Agriculture

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Browsing Agriculture by Author "Abu, Pearl"

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    Genetic diversity and inter-trait relationship of tropical extra-early maturing quality protein maize inbred lines under low soil nitrogen stress
    (Public Library of Science(PLOS), 2021-06-11) Abu, Pearl; Badu-Apraku, Baffour; Ifie, Beatrice E.
    Information on the genetic diversity, population structure, and trait associations of germplasm resources is crucial for predicting hybrid performance. The objective of this study was to dissect the genetic diversity and population structure of extra-early yellow and orange quality protein maize (QPM) inbred lines and identify secondary traits for indirect selection for enhanced grain yield under low-soil nitrogen (LN). One hundred and ten inbred lines were assessed under LN (30 kg ha -1) and assayed for tryptophan content. The lines were genotyped using 2500 single nucleotide polymorphism (SNP) markers. Majority (85.4%) of the inbred lines exhibited wide pairwise genetic distances between 0.4801 and 0.600. Genetic distances were wider between yellow and orange endosperm lines and predicted high heterosis in crosses between parents of different endosperm colors. The unweighted pair group method with arithmetic mean (UPGMA) and the admixture model-based population structure method both grouped the lines into five clusters. The clustering was based on endosperm color, pedigree, and selection history but not on LN tolerance or tryptophan content. Genotype by trait biplot analysis revealed association of grain yield with plant height and ear height. TZEEQI 394 and TZEEIORQ 73A had high expressivity for these traits. Indirect selection for high grain yield among the inbred lines could be achieved using plant and ear heights as selection criteria. The wide genetic variability observed in this study suggested that the inbred lines could be important sources of beneficial alleles for LN breeding programs in SSA.
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    Genetics of extra-early-maturing yellow and orange quality protein maize inbreds and derived hybrids under low soil nitrogen and Striga infestation
    (Crop Science Society of America, 2020-10-21) Badu-Apraku, B.; Abu, Pearl; Ifie, Beatrice
    The development and commercialization of extra-early quality protein maize (QPM)-provitamin A (PVA) hybrids, tolerant of low soil nitrogen (LN) and Striga resistant are essential for addressing the food insecurity and undernourishment challenges currently faced by sub-Saharan Africa (SSA). This study was designed to (i) determine the genetic effects regulating grain yield (GY) and important secondary traits of extra-early yellow and orange QPM-PVA inbred lines under LN, Striga-infested and high-nitrogen (HN) conditions, (ii) investigate whether maternal genes influenced the inheritance of GY and other secondary traits,(iii) assess the GY and stability of the hybrids across the three management conditions, and (iv) examine the relationship between single nucleotide polymorphism (SNP) marker-based genetic distances and GY. Twenty-four inbred lines were used to produce ninety-six single cross hybrids employing the North Carolina Design II. The performance of the hybrids plus four checks was assessed across LN, Striga-infested and HN management conditions in Ghana and Nigeria in 2018. Additive genetic variances were preponderant over non-additive genetic variances for GY and most secondary traits in each and across environments. TZEEQI 358 exhibited significant and positive male and female GCA effects for GY under LN, Striga-infestation, HN and across management conditions indicating that favourable alleles for GY could be donated by TZEEQI 358. Maternal effects regulated the inheritance of plant height under the Striga-infested conditions. Genetic distances were associated with GY under LN, Striga-infestation and HN conditions. TZEEIORQ 58 × TZEEQI 397 demonstrated high GY and stability of performance; therefore, it should be further tested under multiple environments for commercialization.