Identificação de regiões associadas à resistência à plaga tardia e vírus em germoplasma de batata usando marcadores moleculares

The combination of traits of economic interest in new potato cultivars, such as resistance to late blight, viral diseases, and culinary quality are important to achieve their adoption by farmers. In the present work, molecular markers were used to identify regions associated to late blight, the viruses PVY and PLRV resistance, in 50 materials belonging to the National Institute of Agricultural Research (INIA-Venezuela): commercial cultivars, differentials of blight, advanced clones from CIP and hybrids from the Fundación PROINPA of Bolivia. DNA extraction was carried out from vitroplants and known microsatellite, SCAR and CAPS molecular markers were used. Among 96 to 26% of the accessions amplified regions of the QTL tbr of chromosome XII, associated with resistance to blight. Only the differential R9 and crc2/P8 from PROINPA amplified the R1 gene region. Between 18 and 68% of the genotypes presented the regions associated with the PVY and PLRV resistance genes (Ryadg and N genes), respectively; only 10% amplified both regions; while in 24% these genes were not detected, among them are the commercial varieties Granola, Andinita and Cartayita. This study generated valuable information to support genebank curators and breeders in potato genetic improvement programs of this country.La combinación de caracteres de interés económico en nuevos cultivares de papa, tales como la resistencia al tizón tardío, las enfermedades virales, y la calidad culinaria son importantes para lograr su adopción por los agricultores. En el presente trabajo se usaron marcadores moleculares para identificar regiones asociadas a la resistencia del tizón tardío y a los virus PVY y PLRV, en 50 materiales pertenecientes al Instituto Nacional de Investigaciones Agrícolas (INIA-Venezuela): cultivares comerciales, diferenciales del tizón, clones avanzados del CIP e híbridos de la Fundación PROINPA de Bolivia. La extracción del ADN se realizó a partir de vitroplantas y se utilizaron marcadores moleculares tipo microsatélites, SCAR y CAPS conocidos. Entre el 96 al 26 % de las accesiones amplificaron regiones del QTL tbr del cromosoma XII, asociado a la resistencia al tizón. Solo el diferencial R9 y crc2/P8 de PROINPA amplificaron la región del gen R1. Entre el 18 y 68 % de los genotipos presentaron las regiones asociadas con los genes de resistencia al PVY y PLRV (genes Ryadg y N), respectivamente; solo el 10 % amplificaron ambas regiones; mientras que en 24 % no se detectaron estos genes, entre ellos se encuentran las variedades comerciales Granola, Andinita y Cartayita. Este estudio generó información valiosa de soporte a los curadores de los bancos de germoplasma y a los fitomejoradores en los programas de mejoramiento genético de papa del país.A combinação de características de interesse econômico em novas cultivares de batata, como resistência à requeima, doenças virais e qualidade culinária, são importantes para sua adoção pelos produtores. No presente trabalho, marcadores moleculares foram utilizados para identificar regiões associadas à resistência à requeima e aos vírus PVY e PLRV, em 50 materiais pertencentes ao Instituto Nacional de Pesquisa Agropecuária (INIA-Venezuela): cultivares comerciais, diferenciais da requeima, clones avançados do CIP e híbridos da Fundación PROINPA da Bolívia. A extração de DNA foi realizada a partir de vitroplantes e foram utilizados microssatélites, marcadores moleculares SCAR e CAPS conhecidos. Entre 96 a 26% dos acessos amplificaram regiões do QTLtbr do cromossomo XII, associadas à resistência à ferrugem. Apenas o diferencial R9 e crc2/P8 de PROINPA amplificou a região do gene R1. Entre 18 e 68 % dos genótipos apresentaram as regiões associadas aos genes de resistência PVY e PLRV (genes N e Ryadg), respectivamente; apenas 10% amplificou ambas as regiões; enquanto em 24 % esses genes não foram detectados, entre eles estão as variedades comerciais Granola, Andinita e Cartayita. Este estudo gerou informação valiosa para apoiar curadores de bancos de germoplasma e melhoristas de plantas nos programas de melhoramento genético da batata do país

Micropropagación de plantas de lechosa en recipientes de inmersión temporal a partir de brotes axilares Micropropagation of papaya plants in temporary immersion recipients from axilary shoots

