Unravelling the genetic framework associated with grain quality and yield-related traits in maize (Zea mays L.)

Abstract

Maize serves as a crucial nutrient reservoir for a significant portion of the global population. However, to effectively address the growing world population’s hidden hunger, it is essential to focus on two key aspects: biofortification of maize and improving its yield potential through advanced breeding techniques. Moreover, the coordination of multiple targets within a single breeding program poses a complex challenge. This study compiled mapping studies conducted over the past decade, identifying quantitative trait loci associated with grain quality and yield related traits in maize. Meta-QTL analysis of 2,974 QTLs for 169 component traits (associated with quality and yield related traits) revealed 68 MQTLs across different genetic backgrounds and environments. Most of these MQTLs were further validated using the data from genome-wide association studies (GWAS). Further, ten MQTLs, referred to as breeding-friendly MQTLs (BF-MQTLs), with a significant phenotypic variation explained over 10% and confidence interval less than 2 Mb, were shortlisted. BF-MQTLs were further used to identify potential candidate genes, including 59 genes encoding important proteins/products involved in essential metabolic pathways. Five BF-MQTLs associated with both quality and yield traits were also recommended to be utilized in future breeding programs. Synteny analysis with wheat and rice genomes revealed conserved regions across the genomes, indicating these hotspot regions as validated targets for developing biofortified, high-yielding maize varieties in future breeding programs. After validation, the identified candidate genes can also be utilized to effectively model the plant architecture and enhance desirable quality traits through various approaches such as marker-assisted breeding, genetic engineering, and genome editing.

Corn Grain Fatty Acid Contents in Response to Organic Fertilisers from Meat Industry Waste

“…Traits contributing to yield and grain quality are usually antagonistic to each other, and when applying various modifications in agrotechnology, this should be taken into consideration. The forms and amounts of available mineral nutrients in the soil can cause significant changes in the growth character and biochemical composition of plants [55]. According to Gu et al [56], the availability of N reduces oil concentration, while the application of K increases oil content.…”

Meta-Quantitative Trait Loci Analysis and Candidate Gene Mining for Drought Tolerance-Associated Traits in Maize (Zea mays L.)

“…Sharma et al [68] collected 523 QTL to carry out meta-analysis for silage quality traits in maize and also achieved substantial reductions in the size of the confidence intervals. Sethi et al [19] conducted meta-analysis for grain quality and yield-related traits with 2974 initial QTL in maize and obtained a total of 68 MQTL with a mean physical confidence interval of 3.30 Mb. Concerning drought tolerance, Loni et al [16] employed meta-analysis in foxtail millet with 448 initial QTL and identified 41 MQTL.…”

“…The physical position of significant marker-trait associations (MTAs) from these studies was compared with the physical positions of the MQTL. The overlapping MTAs or adjacent MTAs (within 500kb upstream and downstream of the MQTL regions) were considered as verification of the MQTL [19].…”

“…(2) As a second approach, we explored candidate genes within the breeders' MQTL [19,71], which were defined as being composed of more than two original QTL, and having a physical distance < 1 Mb and a genetic map distance < 4 cM.…”

“…Consequently, this method has been widely used in plant genetics and breeding, for example for drought tolerance in foxtail millet [16], yield traits under drought in rice [17], and yield-related traits of wheat [18]. In maize, meta-QTL analysis has been successfully applied to traits associated with grain quality and yield [19], disease resistance [20,21], and nutrient utilization [22].…”