Quality Protein Maize Genotypes Research Articles

Breeding strategies for quality protein maize: A Review

Zein proteins in maize seeds regulate food and feed quality and belong to several subfamilies. Most maize prolamin is α-zeins, which are rich in glutamine, leucine, and proline but lacking in critical amino acids (lysine and tryptophan). RNAi experiments show that 22kD zeins downregulate the quality protein maize (QPM) phenotype, not 19kD. The opaque-2 mutation caused a chalky, soft endosperm and many defects. QPM genotypes with opaque-2 alleles and firm kernels were improved. As opaque-2 is recessive and biochemical lysine and tryptophan analysis is costly, conventional backcrossing alone is not very useful. Markerassisted selection (MAS) allowed top inbreds to be homozygous o2o2 utilizing opaque-2 gene-specific markers. Vivek QPM-9, a mixture of two QPM introgression lines, benefits various clients and customers. This review highlights the breeding strategies for QPM.

Seed Priming for Enhancement of Seed Quality in Quality Protein Maize (QPM) (Zea mays L.)

An investigation was carried out with HQPM-5 maize hybrid and its parental lines HKI-163 and HKI-161 seeds during rabi 2022-23 to evaluate the effect of liquid biofertilizers (Azospirillum, Phosphorus solubilizing bacteria and Potassium solubilizing bacteria) on seed quality attributes in Quality Protein Maize (QPM) genotypes. The seeds were subjected to different concentration and duration of hydropriming and biopriming (Concentration: 10,15 and 20%; Duration: 6,12,18 and 24h). The non primed seeds were used as control. HQPM-5 seeds bioprimed with combination of Azospirillum @ 20 % + Phosphorous solubilizing bacteria @ 20 % + Potassium solubilizing bacteria @ 20 % at 12h (T9) recorded higher seed quality i.e., germination, field emergence, root length, shoot length, seedling length, seedling fresh weight, root dry weight, shoot dry weight, seedling dry weight, seed vigour index I & II, nitrogen and protein content and lower EC of seed leachates than the parental lines, HKI-163 and HKI-161. The overall performance of female parent was found to be better compared to the male parent.

Evaluation of performance and genetic parameters in quality protein maize genotypes

Quality protein maize (QPM) contains opaque-2 mutant genes that increases lysine and tryptophan level which are not normally found in maize. The objective of this study was to evaluate the performance of QPM genotype based on their yield, yield attributing and other relevant characteristics. A varietal trial on QPM was conducted in the research field of Lamahi municipality-3, Dang, Nepal from February to June 2021. This experiment was performed in Randomized Complete Block Design with three replications. Thirteen genotypes of QPM and one standard check (Poshilo Makai-2) were evaluated. Each genotype was assigned an area of 3m × 3m with a net plot area of 452.5m2 per block. Analysis of variance revealed significant data for the most of the genotypes. Four genotypes Rampur-S13FQ-02 Rampur-SO3FQ-02, Rampur-S13FQ010 and Rampur-S13FQ-08 were found superior with a yield of 4.32 t/ha, 3.97 t/ha, 3.89 t/ha, 3.63 t/ha respectively in comparison to the standard check Poshilo makai-2 (2.66 t/ha). Significant and positive correlation were observed for the ear length, ear diameter, number of kernels per ear, number of kernel row per ear, ear weight whereas negative for ear aspect with grain yield was observed. Ear weight without husk had the highest contribution to grain yield. For all observed traits, the coefficient of phenotypic variation (PCV) was found to be higher than that of genotypic coefficient of variation (GCV). The highest GCV, PCV, genetic advance and heritability were observed in ear aspect, thousand grain weight, ear height, plant height respectively. As a result, breeding programs can be further improved by selecting these traits.

