Quality Protein Maize Varieties Research Articles

Economic injury levels of fall armyworm (<i>Spodoptera frugiperda</i> Smith) at early-whorl vegetative growth stage of quality protein maize variety

Economic injury levels of fall armyworm (<i>Spodoptera frugiperda</i> Smith) at early-whorl vegetative growth stage of quality protein maize variety

Genetic Evaluation of Heterosis and Combining Ability of Quality Protein Maize (Zea mays L.) Hybrids under Terminal Heat Stress Conditions

Background: The development of quality protein maize (QPM) hybrids tolerant to terminal stress environments has been an essential strategy for reducing the associated loss in grain yield. A study by Badu-Apraku et al., (2019) employed line × tester analysis in QPM breeding, highlighting its efficacy in selecting QPM hybrids. While QPM varieties resistant to disease, drought and environmental stresses have been developed conventionally, the adoption of improved QPM genotypes in farmers’ field is restricted mainly due to lack of proper team effort among maize breeders, farmers, agricultural extension workers and other relevant stakeholders. Methods: In line × tester mating design, six lines and three testers were crossed under heat stress environment and 18 F1s along with parental lines were evaluated along with check varietal during summer season, 2023, P.G research farm, CUTM, Paralakhemudi, Odisha. The objective of the current study was to evaluate parental lines and its crosses based on combining ability and heterosis. Result: ANOVA revealed significant to revealed significant differences for all the traits between parents, lines, testers and lines vs testers, except for cob height, chlorophyll content and canopy temperature. 𝛔2GCA/𝛔2SCA values for parents/hybrids recorded lower than unity for all the trait studied suggesting preponderance of non-additive gene action. Parental lines CML149, CML143 and CML330 are the best general combiners for early flowering, grain yield per plant and antioxidant status. Among eighteen crosses, two hybrids CML149 × CML330 and CML143 × CML193 recorded significant SCA effects for early flowering, grain yield per plant and antioxidant levels. Hybrids CML149 × CML330 (33.31%) and CML143 × CML193 (28.31%) noted significant standard heterosis for grain yield per plant over commercial check, HQPM-1. Hybrids CML149 × CML330 and CML143 × CML193 were resilient to terminal heat stress as they didn’t exhibit signs of leaf firing, tassel blast, root lodging and loss of yield.

Nutritional characterization of quality protein maize (QPM) (Zea mays L.) protein concentrates

Maize is considered a staple food for the population; however, its protein contribution to the development of individuals is limited by its low quality. Quality protein maize varieties (QPM) have been developed to remedy this. The protein quality presents in protein concentrates obtained from two QPM varieties was evaluated: Sac Beh (SB) and Chichen Itza (ChI), which were compared with a traditional variety (Blanco Uxmal, BU) as a control. All were evaluated with non-nixtamalization (NN) and nixtamalization (N). Amino acid profile, in vitro digestibility, calculated protein digestibility-corrected amino acid score (PDCAAS), calculated protein efficiency ratio (c-PER), and biological value (BV) were determined. The extraction process of the QPM concentrates and nixtamalization had important effects on the essential amino acids Lys and Trp. In vitro digestibility showed significant differences (p < 0.05). The predominant limiting amino acid was tryptophan. The QPMs were closer to the requirements of the FAO/WHO standard, since they obtained chemical score values higher than 100% for His and Leu. PDCAAS values decreased in the amino acid tryptophan of SB and BU nixtamalized maize compared with the NN. PER7 and PER10 values were statistically higher (p < 0.05) in the QPMs compared to the BU control. The estimated biological value showed an imbalance in the concentration of essential amino acids. Lys and Trp in the QPM varieties were not sufficient evidence of increased biological value the proteins, due to the effect of the extraction processes and the alkaline heat treatment to which the maize grains were subjected.

