Targeted mapping and linkage analysis of morphological isozyme, and RAPD markers in peach

Area of Science:

• Plant genetics and genomics
• Molecular biology
• Horticulture

Background:

• Understanding gene linkage and inheritance is crucial for crop improvement.
• Peach [Prunus persica (L.) Batsch] genetics research requires robust mapping tools.
• Previous studies identified some genetic markers but comprehensive mapping was needed.

Purpose of the Study:

• To analyze linkage relationships between morphological and isozyme loci in peach.
• To identify and characterize new genes for traits such as leaf shape and pollen sterility.
• To develop and apply efficient marker-aided selection strategies for peach breeding.

Main Methods:

• Analysis of nine F2 peach families for linkage mapping.
• Utilized 14 morphological and two isozyme loci.
• Employed Random Amplified Polymorphic DNA (RAPD) markers and bulked segregant analysis.

Main Results:

• Established linkage between weeping (We) and white flower (W) genes (33 cM).
• Identified a new willow-leaf character (Wa2) linked to a dwarf phenotype (Dw3) (0.4 cM).
• Discovered a new pollen sterility gene (Ps2) linked to weeping and white flower traits.
• Constructed a preliminary peach genomic map with 83 RAPD markers assigned to 15 linkage groups.
• Successfully identified RAPD markers flanking red-leaf (Gr) and malate dehydrogenase (Mdh1) loci.

Conclusions:

• The study elucidates new gene linkages and identifies novel genetic variants in peach.
• RAPD markers combined with bulked segregant analysis offer an efficient approach for trait mapping.
• These findings support the potential for marker-aided selection in accelerating peach tree breeding.