Potential Uses of Microsatellites in Marker-Assisted Selection for Improved Grain Yield in Wheat

Abstract

Seven hundred and ten wheat genotypes from the Novi Sad Core Collection, originating from 38 countries, have been evaluated for 54 traits under both field and lab conditions during seven growth seasons. In each year, the field experiment comprised 3–7 replications, each with basic plot size of 1.2 m² . Based on the obtained data, a subset of 96 genotypes with the highest phenotypic variability for 26 of the most important breeding traits was identified for screening with microsatellites. A set of 36 SSRs was used for molecular screening, covering the 42 wheat chromosomes. To test the effectiveness of the concept of association between marker alleles and yield, the 96 accessions were grouped according to the presence of particular microsatellite fragments in at least three genotypes and average group yields were compared using one-way ANOVA. Associations were determined for 13 microsatellites (gwm46, gwm155, gwm190, gwm192, gwm295, gwm337, gwm484, gwm539, gwm540, psp3088, psp3103, psp3153 and psp3200). In a subsequent analysis of 20 genotypes with either the highest or lowest yields it was possible to determine the presence of high and low-yielding alleles. Two varieties with the lowest yields in this research carried no high-yielding alleles, while a further four genotypes from the same group carried only two high-yielding alleles. Conversely, cv. Pobeda, which is presently a standard variety in the Commission for Variety Approval of Serbia, possesses all 14 high-yielding alleles, followed by Renesansa, NS 55-25, NS 66/92 and NS 79/90 with 10 high-yielding alleles. In the 20 highest-yielding genotypes, 61.8% of the total alleles were high-yielding alleles, while in the 20 lowest-yielding genotypes the frequency of high-yielding alleles was almost three times lower (22.1%). The difference in informativeness of the 13 microsatellites were determined in terms of their informative value (IV), calculated as the ratio between the number of high-yielding alleles determined in the low and high-yielding genotypes. The results are discussed with emphasis placed on the problems and prospect of such studies in the molecular and breeding context