CREA Journals (Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria)
Not a member yet
791 research outputs found
Sort by
Quantitative Trait Loci Mapping in Maize for Resistance to Larger Grain Borer
Full text linkStorability of maize grain is constrained by the larger grain borer (LGB) (Prostephanus truncatus). Host plant resistance is the most feasible way to manage LGB among smallholder farmers. Breeding for resistance to this pest inmaize is dependent on understanding genetic mechanisms underlying the resistance. The objective of this study was to map quantitative trait loci (QTL) associated with LGB resistance in tropical maize. A mapping populationof 203 F2:3 derived progenies was developed from a cross between susceptible and resistant inbred lines.The F2:3 progenies were crossed to a tester and testcrosses evaluated across six environments, followed by screening for resistance to LGB. Data was collected on husk cover tip length, and grain texture in the field. Biochemical traits were analyzed on the maize grain. Harvested grain was evaluated for resistance and data recorded on grain damage, weight loss, and several insects. Grain hardness was measured as a putative trait of resistance. Univariate analysis of variance for all the traits was done using the general linear model of the statistical analysis system.Genetic mapping was done using Joinmap 4, while QTL analysis was done using PLABQTL. The QTL for resistance were mapped to 6 out of the ten chromosomes. QTL for resistance traits were located in chromosomes 1, 5 and 9.Chromosome 1 had a common QTL linked to protein content, grain hardness, and husk cover tip length. Additive genetic effects were prevalent in all detected QTL. Overall, the studies show that breeding for resistance to LGB is possible
Lessons learned from the past: forestry initiatives for effective carbon stocking in Southern Italy
Full text linkCalabria (Italy) is a particularly interesting region of the Mediterranean basin from the perspective of forest management due to the extension of reforestation activities aimed at soil conservation. According to international agreements, these reforestation activities fulfill other functions as well, including carbon storage. Thus, Calabria was selected as a representative area for a study on the different typologies of forest plantations to verify the effects of these functions. Results showed a significant increment in carbon stock compared to the previous land use (i.e. arable land and pastures) and how the average carbon stock per hectare varies in relation to the species considered at the above- and below-ground levels. Carbon stock was higher in conifers (Calabrian pine, Douglas fir) and lower in broad-leaved trees (Turkey oak, European chestnut). The study analyses demonstrate how, based on different intensities of thinning, the carbon eliminated by trees is reconstituted over time in quantities larger than those eliminated by cutting. This latter aspect is relevant, as forest management allows the partial removal of biomass produced without negatively affecting carbon stock. Consequently, reforestation and sustainable forms of forest management are powerful strategies for mitigating the effects of climate change
Combining ability and heterosis of maize (Zea mays L.) populations from the Algerian Sahara Desert under Mediterranean drought conditions
Full text linkDrought causes significant yield reduction in maize (Zea mays L.), and germplasm from the Saharan Desert offers potential sources of drought tolerance. Our objectives were to estimate heterosis and combining abilityamong Algerian maize populations under drought conditions and to identify populations and crosses as sources of drought tolerance for breeding programs in temperate environments. A diallel design without reciprocal ofsix populations was used. The populations per se, their respective crosses, and checks were evaluated in Algiers (Algeria) in 2016, 2017 and 2018. Algerian maize populations exhibited high phenotypic variability and genetic divergence under water stress. The populations IGS and AOR per se could provide favorable alleles for higher early vigor under drought, MST for reducing anthesis-silking interval (ASI), and both AOR and SHH for increasing yield under water stress. Among all crosses, IGS × MST was the most outstanding cross for reducing ASI, and IGS × SHH and BAH × SHH for increasing yield under water stress. Our results confirm the existence of heterotic relationships among Algerian maize populations from diverse origins under water stres
The predicted impact of climate change on maize production in Northern Serbia
Full text linkThe projected climate change is expected to have detrimental impact on agricultural production in Northern Serbia, which imposes the need to develop mitigation strategies that will provide a stable yield and income of growing plants in the coming years. Maize is the most important crop in Serbia which occupies the largest sown area. In the present study, the aim was to determine how the average yield of rainfed maize will change in near future (2001-2030) relative to the present and if the currently or higher irrigation rate can be used as a strategy to mitigate the effect of predicted weather scenario on maize yield. AquaCrop model was calibrated with the data derived from the field experiment with rainfed and irrigated maize (2015-2018) (relative standard error ≤ 5% in rainfed and ≤ 7.3% in the irrigated trial), which was used for the simulation of maize yield. The results of the validation showed very good performance of the model (root mean square error of 0.22 and 0.16 was obtained for rainfed and irrigated maize, respectively). The model predicts the loss of maize yield of 15% with respect to maize yield from the experiment. In the predicted scenario, irrigation with average irrigation rate of 200 mm applied in the region of Northern Serbia is expected to increase the yield of maize by approximately 28%. Increased irrigation rate (250 and 300 mm) will reduce the yield of maize in comparison to the current one, thus the creation of stable maize hybrids with the increased water use efficiency should be considered as a strategy for alleviating climate change effect on maize production in the near future.
