Genetic diversity and population structure of Saccharum hybrids

PLoS One. 2023 Aug 15;18(8):e0289504. doi: 10.1371/journal.pone.0289504. eCollection 2023.

Abstract

Sugarcane breeding programs incorporate foreign material to broaden the genetic base, expanding the gene pool. In South America, the Inter-university Network for the Development of the Sugarcane Industry (RIDESA) and Estación Experimental Agroindustrial Obispo Colombres (EEAOC) sugarcane breeding programs from Brazil and Argentina, respectively, have never exchanged materials. In that sense, the knowledge of the genetic diversity and population structure among sugarcane genotypes of both germplasm banks, determined in a reliable way through their molecular profiles, will provide valuable information to select the best parental accessions for crossing aimed at the efficient introgression of desirable alleles. For that, the aim was to determine the genetic diversity and population structure of 96 Saccharum commercial hybrids from RIDESA and EEAOC sugarcane breeding programs by using TRAP, SSR and markers related to disease resistance (e.g. Bru1 and G1). Genetic structure was determined through genetic similarity analysis, analysis of molecular variance (AMOVA), Multidimensional scaling (MDS), and a Bayesian method. Average PIC values were 0.25 and 0.26, Ho values were 0.24 and 0.28, and He values were 0.25 and 0.28, for TRAP and SSR primers, respectively. Genetic similarity, MDS, and analysis of structure revealed that Brazilian and Argentinean genotypes clustered in two groups clearly differentiated, whereas AMOVA suggested that there is more variability within programs than between them. Regarding Bru1 markers, Brazilian genotypes showed high frequency of haplotype 1 (71.4%) whereas Argentinean genotypes showed high frequency of haplotype 4 (80.8%); haplotypes 1 and 4 are indicated for the presence and absence of the brown rust resistance gene (Bru1), respectively. Respecting the G1 marker, most of the evaluated genotypes (60.4%) showed the presence of the fragment, in a similar proportion for genotypes of both programs. In conclusion, the exchange of materials, at least the most diverse genotypes, between RIDESA and EEAOC breeding programs will allow extending the genetic base of their germplasm banks, and the knowledge of genetic diversity will help breeders to better manage crosses, increasing the probability of obtaining more productive varieties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bayes Theorem
  • Brazil
  • Genetic Variation
  • Humans
  • Microsatellite Repeats / genetics
  • Plant Breeding
  • Saccharum* / genetics

Grants and funding

MFP was supported by the Estación Experimental Agroindustrial Obispo Colombres (EEAOC, Argentina) through the project titled Evaluation of genetic diversity and varietal identification (CAM.VII.1), by Instituto de Tecnología Agroindustrial del Noroeste Argentino (ITANOA) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET, Argentina) through the Project GENBIONOA and by the Agencia Nacional de Promoción Científica of Argentina (ANPCyT) through the Fondo Nacional de Ciencia y Tecnología (FONCyT), Ministerio de Ciencia, Tecnología e Innovación Productiva (MINCyT) for the project PICT 2020 No 00091. MSC received financial support from the RIDESA - Inter-university Network for the Development of the Sugarcane Industry (Brazil) (Project 23112.012426/2020-04). Guilherme Dias Onorato received a master’s fellowship from CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Finance Code 001). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.