Instituto Nacional Of Investigaciones Agricola Inia

Venezuela, United States

Instituto Nacional Of Investigaciones Agricola Inia

Venezuela, United States
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Filho J.M.C.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Geraldi I.O.,University of Sao Paulo | Barona M.A.A.,Instituto Nacional Of Investigaciones Agricola Inia
Ciencia e Agrotecnologia | Year: 2010

Heterosis has been reported for grain yield in soybeans, and despite the fact that hybrid cultivars have not been used yet, the knowledge of heterosis magnitude is very important for a previous selection of crosses, since heterosis is related to parental divergence. However, the obtention of enough F 1seeds for experimental evaluation in plots is a time-consuming task, and thus, other indicators of the occurrence of heterosis could be very useful. The objective of this work was to evaluate heterosis and its relationship with AFLP molecular genetic distance (DG). Six F1 hybrids, derived from parents with different levels of genetic distances (DG) and their respective parents, were evaluated in completely randomized block designs, with four replications. Heterosis estimates were very different among different crosses, varying from 6.29 to 56.50% for mid-parent heterosis (h mg) and from -0.34 to 51.30% for high-parent heterosis (h gs). Besides, the correlation between heterosis and genetic distances (DG) were very high (0.83 and 0.60, respectively, for h mgand h gs), which indicates that DG can be used as indicative of more divergent crosses, and thus, as one criterion for selection of more divergent parents.


Acevedo Barona M.A.,Instituto Nacional Of Investigaciones Agricola Inia | Colombari Filho J.M.,Embrapa Arroz e Feijao | Santos V.S.,Embrapa Mandioca e Fruticultura | Geraldi I.O.,University of Sao Paulo
Crop Breeding and Applied Biotechnology | Year: 2012

Studies addressing the estimation of genetic parameters in soybean have not emphasized the epistatic effects. The purpose of this study was to estimate the significance of these effects on soybean grain yield, based on the Modified Triple Test Cross design. Thirty-two inbred lines derived from a cross between two contrasting lines were used, which were crossed with two testers (L1 and L2). The experiments were carried out at two locations, in 10 x 10 triple lattice designs with 9 replications, containing 32 lines (Pi), 64 crosses (32 Pi x L1 and 32 Pi x L2) and controls. The variation between (L1i + L2i - Pi) revealed the presence of epistasis, as well as an interaction of epistasis x environment. Since the predominant component of epistasis in autogamous species is additive x additive (i type), we suggest postponing the selection for grain yield to later generations of inbreeding in order to exploit the beneficial effects of additive x additive epistasis.


Contreras G.,Instituto Nacional Of Investigaciones Agricola Inia | Chirinos Z.,University of Zulia | Molero E.,Instituto Nacional Of Investigaciones Agricola Inia | Paez A.,Instituto Nacional Of Investigaciones Agricola Inia
Zootecnia Tropical | Year: 2012

In order to determine body measurements and their relationships through zoometric indexes 49 pure Criollo Limonero bulls were evaluated. Different measures were taken: height to cross (HCR), height to hip (HTH), thoracic perimeter (PTO), hip perimeter (HP), body length (BL), rump width (GRW), thorax width (TW), shank perimeter (SP), rump length (GRL), head length (HL), head width (HW), tail length (TL), tail thickness (TT); and zoometric indexes: Cephalic (CEI), Thoracic (TOI), Body (BOI), Side Body (SBI), Anamorphous (ANI), Pelvian (PEI), Dactylo-thoracic (DTI), Dactylo-costal (DCI), Pelvian Transversal (PTI), Pelvian Longitudinal (PLI), Shank relative thickness (SRI), and Shank load (SLI). Descriptive analysis and Pearson correlation was made with SAS® software. The measures showed low coefficients of variation (3.32 HCR and 10.88 PTO), reflecting a high phenotypic homogeneity. Positive correlation (P<0.001) was found between body weight and morphological characteristics, the thoracic perimeter was the most correlated (r = 0.93). Zoometric Indexes ranged from 2.38 for ANI and 194.03 for PEI. The Criollo Limonero bulls are described as a clearly dolichocephalic biotype, with good morphological uniformity, eumetric, of half-line proportions, concave rump, region dorsal-lumbar ascending towards the rump, and body size in harmony with bone development, shank and legs robust, with tendency to develop muscle tissue in the zone of most valuable cuts and of productive aptitudes for milk and meat production.


