Effect of wounding on pepper fruit resistance to “Botrytis cinérea”

[Resumen] Los frutos son productos perecederos que se encuentran expuestos de forma continua a factores que disminuyen su valor, tanto económico como nutricional, por lo que numerosos estudios se centran en cómo frenar o evitar su deterioro. En este estudio se intentó inducir resistencia frente a Botrytis cinerea en frutos de pimiento verde, Capsicum annuum, mediante la aplicación de heridas y heridas combinadas con etileno sobre la superficie del fruto. Se demostró que tanto las heridas, como la combinación de heridas y etileno no inducen resistencia a Botrytis cinerea en el fruto. Por el contrario las heridas aumentan la susceptibilidad del fruto, ya que al romper la cutícula eliminan la principal barrera defensiva del fruto frente a las infecciones por parte de organismos patógenos. Los análisis bioquímicos realizados sobre pimientos control y heridos mostraron que el contenido de compuestos fenólicos solubles totales permanecía inalterado mientras que el contenido de sólidos solubles totales registraba un aumento significativo en respuesta a las heridas. Además se realizó un muestreo en seis establecimientos comerciales con el fin de determinar si existen heridas u otros daños en los frutos a la venta, demostrándose que si existen diferencias en cuanto a la calidad de los frutos en función del establecimiento elegido.[Resumo] Os froitos son produtos perecedoiros que se atopan expostos de forma continua a factores que diminúen o seu valor, tanto económico como nutricional, polo que numerosos estudios céntranse en como frear ou evitar o seu deterioro. Neste estudio intentouse inducir resistencia frente a Botrytis cinerea en froitos de pemento verde, Capsicum annuum, mediante a aplicación de feridas e feridas combinadas con etileno sobre a superficie do froito. Demostrouse que tanto as feridas, coma a combinación de feridas e etileno non inducen resistencia a Botrytis cinerea nos froitos. Polo contrario, as feridas aumentan a susceptibilidade do froito, xa que ó romper a cutícula eliminan a principal barreira defensiva do froito frente ás infeccións por parte dos organismos patóxenos. As análises bioquímicas realizadas sobre pementos control e feridos amosaron que o contido de compostos fenólicos solubles totais non cambiou, mais o contido en sólidos solubles totais rexistrou un aumento significativo en resposta as feridas. Ademais realizouse unha mostraxe en seis establecementos comerciais coa fin de determinar se existen feridas ou outros danos nos froitos á venda, demostrándose que si existen diferencias en canto á calidade dos froitos en función do establecemento escollido.[Abstract] Fruits are perishable products that are constantly exposed to factors that decrease not only their economical value but their nutritional value too. That is why a high number of researches are based on the way we could stop or avoid their deterioration. In this research, we have tried to induce resistance to Botrytis cinerea in green pepper fruits, Capsicum anuum, by making wounds over the surface of the fruit and treating them with ethylene plus wounds. It has been determined that both, wounds and ethylene plus wounds do not induce resistance to Botrytis cinerea in the fruits. Indeed, wounds caused an increase in susceptibility, because they break the cuticle, the main fruit’s defensive barrier against infections caused by pathogen organisms. Biochemical analysis we have carried out in control and wounded peppers revealed that the content of total soluble phenolic compounds remain unchanged, while the content of total soluble solids increased as a response to wounding. In addition, a comparative study was carried out, surveying six different supermarkets in order to determine if commercial fruits were wounded or damaged in other ways. We found differences in fruit quality among different supermarkets.Traballo fin de grao (UDC.CIE). Bioloxía. Curso 2014/201

The Effect of Sucrose Supplementation on the Micropropagation of Salix viminalis L. Shoots in Semisolid Medium and Temporary Immersion Bioreactors