Revealing the process of storage protein rebalancing in high quality protein maize by proteomic and transcriptomic

Quality protein maize (QPM) (Zea mays L.) varieties contain enhanced levels of tryptophan and lysine, exhibiting improved nutritive value for humans and livestock. However, breeding QPM varieties remains challenging due to the complex process of rebalancing storage protein. This study conducted transcriptome and proteome analyses to investigate the process of storage proteins rebalancing in opaque2 (o2) and QPM. We found a weak correlation between the transcriptome and proteome, suggesting a significant modulating effect of post-transcriptional events on non-zein protein abundances in Mo17o2 and QPM. These results highlight the advantages of proteomics. Compared with Mo17, 672 differentially expressed proteins (DEPs) were identified both in Mo17o2 and QPM, and several of them were associated with storage protein, starch, and amino acid synthesis. We identified 178 non-zeins as DEPs in Mo17o2 and QPM kernels. The up-regulated non-zein DEPs were enriched in lysine, tryptophan, and methionine, which affected the protein quality. Co-expression network analysis identified regulators of storage protein synthesis in QPM, including O2, PBF1, and several transcription factors. Our results revealed how storage protein rebalancing occurs and identified non-zein DEPs that may facilitate superior-quality QPM breeding.

On-farm agronomic performance and farmer preference of quality protein maize grown under conservation agriculture in Southern Africa: a case for Zimbabwe

AbstractMaize is the most important staple food crop in southern Africa with human consumption averaging 91 kg/capita/year. Most smallholder farmers and weaning children depend on maize for much of the daily food requirements and it is the largest contributor of dietary proteins. Despite the development of quality protein maize (QPM) with high tryptophan and lysine content, stunting and kwashiorkor remain high in southern Africa partly due to low adoption of QPM varieties. The objective of this study was to compare the agronomic performance and farmer preferences of new generation of QPM with non-QPM varieties under conservation agriculture on-farm conditions. Eight QPM and four non-QPM varieties were tested on on-farm trials in Zimbabwe during the 2014/15 and 2015/16 cropping seasons at five different locations. Significant differences were detected among the genotypes for the measured traits in the two seasons. Similarly, genotype plus genotype × environment interactions were significant for both seasons for grain yield. Three QPM varieties, SC527, SC535 and SC643, recorded the highest and stable yield. Four QPM varieties, SC643, SC535, SC527 and MQ623, and a non-QPM variety, PAN413, were ranked high among farmers for overall ear characteristics as their most preferred varieties. The high-yielding and stable QPM varieties are likely to be adopted by farmers in southern Africa.

Nutrient composition, starch microstructure and thermal properties, and in vitro availability of selected minerals of nixtamalized Philippine quality protein maize variety IPB Var 6 and the production of healthy loaf bread using nixtamalized corn–wheat flour blends

Corn is one of the most important food crops globally providing at least 30% of the food calories in developing countries. This study aimed to determine the nutritional content and starch properties of nixtamalized Philippine quality protein maize (QPM) variety and its potential as a flour substitute in loaf bread production. The nixtamalized Philippine QPM flour had a significant increase in moisture and calcium contents. In vitro availability of calcium, iron, and zinc was relatively lower and associated with phytate content. The developed loaf bread utilizing the optimum nixtamalized corn–wheat flour blend had improved nutritional value and had no significant difference in sensory characteristics compared with the control loaf bread made from wheat flour. The use of nixtamalized IPB Var 6 flour as an ingredient in loaf bread making improved its crude fiber, calcium, and iron levels and can be a nutritious potential substitute ingredient for baked products. Novelty impact statement The process of nixtamalization can improve the nutritional content of corn and has the potential to improve the quality of a food staple such as loaf bread. Incorporating nixtamalized QPM flour into loaf bread resulted in increased fiber, protein, and calcium contents, and it was also acceptable to the consumers in terms of sensory characteristics and general acceptability. Data on the nutritional content and availability of selected minerals of nixtamalized QPM flour can be used as basis for future researches to optimize the method to maximize its potential effects in the improvement of the nutritional value of QPM, thereby providing a healthier alternative staple for the consumers.

