Novel sources of drought tolerance in sorghum landraces revealed via the analyses of genotype-by-environment interactions

Abstract

Globally, sorghum is the fifth most important crop, which is used for food, feed and fuel. However, its production and productivity are severely limited by various stresses, including drought. Hence, this study aimed to determine the responses of different drought-tolerance related traits in the Ethiopian sorghum germplasm through multi-environment field trials, thereby identifying novel sources of germplasm that can be used for breeding the crop for drought-tolerance. Three hundred twenty sorghum landraces and four improved varieties were grown at three sites within drought-prone areas (Melkassa, Mieso and Mehoni) in Ethiopia. The targeted traits were chlorophyll content at flowering (CHLF), chlorophyll content at maturity (CHLM), green leaf number at flowering (GLNF), stay-green (SG), flag leaf area (FLA), peduncle length (PDL), and panicle exertion (PAE). Multi-variate analyses of the collected data revealed the presence of high phenotypic variation in all traits. The combined and AMMI Analysis of variance showed that phenotypic variation due to the genotypes was higher for SG, CHLM, CHLF and GLNF and lower for FLA, PE and PDL in comparison with variation due to the environments or genotype by environment interactions. High broad sense heritability was observed for CHLF, CHLM, SG, GLNF, FLA, and PDL, whereas PAE showed moderate heritability. Due to the high heritability of chlorophyll content and the relatively small effect of environmental factors on it, it could serve as a criterion for selecting desirable genotypes for drought-tolerant breeding in sorghum. It has been found that chlorophyll content has a significant positive correlation with stay-green and grain yield, indicating that high chlorophyll content contributes to increasing grain yield by delaying the process of leaf senescence. The analyses of AMMI, GGE biplot, and genotype selection index revealed that several sorghum landraces outperformed the improved varieties with respect to CHLF, CHLM, and SG. Such landraces could serve as novel sources of germplasm for improving drought tolerance through breeding.

Genetic Diversity, Correlation and Genotype by Yield by Trait (GYT) Analysis of Grain Yield and Nutritional Quality Traits in Sorghum (Sorghum bicolor [L.] Moench) Genotypes in Tigray, northern Ethiopia

“…They can be also sources of parental lines for further breeding activities. Our finding confirms that the Ethiopian sorghum landraces often harbored various important traits explained by earlier researchers [2,5,22,24].…”

“…Given its center of origin and diversity [19][20], and tremendous variation in agro-ecologies, Ethiopia is harbored with extremely rich genetic diversity of sorghum landraces [2,16,[21][22], which serves as sources of various important traits. For instance, drought tolerance [16,[23][24], nutritional quality traits [21,[25][26], resistance to grain mold [27] and resistant to ergot and green bug [28]. Ethiopia is also among the top nations that have made significant contributions to the sorghum germplasm collections in the world [29].…”

Millets and pseudocereals: A treasure for climate resilient agriculture ensuring food and nutrition security

“…Remarkable progress has been made in this direction. Studies have shown a positive correlation between chlorophyll content and stay-green characteristics, indicating its role in delaying senescence and maintaining higher yield (Enyew et al 2022). Similarly, researchers have identified several QTLs associated with stay-green, providing valuable targets for breeding programs.…”

Diversity and drought indices analysis reveals potential sorghum accessions for post-flowering drought stress tolerance

“…A total of six accessions were better grain yield than Melkam under water-stress regime at Melkassa site. Similarly,Enyew et al (2022) reported that better Ethiopian sorghum accessions that Melkam variety.…”

“…Only one accession showed better grain yield than the B-35 under water-stress regime. Similarly,(Enyew et al, 2022) reported that landrace accessions that had better mean performance than the improved varieties such as B-35 with respect to grain yield and stay-green which considered as potential novel sources of functional drought tolerance.…”