Growth Response and Dry Matter Partitioning of Quality Protein Maize (Zea mays L.) Genotypes under Aluminum Toxicity

In this work, 75 quality protein maize (QPM) inbred lines were evaluated for aluminum tolerance using a nutrient solution assay in a laboratory and a soil-based technique in a greenhouse tunnel. The experiment was set up in a completely randomized design with three replications in the laboratory, and a randomized complete block design was used in the greenhouse. Aluminum toxicity was generated by amending a nutrient solution with 600 µM of aluminum sulfate (Al2 [SO4]3) in the laboratory, and Al2 [SO4]3 was applied at a rate of 24 mg kg−1 of soil in the greenhouse experiment. Relative root length (RRL) and hematoxylin staining (HS) scores were used to identify tolerant genotypes in the laboratory. According to RRL, 94.7% of genotypes were tolerant and 5.3% were sensitive, while Hematoxylin (HS) classified 77.9% of the genotypes as tolerant, and 22.1% as sensitive. RRL and HS presented a very strong negative association (−0.788). In the soil-based method, the experiments were conducted twice in successive summer seasons of 2019 and 2020. Several growth traits were measured and most genotypes that exhibited tolerance in the nutrient solution also had similar tolerance in the soil-based screening technique. Genetic variability for tolerance was identified, revealing potentially useful donors of tolerance genes in breeding programs.

Nitrogen Use Efficiency of Quality Protein Maize (Zea mays L.) Genotypes

Use of more nutrient-use efficient Quality Protein Maize (QPM) varieties will likely play a pivotal role in maintaining or increasing crop yields and nutritional values in fields where soils are degraded. This study aimed to: (i) assess the nitrogen use efficiency (NUE) of different QPM inbred lines at various levels of nitrogen (N) fertilizer application; (ii) determine the relationships among NUE indices and yield; and (iii) determine the appropriate rate of fertilizer application for QPM genotypes under conditions of this study. Thirty-two QPM inbred lines were evaluated at 0, 30, 60, 90 and 120 kg N ha−1 N fertilizer application in a split-plot randomized complete block design with two replicates at the University of Fort Hare Crop Research farm, South Africa. Results revealed highly significant differences (p ≤ 0.001) for total nitrogen in biomass (Bio Total N), total nitrogen in grain (G Total N), grain yield, NUE and almost all the indices estimated across N levels. The top three genotypes which showed high-yielding potential at 30 kg N ha−1 include L2 (6.24 t/ha), L3 (6.47 t/ha) and L4 (6.34 t/ha), and were considered the most N-efficient genotypes under low N soils. The highest grain yields (6.74 t/ha) and highest NUtE (Nitrogen Utilization Efficiency) (1.93 kg grain/total N) were obtained at 90 kg N ha−1. Highly significant and positive correlation coefficients were found between NUE and yield (+0.9), NUE and NUtE (+0.9), NUE and HI (Harvest Index) (+0.5), NUtE and yield (+0.99), HI and yield (+0.5) and NUtE and HI (+0.5). Highest nitrogen uptake efficiency (NUpE) was obtained from the lowest fertilizer rate, which was 30 kg N ha−1.

Marker assisted conversion of maize inbred lines to quality protein maize (GPM) adapted to temperate climate

Maize is a poor source of protein both for humans and monogastric animals due to the lack of essential amino acids, such as lysine and tryptophan. Naturally occurring opaque2 (o2) mutation increases content of these amino acids, but also confers an undesirable phenotype leading to low yields. Quality protein maize (QPM) is agronomically acceptable and nutritionally improved opaque2 maize obtained through conventional breeding. Marker assisted breeding program aimed at developing QPM genotypes for growing in temperate regions is being conducted at Maize Research Institute Zemun Polje (MRIZP). The results presented in this paper relate to foreground selection aimed to identify plants that attained homozygosity at o2 locus in BC2F2 generation in conversion of four MRIZP commercial inbred lines. Maize inbred line ZPL5 converted to its QPM counterpart and adapted to temperate climate was used as o2 donor to the four recurrent parents (RP). Foreground selection was carried out with gene-specific markers phi057 and umc1066, both segregating as per the expectation. The percentage of recessive homozygotes in BC2F2 generation was approximately 25% (24.6% in RP1, 23.3% in RP2, 25% in RP3 and 24.4% in RP4). After the self-pollination of selected recessive homozygotes, BC2F3 progenies were screened for phenotypic and biochemical characteristics to confirm their nutritional and agronomical superiority. The results of scoring endosperm modifications revealed over 95% of hard endosperm kernels. The average tryptophan content ranged from 0.070% in RP1 to 0.087% in RP3. Out of 39 derivations from four lines, 19 had tryptophan content above the QPM threshold (0.075%). A total of 16 derivations were chosen for their highest tryptophan content. Their quality index was increased by 2-46% relative to the recurrent parent. These line will serve as an important breeding material for developing QPM maize hybrids adapted to temperate regions.

