Maize Combined Insect Resistance Genomic Regions and Their Co-localization With Cell Wall Constituents Revealed by Tissue-Specific QTL Meta-Analyses

Abstract

Combinatorial insect attacks on maize leaves, stems, and kernels cause significant yield losses and mycotoxin contaminations. Several small effect quantitative trait loci (QTL) control maize resistance to stem borers and storage pests and are correlated with secondary metabolites. However, efficient use of QTL in molecular breeding requires a synthesis of the available resistance information. In this study, separate meta-analyses of QTL of maize response to stem borers and storage pests feeding on leaves, stems, and kernels along with maize cell wall constituents discovered in these tissues generated 24 leaf (LIR), 42 stem (SIR), and 20 kernel (KIR) insect resistance meta-QTL (MQTL) of a diverse genetic and geographical background. Most of these MQTL involved resistance to several insect species, therefore, generating a significant interest for multiple-insect resistance breeding. Some of the LIR MQTL such as LIR4, 17, and 22 involve resistance to European corn borer, sugarcane borer, and southwestern corn borer. Eleven out of the 42 SIR MQTL related to resistance to European corn borer and Mediterranean corn borer. There KIR MQTL, KIR3, 15, and 16 combined resistance to kernel damage by the maize weevil and the Mediterranean corn borer and could be used in breeding to reduce insect-related post-harvest grain yield loss and field to storage mycotoxin contamination. This meta-analysis corroborates the significant role played by cell wall constituents in maize resistance to insect since the majority of the MQTL contain QTL for members of the hydroxycinnamates group such as p-coumaric acid, ferulic acid, and other diferulates and derivates, and fiber components such as acid detergent fiber, neutral detergent fiber, and lignin. Stem insect resistance MQTL display several co-localization between fiber and hydroxycinnamate components corroborating the hypothesis of cross-linking between these components that provide mechanical resistance to insect attacks. Our results highlight the existence of combined-insect resistance genomic regions in maize and set the basis of multiple-pests resistance breeding.

DArT-seq based SNP analysis of diversity, population structure and linkage disequilibrium among 274 cowpea (Vigna unguiculata L. Walp.) accessions

“…In the present study, LD declined rapidly below 0.2, reaching 0.1 at a distance of 26. 16 kb, suggesting there is potential for genome wide association studies and candidate gene selection [43]. A number of markers distributed on different chromosomes in the genome were in true LD and could serve the purpose.…”

Trend of Biotechnology Applications in Pest Management: A Review

“…These are (i) MAS and MAB, (ii)Multiple resistance, (iii) Quantitative resistance (QR), (iv) Durable resistance, (v) Gene pyramiding and (vii) Gene stacking. MAS insects resistance in rice (Shabanimofred et al, 2015;Venkanna et al, 2018;Jaiswal et al, 2018) Striga resistance in sorghum (Yasir and Abdalla, 2013, Yohannes et al, 2015Ali et al, 2016), multiple insects resistance in maize (Badji et al, 2018) multiple resistances to herbicides (Gressel, 2000;Neve et al, 2009) Quantitative resistance (QR)…”

Identification of genomic regions associated with shoot fly resistance in maize and their syntenic relationships in the sorghum genome

“…Numerous studies have been conducted to map QTLs for resistance to European corn borer, Mediterranean corn borer, Asian corn borer, sugarcane borer, maize weevil, Southwestern corn borer, and fall army worm [34]. However, no information is available about the number, mode of action, and location of QTLs governing shoot fly resistance in maize.…”

“…The previous studies concluded that disease and insect resistance genes in maize appear in "clusters" [38]. The detected bins in the experiment (1.02-03, 1.09, 2.05, 6.00-6.01, 9.03 and 9.05-06) have been reported in different studies for insect resistance especially to European corn borer, fall army worm and maize weevil as presented in S1 Table. Based on meta QTL analysis, Badji et al [34] highlighted the presence of combined insect resistance genomic regions in maize and thus, could form the basis for multiple pest's resistance breeding. This…”