Evaluation of Quality Protein Maize Variety under Integrated Uses of Different Fertilizer Sources in Jimma, South Western Ethiopia

Studies on the combined use of organic and inorganic fertilizers for maize are lacking at Jimma conditions. Therefore, a field experiment was conducted to determine the effect of integrated uses of organic with inorganic fertilizers sources on productivity of quality protein maize (QPM) variety BHQPY545 at Kersa, Omonada woreda and Jimma on station, Southwestern Ethiopia during 2016 and 2017 main cropping seasons and one year validation at Omonada woreda. The experiment involved factorial combinations of inorganic and organic fertilizer with negative control, 150 kg ha -1 NPSZnB+140 kg ha -1 urea top dressed, recommended NP 2 O 5 (92/69 kg ha -1 ), 100% compost, 25% compost + 75% recommended NP, 50% compost + 50% recommended NP, 75% compost + 25% recommended NP and 100% compost + 100% recommended NP fertilizer which was laid out in randomized complete block design (RCBD). The compost was added based on N equivalency of recommended fertilizer rate. Data on yield and yield components of maize were subjected to ANOVA using SAS version 9.3. The over location and year highest grain yield (8443 kg ha -1 ) and above ground biomass (21.52 t ha -1 ) was obtained from 100% compost + 100% recommended NP fertilizer. Partial budget analysis revealed 100% compost + 100% recommended NP fertilizer realized the maximum net return (39,718 ETB) with marginal rate of return (94%). From farmers decision point and current on farm input availability and technical feasibility and economic analysis, 92/69 kg ha -1 N/P 2 0 5 fertilizer application taken as optimal fertilizer application and recommended for production of BHQPY545 in Jimma area and other similar humid agro-ecologies of southwestern Ethiopia. Keywords : Grain yield, inorganic fertilizer, organic fertilizer, recommended fertilizer rate, soil health. DOI: 10.7176/ALST/88-01 Publication date: July 31 st 2021

Quality protein maize (QPM): Importance, genetics, timeline of different events, breeding strategies and varietal adoption

AbstractLysine and tryptophan are two essential amino acids and these are deficit in maize grain thus posing the problem of nutritional deficiencies in the consumers. A wide range of deficiency symptoms like cognitive disorder, kwashiorkor disease, reduced appetite, impaired skeleton development, delayed growth and aberrant behaviour are associated with lysine and tryptophan deficiency. These amino acids are also important to cure the Pellagra disease. Researchers identified several mutants in maize especially opaque‐2 which are responsible for higher lysine and tryptophan contents. Few years later, it was observed that opaque‐2 mutant has several pleiotropic effects on maize grain and plant. Efforts of researchers are spanning over the period of four decades to develop quality protein maize (QPM). QPM is described as nutritionally superior maize with high lysine and tryptophan contents and desired kernel characteristics as compared to its normal maize counterparts. Biological value of QPM was almost equivalent to egg protein. Breeding of maize for quality protein is based on three genetic systems like opaque‐2 genetic system, endosperm modifier genetic system and associated gene systems. Keeping in view the importance of QPM, current review article is compiled to discuss the genetic basis, genetic systems and breeding strategies. Timeline for various events is also drafted like discovery of various mutants, several conventional and modern approaches for development and deployment of QPM varieties across the world. Despite its nutritional benefits, the rate of adoption of QPM is generally at low pace in the developing world and this review article discuss the challenges and potential opportunities for QPM adoption.

Expression profile of protein fractions in the developing kernel of normal, Opaque-2 and quality protein maize

Maize protein quality is determined by the composition of its endosperm proteins, which are classified as nutritionally poor zeins (prolamin and prolamin-like) and nutritionally rich non-zeins (albumin, globulin, glutelin-like, and glutelin). Protein quality is considerably higher in opaque-2 mutants due to increased content of non-zeins over zeins. However, the opaque-2 endosperm is soft, which leads to poor agronomic performance and post-harvest infestation. Endosperm modification of opaque-2 had led to the development of Quality Protein Maize (QPM), which has higher protein quality along with hard kernel endosperm. The present study was planned to analyze the expression dynamics of different protein fractions in the endospem of developing maize kernel in normal, opaque-2 and QPM in response to the introgression of endosperm modifiers. Results revealed that albumin and globulin content decreases, whereas, prolamin, prolamin-like, glutelin-like, and glutelin content increases with kernel maturity. It has been observed that opaque-2 mutation affects protein expression at initial stages, whereas, the effect of endosperm modifiers was observed at the intermediate and later stages of kernel development. It has also been noted that prolamin, glutelin, and glutelin-like fractions can be used as quick markers for quality assessment for differentiating QPM varieties, even at the immature stage of kernel development. Overall, the present study implicates the role of different protein fractions in developing and utilizing nutritionally improved maize varieties.

