Kaesel Jackson Damasceno e Silva

Adaptabilidade e estabilidade produtiva de feijão‑caupi de porte semiprostrado

The objective of this work was to evaluate the yield adaptability and stability of semi-prostrate cowpea (Vigna unguiculata) genotypes. Twenty cowpea genotypes were evaluated using the additive main effects and multiplicative interaction (AMMI) model with supplementary genotype and environment. The trials were carried out in nine environments (Balsas, MA, 2010; Balsas, MA, 2011; Bom Jesus, PI, 2010; Bom Jesus, PI, 2011; Sao Raimundo das Mangabeiras, MA, 2010; Sao Raimundo das Mangabeiras, MA, 2011; Sao Joao do Piaui, PI, 2011; Campo Grande do Piaui, PI, 2011; Buriti, MA, 2011) of the Mid-North region of Brazil in a randomized complete block design with 20 treatments and four replicates. The effects of genotypes, environments, and genotype x environment interaction were significant. Genotypes differed as to yield adaptability and stability. The line MNC03-736F-2 presented genes for yield adaptability and stability. Among the evaluated genotypes, BR 17-Gurgueia and Pingo-de-Ouro-1-2 are the most predictable, and BRS Xiquexique is the most adapted. Among the test sites, Balsas, MA is the most appropriate for selection of genotypes superior for yield adaptability and stability.

Diferenciação genética entre procedências de açaizeiro por marcadores RAPD e SSR

Diferenciacao genetica refere-se a distribuicao da variabilidade entre e dentro de populacoes, procedencias ou outros tipos de agrupamentos. Seu conhecimento e importante para estabelecer estrategias de coleta, conservacao e manejo de germoplasma de qualquer especie. Neste trabalho, avaliou-se a diferenciacao genetica entre procedencias de acaizeiro que compoem a colecao da Embrapa Amazonia Oriental, por meio de marcadores RAPD e SSR. Para tanto, foram utilizados DNAs de 107 acessos, representantes de 17 regioes geograficas diferentes e utilizados em PCR com 28 primers RAPD e sete primers SSR. Os dados foram submetidos a analise de variância molecular (AMOVA) com estrutura hierarquica desbalanceada. Altos niveis de diferenciacao genetica foram registrados entre procedencias, com 0,301 para o marcador dominante e 0,242 para o co-dominante. Para os dois marcadores, a AMOVA apresentou grande variabilidade dentro das procedencias (acima de 69%). O pequeno tamanho amostral das procedencias do Maranhao pode ter contribuido para a diferenciacao significativa entre procedencias. Os dados obtidos por esses marcadores foram concordantes quanto a distribuicao da variacao genetica entre e dentro de procedencias dessa palmeira.

Potencial genético de progênies de feijão-caupi segregantes quanto ao tipo da inflorescência

The objective of this work was to evaluate the genetic yield potential of segregating cowpea progenies regarding inflorescence type. Sixty-eight F4 progenies obtained from the backcrosses (TV x 5058-09C x Curly-purple) x TV x 5058-09C, and (AU94-MOB-816 x Curly-purple) x AU94-MOB-816, with parents, were evaluated. Two experiments were carried out in a randomized complete block design with 17 progenies and four replicates, in a split-plot arrangement regarding inflorescence: simple and composite. The statistical analysis was carried out by mixed models via REML/BLUP procedure. The estimates of genetic variance were significant for all evaluated traits. The traits peduncle length, average number of pods per peduncle, and initial flowering showed high variability and expression of the composite inflorescence genetic component. Progenies with simple inflorescence show similar genetic yield potential to the progenies with composite inflorescence. The progenies resulting from the backcrosses (AU94-MOB-816 x Curly-purple) x AU94-MOB-816 are promising as a strategy to increase the current levels of grain yield in cowpea.

Phenotypic correlations between combining abilities of F2 cowpea populations

Cowpea is a crop that has become socio-economically relevant, mainly in developing countries. Correlation studies are important to determine the association between quantitative traits and yield to guide the selection, i.e., choose direct or indirect selection. The objective was to estimate the correlations between six agronomic traits in cowpea as well as the correlations between the estimates of combining abilities of parents. Genotypes with high pod weight and pod length, 100-grain weight, and number of beans per pod should be used to improve grain yield in cowpea. The breeder should preferably insert plants into his group of crosses that have a high combining ability for pod length, number of grains per pod and yield per plot.

Path analysis of iron and zinc contents and others traits in cowpea

The objective of this study was to estimate the direct and indirect effects of agronomic and culinary traits on iron and zinc contents in 11 cowpea populations. Correlations between traits were estimated and decomposed into direct and indirect effects using path analysis. For the study populations, breeding for larger grain size, higher number of grains per pod, grain yield, reduced cooking time, and number of days to flowering can lead to decreases in the levels of iron and zinc in the grain. Genetic gains for the iron content can be obtained by direct selection for protein content by indirect effects on the number of grains per pod, 100-grain weight and grain yield. The positive direct effect of grain size and protein content on the zinc content indicates the possibility of simultaneous gain by combined selection of these traits.