Protein quality and quantity of quality protein maize (QPM) and non‐QPM hybrids under optimal and low nitrogen conditions

AbstractBackground and objectivesQuality protein maize (QPM) nutritional quality involves high total protein content but reduced zein accumulation in maize endosperm, leading to increased non‐zein proteins, hence higher levels of essential amino acids such as lysine and tryptophan. The aim of this study was to assess the effect of low nitrogen (N) conditions in one location, and optimum conditions in three locations, on zein proteins in 10 QPM hybrids developed by the International Maize and Wheat Improvement Centre (CIMMYT) compared to two non‐QPM checks.FindingsWith a few exceptions, total protein content, and γ‐ and α‐zein peak areas were significantly reduced under low N compared to optimal conditions, while β‐zein increased. Non‐QPM hybrids had higher protein content than QPM hybrids, and QPM hybrids had higher γ‐zein than non‐QPM in all environments. Higher α‐zein values than other zein types were observed in non‐QPM than in QPM genotypes in all environments.Significance and noveltyLow N significantly reduced protein content and all the zein fractions except for β‐zeins, which were increased. The advantages of a decrease in zein fractions in QPM under low N conditions were offset by a large decrease in grain protein content.

RENDIMIENTO Y CALIDAD INTRÍNSECA DE CRUZAS DE MAÍZ DE CALIDAD PROTEÍNICA EN AMBIENTES DE VALLES ALTOS DE MÉXICO

El grano de maíz es deficiente en lisina y triptófano, aminoácidos esenciales para la alimentación humana. La generación de genotipos con granos más nutritivos puede incidir de manera favorable en la salud de la población. El objetivo de esta investigación fue determinar el efecto de localidad sobre el rendimiento, las propiedades físicas y la calidad de la proteína del grano de 18 cruzas simples de maíz con calidad proteínica (QPM) (Zea mays L.). Los genotipos QPM resultaron de la cruza de seis líneas androestériles QPM (LQ1, LQ2, LQ3, LQ4, LQ5 y LQ6) y tres líneas élite QPM (CML173, CML354 y CML352), y se evaluaron en dos localidades: FESC-UNAM y CEVAMEX-INIFAP, en primavera y verano de 2014. Las variables evaluadas fueron el rendimiento, peso hectolítrico, peso de cien granos, índice de flotación, proteína, lisina, triptófano e índice de calidad, en el Laboratorio de Maíz del INIFAP. Para todas las variables se realizó un análisis de varianza combinado e individual y se realizó una prueba de comparación de medias (Tukey). Las cruzas simples con productividad mayor y mejores características físicas de calidad (en ambas localidades) fueron LQ6 x CML352, LQ3 x CML352 y LQ4 x CML354, presentaron granos de tamaño mediano y de textura intermedia y dura. Solo la cruza LQ5 x CML354 presentó el porcentaje de triptófano y lisina cercanos a lo indicado en la literatura para declarar a un maíz como de calidad proteínica.