Título en ingles: Micropropagation of papaya plants in temporary immersion recipients from axilary shootsTítulo corto: Micropropagación de lechosa en recipientes de inmersión temporal.Resumen: Se estandarizaron las condiciones de iniciación, multiplicación, enraizamiento y aclimatización de plantas hermafroditas de lechosa cv Maradol provenientes de brotes axilares, producidos en recipientes de inmersión temporal RITA®. En cada envase, contentivo de 200 ml de medio de cultivo líquido de Fitch, se colocaron cuatro brotes de 2 a 3 cm de longitud. Los biorreactores se conectaron a tres líneas de inmersión de 5, 2 y 1 min cada 4h y se colocaron 6 envases en promedio por línea, en condiciones de fotoperíodo de 16 h. Transcurridos 30 a 45 días, se cuantificaron los brotes y se clasificaron de acuerdo al tamaño: 2 cm (pequeños), entre 2 a 3 cm (medianos),  ˃ 3 cm con y sin raíz (grandes). Los dos primeros tipos de brotes se continuaron multiplicando en los mismos medios; y los más elongados se aclimatizaron utilizando el Sistema Autotrófico Hidropónico (SAH). Se determinó la sanidad y la fidelidad de las plantas producidas mediante pruebas de ELISA y RAPD, respectivamente. Durante un periodo de 6 meses se reciclaron un total de 47 recipientes, los cuales produjeron 1.091 brotes: 377  pequeños; 482 medianos; 175 grandes sin raíz y 57 con raíz. Usando el SAH se obtuvo 89,5% de plantas aclimatizadas cuando se usaron brotes enraizados, y 41,6% a partir de brotes sin  raíces. Con la combinación de las técnicas RITA y SAH se logró un sistema continuo y eficiente de producción de plantas sanas y fieles al tipo, en comparación con los métodos convencionales de micropropagación y aclimatización.Palabras clave: Carica papaya, RITA®, sistema autotrófico, estabilidad genética.Key words: Carica papaya, RITA®, autotrophic system, genetic stability.Recibido: mayo 16 de 2014   Aprobado: abril 21 de 2015We standardized initiation, multiplication, rooting and acclimatization conditions of papaya cv Maradol hermaphrodite plants from axillary buds produced in temporary immersion reactor RITA®. Recipients contained 200 ml of Fitch liquid culture medium, and four shoots of 2 to 3 cm. in length were placed in each. The bioreactors were connected to three different immersion lines of 5, 2, and 1 min each 4h, with 6 containers per line on average, in 16 h photoperiod. After 30 to 45 days, the shoots produced were quantified and classified according to size: 2 cm (small), from 2 to 3 cm (medium), 3 cm with or without roots (large). The first two types of shoots were multiplied in the same culture media, and more elongated shoots were acclimatized using Autotrophic Hydroponic System (AHS). The sanity and fidelity of the produced plants were determined using ELISA and RAPD, respectively. For a period of six months 47 vessels were recycled and 1,091 shoots were produced: 377 small; 482 medium; 175 large without roots and 57 rooted shoots. Using AHS, 89.5% acclimatized plants were obtained when rooted shoots were used, and 41.6% from rootless shoots. With the combination of RITA and AHS techniques we achieved a continuous and efficient production of healthy and true to type papaya plants, in comparison to conventional micropropagation and acclimatization procedures.Key words: Carica papaya, RITA®, autotrophic system, genetic stability

Selección de plantas élites de lechosa ‘Maradol’ para la producción de semillas de calidad

The cultivar Red Maradol native of Cuba, has morphological and agronomic features superior to local cultivars and adapted to soils and climates of Venezuela; that is why it is grown in a greater proportion and has been widely accepted by farmers, traders and consumers. However, the lack of availability and high cost of imported seeds limit its expansion in the country. The aim of this work was to select andromonoecious plants from different sources and locations, based on morphological and agronomic characteristics, and produce good quality seeds by self-pollinations. The characteristics for selection were based on those of the cultivar, such as: beginning of flowering between 3 and 4 months after transplant to the field, height of flowering less than or equal to 80 cm, beginning of fruiting before 4 months, height of plants less than 2 m, among others features. Selected plants showed low percentage of sterility, 30 and 64 fruits.plant-1, fruit weights between 1.4 to 1.7 kg, and estimated yields between 42.5 and 98.50 kg.plant-1 yields. Regarding fruit quality, they were elongated and smooth, wide orange-red color pulp. These populations are considered the basis for the production of good quality seeds, to continue the process of selection of more productive pure lines and hybrids.</jats:p

Identification of regions associated to the late blight resistance and viruses in potato germplasm using molecular markers

The combination of traits of economic interest in new potato cultivars, such as resistance to late blight, viral diseases, and culinary quality are important to achieve their adoption by farmers. In the present work, molecular markers were used to identify regions associated to late blight, the viruses PVY and PLRV resistance, in 50 materials belonging to the National Institute of Agricultural Research (INIA-Venezuela): commercial cultivars, differentials of blight, advanced clones from CIP and hybrids from the Fundación PROINPA of Bolivia. DNA extraction was carried out from vitroplants and known microsatellite, SCAR and CAPS molecular markers were used. Among 96 to 26% of the accessions amplified regions of the QTL tbr of chromosome XII, associated with resistance to blight. Only the differential R9 and crc2/P8 from PROINPA amplified the R1 gene region. Between 18 and 68% of the genotypes presented the regions associated with the PVY and PLRV resistance genes (Ryadg and N genes), respectively; only 10% amplified both regions; while in 24% these genes were not detected, among them are the commercial varieties Granola, Andinita and Cartayita. This study generated valuable information to support genebank curators and breeders in potato genetic improvement programs of this country.</jats:p

