Identifying Interspecific Hybrid Offspring of Apple and Pear.

Area of Science:

• Plant genetics
• Molecular biology
• Agricultural science

Background:

• Distant hybridization in Rosaceae, like apple (Malus domestica) and pear (Pyrus communis), introduces novel traits but poses identification challenges due to maternal inheritance.
• Early-stage visual identification of distant hybrids is difficult, hindering breeding programs.

Purpose of the Study:

• To develop effective molecular markers for identifying distant apple and pear hybrid offspring.
• To address the longstanding challenge of distinguishing hybrid progeny from parental lines.

Main Methods:

• Whole-genome resequencing of apple 'Golden Delicious' and pear 'Yan Zhuang', and their 62 hybrid offspring.
• Genomic variation analysis to identify apple-specific InDel markers with high polymorphism.
• Selection and validation of 51 effective InDel markers for hybrid identification.

Main Results:

• Significant genetic diversity was found between apple and pear.
• 51 effective InDel markers were identified, reliably identifying distant hybrids.
• Four markers (InDel1-7, InDel2-3, InDel3-1, InDel4-3) achieved 100% identification in the primary population.
• Markers showed high transferability and identification efficiency across different hybrid populations.

Conclusions:

• An efficient molecular marker system based on InDel variation was developed for identifying apple and pear distant hybrids.
• This system provides a valuable tool for accelerating the breeding of new Rosaceae fruit tree varieties.