[Abstract] The effect of sucrose concentration on the micropropagation of axillary shoots of willow was investigated. The following factors were examined: the culture system (semisolid medium in glass jars versus liquid medium in temporary immersion bioreactors), the type of explant (apical and basal sections), the frequency of immersion, and CO₂ enrichment. Shoots and leaf growth were significantly higher in RITA® bioreactors than in the jars for all the sucrose treatments. Apical or basal sections of willow cultured in bioreactors under high light intensity (150 µmol m⁻² s⁻¹) and ventilated six times a day with CO₂-enriched air were successfully proliferated without sucrose, whereas shoots cultured in jars did not proliferate well if sucrose concentration was 0.5% or lower. More roots were formed when sucrose was added to the medium. Shoots cultured in bioreactors were successfully acclimatized irrespective of the sucrose treatment and the root biomass when transferred to ex vitro conditions. This is the first report of photoautotrophic willow micropropagation, our results confirm the importance of proper gaseous exchange to attain autotrophy during in vitro propagation.This research was funded by Xunta de Galicia (Spain) (projects IN607A and Contrato Programa 2019-2020), by CYTED (P117RT0522) and by CSIC (COOPB20584)Xunta de Galicia; IN607AConsejo Superior de Investigaciones Científicas; COOPB2058

Micropropagation of Plum (Prunus domestica L.) in Bioreactors Using Photomixotrophic and Photoautotrophic Conditions

[Abstract] In this study, we propagated two old Galician plum varieties in liquid medium using a temporary immersion system with RITA© bioreactors. Environmental variables including culture system, light intensity, CO2 enrichment, immersion frequency and sucrose supplementation were evaluated in relation to in vitro proliferation, physiological status and ex vitro performance. Bioreactors were superior to jars for culturing shoots in photomixotrophic conditions, producing up to 2 times more shoot numbers and up to 1.7 times more shoot length (depending on the genotype) using shoot clusters. The number and quality of shoots were positively influenced by the sucrose concentration in the medium, plus by the light and gaseous environment. For individual apical sections the best response occurred with 3% sucrose, 150 µmol m−2 s−1 photosynthetic photon flux density and 2000 ppm CO2, averaging 2.5 shoots per explant, 26 mm shoot length and 240 mm2 leaf area, while with 50 µmol m−2 s−1 light and ambient CO2 (400 ppm) values decreased to 1.2 shoots per explant, 14 mm of shoot length and 160 mm2 of leaf area. Shoots cultured photoautotrophically (without sucrose) were successfully rooted and acclimated despite of showing limited growth, low photosynthetic pigments, carbohydrate, phenolic and antioxidant contents during the multiplication phase.This research was funded by Xunta de Galicia (Spain) (project IN607A 2021), by CYTED (P117RT0522), and by CSIC (PIE 202140E015, COOPB20584)Xunta de Galicia; IN607A 2021Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (CYTED); P117RT0522Consejo Superior de Investigaciones Científicas; COOPB2058

Effect of Sucrose on Growth and Stress Status of Castanea sativa x C. crenata Shoots Cultured in Liquid Medium

[Abstract] Current breeding programs aim to increase the number of ink-tolerant chestnut trees using vegetative propagation of selected genotypes. However, the commercial vegetative propagation of chestnut species is still a bottleneck for the forest industry, mainly due to problems in the rooting and acclimation of propagules. This study aimed to explore the potential benefits of decreasing sucrose supplementation during chestnut micropropagation. Explants were cultured with high light intensity and CO2-enriched air in temporary or continuous immersion bioreactors and with different sucrose supplementation to evaluate the impact of these treatments on growth, rooting and physiological status (monosaccharide content, soluble phenolics and antioxidant activity). The proliferation and rooting performance of shoots cultured by continuous immersion decreased sharply with sucrose concentrations lower than 1%, whereas shoots cultured by temporary immersion grew and rooted successfully with 0.5% sucrose. These results suggest this system is appropriate to culture chestnut with low sucrose concentration and to explore photoautotrophic propagation of this species.This research was funded by Xunta de Galicia (Spain) (projects IN607A 2021), by CYTED (P117RT0522), and by CSIC (PIE 202140E015, COOPB20584)Xunta de Galicia; IN607A 2021Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (CYTED); P117RT0522Consejo Superior de Investigaciones Científicas; PIE 202140E015Consejo Superior de Investigaciones Científicas; COOPB2058