Analysis of genetic divergence and population structure through microsatellite markers in normal and quality protein maize genotypes from NW Himalayan region of India

Maize is a self-compatible but largely cross pollinated crop and considered as the staple food in many developing countries. The present study was designed to examine the best polymorphic SSR markers of any maize variety and the assessment of population structure variation and genetic diversity among normal and quality protein maize genotypes. The markers used were found highly polymorphic, that can be effectively used for maize genotypes across the geographical regions. The PIC values for all SSR markers in 47 maize genotypes varied from 0.20 to 0.85 with a mean of 0.57 whereas, gene diversity ranged from 0.23 to 0.86. On the basis of SSR analysis and obtained PIC value (≥ 0.75), gene diversity (≥ 0.79), inbreeding coefficient (≥ 0.97) and polymorphic alleles (≥ 8), six highly polymorphic SSR loci, umc2071, umc1077, umc2163, umc1804, phi026 and umc1799 were observed. The clustering of the maize genotypes was found to be largely based on their centre of development, quality nature and parentage involved. The clustering of the maize genotypes was largely based on their centre of development, quality nature and parentage involved. The genotype CM212 is one of the parent of VQL1 which was converted through MAS, hence clustered with CM212. Likewise, the QPM inbred line VQL373 was derived from the V373 recipient parent through marker assisted conversion, hence clustered together. The finding of this study showed parentage influencing more than the quality related genes. The inferred ancestry at K = 2 suggested that the maize genotypes were grouped into two populations.

Physiological Basis of Yield Differences in Quality Protein Maize Genotypes of Different Maturity Groups

Yield performance of early maturing maize (Zea mays L.) varieties in the rainforest agroecology of southwest Nigeria, is lower than that of intermediate varieties and that there was no yield advantage in the late varieties over the intermediate maturing varieties. However, the physiological basis of yield differences is yet to be fully investigated. This study was carried out to investigate the physiological basis underlying yield differences in quality protein maize genotypes of different maturity groups. Field experiment was conducted as randomized complete block design (RCBD) with three replicates at Institute of Agricultural Research and Training, Obafemi Awolowo University, Moor Plantation, Ibadan during 2013 and 2014 cropping seasons. The results indicated that season influenced days to 50% Anthesis (DTA), days to 50% silking (DTS), anthesis silking interval (ASI), plant height (PLHT), ear height (EHT), ear per plant (EPP), ear aspect (EASP), kernel width (KWDT) and grain yield (GYD). Maturity groups also influenced DTA, DTS, PASP, PLHT, EHT, and with no effect on GYD. The overall mean grain yields across seasons were 4.44, 4.16, 3.64 and 3.36 t/ha for season 1, 2, 3 and 4, respectively. It was concluded from this study that all the maturity groups used had similar grain yield.

Carbohydrate Metabolism in the Developing Kernel of Normal, Sweet Corn and Quality Protein Maize

Maize is an important food crop widely used in the milking stage for human consumption. Although some mutants like su1 and sh2 exhibits considerable amount of sweetness during milking stage, but the expression of sugars and the associated enzymes is not well understood in the developing maize kernel. The present study was planned to evaluate the time course expression of sugars (fructose, sucrose, glucose, sorbitol and starch) and enzymes (invertase, sucrose synthase and hexokinase) in the developing kernel of normal, sweet corn and quality protein maize. The results revealed higher concentrations of free sugars in the initial stages of kernel development. Sweet corn possesses significantly higher concentration of sugars and low concentrations of starch as compared to normal and quality protein maize (QPM) genotypes in the milking stage of kernel. The invertase activity was found to be maximum in the initial stages of kernel development and then showed a declining trend. In contrast, the activity of sucrose synthase was found low at 15 DAP but increased at 30 and 45 DAP. The activity of hexokinase was found low at the initial stages which further reduced significantly (47%) with increasing DAP. However, the activity of hexokinase was found lowest in sweet corn at 15 DAP but increased drastically and showed maximum content at 30 and 45 DAP.

