Development of a cassava core collection based on single nucleotide polymorphism markers

Area of Science:

• Agricultural Science
• Genetics
• Plant Breeding

Background:

• Cassava (Manihot esculenta Crantz) is a vital food crop, particularly in tropical regions.
• Maintaining genetic diversity within germplasm collections is crucial for crop improvement and breeding programs.
• Developing representative core collections aids in efficient management and utilization of large germplasm resources.

Purpose of the Study:

• To develop core collections from the largest Brazilian cassava germplasm using a maximization strategy.
• To assess the effectiveness of different-sized core collections in capturing genetic diversity.
• To identify an optimal core collection for maximizing genetic conservation and facilitating future breeding efforts.

Main Methods:

• Utilized 402 single nucleotide polymorphism (SNP) markers to genotype the entire cassava collection.
• Applied a maximization strategy to select subsets of accessions for core collections (PoHEU, MST64, PoRAN, MST128, MST256, MST384).
• Analyzed allele capture and diversity parameters across different core collection sizes compared to the complete collection.

Main Results:

• All 798 identified alleles were captured in all developed core collections.
• Minimal alterations in diversity parameters were observed between core collections and the complete collection.
• The PoHEU core collection (61 accessions, 4.7% of total) optimally represented the complete collection, maximizing genetic conservation and distances between accessions.

Conclusions:

• The PoHEU core collection effectively maximizes genetic conservation of the Brazilian cassava germplasm.
• This core collection enables focused efforts for characterization and evaluation, leading to enhanced diversity and genetic gains in breeding.
• The study demonstrates the utility of SNP markers and maximization strategy for developing efficient cassava core collections.