Papers by Hernan Laurentin
Agronomía Tropical, Jun 1, 2014
Evaluación de la esporulación de Fusarium oxysporum f. sp. sesami en dos medios de cultivo y dos ... more Evaluación de la esporulación de Fusarium oxysporum f. sp. sesami en dos medios de cultivo y dos metodologías de inoculación en ajonjolí (Sesamum indicum) Sporulation evaluation of Fusarium oxysporum f. sp. sesami in two culture media and two inoculation methods on sesame (Sesamum indicum L.
Sesame and Safflower Newsletter, 1999
Genotype by environment (G 9 E) interactions complicate genotype selection in breeding programs. ... more Genotype by environment (G 9 E) interactions complicate genotype selection in breeding programs. In south Louisiana, sugarcane is cultivated under a wide range of environments including soil types and cultural management practices. To evaluate experimental genotypes in different environments, the variety development program places experimental varieties in cooperator's fields across the sugarcane growing region as part of the selection process. The yield data of these varieties are affected by genotypic and genotype by environmental (GGE) interactions. In this study, the sugar yield data of eleven check varieties sampled over 4 years, including 2-4 crops across 21 locations, were analyzed by GGE biplot software in order to visualize GGE effects. GGE biplots enable the identification of ideal environments for evaluation of different genotypes and genotype performance and stability. Our goal was to assess the stability and representativeness of each check variety and find the best descriptive and representative test evaluation sites within the region using the GGE biplot method. The resulting graphical patterns and statistical analysis suggest yield variability is strongly dependent on crop, year, and variety. No consistent regional or soil patterns were observed. However, there were significant differences among locations for yield discrimination. Yield stability significantly varied by genotype in large plot trials ''outfield'' and in the small plot trials ''nurseries'' with some crop years were more representative than others. The results indicate that each crop year has unique growth conditions that affect yield and selection, and highly discriminating locations and stable cultivars were identified to improve selection.
Biotecnología en el Sector Agropecuario y Agroindustrial, Jul 1, 2020
Germination in a venezuelan type of Capsicum chinense jacq.: influence of fruit ripening and seed... more Germination in a venezuelan type of Capsicum chinense jacq.: influence of fruit ripening and seed extraction from the fruit* Germinación de un tipo venezolano de Capsicum chinense jacq.: influencia de la maduración del fruto y de la extracción de la semilla desde el fruto Germinação em tipo venezuelano de Capsicum chinense jacq.: influência do amadurecimento de frutas e extracção de sementes do fruto GARRIDO, LUZ 1 ; LAURENTIN, HERNÁN 2 Historial del Artículo Recibido para evaluación: 22 de Marzo 2020. Aprobado para publicación: 3 de Junio 2020. * Proyecto de investigación de origen: "Estudios básicos sobre el ají dulce (Capsicum sp.) para la optimización de su producción hortícola".
Bioagro, Dec 1, 2012
La enfermedad causada por Macrophomina phaseolina, denominada pudrición carbonosa, representa una... more La enfermedad causada por Macrophomina phaseolina, denominada pudrición carbonosa, representa una amenaza para la producción de ajonjolí (Sesamum indicum L.) en Venezuela. Debido a que una de las estrategias de control es el uso de resistencia genética, se requiere información acerca de la variabilidad del patógeno. Con el fin de caracterizar fenotípica y molecularmente a este hongo en la zona de producción de ajonjolí de los llanos occidentales de Venezuela, se determinó la velocidad de crecimiento, producción de microesclerocios, color de micelio y presencia de micelio aéreo en siete aislamientos del hongo obtenidos de material vegetal enfermo en distintos puntos ubicados en una zona de aproximadamente 2500 km 2. La caracterización molecular se logró mediante RAPD con el uso de 13 oligonucleótidos. En la evaluación fenotípica se observó variabilidad en la velocidad de crecimiento (entre 0,70 y 0,93 mm•h-1), producción de microesclerocios (entre 18 y 56 en 100 µL) y presencia de micelio aéreo (en sólo dos aislamientos). El color de micelio fue gris oscuro para todos los aislamientos. Con relación a la caracterización molecular se lograron productos de amplificación con 10 de los oligonucleótidos, los cuales generaron 81 bandas, todas polimórficas. Mediante un fenograma y un análisis de coordenadas principales se generó un agrupamiento muy similar entre los aislamientos, en el cual, aún cuando no hay una relación muy clara con respecto a la procedencia geográfica, hay la tendencia a separarlos según la margen del principal curso de agua (río Acarigua) de la zona en la cual fueron colectados.