Effect of thermal processing on total polyphenol content in the grain of cowpea cultivars

Cowpea grain is noteworthy due to its functional properties, which are probably a result of the synergistic action of its nutrients and bioactive compounds. Since these compounds undergo the effects of thermal processing, the aim of the present study was to verify the influence of cooking on the total polyphenol content of the grain of cowpea cultivars. Samples were obtained from the experimental area of Embrapa Meio-Norte, located at 5°5’ S and 42°48’ W, at an altitude of 72 metres. Meal (0.5 mesh) resulting from the raw grain being ground in a cyclone rotor mill (Tecnal model TE-651/2-T), and cooked beans (with no maceration, at a bean to water ratio of 1:5 (w/v), cooked in a domestic pressure cooker (2 L) for 780 seconds) were stored in airtight containers under refrigeration (8 °C) for analysis, which was carried out in triplicate. Total phenolic content was determined by spectrophotometry (λ = 765 nm), using Folin-Ciocalteau reagent. The total phenolic content, mg GAE (gallic acid equivalent)/100g, in the raw grain of the BRS Marataoa, BR 17-Gurgueia, BRS Itaim, BRS Cauame and BRS Guariba cultivars was 295.23, 255.67, 132.32, 98.14 and 89.43 respectively. After cooking, the content was 405.87, 255.4, 161.71, 127.79 and 111.92 respectively, considering both grain and broth. This rise may have been the result of increased solubilisation and extraction of the compounds, due to the softening or rupture of the plant cells. It was concluded that, considering both grain and broth, the total phenolic content increased after cooking; the BRS Marataoa and BR 17-Gurgueia cultivars showed the highest levels.

Cheese bread enriched with biofortified cowpea flour

The development and enrichment of food are of great importance not only for the industry but also to improve the populations nutrition, where you can create new products or optimize existing ones. The consumption of fortified products in the diet is an option for the control of deficiency diseases. This study aimed to develop enriched cheese bread with whole biofortified cowpea flour and evaluate their acceptance and chemical composition. Two formulations, F1 and F2, were prepared containing 5.6 and 8% of cowpea flour as a substitute for starch, respectively. To check acceptance, three sensory tests were used (Hedonic Scale, Purchase Intent, and Paired Comparison), F1 being sensory viable according to assessors, being chemically analyzed. Minerals were determined by atomic emission spectrometry with inductively coupled plasma source. The moisture was determined by drying at 105 °C, ash by calcination in muffle at 550 °C, proteins by the macro-Kjeldahl method, and lipids by hot extraction in a Soxhlet extractor. Carbohydrates were obtained by difference and the calories were calculated. The addition of cowpea increased the amounts of copper, iron, phosphorus, magnesium, manganese, and zinc, as well as protein and carbohydrate values. On the other hand, there was a reduction of the moisture concerning lipids and the total caloric value compared to the standard formulation. It was concluded , therefore, that the cowpea, a regional raw material in market expansion is presented as an option for the enrichment of baked foods that do not contain gluten, such as cheese bread.

Evolution of methodology for the study of adaptability and stability in cultivated species.

The GxE interaction only became widely discussed from evolutionary studies and evaluations of the causes of behavioral changes of species cultivated in environments. In the last 60 years, several methodologies for the study of adaptability and stability of genotypes in multiple environments trials were developed in order to assist the breeders choice regarding which genotypes are more stable and which are the most suitable for the crops in the most diverse environments. The methods that use linear regression analysis were the first to be used in a general way by breeders, followed by multivariate analysis methods and mixed models. The need to identify the genetic and environmental causes that are behind the GxE interaction led to the development of new models that include the use of covariates and which can also include both multivariate methods and mixed modeling. However, further studies are needed to identify the causes of GxE interaction as well as for the more accurate measurement of its effects on phenotypic expression of varieties in competition trials carried out in genetic breeding programs.

Identifying lines of the black-eyed cowpea having high productivity and quality commercial grain

The black-eyed cowpea, is consumed in Brazil and valued in various other countries, and for this reason, can be found on the domestic market, showing the potential for export. The aim of this study was to identify lines of the black-eyed cowpea having high productivity and quality commercial grain. Twenty-four lines of black-eyed commercial subclass of cowpea, taken from the breeding program of Embrapa Meio-Norte, and two controls (BRS Itaim and CB-27) were evaluated. The experiments were carried out in Nova Ubirata, in the State of Mato Grosso, Brazil (MT) during 2014, and in Primavera do Leste MT and Sinop MT during 2015, in the off-season; planting was in February/March and harvesting in May/June. The experimental design was of randomised complete blocks with four replications, in plots of 4 rows of 5 metres spaced 0.45 metres apart. Crop value, lodging and grain productivity were evaluated. The occurrence of blemished grain was also assessed, both by counting the blemished grain (visual selection), and by colorimetric analysis, using the CIE L* a* b* colour scale. Four lines showed potential for inclusion in the trials for crop value and use (VCU) as per the recommendation of the State of Mato Grosso, by combining grain productivity comparable to that of the BRS Itaim cultivar and a low percentage of blemished grain. Visual evaluation by counting the blemished grain, was efficient in identifying lines of the black-eyed cowpea with better grain quality in relation to the BRS Itaim cultivar. Colour reading using the CIE L* a* b* scale did not satisfactorily differentiate the occurrence of blemished grain in lines of the black-eyed cowpea.