Validation of microsatellite molecular markers linked with resistance toBipolaris sorokinianain wheat (Triticum aestivumL.)

Abstract

SUMMARYSpot blotch disease caused by Bipolaris sorokiniana (Sacc.) Shoem causes yield losses and reduces grain quality in wheat. Molecular markers reported to be linked with resistance to B. sorokiniana could accelerate the identification of resistant genotypes as they are independent of the environmental effect. However, before they can be utilized for marker assisted selection (MAS), validation in an independent population is required. The objective of the present study was therefore to validate three simple sequence repeat (SSR) molecular markers (Xwgm570, Xgwm544 and Xgwm437) linked with resistance to B. sorokiniana. The markers were validated using 66 wheat genotypes comprising 11 parental genotypes and 55 F2 progenies. Single marker analysis was performed using simple linear regression to ascertain the relationship between the marker and the trait. All the markers were confirmed to be associated with resistance. They all gave significant association with resistance to B. sorokiniana. The markers amplified DNA fragments in the resistant parental genotypes that were similar to those observed in resistant F2 progenies, but absent in the susceptible ones. Hence, these markers could be useful in increasing the efficiency of selection for resistance to B. sorokiniana in wheat breeding. Since the R2 values are low, a combination of two or three SSR markers can be employed during MAS. This was evident by the multiple linear equation which gave a combined R2 value of 18·0%, obtained from the inclusion of all three markers.

Improvement of Cercospora leaf spot and powdery mildew resistance of mungbean variety KING through marker-assisted selection

“…Similarly, this strategy has also been successfully used to transfer gene (s)/QTL for disease resistance in several legume crops including common bean, chickpea and soybean (Garzón et al ., 2008; Carneiro et al ., 2010; Varshney et al ., 2014; Maranna et al ., 2016). However, before using markers linked to resistance genes in MAS, they should be validated in an independent population to identify polymorphisms (Tembo et al ., 2017).…”

Genetics of Resistance to Common Root Rot (Spot Blotch), Fusarium Crown Rot, and Sharp Eyespot in Wheat

“…A phenotypic screening of 11 parental genotypes and 55 F 2 lines identified “19HRWSN6” as a resistant source. Subsequent simple linear regression analysis revealed SSR markers on chromosomes 5B, 6A, and 7D associated with resistance to B. sorokiniana ( Tembo et al, 2017 ). There has been recent progress in drafting the physical genome of hexaploid wheat ( Appels et al, 2018 ), and high-throughput SNP toolkits are now available for GWAS on various complex traits of wheat ( Sun et al, 2020 ).…”