Characterization and genetic differences analysis in adventitious roots development of 38 Populus germplasm resources

Area of Science:

• Plant genetics and genomics
• Molecular biology
• Forestry and horticulture

Background:

• Adventitious roots development (ARD) is crucial for vegetative propagation in poplar clones.
• Understanding the genetic mechanisms underlying ARD is essential for improving poplar breeding.
• Previous studies have not fully elucidated the genomic and transcriptomic basis of ARD variation.

Purpose of the Study:

• To select poplar clones exhibiting excellent adventitious roots development (ARD).
• To investigate the genomic and transcriptomic differences between poplar clones with high and low ARD.
• To identify key genes and molecular pathways involved in poplar ARD.

Main Methods:

• Comprehensive evaluation of 38 poplar germplasm resources for ARD traits.
• Genomic analysis including cross-population composite likelihood ratio (XP-CLR) and variation detection (SNPs, Indels).
• Transcriptomic analysis using weighted gene co-expression network analysis (WGCNA).

Main Results:

• Clustering identified excellent ARD in specific clones (e.g., P.×canadensis 'Guariento').
• Genomic analysis revealed significant positive selection regions and variations associated with ARD.
• Eight putative genes, including CSD1, WRKY6, and SWEET17, were identified as potentially important for ARD, with SWEET17 showing a specific mutation in poor ARD clones.

Conclusions:

• This study successfully identified elite poplar clones for ARD and provided a molecular basis for their development.
• The identified genes and genetic variations offer valuable targets for marker-assisted selection in poplar breeding programs.
• Findings contribute to a deeper understanding of ARD mechanisms, facilitating genetic improvement of poplar for enhanced propagation.