Time filter

Source Type

Dipti S.S.,International Rice Research Institute | Bergman C.,University of Nevada, Las Vegas | Indrasari S.D.,Indonesian Center for Rice Research Padi | Herath T.,Industrial Technology Institute | And 10 more authors.
Rice | Year: 2012

It is internationally accepted that malnutrition and chronic diseases in developing countries are key limitations to achieving the Millennium Development Goals. In many developing countries, rice is the primary source of nutrition. In those countries, the major forms of malnutrition are Fe-induced anaemia, Zn deficiency and Vitamin A deficiency, whereas the major chronic disease challenges are Type II diabetes, cardiovascular disease and some cancers. There is a growing corpus of evidence regarding both limitations and opportunities as to how rice could be an effective vehicle by which to tackle key nutrition and health related problems in countries with limited resources. Rice breeding programs are able to focus on developing new varieties carrying enhanced amounts of either Fe, Zn or betacarotene because of large public investment, and the intuitive link between providing a mineral/vitamin to cure a deficiency in that mineral/vitamin. By contrast, there has been little investment in progressing the development of particular varieties for potential impact on chronic diseases. In this review article we focus on the broad battery of evidence linking ricerelated nutritional limitations to their impact on a variety of human health issues. We discuss how rice might offer sometimes even simple solutions to rectifying key problems through targeted biofortification strategies and finally, we draw attention to how recent technological (-omics) developments may facilitate untold new opportunities for more rapidly generating improved rice varieties specifically designed to meet the current and future nutritional needs of a rapidly expanding global population. © 2012 Dipti et al.


Chassaigne-Ricciulli A.,Fundacion para la investigacion Agricola Danac | Barrientos-Acosta V.,Fundacion para la investigacion Agricola Danac | Hernandez-Jimenez A.,University Centroccidental Lisandro Alvarado
Bioagro | Year: 2012

Maize (Zea mays L.) is produced in Venezuela in a wide diversity of agro ecological conditions. Among the most important biotic and abiotic limitations, there are diseases, soil oxygen deficit due to excess of rains, water deficit by drought, soil acidity and low soil fertility. Population genetic improvement facilitates the selection of open pollinated varieties and inbred lines. The objective of this research was to synthesize and to start the improvement of the white grain basic maize population FD-01B, with genetic base for adaptation to adverse factors in three maize-producer States of Venezuela. Seven populations and varieties and three pool of improved inbred lines were used as progenitors. From the original population FD-01B, 900 S1 families were selected, 300 were randomized to Portuguesa (P), Yaracuy (Y) and Guárico (G) states, thus starting the genetic improvement through recurrent selection of S1 families from FD-01BP, FD-01BY and FD-01BG. This research allowed to synthesize a new maize population and to start improving of three subpopulations adapted to adverse agro ecological conditions in Venezuela. The population FD- 01B original and subpopulation seeds are available for breeding programs of public and private entities.


Medina A.,University Centroccidental Lisandro Alvarado | Gonzalez-Vera A.,Fundacion para la Investigacion Agricola Danac | Pineda J.,University Centroccidental Lisandro Alvarado | Hernandez A.,University Centroccidental Lisandro Alvarado
Bioagro | Year: 2012

The banded leaf of maize is the primarily disease in corn fields in Portuguesa State, Venezuela. The objectives of this study were to determine the incidence and carry out cultural and pathogenic characterization of binucleate Rhizoctonia strains isolated from typical symptoms of the banded leaf of maize. From samples collected in 2006, fungus strains were isolated in semi selective media and they were purified by growing hyphae tips. Nuclear staining was used to verify the number of nuclei per cell, and it allowed to find that 39.68 % of the isolates belonged to binucleate Rhizoctonia. Isolates were characterized by measuring the formation of sclerotia and growth velocity in PDA medium. Two pathogenicity tests were performed: a) in greenhouse, where agar-mycelium discs were inoculated in basal leaves of healthy maize plants, and b) in laboratory, where a grain of rice colonized by the fungus was placed on the adaxial part of healthy leaves in 2 ppm kinetin solution. The results in greenhouse indicated that the 16 tested strains caused symptoms in 100 % of the inoculated seedlings, being a response similar of the control Rhizoctonia solani AG1 IA. Only 31.2% of strains and isolates formed sclerotia, and the most aggressive isolates (M2C1, M4G4, M5B1, and M1F3) showed an average growth rate of 1.1 cm per day, under laboratory conditions. We conclude that Ceratobasidium (= binucleate Rhizoctonia) emerges as a pathogen of the complex banded leaf of maize, in Portuguesa State, Venezuela.