Heterosis of early generation white maize (Zea mays L.) Inbred lines for yield and yield components in mid altitude sub-humid agroecology of Ethiopia
Full text linkThe objectives of this study were to calculate heterosis of twelve inbred lines of white maize and identify good hybrids based on grain yield data and other yield-related traits. Thirteen inbred lines (13) were crossed in 2017 with two inbred line testers using a line by tester mating design. Twenty-six crosses were generated and evaluated in a randomized incomplete block design (RCBD) with two standard checks and 3 replications during the long rainy seasons between June to December, 2018 at Bako National Maize Research Center, Ethiopia. Also, adjacentto the hybrid trial, thirteen parental lines with the two tester lines were evaluated using RCBD with three replications. Mean separation was done using least significant differences (LSD). The overall mean grain yields (GY) of the genotypes (crosses) were 6.32 t/ha ranging from 5.21 t/ha to 8.19 t/ha. Heterosis for mid parent, better parentand standard were estimated for inbred lines. The highest significant positive heterosis over the best standard check for GY was recorded for L10 XT2 (334.21%). Inbred lines that showed positive heterosis over better parent and midpart for GY can used for germplasm source for maize breeder
Evaluation of multi-environment grain yield trials in maize hybrids by GGE-Biplot analysis method
Full text linkExperiments were conducted in 2014 and 2015 at locations from Sakarya, Adana, Sazak, Ceyhan, Yuregir, Bursa, Antalya, Samsun, and Izmir. PR31G98, PR31A34, Kalumet, P 3167, Adasa16, 72MAY99, PAN34015, P1429, ZP873, MAS71B, MAS78T, Sagunto, SY Hydro, PL 772, LG30600, P1758, P2088, Kebeos and Kamperos hybrid dent corn cultivars were used as plant material. Experiments were conducted in a randomized block design with four replications. The primary objective of the study was to determine the stability of 19 hybrid dent corn cultivars in 16 environments with the aid of GGE-Biplot analysis. According to variance analysis concerning grain yield data, genotype × environment interaction was found to be significant. Considering the total variation in grain yields, the environment represented 82.32% of total variation. Genotype and genotype × environment interaction constituted 9.33% and 8.36% in total variation, respectively. GGE-biplot analysis explained 65.91 % of the total variation. Experimental environments were distributed over four mega-environments. E8 with a close position to average environment coordinate (AEC) and high vector length was identified as the environment with the largest capability of representing the different environments and largest genotype separation power. Despite the high grain yield scores of G8, G17 and G18 genotypes, G8 with a close position to AEC was identified as the most stable genotype
Screening methods, genetic variability and correlation studies for Aspergillus flavus resistance in sub-tropical maize (Zea mays L.)