Evaluation of Genetic Diversity of QPM, Provit-A, and Elite Maize Inbreds Resistant to Downy Mildew Disease Using Simple Sequence Repeats

&lt;p&gt;Functional maize tends to be more susceptible to major maize diseases, particularly Downy mildew. Among the functional maize are Quality Protein Maize (QPM) and Provit A maize. The presence of higher amino acid and beta carotene in functional maize might have caused these types of maize more susceptible to Downy mildew disease. The objective of the research was to identify the heterotic pairs among maize inbreds i.e. QPM, Provit A, and local maize varieties resistant to Downy mildew disease using Simple Sequence Repeats (SSR) marker. The research was conducted from April to July 2017 at the Molecular Biology Laboratory of Indonesian Cereals Research Institute. A total of five QPM inbreds, 15 Provit A inbreds, and 11 Downy mildew resistant local varieties of maize were used in the experiment using 34 SSR markers. Results indicated that among 34 SSR locus analysed, variation of allele lengths ranged from 74 bp to 500 bp. A total of 125 alleles ranging from two to nine alleles per locus with an average of 3.68 alleles were generated. The data indicated wide genetic variations among characters. DNA band profile showed that nc130 marker produced the highest PIC (over 0.83) and allele value (8.00). Genetic distance analysis found a total of 21 heterotic genotypes with genetic distance exceeds 0.65. &lt;/p&gt;

Seed Vigour of Quality Protein Maize Varieties Belonging to Different Maturity Groups

Laboratory tests were carried out to investigate inherent quality differences among stored seeds of early, intermediate and late-maturing quality protein maize using completely randomized design (CRD) with three replications at the Seed Testing Laboratory of the Institute of Agricultural Research and Training, Obafemi Awolowo University, Moor Plantation, Ibadan, Nigeria for two consecutive years (2014 and 2015). From the results, germination and accelerated ageing germination traits were affected by the storage period. Similarly, the seed performance on germination, accelerated ageing and the conductivity test were seen to be better in early-maturing than in other maturing maize genotypes. The speed of germination measured as the germination index was low; ranging from 3.24-3.68 days after sowing (DAS) irrespective of the maturity group. Seedling traits measured after physiological quality tests were equally affected by the storage period and the maturity group. All the seedling traits measured were better in the early-maturing genotypes. Seed quality measured by laboratory quality assessments showed that genotypes in the early-maturing group are of high quality. Seeds of early-maturing genotypes retained significantly higher physical and physiological quality parameters and appear to have inherent potential to withstand effects of deterioration due to their slower rate of quality decline.

Yield, Tryptophan and Lysine Content of Two Quality Protein Maize Varieties in Two Luvisols with Bio Fertilization in Yucatan, Mexico

This work was carried out in Yucatan Mexico aiming to evaluate the yield performance, Tryptophan (Trp) and Lysine (Lys) contents of two quality protein maize varieties (Sac Beh and Chichen Itza) growing in two Luvisols with low (Lot 1) and high (Lot 2) intensive agricultural use. Six treatments resulted from combining the two varieties with chemical fertilizers (60-80-00):(N-P205-K2O) alone or supplemented with biofertilizers (60-80-00 + Mycorrhizae + Azospirillum) and the control (00-00-00). The variables were: yield (t·ha?1), Trp, Lys (g of amino acid/100 g of protein), Ashes (%) and Crude Protein (%). A Randomized block design was used with three replications for yield, ashes and crude protein and two replications for Trp and Lys. Statistical differences were found only in ashes. Regardless of the intensive soil use both varieties showed good yields, ranging from 5.0 to 6.5 t·ha?1. Higher yields were documented in the low intensive use Luvisol (Lot 1). The higher yields, in Lot 1, were obtained with (T Chem-Bio) whilst in Lot 2 was with (T Chem). Yields increased with the application of chemical fertilizers alone or in combination with biofertilizers but the amount of Trp and Lys decreased. Sac Beh showed to have better protein quality than Chichen Itza but none of them reached the optimal ranges reported in the literature, so more evidence is required to start with a plan to rescue and maintain the protein quality of both varieties.