Bastidas Y.,University Centroccidental Lisandro Alvarado | Chassaigne A.,Fundacion para la Investigacion Agricola DANAC | Alezones J.,Fundacion para la Investigacion Agricola DANAC | Hernandez A.,University Centroccidental Lisandro Alvarado
Bioagro | Year: 2015

Maize in Venezuela is affected by several pathogenic fungi that cause yield reduction and damaged grain. The small and medium farmers demand affordable cultivars with high yield potential and good agronomic performance. The maize breeding program of DANAC Foundation offers open pollinated varieties (OPV) as an alternative for low income producers. In 2011 trials were conducted in order to characterize two new DANAC OPV and compare them with four commercially available varieties. Trials for agronomic performance evaluation were planted in two farms located in Tucupido (Guárico State) and San Javier (Yaracuy State). Simultaneously, these cultivars were evaluated in laboratory conditions for resistance to Fusarium verticilloides (FV) and Aspergillus flavus (AF) through seed inoculation, and Rhizoctonia solani (RS) through plant inoculation. No interactions cultivars by location were detected, except for the flowering time. The highest yields were observed in Tucupido. The new variety DANAC-5021 had the highest value for days to anthesis at both locations, and in the pooled analysis showed the highest grain yield (4708 kg·ha-1), endosperm fraction (78.2%) and specific gravity (0,804 kg·L-1), and the lowest value for lodging (less than 4%). The new variety DANAC-5023 was more resistant than any other cultivar against AF and FV grain colonization and against RS plant infection. The superior performance of these new varieties evidence the positive effect of selecting parents of OPVs for high per se yield and enhanced resistance to pathogens. © 2015, Universidad Centroccidental Lisandro Alvarado (UCLA). All rights reserved.


Gonzalez-Vera A.,Fundacion para la Investigacion Agricola Danac | Graterol E.,Fundacion para la Investigacion Agricola Danac | Borges B.,Fundacion para la Investigacion Agricola Danac | Hernandez F.,Fundacion para la Investigacion Agricola Danac
Bioagro | Year: 2011

The rice (Oryza sativa L.), in Venezuela, is affected by sheath blight caused by Rhizoctonia solani (teleomorph = Thanatephorus cucumeris). No complete resistance has been found in the world. In consequence, breeding programs should evaluate many cultivars for selecting those with the best quantitative level of resistance. The objectives were to compare methods of evaluation and cultivars reaction for resistance to the sheath blight caused by R. solani AG-1 IA. The evaluation methods were microchamber and mycelium ball in greenhouse conditions, kinetin test in laboratory and colonized rice infestation under field conditions. The cultivars were 23 genotypes of rice, including control varieties. Three haplotypes of R. solani, previously characterized, were used for the inoculations. The experimental designs were randomized complete block with three replications. The effectiveness of the trials was determined based on the discrimination of controls with well-known reaction and the best correlation of the laboratory and greenhouse methods with the field results. The method of microchamber using the isolate A5B4 (64) had the best correlation with field results (r = 0.50 on average), followed by the method of ball mycelium (r = 0.49, on average). The control cultivars 'Tetep' (resistant) and 'Lemont' (susceptible) were consistent across the experiments. The principal component analysis identified the genotypes CT15150-M-11-4-3-2-M (derived from a cross with O. glaberrima), 'SD20A' and 'DSativa' with the best levels of resistance. These results indicate the existence of reliable methods to evaluate this disease and adapted cultivars with resistance to rice sheath blight.