Reaction of New Quality Protein Maize Genotypes to Striga asiatica

Striga asiatica (L.) Kuntze, an obligate hemiparasite, can cause grain yield loss of 20 to 80% in cereal crops such as maize (Zea mays L.). In Sub‐Saharan Africa, maize breeding programs have focused on productivity of normal endosperm maize under Striga infestation while neglecting quality protein maize (QPM). This study aimed at determining levels of resistance or tolerance of eight new QPM genotypes and four non‐QPM checks to Striga asiatica in the field, pot, and agar gel experiments. Under field conditions, genotypes were evaluated in three different Striga‐endemic locations during the 2014–2015 and 2015–2016 cropping seasons using a four‐by‐three α‐lattice design with three replications. In the pot experiment, genotypes were arranged in 12 × 2 factorial treatments in a six‐by‐four α‐lattice design replicated four times. In the agar gel experiment, genotypes were arranged in a randomized complete block design replicated four times. In the field experiment, genotype × environment interaction was significant (p < 0.001) for grain yield, and MQ623, SC643, SC527, and SC535 were high yielding and more stable than non‐QPM genotypes. In the pot experiment, these genotypes also exhibited desirable Striga tolerance, whereas variation was significant (p < 0.05) for Striga treatments and genotype main effects, as well as for Striga × genotype interaction for root biomass and root/shoot biomass ratio. Five QPM genotypes (MH1416, MQ623, SC643, SC527, and SC535) produced higher and more stable grain yields than most of the non‐QPM checks in Striga‐infested fields. These genotypes provided alternative QPM sources that can perform relatively well in Striga‐endemic areas.

Breeding for Quality Protein Maize (QPM) Varieties: A Review

The nutritional evaluation of quality protein maize (QPM) in feeding trials has proved its nutritional superiority over non-QPM varieties for human and livestock consumption. The present paper reviews some of the most recent achievements in development of QPM varieties using both conventional and molecular breeding under stressed and non-stressed environments. It is evident that numerous QPM varieties have been developed and released around the world over the past few decades. While the review points out some gaps in information or research efforts, challenges associated with adoption QPM varieties are highlighted and suggestions to overcome them are presented. The adoption of released varieties and challenges facing QPM production at the farmer level are also mentioned. Several breeding methods have been conventionally used to develop QPM varieties in stressed (drought, low soil nitrogen, resistance to grey leaf spot, Turcicum leaf blight, ear rot, and Striga) and non-stressed environments. At least three genetic loci have been found to be implicated in controlling the levels of a protein synthesis factor correlated with lysine. They have been mapped on chromosomes 2, 4, and 7. While the use of molecular approaches will improve the efficiency and speed of variety development, the cost implications might limit the use of these technologies in the developing world. More emphasis should be given to breeding QPM for tolerance to environmental stresses, such as low soil pH, heat, and combined heat and drought stress. The post-harvest attack of QPM grains should also be considered. The adoption of QPM genotypes by farmers has been found to be limited mainly due to the minimal collaboration between maize breeders, farmers, agricultural extension workers, and other relevant stakeholders, as well as the need for isolating QPM varieties from normal maize. Therefore, there is need to use participatory plant breeding (PPB) and/or participatory variety selection (PVS) to enhance and improve the adoption of QPM varieties.

The ND EarlyQPM program: developing the next generation of healthier maize (Zea mays L.) products