Micropropagación de plantas de lechosa en recipientes de inmersión temporal a partir de brotes axilares Micropropagation of papaya plants in temporary immersion recipients from axilary shoots

Se estandarizaron las condiciones de iniciación, multiplicación, enraizamiento y aclimatización de plantas hermafroditas de lechosa cv Maradol provenientes de brotes axilares, producidos en recipientes de inmersión temporal RITA®. En cada envase, contentivo de 200 ml de medio de cultivo líquido de Fitch, se colocaron cuatro brotes de 2 a 3 cm de longitud. Los biorreactores se conectaron a tres líneas de inmersión de 5, 2 y 1 min cada 4h y se colocaron 6 envases en promedio por línea, en condiciones de fotoperíodo de 16 h. Transcurridos 30 a 45 días, se cuantificaron los brotes y se clasificaron de acuerdo al tamaño: < 2 cm (pequeños), entre 2 a 3 cm (medianos),  ˃ 3 cm con y sin raíz (grandes). Los dos primeros tipos de brotes se continuaron multiplicando en los mismos medios; y los más elongados se aclimatizaron utilizando el Sistema Autotrófico Hidropónico (SAH). Se determinó la sanidad y la fidelidad de las plantas producidas mediante pruebas de ELISA y RAPD, respectivamente. Durante un periodo de 6 meses se reciclaron un total de 47 recipientes, los cuales produjeron 1.091 brotes: 377  pequeños; 482 medianos; 175 grandes sin raíz y 57 con raíz. Usando el SAH se obtuvo 89,5% de plantas aclimatizadas cuando se usaron brotes enraizados, y 41,6% a partir de brotes sin  raíces. Con la combinación de las técnicas RITA y SAH se logró un sistema continuo y eficiente de producción de plantas sanas y fieles al tipo, en comparación con los métodos convencionales de micropropagación y aclimatización

Micropropagación de plantas de lechosa en recipientes de inmersión temporal a partir de brotes axilares

We standardized initiation, multiplication, rooting and acclimatization conditions of papaya cv Maradol hermaphrodite plants from axillary buds produced in temporary immersion reactor RITA®. Recipients contained 200 ml of Fitch liquid culture medium, and four shoots of 2 to 3 cm. in length were placed in each. The bioreactors were connected to three different immersion lines of 5, 2, and 1 min each 4h, with 6 containers per line on average, in 16 h photoperiod. After 30 to 45 days, the shoots produced were quantified and classified according to size: 3 cm with or without roots (large). The first two types of shoots were multiplied in the same culture media, and more elongated shoots were acclimatized using Autotrophic Hydroponic System (AHS). The sanity and fidelity of the produced plants were determined using ELISA and RAPD, respectively. For a period of six months 47 vessels were recycled and 1,091 shoots were produced: 377 small; 482 medium; 175 large without roots and 57 rooted shoots. Using AHS, 89.5% acclimatized plants were obtained when rooted shoots were used, and 41.6% from rootless shoots. With the combination of RITA and AHS techniques we achieved a continuous and efficient production of healthy and true to type papaya plants, in comparison to conventional micropropagation and acclimatization procedures.Se estandarizaron las condiciones de iniciación, multiplicación, enraizamiento y aclimatización de plantas hermafroditas de lechosa cv Maradol provenientes de brotes axilares, producidos en recipientes de inmersión temporal RITA®. En cada envase, contentivo de 200 ml de medio de cultivo líquido de Fitch, se colocaron cuatro brotes de 2 a 3 cm de longitud. Los biorreactores se conectaron a tres líneas de inmersión de 5, 2 y 1 min cada 4h y se colocaron 6 envases en promedio por línea, en condiciones de fotoperíodo de 16 h. Transcurridos 30 a 45 días, se cuantificaron los brotes y se clasificaron de acuerdo al tamaño: 3 cm con y sin raíz (grandes). Los dos primeros tipos de brotes se continuaron multiplicando en los mismos medios; y los más elongados se aclimatizaron utilizando el Sistema Autotrófico Hidropónico (SAH). Se determinó la sanidad y la fidelidad de las plantas producidas mediante pruebas de ELISA y RAPD, respectivamente. Durante un periodo de 6 meses se reciclaron un total de 47 recipientes, los cuales produjeron 1.091 brotes: 377 pequeños; 482 medianos; 175 grandes sin raíz y 57 con raíz. Usando el SAH se obtuvo 89,5% de plantas aclimatizadas cuando se usaron brotes enraizados, y 41,6% a partir de brotes sin raíces. Con la combinación de las técnicas RITA y SAH se logró un sistema continuo y eficiente de producción de plantas sanas y fieles al tipo, en comparación con los métodos convencionales de micropropagación y aclimatización