CREA Journals (Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria)
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Stand structure and anatomical, physical and mechanical characterisation of sessile oak (Quercus petraea Liebl.) wood from central Italy aged coppices.
Full text linkThe present paper aims to implement the knowledge on sessile oak (Quercus petraea (Matt.) Liebl.) in Mediterranean area where, although present, for natural or anthropogenic causes, the species is rare. The focus is on two sessile oak stands in Tuscany (central Italy), classified as worthy of protection for their importance both in a local-national and European context. In addition to the environmental and stand structural characteristics, some technological properties of sessile oak wood grown there, comparing the obtained results to the bibliographic data were provided. The examined wood characteristics are anatomical parameters (growth ring thickness, earlywood and latewood thickness, fiber length, earlywood and latewood vessel diameter, amount of earlywood and latewood vessel) and the physical and mechanical parameters (density, modulus of elasticity, strength, hardness). No appreciable technological differences issued between the examined wood in the two stands and the wood from the same species, but from other Italian and French provenances, obtained from literature. Results highlighted, although managed as coppice in the past, the material is suitable for the reforestation of this endangered species in suitable areas, always taking into account that the quality of the wood is determined not only by the basic technological properties of a certain wood, but also, and mostly, by the growing conditions of the trees and particularly by the sylvicultural management of the stand
Heterotic and heritability pattern of grain yield and related traits in doubled haploid f1 hybrids of maize (Zea mays L.)
Full text linkIn this study, fifteen cross combinations evolved from five doubled haploid maize lines, and three open-pollinated varieties used as testers were evaluated for broad-sense heritability, narrow-sense heritability, heterosis, and heterobeltiosis values during 2017-18. The broad-sense heritability and narrow-sense heritability recorded higher for all the studied traits. Higher broad-sense heritability was recorded for grains per cob (99.6%), grain yield per plant (98.8%), cob length (98.2%), and kernels per cob row (98.1%). Higher narrow-sense heritability was foundin grain yield per plant (87.7%), cob height (79.8%), kernel per cob row (79.5%), cob diameter (68.7%) and grains per cob (66.1%). Most of the crosses exhibited very high values of heterosis and heterobeltiosis and ranged from -0.01 to 37.3 % percent for grain yield. The F1 hybrids, L1×T1, L1×T2, L1×T3, L2×T2, L4×T1, L4×T2, L5×T1, L5×T2, L5×T3, L2×T3, L3×T3, and L5×T3 were shown to be the best with very good heterosis and heterobeltiosis values for most of the grain yield-related traits. Heterosis and heritability analysis indicated that these doubledhaploid lines evolved from a very narrow genetic source (single cross F1 hybrid) showed a great potential toward improvement in grain yield and its related traits. It is recommended that instead of crossing them with low yielding open-pollinated varieties as testers these lines must be crossed in diallel mating designfor further revealing their potential toward grain yield and its related traits
Maize (Zea mays L.) cyclical populations response over diverse environments - developed via recurrent selection
Full text linkThe recurrent selection currently exists as a cyclical breeding technique that has been widely used for improvementin maize (Zea mays L.). In Pakistan maize crop is mainly grown in two seasons i.e., spring (sown duringFebruary 10 to March 10) and summer (sown during June 20 to July 20). Maize base population 'PSEV3' was developedthrough selfed progeny recurrent selection for three years in five consecutive crop seasons (during springand summer - 2014 and 2015, and spring - 2016). During Summer 2017, the present study was aimed to assessthe mean performance of maize improved populations C1 (based on S1 lines) and C2 (based on S2 lines) developedthrough selfed progeny recurrent selection, in comparison to base population (PSEV3-C0) and check genotypes(cultivars Azam and Jalal, and hybrid Kiramat) for earliness and yield traits across four environments (two eachlocation and planting time). Genotypes, locations, and planting times exhibited significant (p≤0.01) differences forthe majority of the traits. However, genotype by location, genotype by planting time, and genotype by locationby planting time interactions were nonsignificant for most of the variables. By comparing with base populationand check genotypes, the improved maize populations [PSEV3 (S1)-C1 and PSEV3 (S2)-C2] showed the best performanceby having early maturity with increased grain yield across the locations and planting times. However, theC2 population was leading, followed by C1 as compared to the original population (C0) and check genotypes forthe majority of the traits. Overall, the selfed progeny recurrent selection was found effective in improving maizebase population 'PSEV3' for maturity and yield related traits