There is a need to develop the next generation of healthier crop products for an improved human and animal nutrition. Maize (Zea mays L.) cultivars with improved amino acid profiles are essential to diets focused on this crop. Breeders have added crop value with the development of quality protein maize (QPM). However, QPM cultivars have never been an option to farmer and ranchers in short-season environments. The objectives of this research were: (1) to adapt QPM genotypes to the northern U.S. through the North Dakota (ND) EarlyQPM Program, and (2) to develop new early generation SS and non-SS short-season QPM lines and populations for breeding purposes. Fifty-three inbred lines, including 47 QPM donor lines, five experimental North Dakota State University (NDSU) lines, and one ex-PVP line from industry, were selected to produce 94 early-QPM backcross populations. Considering earliness, protein content, and amino acid levels, 218 early generation lines were selected for producing testcrosses with industry testers. Experiments evaluating testcrosses were arranged in 10 × 10 and 12 × 12 partially balanced lattice designs across three ND locations in 2013 and 2014. A total of 48 lines were selected for further development, 17 representing the Stiff Stalk (SS) heterotic group and 31 representing the non-SS group. Selected lines showed, in hybrid combinations, not only above average grain yield, rate of dry down, and total protein content but also high levels of lysine, tryptophan, and methionine essential amino acids for feedstock nutrition. The results of this research show, for the first time, the successful adaptation of QPM genotypes to short-season environments. As a result, new ND EarlyQPM germplasms and lines have been developed for potential release.

Evaluation of Quality Protein Maize Genotypes for Grain Yield in Mid Hill Districts of Nepal

The present study pertaining to the identification of high yielding quality protein maize genotypes was conducted under coordinated varietal trials (CVT) at Khumaltar (Lalitpur) and Kabre (Dolakha) from 2011 to 2012 summer season and under coordinated farmers' field trials (CFFT) at Lumle (Kaski), Kimugaun (Dailekh) and Kabre (Dolakha) in 2011 summer season and at Dailekh and Kabre in 2012 summer season. The results of these trials showed that the genotypes namely Obatanpa followed by S99TLWQ-B and S01SIYQ produced the highest grain yield under coordinated varietal trials and genotypes namely S99TLYQ-B followed by S01SIWQ-3 and Poshilo Makai-1 produced the highest grain yield under coordinated farmers' field trials across testing sites and years. It is suggested that the superior genotypes derived from CFFT could be released and then recommended to farmers of mid hills of Nepal.International Journal of Life Sciences 10 (1) : 2016; 7-9

Performance evaluation of quality protein maize genotypes across various maize production agro ecologies of Nepal

To identify superior quality protein maize genotypes for grain yield under different agro climatic conditions of terai and hill districts in Nepal, the coordinated varietal trials (CVT) were conducted at Dailekh, Doti, Salyan, Lumle and Pakhribas in 2013 and Salyan, Pakhribas and Kabre in 2014 during summer season and coordinated farmer’s field trials (CFFT) at Surkhet and Dailekh in 2013 and Salyan, Pakhribas and Khumaltar in 2014 during summer season. The experiment was carried out using randomized complete block design with three replications for CVT and CFFT. Across the locations and years the superior genotypes found under CVT were S01SIYQ, S01SIWQ-2 and Poshilo Makai-1 where as S99TLYQ-HG-AB, S99TLYQ-B and Poshilo Makai-1 were found superior genotypes under CFFT. The superior genotypes derived from CFFT will be promoted further for similar environments across the country.Journal of Maize Research and Development (2015) 1(1):21-27DOI: http://dx.doi.org/10.5281/zenodo.34282

Grain Yield Stability of Quality Protein Maize Genotypes across Diverse Environments of Terai and Mid Hills in Nepal

Maize is produced in diverse environmental conditions in Nepal. National Maize Research Program regularly tests maize genotypes for their grain yield stability in highly diverse environments. The objective of this paper is to estimate grain yield stability of quality protein maize genotypes across different environments. Two quality protein maize genotypes namely Poshilo Makai-1 and S99TLYQ-HG-B along with Farmer’s variety were tested at nine different locations of Nepal in four consecutive years before 2013 under farmer’s fields. Alpha-lattice design with two replications was used. The results of these studies revealed that S99TLYQ-HG-B was more stable followed by Poshilo Makai-1 as compare to Farmer’s variety. The overall higher mean grain yield and regression coefficient (b) near to unity showed that S99TLYQ-HG-B is the most adaptive genotype across the tested environments. However, more than unity regression coefficient (b) indicates that Poshilo Makai-1 could be the recommended variety for better environments under farmers’ management.

