Deciphering Genotype-By-Environment Interaction for Target Environmental Delineation and Identification of Stable Resistant Sources Against Foliar Blast Disease of Pearl Millet

Abstract

Once thought to be a minor disease, foliar blast disease of pearl millet, caused by Magnaporthe grisea, has recently emerged as an important biotic constraint for pearl millet production in India. The presence of a wider host range as well as high pathogenic heterogeneity complicates host–pathogen dynamics. Furthermore, environmental factors play a significant role in exacerbating the disease severity. An attempt was made to unravel the genotype-by-environment interactions for identification and validation of stable resistant genotypes against foliar blast disease through multi-environment testing. A diversity panel consisting of 250 accessions collected from over 20 different countries was screened under natural epiphytotic conditions in five environments. A total of 43 resistant genotypes were found to have high and stable resistance. Interestingly, most of the resistant lines were late maturing. Combined ANOVA of these 250 genotypes exhibited significant genotype-by-environment interaction and indicated the involvement of crossover interaction with a consistent genotypic response. This justifies the necessity of multi-year and multi-location testing. The first two principal components (PCs) accounted for 44.85 and 29.22% of the total variance in the environment-centered blast scoring results. Heritability-adjusted genotype plus genotype × environment interaction (HA-GGE) biplot aptly identified “IP 11353” and “IP 22423, IP 7910 and IP 7941” as “ideal” and “desirable” genotypes, respectively, having stable resistance and genetic buffering capacity against this disease. Bootstrapping at a 95% confidence interval validated the recommendations of genotypes. Therefore, these genotypes can be used in future resistance breeding programs in pearl millet. Mega-environment delineation and desirability index suggested Jaipur as the ideal environment for precise testing of material against the disease and will increase proper resource optimization in future breeding programs. Information obtained in current study will be further used for genome-wide association mapping of foliar blast disease in pearl millet.

Multi-environment evaluation of rice genotypes: impact of weather and culm biochemical parameters against sheath blight infection

“…The role of G x E is essential for identifying and evaluating durable resistance sources ( Singh et al., 2020 ). G x E interaction studies might give an insight into repeated field plots and greenhouse ratings in view of G x E. Several G x E studies have been documented for various diseases in rice, wheat, sorghum, and pearl millet crops ( Mukherjee et al., 2013 ; Das et al., 2019 ; Persaud et al., 2019 ; Kirtphaiboon et al., 2021 ; Sankar et al., 2021 ). However, stability analysis and G x E for sheath blight of rice have not been widely studied, and few reports are available ( Persaud et al., 2019 ).…”

Identification of new stable resistant sources and assessing agro-morphological performance of sponge gourd germplasm against Tomato Leaf curl New Delhi Virus incidence

“…Thus, genotypes identified as ideal and desirable with durable resistance, would be valuable genetic resources in future resistant breeding programs in sponge gourd against ToLCNDV. Similarly resistant genotypes were also identified in various crops against different pathogens ( Parihar et al., 2017 ; Das et al., 2020 ; Singh et al., 2020 ; Sankar et al., 2021 ).…”

“…For this purpose, researchers have widely embraced various multivariate techniques and recent approaches like the Genotype plus Genotype × Environment Interaction (GGE) biplot to assess the significance of Genotype × Environment Interaction (GEI). The GGE biplot is a graphical representation methodology that employs indirect selection, effectively removing the main environmental effects and considering only the genotypic main effects and GEI in multilocational trials ( Yan et al., 2000 ; Yan and Kang, 2003 ; Parihar et al., 2017 ; Singh et al., 2020 ; Sankar et al., 2021 ). The genotype by yield × trait (GYT) biplot is used to address the problem of combining yield with other important traits and aids in genotype evaluation for multiple traits ( Yan and Frégeau-Reid, 2018 ; Merrick et al., 2020 ; Ebrahimi, 2023 ).…”

Genotype-by-environment interactions for starch, mineral, and agronomic traits in pearl millet hybrids evaluated across five locations in West Africa

“…The Sadore environment is a more ideal test environment, which has a high discriminating ability and a representative and identified ranking of genotypes that are not much varied across the environments; meanwhile, the respective genotypes (G16 and G1) are stable and eminently performed genotypes across the environments. These lines of pearl millet can be considered a good source of dietary fibres and have a low glycaemic index with increased levels as compared to other cereals ( Sankar et al., 2021 ). Similarly, SDS are an equally important component of carbohydrates that gets processed in the small intestine and helpful in type 2 diabetes management by releasing the energy slowly.…”