Identification of charcoal rot resistance QTLs in sorghum using association and in silico analyses

Abstract

Charcoal rot disease, a root and stem disease caused by the soil-borne fungus Macrophomina phaseolina (Tassi) Goid., is a major biotic stress that limits sorghum productivity worldwide. Charcoal rot resistance-related parameters, e.g., pre-emergence damping-off%, post-emergence damping-off%, charcoal rot disease severity, and plant survival rates, were measured in a structured sorghum population consisting of 107 landraces. Analysis of variance of charcoal rot resistance-related parameters revealed significant variations in the response to M. phaseolina infection within evaluated accessions. Continuous phenotypic variations for resistance-related parameters were observed indicating a quantitative inheritance of resistance. The population was genotyped using 181 simple sequence repeat (SSR) markers. Association analysis identified 13 markers significantly associated with quantitative trait genes (QTLs) conferring resistance to charcoal rot disease with an R value ranging between 9.47 to 18.87%, nine of which are environment-specific loci. Several QTL-linked markers are significantly associated with more than one resistance-related parameter, suggesting that those QTLs might contain genes involved in the plant defense response. In silico analysis of four novel major QTLs identified 11 putative gene homologs that could be considered as candidate genes for resistance against charcoal rot disease. Cluster analysis using the genotypic data of 181 SSR markers from 107 sorghum accessions identified 12 main clusters. The results provide a basis for further functional characterization of charcoal rot disease resistance or defense genes in sorghum and for further dissection of their molecular mechanisms.

Genetic Diversity Studies and Identification of Molecular and Biochemical Markers Associated with Fusarium Wilt Resistance in Cultivated Faba Bean (Vicia faba)

“…Resistance in these genotypes may be due to their genetic variations (Colditz et al, 2004;Mahmoud et al, 2015;Nyamsuren et al, 2003). These results also, in agreement with Kamboj et al (1990) and Mahmoud et al (2018) they mentioned that the inheritance of resistance to vascular wilt is controlled by independently segregating genes based on the reaction of individual plants.…”

Macrophomina phaseolina: General Characteristics of Pathogenicity and Methods of Control

“…Notably, the identification and mapping of QTLs associated with resistance to M. phaseolina, revealed candidate genes with potential for further functional genomics analysis and it may facilitate breeding and molecular engineering progress against this pathogen (Srinivasa Reddy et al, 2007;Muchero et al, 2011;Tomar et al, 2017;Mahmoud et al, 2018;da Silva et al, 2019).…”

A novel Arabidopsis pathosystem reveals cooperation of multiple hormonal response-pathways in host resistance against the global crop destroyer Macrophomina phaseolina

“…Recent research with crop plants has contributed valuable information using Mp -susceptible-versus-resistant variety phenotyping 19,34 and genetic studies 35–37 . This ongoing work is conducted in the field, greenhouse and laboratory.…”