Growth and Development of Quality Protein Maize (QPM) Genotypes As Influenced by Irrigation and Plant Population in a Sudan Savanna Ecology, Nigeria

An experiment was carried out to assess the growth and development of quality protein maize (QPM) genotypes to various plant populations under different irrigated conditions in a semi arid ecology of Northern Nigeria. Field trials were conducted at the Irrigation Research Station, Institute for Agricultural Research, Kadawa (11 o 39’ N, 08 o 20’ E) and 500 m above sea level) for three years, 2007, 2008 and 2009 during dry seasons to study the effect of three maize ( Zea mays L .) genotypes (TZE - W Pop X 1368, EV - DT W99 STR and DMR - ESRW), four plant populations (33,333, 44,444, 55,555 and 66,666 plants ha - 1 ) and three irrigation scheduling regimes (40, 60 and 80 centibars soil moisture tension) on the growth and development of QPM. This was a three trial experiment with factors arranged in a split plot design, whereby genotype and irrigation scheduling

Interactive Effects of Genotype X Year on Disease Reactions , Grain Yield and Other Agronomic Traits of Newly Developed Quality Protein Maize in Nigeria = تأثير التداخل بين المورثات و السنة على التفاعل المرضي ، إنتاج الحبوب و الصفات الزراعية الأخرى للذرة المطورة حديثا عالية المحتوى البروتيني في نيجيريا

Experiments were conducted on six newly developed open pollinated quality protein maize (QPM) genotypes and two check entries for three years (2009-2011). The objective was to assess their yield potentials and disease tolerance/ resistance in the southern Guinea savanna agro-ecology of Nigeria. Genotype and year of evaluation were significant for (P<0.01 and <0.05) for grain yield, harvest moisture and lodging characteristics. Genotypes x year interactive effect for grain yield revealed different genotypic performance of the genotypes tested with two checks (Oba-Super 1 and DMR-LSR-Y) being responsible for the significant differences obtained in the three years of evaluation. Average grain yield was significantly higher in the year 2011 compared to 2009 and 2010. All the genotypes tested were moderately tolerant to the five diseases ranging from 1.5 (Streak virus) in Oba-Super 1 (check) to 2.9 (Southern leaf blight, Curvularia leaf spot and Leaf rust) in the ART98-SW6-OB and ART98-SW4-OB respectively. Ear rot mostly affected the leaves among diseases with a range of 2.3 to 2.8 in TZPB-OB and DMR-LSR-Y respectively.. Four QPM genotypes (ART98-SW5-OB, ART98-SW4-OB, TZPB-OB and ART98-SW6-OB) were superior for grain yield with yield advantage of 28% over the best OPV check. These QPM genotypes can therefore serve as useful replacement for existing cultivars and also as source of genes for future maize breeding activities in the development of superior maize varieties with high protein contents for the savanna agro-ecology.

Host–pathogen interaction of maize (Zea mays L.) and Aspergillus niger as influenced by arbuscular mycorrhizal fungi (Glomus deserticola)

This study was carried out to investigate the interaction of maize and Aspergillus niger as influenced by arbuscular mycorrhizal fungi (AMF). Three quality protein maize (QPM) genotypes (ILE1-OB, ART-98-SW5-OB and ART-98-SW6-OB) and two market accessions (Ilishan and Shagamu) were evaluated in a pot experiment conducted under natural environment conditions at the Research and Teaching Farm of Babcock University, Ogun State, Nigeria. AMF (Glomus deserticola) in mixtures of soil and root fragments was inoculated at the rate of 15 g per plant, while maize was artificially infected with A. niger (15 cfu ml−1) in each designated pots. The coefficient of emergence (COV), percentage emergence (% E) and disease severity were determined using standard methods. Generally, plants treated with AMF only produced the highest cumulative cob yield (18 g), followed by plants treated with AMF and A. niger (15 g) and then control (12 g), while the least was recorded for only A. niger-treated plants (4 g).