Development and Quality Evaluation of Commercial Maize Products

The composition of maize endows it with many health benefits. However, maize is naturally deficient in lysine and tryptophan, which are two of eight amino acids regarded as essential for humans and are necessarily to be part of a balanced diet. In light of the above deficiency found in traditional maize the use of Quality Protein Maize (QPM) has brought its usage more productive. QPM differs from common maize in the weight distribution of the five protein fractions. The extent of the change is variable and affected by genotype and cultural conditions. It has been found, however, that the opaque-2 gene reduces the concentration of zein by some 30 percent. As a result, lysine and tryptophan content is higher in QPM varieties than in common maize. QPM based value added products are not available in the market for the consumer, even though products developed from maize have high market potential and are most important food alternative to protein malnourished and gluten sensitive patients. Centre of Excellence on Processing &amp; Value Addition of Maize” initiated in 2014 under nutri farm pilot scheme, Government of India, has developed more than 20 innovative products of maize (Bakery products: Nankhatai, Bread, Toast, Cakes, Salted Cookies, Soya Protein Biscuit, Coconut Cookies, Muffins; Extruded Products: Whey and Butter milk based Pastine, Puffcorn; Traditional Prodcuts: Fortified popcorn, Khaman, Dhokla, Ladoo, Namkeen, Shakkarpara, Mathri). Most of the products have been analyzed for their nutrient content at Food Laboratory of Junagadh Agriculture University, Junagadh, Gujrat. Further they were subjected to panel of judges &amp; consumers for their organoleptic acceptability and they all were found in the category of “liked moderately” to “liked extremely” category of 9 point hedonic scale. Out of several developed few products like Nankhatai, Pastine Khaman, coconut cookies &amp; cake were introduced to market, small shops, &amp; bakery outlets. It was observed that these products have great market potential and may be introduced as the alternatives/ replacement to the refined wheat flour. Results showed that the protein concentrations improved in the developed QPM based products. Salted biscuits were consumable by all age group as snack with tea or coffee. Pasta is partially cooked extruded product which was strongly liked by children and has high market potential. It can be concluded that incorporation of quality protein maize in place of refined wheat flour improved the quality of the maize products in terms of organoleptic acceptability and nutritional parameters. Hence blend of QPM flour and refined wheat flour has potential as an alternative to replace refined wheat flour intake for better health and innovative commercializable product.

Simulation of Growth and Leaf Area Index of Quality Protein Maize Varieties in the Southwestern Savannah Region of the DR-Congo

Logistic and exponential approaches have been used to simulate plant growth and leaf area index (LAI) in different growing conditions. The objective of the present study was to develop and evaluate an approach to simulate maize LAI that expresses key physiological and phonological processes using a minimum entry requirement for Quality Protein maize (QPM) varieties grown in the southwestern region of the DR-Congo. Data for the development and testing of the model were collected manually in experimental plots using a non-destructive method. Simulation results revealed measurable variations between crop seasons (long season A and short season B) and between the two varieties (Mudishi-1 and Mudishi-3) for height, number of visible leaves, and LAI. For both seasons, Mudishi-3, a short stature variety was associated with expected stable yield based on simulation data. In general, the model simulated reliably all the parameters including the LAI. The LAI value for mudishi-1 was higher than that of Mudishi-3. There were significant differences among the model parameters (K, Ti, a, b, Tf) and between the two varieties. In all crop conditions studied and for the two varieties, the senescence rate (a) was higher, while the growth rate (b) was lower compared to the estimates based on the STICS model.