Contreras G.,Instituto Nacional Of Investigaciones Agricola Inia | Chirinos Z.,University of Zulia | Zambrano S.,Instituto Nacional Of Investigaciones Agricola Inia | Molero E.,Instituto Nacional Of Investigaciones Agricola Inia | Paez A.,Instituto Nacional Of Investigaciones Agricola Inia
Revista de la Facultad de Agronomia | Year: 2011

The "Criollo Limonero" is considered a "Tropical Bos taurus" by their adaptation to the tropical dry forest conditions, fertility and milky temperament. The objective of this study was to characterize morphologically and to determine zoometric indexes. 122 cows with average 9.05 years old and 403.86 kg of body weight, belonging to the National Institute of Investigations Agricultural (INIA), Carrasquero Station of Venezuela were evaluated. Thirteen morphological measurements and twelve zoometric indexes were considered: Cephalic (CEI), Thoracic (TOI), Body (BOI), Side Body (SBI), Anamorphous (ANI), Pelvian (PEI), Dactylo-thoracic (DTI), Dactylo-costal (DCI), Transversal pelvian (TPI), Longitudinal pelvian (LPI), Shank relative thickness (SRI), and Shank load (SLI). Statistical analyses were performed using the SAS®. Correlation between variables were low (3.27 height at wither and 10.41 rump width), reflecting a high phenotypic homogeneity. Positive correlation (P<0001) between body weight and some morphological characteristics, the thoracic perimeter showed highest correlation (r= 0.68). The studied population characterized as a biotype dolichocephalic (CEI=46.36±3.70), of half-line proportions (TOI=70.06±2.84; ANI=2.45± 0.19) of calving ease (PEI=153.90 ± 18.44), with good ability for milk production in harmony with bone development (DTI=10.14±0.62, DCI= 20.29±1.24; SRI=14.19±0.71), and according to the pelvis indexes (TPI=47.48±4.82; LPI= 30.58±1.98), indicate an intermediate trend of the animal to develop more muscle tissue in the area of most valuable cuts, aptitude for dual purpose.


Figueredo L.,Instituto Nacional Of Investigaciones Agricola Inia | Andrade O.,Instituto Nacional Of Investigaciones Agricola Inia | Cova J.,Instituto Nacional Of Investigaciones Agricola Inia | Mora O.,Instituto Nacional Of Investigaciones Agricola Inia | Aza G.,Instituto Nacional Of Investigaciones Agricola Inia
Entomotropica | Year: 2012

To determine the spatial and temporal distribution of nymphs in sugar cane using a Geographical Information System (GIS), a study was conducted in the INIA- Yaracuy in 2007. Thirty points were georeferenced and nine cultivars of sugar cane were selected. The incidence of nymphs per stem (Int) was determined at each point. The information was analyzed, the index of Morisita (Id) was applied to determine the spatial distribution pattern of the nymph and the GIS generated maps Int. The results indicate that the incidence varies with the cultivar being V98-87 who presented greater value. The presence of nymphs was influenced by the precipitation. According to Id and maps, the spatial distribution pattern of the nymph is aggregated, with focus heterogeneous, but without a constant or progressive behavior in space and time. This could be attributed to the environment is not uniform and the presence of mixed or superposition of generations. The characterization of the spatial distribution of the nymph improves application of measures in the integrated pest management and optimizes sampling methods. © 2012, Sociedad Venezolana de Entomología.

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