Genetics of Testcrossed Streak Virus Resistance Carotene Quality Protein Maize

Genetics of Testcrossed Streak Virus Resistance Carotene Quality Protein Maize

Development of Provitamin A quality protein maize (PVA-QPM) conferring resistance to maize streak virus (MSV)would reduce the prevalence of the disease, alleviate malnutrition and increase food security in sub-Saharan Africa. This study wasconducted to (i) evaluate early maturing PVA-QPM inbreds and their derived testcross hybrids for grain yield, MSV-resistant,carotenoids, and tryptophan contents, (ii) estimate the combining ability of the MSV-resistant PVA-QPM testcrosses for all traits. Fiveimproved open-pollinated MSV resistance cultivars and five early maturing PVA-QPM inbreds were crossed in a half-diallel fashionwithout reciprocals. The derived forty-five F1 topcrosses, ten parental materials, and two commercial hybrids that served as controlswere tested at the Lower Niger River Basin Development Authority in Oke-Oyi, Nigeria, during rain-fed of the year 2019 and 2020. ThePVA-QPM inbreds from TZEIORQ 13, TZEIORQ 29, and TZEQI 82 that were crossed with MSV resistance AK-9528-DMRSR andPop 28 SR appeared potentially useful combinations for enhancing grain yield, MSV-resistant, carotenoids, and tryptophan contents,Testcrossed TZEQI 82 × AK-9528-DMRSR POP 28 SR, TZEQI 82 × ACR. 91 SUWAN-1-SR C1 and TZEQI 82 × IK.91 TZL COMP3-Y C1 were most outstanding for all measured grain yield and nutrient contents. Additive genetic effects were preponderant overnon-additive genetic effects under artificial infection of MSV disease. These three promising MSV resistance PVA-QPM hybridsshould be evaluated under on-farm multiplication trials for stability performance and adaptation to reduce malnourishment and foodself-sufficiency in SSA. Also, further researches on genomic analyses of the superior testcrosses are desirable.