Introgression of QTLs for Drought Tolerance into Farmers’ Preferred Sorghum Varieties

Abstract

Sorghum is a major staple food crop for the people in semi-arid areas of Africa and Asia. Post-flowering drought is a global constraint of sorghum production. The study aimed to improve stay-green (STG) characteristics of farmer-preferred sorghum varieties in Tanzania using marker-assisted backcrossing. A total of 752 individuals representing five BC2F1 populations and their parents were genotyped using previously reported KASP markers linked with STG 3A and STG 3B quantitative trait loci (QTL). In the BC2F1 populations, the maximum number of individuals with heterozygous alleles were observed in S35*Pato background (37) whereas only seven individuals derived from the B35*Wahi parents’ background contained heterozygous alleles. Of the 30 single nucleotide polymorphism (SNP) markers, favourable alleles were observed at 18 loci in BC2F1 populations. In the BC2F1 generation, the highest (0.127 kg/panicle) grain yield was observed in the B35*NACO Mtama 1 background population. The genotypic analysis revealed the presence of favourable alleles in homozygous conditions at markers loci associated with STG 3A and STG 3B QTLs in BC2F3 populations, suggesting successful introgression of STG QTLs from the donor parents to the recurrent parents. Across water irrigation regimes, the highest (0.068 kg/panicle) mean grain weight was observed in the genotype NA316C. Therefore, our study demonstrated the utility of marker-assisted backcrossing for drought tolerance improvement of locally adapted sorghum varieties in Africa.

New strategies to address world food security and elimination of malnutrition: future role of coarse cereals in human health

“…Therefore, germplasm resources with different characteristics must be collected and mined for superior genes. The following traits have been suggested as key indicators of drought-tolerant crops: short growth cycle (Mwamahonje et al, 2021), high root density (Kothari et al, 2020), high osmoregulatory activity in roots (Haling et al, 2013), high stomatal conductance (Leybourne et al, 2022), high leaf relative water content (RWC) (Yamamoto et al, 2000), optimal water utilization (Guenther et al, 2003), and high plasticity (Gano et al, 2021).…”

Life Cycle Sustainability Assessment—A Survey Based Potential Future Development for Implementation and Interpretation

“…A weighting between the three dimensions is not foreseen in the interpretation phase, since the three individual assessments are equivalent, and no compensation is made. [4,5] Various challenges in the application and interpretation of LCSAs became apparent [7,8]-although the LCSA brings with it a great opportunity: a holistic and lifecycle-based assessment.…”

“…The LCSA was initially developed in 2008/2010. [5,6] Since 2012, there has been a significant increase in LCSA studies [6], from which a variety of challenges related to LCSA emerge [7][8][9][10]. Among other things, the reviewed LCSA studies called for improvements in application, interpretation and communication, without clear indications of what those improvements might be [7].…”

Drought Tolerance and Application of Marker-Assisted Selection in Sorghum

“…Those QTLs have high efficiency for delaying leaf senescence during post-flowering drought stress. Mwamahonje et al [ 90 ] introduced Stg3A and Stg3B QTLs into farmers’ preferred sorghum varieties in Tanzania. The QTLs were successfully introgressed by snpSB00049, snpSB00053, and snpSB00054 SNPs markers for Stg3A QTL and snpSB00101, snpSB00102, and snpSB00103 SNPs markers for Stg3B QTL, which accounted 30% of grain yield increase and stay-green in the water-stressed environments.…”