Micropropagación y análisis bioquímico de mimbrera, castaño y ciruelos cultivados en biorreactores con diferentes concentraciones de sacarosa

Programa Oficial de Doutoramento en Bioloxía Celular e Molecular . 5004V01[Resumen] Se ha investigado el efecto de la concentración de sacarosa en el medio de cultivo sobre el desarrollo de brotes axilares de tres especies leñosas cultivadas in vitro en medio líquido en biorreactores, con el objetivo de conseguir su propagación fotoautotrófica. El material vegetal consistió en dos clones de Castanea sativa x Castanea crenata, que se cultivaron en un sistema de inmersión temporal Plantform® y en un sistema de inmersión continua de 6 litros, en dos variedades locales de Prunus doméstica y en un clon de Salix viminalis, que se cultivaron en biorreactores de inmersión temporal RITA®. Para lograr la propagación fotoautotrófica los cultivos crecieron con intensidad de luz media o alta (50 o 150 μmol m-2 s-1) y fueron suplementados o no con aire enriquecido con CO2. A fin de caracterizar el efecto de la sacarosa y las condiciones de cultivo en el desarrollo de los explantos se analizaron sus medidas morfológicas, compuestos fenólicos solubles totales, compuestos antioxidantes, pigmentos fotosintéticos, contenido en azúcares, capacidad de enraizamiento y aclimatación. Se ha conseguido cultivar la mimbrera sin azúcar exógeno y reducir hasta un sexto y un tercio la concentración de azúcar convencional en castaño y ciruelos, respectivamente[Resumo] Investigouse o efecto da concentración de sacarosa no medio de cultivo no desenvolvemento de brotes axilares de tres especies leñosas cultivadas in vitro en medio líquido en biorreactores, co obxectivo de conseguir a súa propagación fotoautótrofa. O material vexetal estaba formado por dous clons de Castanea sativa x Castanea crenata, que se cultivaron nun sistema de inmersión temporal Plantform® e nun sistema de inmersión continua de 6 litros, dúas variedades locais de Prunus domestica e un clon de Salix viminalis. cultivados en biorreactores de inmersión temporal RITA®. Para conseguir a propagación fotoautótrofa, os cultivos cultiváronse con intensidade luminosa media ou alta (50 ou 150 μmol m-2 s-1) e complementáronse ou non con aire enriquecido en CO2. Para caracterizar o efecto da sacarosa e as condicións de cultivo no desenvolvemento dos explantos, analizáronse as súas medidas morfolóxicas, compostos fenólicos solubles totais, compostos antioxidantes, pigmentos fotosintéticos, contido en azucres, capacidade de enraizamento e aclimatación. Foi posible cultivar o vimbio sen azucre esóxeno e reducir a concentración de azucre convencional en castiñeiros e ameixeiras ata nun sexto e nun terzo, respectivamente.[Abstract] The effect of sucrose concentration in the culture medium on the development of axillary shoots of three woody species grown in vitro in liquid medium in bioreactors has been investigated, with the aim of achieving their photoautotrophic propagation. The plant material consisted of two clones of Castanea sativa x Castanea crenata, which were grown in a Plantform® temporary immersion system and in a 6-liter continuous immersion system, two local varieties of Prunus domestica and one clone of Salix viminalis, which were grown in RITA® temporary immersion bioreactors. To achieve photoautotrophic propagation, cultures were grown with medium or high light intensity (50 or 150 μmol m-2 s-1) and were supplemented or not with CO2 enriched air. In order to characterize the effect of sucrose and culture conditions on the development of explants, their morphological measurements, total soluble phenolic compounds, antioxidant compounds, photosynthetic pigments, sugar content, rooting capacity and acclimatization were analyzed. It has been possible to grow willow without exogenous sugar and reduce the concentration of conventional sugar in chestnut and plum trees by up to one sixth and one third, respectively