Transcriptome-guided breeding for Paspalum notatum: producing apomictic hybrids with enhanced omega-3 content

Area of Science:

• Plant breeding and genetics
• Nutritional biochemistry
• Animal science

Background:

• A low omega-6:omega-3 fatty acid ratio in milk fat improves human health.
• Forage lipid composition impacts ruminant milk and methane emissions.
• Developing apomictic Paspalum notatum with high alpha-linolenic acid is desirable.

Purpose of the Study:

• To develop Paspalum notatum genotypes with high alpha-linolenic acid (18:3) content.
• To achieve clonal reproduction via seeds (apomixis) in these genotypes.
• To assess the potential for improving livestock product quality and reducing methane emissions.

Main Methods:

• Transcriptome assembly and analysis of Paspalum notatum.
• Identification and expression analysis of lipid metabolism genes (SDP1, PXA1) using qPCR.
• Fatty acid profiling using FAME-GC-MS.
• Hybridization between sexual and apomictic genotypes.

Main Results:

• Reduced expression of SDP1 and PXA1 was observed in a polyploid sexual genotype (Q4188).
• Genotype Q4188 exhibited increased alpha-linolenic acid (18:3) content.
• Two apomictic F1 hybrids (JS9, JS71) were produced with reduced SDP1/PXA1, higher 18:3, and clonal reproduction.

Conclusions:

• Apomixis breeding successfully generated Paspalum notatum with enhanced nutritional traits.
• These hybrids offer potential for improving milk and meat quality.
• The developed genotypes may contribute to reduced methane emissions in grazing livestock.