Evaluación de la esporulación de Fusarium oxysporum f. sp. sesami en dos medios de cultivo y dos metodologías de inoculación en ajonjolí (Sesamum indicum) Sporulation evaluation of Fusarium oxysporum f. sp. sesami in two culture media and two inoculation methods on sesame (Sesamum indicum L.)
Variability studies for yield and yield components in white-grain sesame
Sesame and Safflower Newsletter, 2002
Interpreting genotype×environment interaction in sesame (Sesamum indicum L.)
The Journal of Agricultural Science, Dec 20, 2006
An understanding of genotype by environment (G×E) interaction would be useful for establishing br... more An understanding of genotype by environment (G×E) interaction would be useful for establishing breeding objectives, identifying the best test conditions, and finding areas of optimal cultivar adaptation. Data from field assays including eight environments and eight elite lines were analysed to identify environmental and genotypic variables related with G×E interaction for yield in sesame multi-environment trials in Venezuela. Both predictable and unpredictable environmental variables were recorded. Yield components were recorded as genotypic variables. Yield and yield components were used to perform additive main effect and multiplicative interaction (AMMI) analysis. Significant differences…
Evaluation of two cycles of recurrent selection for high seed yield in a population of sesame
espanolEl girasol (Helianthus annuus L.) representa una alternativa para la obtencion de aceite e... more espanolEl girasol (Helianthus annuus L.) representa una alternativa para la obtencion de aceite en Venezuela, lo cual es de gran relevancia ante el marcado defi cit en la produccion nacional. Como en todo proceso agricola, la semilla es determinante; sin embargo, en el pais, el rubro girasol esta sustentado en semilla importada. Esto, hace necesario el inicio de un programa nacional de semilla de girasol, el cual requiere de acciones previas dirigidas al mejoramiento genetico. El presente trabajo tuvo como objetivo caracterizar morfologica y molecularmente tres poblaciones segregantes de girasol provenientes de tres hibridos comerciales, con el fi n de determinar su utilidad como poblaciones basicas geneticamente variables para el inicio de ciclos de seleccion. Se estudiaron 18 variables morfologicas en 120 plantas de cada poblacion segregante, y se utilizaron 5 oligonucleotidos RAPD usando el ADN de 24 plantas de cada poblacion. Mediante la distribucion de frecuencias, pruebas de med...
Biotecnología en el Sector Agropecuario y Agroindustrial, 2019
El ajonjoli es un cultivo importante en regiones tropicales, el cual es afectado por hongos del s... more El ajonjoli es un cultivo importante en regiones tropicales, el cual es afectado por hongos del suelo como Macrophomina phaseolina y Fusarium sp. Con el objetivo de identificar y caracterizar a Fusarium spp. como causante de pudricion en plantas de ajonjoli en campo, se obtuvieron diez aislados. Once caracteristicas distintivas a nivel taxonomico se determinaron sobre los diez aislados, y adicionalmente se midio la velocidad de crecimiento en capsulas de Petri. A nivel molecular, la caracterizacion de los diez aislados, se desarrollo utilizando la tecnica molecular de ADN polimorfico amplificado al azar (RAPD) mediante el uso de cinco cebadores o “primers”. Se identificaron tres especies de Fusarium oxysporum (2 aislados), Fusarium solani (7 aislados) y Fusarium semitectum (1 aislado). Investigaciones anteriores al presente trabajo indican que el ajonjoli es solo afectado por F. oxysporum f. sp . sesami , solo un reporte previo indica que tambien F. solani causa la pudricion de Fusa...
Evaluación de dos ciclos de selección recurrente para altos rendimientos de semilla en una población de ajonjolí
Agronomía Trop, 2000
In 1989 a program of recurrent selection for high seed yields was started on a population of sesa... more In 1989 a program of recurrent selection for high seed yields was started on a population of sesame originated fromm 25 diverse materials. In 1995 two cycles had been completed and the parents of the third cycle were selected. The unit of selection and recombination for C0 and ...
Phenotypic and molecular characterization of Macrophomina phaseolina (Tassi) Goid. coming from the sesame production zone in Venezuela
Relationship between metabolic and genomic diversity in sesame (Sesamum indicum L.)
