Identification of novel SNP alleles linked to brown rust resistance in sugarcane

SOLANA CHAVES ; SANTIAGO OSTENGO; ROMINA PRISCILA BERTANI; ANDREA NATALIA PEÑA MALAVERA; ATILIO PEDRO CASTAGNARO ; MÓNICA GRACIELA BALZARINI; JOSEFINA RACEDO

Hyderabad

Congreso; XXXI International Society of Sugar Cane Technologists Congress; 2023

International Society of Sugar Cane Technologists

Sugarcane brown rust, caused by Puccinia melanocephala, is a foliar disease that occurs inmany production areas worldwide. The development of resistant cultivars is the main controlstrategy due to its efficiency and sustainability. The aim of this work was to identify genomicregions associated with brown rust resistance in sugarcane, different from the well-knownresistant gene Bru1. A Selective Genotyping approach was carried out with an F1 progeny of300 clones obtained from a cross between TUC 00-36 (highly susceptible) and RA 87-3 (highlyresistant). A total of 60 out of the 300 clones were selected according to their reactions to brownrust. The selected population was rated for brown rust reactions under natural infection in thefield during two crop seasons and under artificial infection in a greenhouse. Whole-genomeprofiling of the population and their progenitors were obtained by DArTSeq technology. Fieldevaluations showed that 36 clones were rated as resistant and 24 clones as susceptible. Undercontrolled conditions, 35 clones were rated as resistant and 25 as susceptible to the disease.From the DArTSeq genotyping technology a total of 23,299 SNP markers were obtained. TheSingle Marker Analysis and the frequencies analysis showed 48 markers significantly linked tothe resistant trait. A multiple regression analysis showed 34 markers significantly linked to theresistance alleles that jointly explained 69% and 66% of the total phenotypic variation observed(R2) for field and controlled conditions, respectively. These marker loci could be used inmolecular-marker-assisted breeding for a more accurate selection of resistant clones with thenovel resistant sources. This will expand the spectrum of cultivars harboring different resistancealleles in field with the consequent broaden of the lifetime of resistance sources.