Genetic basis and the current breeding efforts for quality protein maize in Southern Africa

Maize (Zea mays L.) is deficient in essential amino acids, lysine and tryptophan. Opaque-2 maize mutant discovery that is high in lysine and tryptophan, offers an avenue for maize protein quality improvement. Quality protein maize (QPM), a product of the extensive development of the Opaque-2 mutant, is an affordable and viable option for overcoming the scourge of protein malnutrition in humans and monogastric livestock especially in sub-Saharan Africa. The objective of this review was to scrutinise the genetic basis of quality protein maize (QPM), and current breeding efforts, and propose potential uptake pathways for QPM products in southern Africa. The conventional QPM breeding methods are based on phenotypic selection to identify genotypes carrying the recessive Opaque-2 alleles. However, phenotypic selection is negatively influenced by the environment and has huge drain on resources such as time, money and labour, with low genetic gains. From this, marker assisted breeding methods are clearly the most efficient way of QPM breeding. Institutions such as the International Maize and Wheat Improvement Centre (CIMMYT) are currently employing molecular breeding in QPM breeding programmes so as to quicken and ease the process of QPM breeding. To date, a number of QPM varieties have been released and are being promoted using various pathways and policies.Key words: Opaque-2 gene, phenotypic selection, QPM, Zea mays L.

Quality protein maize (QPM) for school feeding in Ethiopia: stakeholders consultation, sensory evaluation and potential impact

Recently there is an increased attention among policy and research practitioners on the link between school feeding programs (SFP) and agricultural development. Through purchases and procurement of locally produced foods, SFP are thought to enhance the domestic production and demand for food and stimulate local agricultural economy. Quality protein maize (QPM) varieties, which are being disseminated in Ethiopia by CIMMYT, are superior to conventional maize (CM) varieties in their protein quality. However, for QPM to be adopted in SFP, sensory acceptance by the end-users should be assessed, specifically when the targets beneficiaries are young children. Furthermore, the potential challenges and opportunities for its supply to SFPs should be analysed by involving pertinent stakeholders involved in maize value chain. Thus, the objective of this study is to assess sensory evaluation of QPM among 95 adolescent girls in two primary schools in Ethiopia on a popular local porridge-like product Kinchie through central location testing, and also assess potential challenges and opportunities in QPM production and distribution through stakeholders’ consultation. Results of sensory evaluation showed that Kinchie made from QPM varieties, both yellow QPM (BHPQY 545) and white QPM (AMHP 760Q), were much appreciated for aroma, taste and overall appreciations. Nevertheless, among QPM varieties, the students liked the Kinchie made from yellow QPM (BHQPY 545) more than Kinchie made from a white colored QPM (AMH 760Q) in all sensory attributes except appearance. The result also showed that the effect of order of food presentation had a significant and positive effect only for aroma (P< .05). Stockholder consultation result also showed that local maize grain producers and traders and other institutions involved in maize value chain were enthusiastic to engage in QPM production and supply through contract farming. In conclusion, consumer acceptance is unlikely to impede uptake and impact of QPM use in the place of CM varieties in SFPs.

Influence of Tillage Systems on Diversity and Abundance of Insect and Nematode Pests of Maize in Malete, Kwara State, Nigeria

Pests are major biotic factors causing up to 45% yield reduction in maize production in sub-Saharan Africa. To develop improved methods for maize management, the species and abundance of insects and nematodes associated with ten quality protein maize varieties (QPMVs) were evaluated with two commonly used tillage practices, ‘plough only plots (POP)’ and ‘plough and harrow plots (PAHP)’. The experiment was carried out using QPMVs at the Teaching and Research Farm of the Kwara State University, Malete, Nigeria, and arranged in a randomized complete block design with 11 treatments replicated 3 times, including local check “pambo”. A total of 833.1±4.0 and 799.3±3.4 arthropods specimens were collected from POP and PAHP, respectively, comprising 8 orders and 18 families. Ootheca mutabilis was the most abundant species with 5.47% (POP) and 5.68% (PAHP) and the least abundant was Rhopalosiphum maidis 1.82% (POP) and 1.80% (PAHP). As indicated by Shannon Wiener (3.46±0.023) and Simpson indices (0.97±0.0008) there are even distribution in the tillage practices. Three genera of plant parasitic nematodes (PPNs) were identified, Meloidogyne spp. (POP (78.33±19.65), PAHP (1.33±0.33), Pratylenchus spp. (POP (41.67±9.26), PAHP (5.00±2.31), and Helicotylenchus spp. (POP (58.33±38.35), PAHP (23.33±14.50). The use of PAHP tillage practices is effective in reducing insects and nematodes associated with maize in Nigeria and therefore recommended for the management of both pests in maize production.