Genetic variation in oriental tobacco (Nicotiana tabacum L.) by agro-morphological traits and simple sequence repeat markers Variação genética em tabaco oriental (Nicotiana tabacum L.) por marcadores agro-morfológicos e traços simples de repetição de sequência
DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2013
Investigation of Genetic Variability among Twenty Sesame (Sesamum indicum L.) Venezuelan Cultivars Using Amplified Fragments Length Polymorphisms (AFLP)
wwwuser.gwdg.de
Sesame (Sesamum indicum L.) is one of the most ancient crops. It is grown in tropical and subtrop... more Sesame (Sesamum indicum L.) is one of the most ancient crops. It is grown in tropical and subtropical areas on 6.5 million of hectares worldwide. Sesame seeds are highly nutritive and they are used for direct consumption and as an oil source of excellent quality. Venezuela is the 7th ex- ...
Genetische Diversität in Sesam (Sesamum indicum L.): Genomebene, Profile der Sekundärmetabolitenproduktion und Wirkung von Sesam-Extracten auf mikrobielle Krankheitserreger
Zusammenfassun
Sesame (Sesamum indicum L.) is an important crop in tropical and subtropical areas. Sesame seed i... more Sesame (Sesamum indicum L.) is an important crop in tropical and subtropical areas. Sesame seed is traditionally used for direct consumption, because of its high nutritional value (50 % oil and 25 % protein), and as a source of oil of excellent quality. Potentially beneficial effects of sesame on human health have recently renewed the interest in this ancient crop. Information on the genetic diversity in sesame is limited, only some studies about morphological diversity have been carried out, and generally, these studies have been focused on regional interest. To overcome this gap of knowledge in sesame, this research was achieved to know how diverse is a sesame germplasm collection containing both accessions from different origin regions, and commercial cultivars or experimental lines. Genetic diversity was assessed at three different levels: DNA (by means of amplified fragment length polymorphism or AFLP), metabolic profiles, and functional metabolites (by means of effect of plant extracts on soil-borne pathogenic fungi). Individual outputs for every approach were obtained, but also information about usefulness of AFLP for identifying sesame cultivars, optimal conditions for bioassays, and identification of sesame accessions potentially valuables for breeding and/or production of natural compounds against soil-borne fungi The assessment by means of AFLP resulted in a high level of variability within all diversity centres except Central Asia. No association between geographic origin and AFLP patterns was found. Most
BMC Genomics, 2008
Background Diversity estimates in cultivated plants provide a rationale for conservation strategi... more Background Diversity estimates in cultivated plants provide a rationale for conservation strategies and support the selection of starting material for breeding programs. Diversity measures applied to crops usually have been limited to the assessment of genome polymorphism at the DNA level. Occasionally, selected morphological features are recorded and the content of key chemical constituents determined, but unbiased and comprehensive chemical phenotypes have not been included systematically in diversity surveys. Our objective in this study was to assess metabolic diversity in sesame by nontargeted metabolic profiling and elucidate the relationship between metabolic and genome diversity in this crop. Results Ten sesame accessions were selected that represent most of the genome diversity of sesame grown in India, Western Asia, Sudan and Venezuela based on previous AFLP studies. Ethanolic seed extracts were separated by HPLC, metabolites were ionized by positive and negative electrospr...
The objective of this work was to determine the inheritance mode of seed coat color in sesame. Tw... more The objective of this work was to determine the inheritance mode of seed coat color in sesame. Two crosses and their reciprocals were performed: UCLA37 x UCV3 and UCLA90 x UCV3, of which UCLA37 and UCLA90 are white seed, and UCV3 is brown seed. Results of reciprocal crosses within each cross were identical: F1 seeds had the same phenotype as the maternal parent, and F2 resulted in the phenotype brown color. These results are consistent only with the model in which the maternal effect is the responsible for this trait. This model was validated by recording the seed coat color of 100 F2 plants (F3 seeds) from each cross with its reciprocal, in which the 3:1 expected ratio for plants producing brown and white seeds was tested with the chi‑square test. Sesame seed color is determined by the maternal genotype. Proposed names for the alleles participating in sesame seed coat color are: Sc1, for brown color; and Sc2, for white color; Sc1 is dominant over Sc2.O objetivo deste trabalho foi d...
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Papers by Hernan Laurentin