Proteomic profiling of quality protein Maize kernels using mass spectrometry
Full text linkMaize (Zea mays L.) is the third most crucial crop worldwide and is of paramount importance in both humansand livestock diets. Conventional maize varieties have less than half of the amino acids recommended for humannutrition, and this deficiency results in an imbalance of amino acids and low protein content, which has been associatedwith several pathologies, including malnutrition. Thus, different countries have focused on research onfortified foods, such as quality protein maize (QPM) noting that these improved varieties may contain up to 100%more essential amino acids residues than conventional maize. Hence, this study aimed to characterize throughtandem mass spectrometry and bioinformatics analysis, relative expression of polypeptides contained in a hybridvariety of QPM, which allow to identify potential markers with implications in the management and improvementof this crops maintaining their intrinsic characteristics. We identify 262 polypeptides, highlighting those related tomolecular function (catalytic activity, structural molecule activity, and binding) and biological process (cellular andmetabolic process). These results provide the necessary information, not only for the characterization of the QPMproteome through novel tools such as proteomics, but also to describe mechanisms related to different biologicalprocesses such as the embryogenesis, development and growth of grains and eventually plants. PotentiallyIt promotes the discovery of molecular markers (biomarkers) that would allow the improvement of agronomicalprocesses
Triallel analysis for grain yield and its components over pooled environments in maize ( Zea mays L.)
No full textSeven parents were utilized in crossing programme to produce 21 single crosses and 105 three-way crosses tostudy gene actions for grain yield and yield contributing characters. Triallel analysis was conducted for importantyield components i.e.,ear length, ear diameter, number of kernel rows ear-1, number of kernels row-1, 100-grainweight, shelling percentage and grain yield. Significance of 1-line general line effects of both first and secondkind, 2- line specific effects of first kind and second kind as well as 3-line specific effects for all the yield and yieldcontributing traits except number of kernels row-1 in case of 3-line specific effects suggested the major role of allthree types of epistatic components viz., additive × additive, additive × dominance, dominance × dominance,in addition to the additive and dominance gene actions in the expression of these traits. For grain yield, BML-51was a good general combiner both as grandparent and immediate parent while BML-32 and BML-14 were goodgeneral combiners as immediate parent. (BML-51 × BML-6) and (BML-32 × BML-13) had desirable 2-line effectsof first and second kind. Crosses viz., (BML-14 × BML-6) × BML-51, (BML-32 × BML-6) × BML-51and (BML-51 ×BML-10) × BML-6 were the best performing triplets with desirable 1-line general and 2-line specific effects. Parentorder effects i.e. the order of lines utilized in three-way crosses were clearly elucidated, the order of in whichcrosses will be effected for obtaining superior hybrids with high grain yield
Screening of genetic variability in Turkish maize landraces for protein and starch related traits
Full text linkLocal populations of maize are valuable resources to maintain the genetic variability within the species. Breedingprograms in many different countries try to characterize and exploit such germplasm. The objective of this studywas to evaluate 192 Turkish maize landraces for their variation in terms of protein ratio, the amino acids that affectthe protein quality, starch ratio as well as its fractions. Field experiment was carried out at the Crop Research andApplication Unit of ÇanakkaleOnsekiz Mart University Agricultural Faculty Farm, and used and augmented designwith 6 blocks. Each block contained 32 landraces and 7 standard hybrids. Data were collected on protein, lysine,tryptophan, starch, amylose, and amylopectin content. Analysis of variance was run, and genetic calculationswere utilized to determine the heritability values. The results suggested that Turkish maize landraces possess aconsiderable variation for protein and starch traits. The ranges determined for protein, starch, amylose, amylopectin,lysine, and tryptophan were 6.56-16.50%, 56.38-79.63%, 2.09-35.25%, 64.75-97.91%, 0.12-0.93%, and0.03-0.09%, respectively. The broad sense heritability values for the investigated traits were between 16-53%.Several landraces were detected to be superior to the standard varieties for some traits and considered to bevaluable genetic material for the breeding studies to come