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.

Evaluation of grain yield and related agronomic traits of quality protein maize hybrids in Southern Africa

Maize is the major staple food in southern Africa with human consumption averaging 91 kg capita−1 year−1, and normal maize is nutritionally deficient in two essential amino acids: tryptophan and lysine. Despite the development of quality protein maize (QPM) with high tryptophan and lysine, stunting and kwashiorkor remain high in sub-Saharan Africa due to lack of high yielding and adapted QPM varieties. This study aimed at evaluating a new generation of QPM varieties for yield and related agronomic traits. Before the QPM varieties were validated on-farm, they were simultaneously selected on-station under five different management conditions. In the 2014/2015 season, 10 elite QPM varieties were selected from on-station trials based on high grain yield and stability, and were compared with the best commercial check varieties on-farm. During the 2015/2016 season, some poorly performing QPM varieties were dropped while new ones were added, resulting in 12 elite QPM varieties being evaluated on-farm. Analysis of variance for the 2014/2015 season showed non-significant hybrid × management condition interaction. Mean grain yields across management conditions ranged from 1.5 to 4 t ha−1 and were higher under mild stress (2.3–5.5 t ha−1) compared to random stress conditions (1.1–2.9 t ha−1). Broad sense heritability estimates were low to moderate (11–69%), and thus could still permit effective selection of better genotypes. Yield advantage ranged from 12 to 25% across the 2 years, suggesting effective genetic gains in QPM breeding. QPM hybrids CZH132044Q, CZH142238Q and CZH142236Q were stable and high yielding. Promotion of such QPM hybrids may help reduce protein energy malnutrition.

Potential for quality protein maize for reducing proteinenergy undernutrition in maize dependent Sub-Saharan African countries: A review

Most cereal crops, including maize ( Zea mays L .), are deficient in essential amino acids, such as lysine and tryptophan; hence they are poor in protein quality. A mutant maize with elevated levels of lysine and tryptophan was developed by the International Maize and Wheat Improvement Centre (CIMMYT) and was called quality protein maize (QPM). Nonetheless, people in sub-Saharan Africa (SSA) continue to use normal endosperm maize (non-QPM) instead of QPM. The objective of this article was to examine the existing information on institutional arrangements, infrastructure and social systems hampering adoption of QPM and to identify opportunities for promoting the campaign for its utilisation in SSA, through innovative research for development initiatives. It is clear that QPM has superior nutritional value, both to humans and to monogastric animals compared to non-QPM. Lack of sound policies and awareness among farmers about the existence and advantages of QPM are some of major drawbacks to QPM adoption and realisation of its benefits. Most farmers hardly believe information regarding nutritional composition of varieties, without convincing visual evidence such as grain yield from demonstration plots. Many African governments have mounted campaigns geared to promote adoption of QPM varieties. Varying levels of QPM adoption have been recorded in South Africa, Burkina Faso, Uganda and Ghana with high QPM production under areas ranging from 12 500 to 71 250 ha. In order to reduce protein-energy undernutrition (PEU), SSA countries should implement policies that promote QPM adoption such as providing farmers with a premium price for the QPM grain. Results from meta-analysis community based studies revealed that QPM based diets resulted in a 12% improvement on weight and 9% increase in height in infant and young children compared to non-QPM based diets. Therefore, quality protein maize bears great potential for reducing PEU and its adoption could be high given that most SSA countries depend on maize as the major source of calories and protein. Key Words : Bio-fortification, lysine, malnutrition, tryptophan, Zea mays L.