Full text linkMaize is an important cereal crop and a significant contributor to global food and nutritional security. The consumption and nutritional qualities of maize are severely affected by aflatoxin B1. Aflatoxin B1 is a potent carcinogenic,mutagenic and teratogenic secondary metabolite produced by Aspergillus flavus. Nonchemical and sustainable management of aflatoxin B1 contamination necessitates resistant maize inbred lines for aflatoxigenicA. flavus and subsequent production of aflatoxin B1. In the present investigation, we have screened thirty diverse Indian maize inbred against aflatoxigenic isolates AF1 and AF3 using kernel screening assay (KSA) method and indirect competitive ELISA (Enzyme-Linked Immunosorbent Assay). The results showed the lower A. flavus colonization (13.33-23.33%) in five maize inbred lines viz., M6, M7, M9, M17 and M22. Similarly, the inbred lines M3, M8, M14, M15 and M17 showed lower aflatoxin B1 concentration (0.09-7.03 μg/g) under both AF1 and AF3 infections. We showed the association and reliability between the rapid lab based KSA screening Side Needle Spore Suspension (SNSS) inoculation methods with five tolerant inbred lines and susceptible lines M2, M4 and M5 and check line M24. The five inbred lines viz., M6, M7, M9, M17 and M22 showed the least infection in field condition (1-2%) compared to M2, M4, M5 and check M24 (92%). Our investigation showed that KSA could be employed for rapid screening of maize genotypes for aflatoxin tolerance and the SNSS inoculation method is more effective in the field. Further, five inbred lines M6, M7, M9, M17 and M22, identified as the resistant source to aflatoxin,could be employed as candidates for basic and applied maize research in the Indian maize breeding programme
Comparison among four maize varieties in conventional and low input cultivation
Full text linkIn this work we compared, using a randomized block design, four early maize (Zea mays L.) varieties: three traditional varieties (Millo Corvo, Scagliolo, Agostanello) and one modern hybrid (LG 25.38) grown in conventional vs low input farming. We recorded different agronomic parameters and we performed bromatological and ICP-MS analyses, and also quantified carotenoids, anthocyanins and mycotoxins. The analysis of agronomic parameters showed a general trend of better yields from conventional farming. Bromatological analysis did not show significant differences, we found more differences among varieties than between conventional and low input farming. Regarding minerals analysis, with the exception of the iron content, which was significantly higher from low input farming, we found high variability among the genotypes studied. The anthocyanins content, analyzed in the colored variety Millo Corvo, showed a statistically higher value in low imput farming. Finally, in both cultivation methods the level of fumonisins contamination was under the threshold limit. Taken together our data suggest that the effect of the genotypes was considerably higher than the effect of the cultivation method, hence it is the choice of the variety that will determine the nutritional value of the product harvested
Heredity of chloroplast pigments parameters of maize (Zea mays L.)
Full text linkThe environmental adaptation of maize germplasm is mainly controlled by certain genes. This factor is influenced by both the genotype and the environment itself. The gene is able to express itself in the germination and seedling vigor under the occurring conditions. The following 13 maize cultivars were used: NK Cooler, Delitop, Gazele, NK Ravello, ES Palazzo, ES Paroli, Clarica, PR 39 G 12, SY Cooky, Drim, SY Mascotte, ES Fortran and PR 39 K 13. The experimental design was completely randomized, with four replications. Selection for high and low chlorophyll content was performed in the field using the SPAD chlorophyll meter, and response to selection was measured in field evaluations of the populations. We evaluated the SPAD, content of: chlorophyll a, chlorophyll b, chlorophyll a+b, chlorophyll a/b and carotenoids. Data were submitted to analysis of variance. For comparison of means, we adopted the Tukey’s honestly significant difference at the 0.05 level. The coefficients of phenotypic, genotypic and environmental variation as well as heritability and genetic gain were estimated. The results indicated genetic variability for the different traits of the studied chloroplast pigments, with high heritability and possible genetic gain with the potential to be used in breeding programs
Macroelement and nitrate contents in maize leaves under different nitrogen fertilization
Full text linkThe aim of this research was to quantify the effect of fertilization with different nitrogen levels and different type of fertilizers in three developmental stages of maize plants (5 leaves, flowering and milk maturity). Five nitrogen levels (80 kg/ha; 120 kg/ha.; 160 kg/ha; 200 kg/ha and 240 kg/ha) and two type of nitrogen fertilizers (Ammoniumnitrate and Urea) were applied in the experimental trials. The response of maize to the fertilization levels and type of fertilizers showed some influences on chemical content of maize leaves in different developmental stages. The total nitrogen and nitrates content increased at the same time with fertilization level, but the other chemical elementcontents (calcium, phosphorus pentoxide, calcium, potassium, magnesium) decreased when high quantities (240kg/ha) of fertilizers are used. Additionally, this study showed that the nitrates content was highest in the first development stage of plants, especially when ammonium nitrate fertilizer was used