Genetic diversity and population structure of Saccharum hybrids

PERERA, M. F.; OSTENGO, S; ALMEIDA BALSALOBRE, T.W; DIAS ONORATO, G.; NOGUERA, A.S; HOFFMANN, H.P.; SAMPAIO CARNEIRO, M.

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2023

1932-6203

Sugarcane breeding programs incorporate foreign material to broaden the genetic base,expanding the gene pool. In South America, the Inter-university Network for the Developmentof the Sugarcane Industry (RIDESA) and Estacio´n Experimental Agroindustrial ObispoColombres (EEAOC) sugarcane breeding programs from Brazil and Argentina, respectively,have never exchanged materials. In that sense, the knowledge of the genetic diversity andpopulation structure among sugarcane genotypes of both germplasm banks, determined in areliable way through their molecular profiles, will provide valuable information to select thebest 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 Saccharumcommercial hybrids from RIDESA and EEAOC sugarcane breeding programs byusing TRAP, SSR and markers related to disease resistance (e.g. Bru1 and G1). Geneticstructure was determined through genetic similarity analysis, analysis of molecular variance(AMOVA), Multidimensional scaling (MDS), and a Bayesian method. Average PIC valueswere 0.25 and 0.26, Ho values were 0.24 and 0.28, and He values were 0.25 and 0.28, forTRAP and SSR primers, respectively. Genetic similarity, MDS, and analysis of structurerevealed that Brazilian and Argentinean genotypes clustered in two groups clearly differentiated,whereas AMOVA suggested that there is more variability within programs than betweenthem. 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 resistancegene (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 bothprograms. In conclusion, the exchange of materials, at least the most diverse genotypes,between RIDESA and EEAOC breeding programs will allow extending the genetic base oftheir germplasm banks, and the knowledge of genetic diversity will help breeders to bettermanage crosses, increasing the probability of obtaining more productive varieties.