Physiological analysis and nutritional quality of maize: a comparative study between hybrid and landraces varieties
Full text linkMaize (Zea mays L.) is important for animal production systems, and the use of unimproved maize varieties has increasinglybecome a viable option for small farmers. This study aimed to characterize and evaluate the physiologicaland feed potential of maize populations, as a raw material for silage production, in the mesoregion of the AltoParanaiba, Minas Gerais (MG). We used nine varieties of unimproved maize from the Germplasm Bank at EmbrapaMaize & Sorghum - BAGMilho (Sete Lagoas, MG), as follows: (milho stands for maize; crioulo, for landrace) MG110 – Milho Amarelão, MS 043 – Crioulo, MG 083 – Milho Branco, RN 013 – Milho Metro, MG 073 – Milho Vermelhinho,MS 016 – Palha Roxa 90, MG 079 – Milho Cunha, RR 040 – Crioulo de Roraima, AC 015 – Milho Bolivianoand a commercial hybrid variety of Pioneer, P4285. The hybrid maize Pioneer P4285 showed better physiologicaland nutritional performance. Among the accessions of the Germplasm Bank, the MG 110 – Milho Amarelão andMG 015 – Milho Boliviano were distinguished by their physiological adaptation to the Cerrado of Minas Gerais,and for showing characteristics suitable for use in the silage process for animal feed
Exploring chemical composition and genetic dissimilarities between maize accessions
Full text linkThe capacity of maize (Zea mays L.) accessions to tolerate drastically extreme conditions in Iraq, contributes to thecharacterization of the genetic resources for germplasm management and the identification of the finest genotypesfor genetic improvement. Therefore, breeding maize program requires knowledge of genetic variation andgenetic structure. A total of 25 maize accessions from three regions (Iraq-Sulaimani, Iraq-Erbil and Iran-Sanandaj)were genotyped by chemical and phytochemical components and simple sequence repeats (SSR) markers to evaluategenetic diversity, population composition and the relationships between genetic and chemical compositiondissimilarities. In terms of proximate and phytochemical parameters, the maize accessions exhibited large significantdisparity, in which oil, phenol contents and 2,2-diphenyl-1-picrylhydrazyl (DPPH) characteristic appeared tobe the most discriminating features of maize accessions. Altogether, 18 SSR markers produced 77 polymorphicalleles across the 25 samples, and the chosen SSR was extremely informative with polymorphic information content(PIC) varied from 0.91 (Bnlg1890) to 0.37 (Umc1630 and Bnlg1189), as well as gene diversity (ranging from0.48 to 0.91, with an average of 0.75) illustrating the broad genetic variability of the accessions investigated.Molecular variance assessment (AMOVA) showed that there was only 21% genetic variation among populations.Pairwise PhiPT distance (0.10 to 0.31) stated high population distinctions among the populations investigated. Inaddition, the accessions from three regions were differentiated into seven clusters by both methods; clusteringand population structure analysis and the accessions are not grouped in term of geographic locations. Both chemicalcomposition and SSR markers differentiated 25 maize accessions. The results of the Mantel test exhibited asignificant positive linkage between chemical components and SSR matrices. The results of this research revealedthat maize accessions have a broad genetic diversity that provides a source of new and unique alleles that arehelpful for maize breeding programs to address the continuing and future significant challenges and determiningcollections of well-known cultivars and disparities between them
Hierarchical Factor Classification of Dendrochronological Time-Series
Full text linkIn this paper, Hierarchical Factor Classification (HFC), an exploratory method of classification of characters is introduced, in comparison with Principal Component Analysis (PCA) in order to show its advantages, in particular when dealing with time series. Exploratory data analysis may play a very relevant role in the understanding of the structure of a data set prior the use of statistical methods – as hypothesis testing and inference, and models. The study of tree-rings time series through exploratory methods may also take advantages, by allowing some interpretation to be further checked via a small number of statistical tests. In particular, while providing overall results close to those of PCA, HFC complements it, by providing a classification of the time-series and estimating a representative chronology for each group, common to the clustered ones. As case study, a data set is taken from literature, composed by five synchronous 79 years-long chronologies of Pinus pinea L., from five different populations scattered along the Tyrrhenian coast in peninsular Italy. HFC suggests how conveniently aggregate the chronologies, by showing similarities and differences between them, otherwise unnoticed, suggesting to limit the aggregation to three chronologies only