Gonzalez A.,Fundacion para la Investigacion Agricola Danac | Labrin N.,Fundacion para la Investigacion Agricola Danac | Alvarez R.M.,Instituto Nacional Of Investigaciones Agropecuarias Inia | Jayaro Y.,Fundacion para la Investigacion Agricola Danac | And 3 more authors.
Revista de Biologia Tropical | Year: 2012

Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the "Rice hoja blanca virus". During 2006-2007 we carried out research under greenhouse conditions at Fundación Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundación Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition). Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control 'Bluebonnet 50' was consistently susceptible across experiments and the resistant control 'Makalioka' had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and oviposition. The genotype 'FD0241-M-17-6-1-1-1-1' was identified with possible tolerance to the direct damage of sogata. Rev. Biol. Trop. 60 (1): 105-117. Epub 2012 March 01.


PubMed | Fundacion para la Investigacion Agricola Danac
Type: Journal Article | Journal: Revista de biologia tropical | Year: 2012

Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the Rice hoja blanca virus. During 2006-2007 we carried out research under greenhouse conditions at Fundaci6n Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundaci6n Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition). Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control Bluebonnet 50 was consistently susceptible across experiments and the resistant control Makalioka had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and oviposition. The genotype FD0241-M-17-6-1-1-1-1 was identified with possible tolerance to the direct damage of sogata.


Alezones J.,Fundacion para la Investigacion Agricola Danac | Avila M.,Fundacion para la Investigacion Agricola Danac | Chassaigne A.,Fundacion para la Investigacion Agricola Danac | Barrientos V.,Fundacion para la Investigacion Agricola Danac
Archivos Latinoamericanos de Nutricion | Year: 2010

In Venezuela, white corn is the most important crop regarding production, harvest area and consumption. One of its main by-products is corn oil, whose positive effect on health caused by the high content of unsaturated fatty acids has been widely recognized. In order to characterize the fatty acids profile of twelve white grained maize hybrids extensively grown in Venezuela, and the effect that divergent localities has on this profile, three semi commercial scale trials where established in Portuguesa, Yaracuy and Guárico states. Proportions of the main fatty acids in the raw oil of the different grain samples were determined using gas chromatography. Significant differences (p<0,01) between hybrids were found for arachidic, palmitic, stearic, oleic, gadoleic and linoleic acids; non significant differences were found for linolenic acid. Significant differences between localities were found for all the fatty acids evaluated. High and significant correlations between fatty acids content were found; the most important relations were: linoleic-oleic (Rho= -0,98**), arachidic-palmitic (Rho= -0,61**), linoleic-stearic (Rho= -0,61**) and oleic-stearic (Rho= 0,58**). Corn produced in Venezuela presents lower levels of linoleic and higher levels of palmitic, stearic and oleic acids than the levels found in temperate corn. These differences involve significant changes in the nutritional properties of Venezuelan corn oil that should be considered in the development of new cultivars and industrial processes for oil production.


PubMed | Fundacion para la Investigacion Agricola Danac
Type: Journal Article | Journal: Archivos latinoamericanos de nutricion | Year: 2013

The appearance of rice grain is a key aspect in quality determination. Mainly, this analysis is performed by expert analysts through visual observation; however, due to the subjective nature of the analysis, the results may vary among analysts. In order to evaluate the concordance between analysts from Latin-American rice quality laboratories for rice grain appearance through digital images, an inter-laboratory test was performed with ten analysts and images of 90 grains captured with a high resolution scanner. Rice grains were classified in four categories including translucent, chalky, white belly, and damaged grain. Data was categorized using statistic parameters like mode and its frequency, the relative concordance, and the reproducibility parameter kappa. Additionally, a referential image gallery of typical grain for each category was constructed based on mode frequency. Results showed a Kappa value of 0.49, corresponding to a moderate reproducibility, attributable to subjectivity in the visual analysis of grain images. These results reveal the need for standardize the evaluation criteria among analysts to improve the confidence of the determination of rice grain appearance.

Loading Fundacion para la Investigacion Agricola Danac collaborators
Loading Fundacion para la Investigacion Agricola Danac collaborators