Secado y almacenamiento de semillas de mandarino 'Cleopatra'

The objetives of this work were to evaluate the effect of the treatment with chemical products and the humidity content for conservation of seeds of ‘Cleopatra’ mandarin (Citrus reshni Hort ex Tan). Seeds with 14.7% of moisture content were treated with four fungicides and 8-hydroxyquinoline and stored at 4±2°C for one year. Three groups of seeds with 5.0, 14.7% and 26.8% of moisture content were stored as above. Germination and emergence were evaluated at the beginning of the two experiments, at six and twelve months of storage. In the test with chemical products, storage of seeds with 14.7% of moisture content was possible only for six months, with higher percentages of germination and emergence (59.3% and 54.0%, respectively), while in seeds without chemical treatment percentages of germination and emergence were about 33.3% and 27.3%, repectively. As far as the moisture content of the seed is concerned, at six months of storage the highest seedlings emergence (63,6% and 58.0%) were obtained, in seeds with 26.8% and 5% of moisture, respectively. Twelve-months-seeds with 5% of moisture content caused 75.6% of emergence.The objetives of this work were to evaluate the effect of the treatment with chemical products and the humidity content for conservation of seeds of 'Cleopatra' mandarin (Citrus reshni Hort ex Tan). Seeds with 14.7% of moisture content were treated with four fungicides and 8-hydroxyquinoline and stored at 4±2°C for one year. Three groups of seeds with 5.0, 14.7% and 26.8% of moisture content were stored as above. Germination and emergence were evaluated at the beginning of the two experiments, at six and twelve months of storage. In the test with chemical products, storage of seeds with 14.7% of moisture content was possible only for six months, with higher percentages of germination and emergence (59.3% and 54.0%, respectively), while in seeds without chemical treatment percentages of germination and emergence were about 33.3% and 27.3%, repectively. As far as the moisture content of the seed is concerned, at six months of storage the highest seedlings emergence (63,6% and 58.0%) were obtained, in seeds with 26.8% and 5% of moisture, respectively. Twelve-months-seeds with 5% of moisture content caused 75.6% of emergence.Los objetivos del trabajo fueron evaluar el efecto del tratamiento con productos químicos y contenido de humedad en la conservación de semillas de mandarino 'Cleopatra' (Citrus reshni Hort ex Tan). Semillas con 14,7% de humedad tratadas con cuatro funguicidas y 8-hidroxiquinoleina, fueron almacenadas a 4±2°C durante un año, al igual que tres lotes de semillas con 5,0%, 14,7% y 26,8% de humedad, tratadas con y sin 8-hidroxiquinoleina. Se evaluó la germinación y emergencia al inicio del experimento, a los seis y 12 meses de almacenamiento. En la prueba con productos químicos, el almacenamiento de semillas con 14,7% de humedad sólo fue viable hasta los seis meses, con mayores porcentajes de germinación y emergencia (59,3% y 54,0%, respectivamente), mientras que, en las semillas sin tratamiento químico fue de 33,3% y 27,3%, respectivamente. En relación con el contenido de humedad de las semillas, a los seis meses de almacenamiento se obtuvo mayor emergencia de plántulas (63,6% y 58,0%) en semillas con 26,8% y 5%, mientras que a los 12 meses, las semillas con 5%, de humedad tuvieron 75,6% de emergencia

Poliembrionia e identificação de seedlings zigóticos e nucelares de limão volkameriano com RAPD

The objectives of this work were to evaluate the frequency of polyembryony, and to identify zygotic and nucellar seedlings of Citrus volkameriana using RAPD. Twenty-five polyembryonic and eight monoembryonic seeds were cultivated in vitro for six months. DNA from seedlings was extracted and used in combination with five RAPD primers to identify zygotic or nucellar origin of the seedlings. Environmental conditions of the year affected significantly (P≤0.05) the morphological characteristics of fruits and the number of embryos per seed. Polyembryonic seeds ranged from 30.9%, 44.8% to 54.4% over three years. Morphological characteristic was not correlated with polyembryony. In vitro culture enable all embryos of each seed to grow, favoring the percentage of seedlings identified as zygotic. In polyembryonic and monoembryonic seeds, 25.9% and 87.5% of the seedlings, respectively, were sexually originated. In polyembryonic seeds, not all zygotic seedlings were produced by small embryos located at the micropyle.Os objetivos deste trabalho foram avaliar a freqüência da poliembrionia e indentificar os seedlings zigóticos e nucelares de Citrus volkameriana usando RAPD. Cultivaram-se in vitro 25 sementes poliembriônicas e 8 monoembriônicas, por seis meses. Extraiu-se o DNA dos seedlings e usou-se em combinação com cinco primers RAPD para identificar a origem zigótica e nucelar das plântulas. Os resultados mostraram que as condições ambientais do ano afetaram significativamente (P≤0,05) as características morfológicas dos frutos e o número de embriões por semente. Os índices de sementes poliembriônicas variaram nos três anos de avaliação (30,9%, 44,8% e 54,4%). As características morfológicas não se correlacionaram com a poliembrionia. A cultura in vitro possibilita que todos os embriões de cada semente cresçam, favorecendo os seedlings identificados como zigóticos. Nas sementes poliembriônicas e monoembriônicas, 25,9% e 87,5% dos seedlings, respectivamente, originaram-se sexualmente. Nem todos os seedlings zigóticos foram produzidos por embriões localizados no micrófilo das sementes poliembriônicas

Enraizamiento de estacas en tres cultivares de arándano (Vaccinium corymbosum L.)

Objective: To evaluate the effect of indolbutyric acid (IBA) on rotting of three blueberry cultivars (Vaccinium corymbosum L.) Biloxi, Victoria and Ventura. Design/methodology/approach: The experimental design was the completely randomized with factorial arrangement 3 x 4. Herbaceous cuttings of blueberry cultivars Biloxi, Victoria and Ventura, with 7 cm length and 2 mm diameter, were collected at the end in April 2017. The IBA concentrations were tested 0, 1 000, 2 000 and 3 000 mg L-1. The cuttings were placed in peat and perlite substrate (50:50, v:v). Forty days after, the variables evaluated were rooting percent, cuttings died percent, number and length of primary roots, number of secondary roots, and survival percent after the transplant. Test of medians comparison Tukey (0.05) was did for the variables, except for all percent. Results: The Victoria cultivar presented the higher average rooting percent with 61 %, moreover it obtained the less cuttings died percent. For the variables evaluated from roots, only number of primary roots and number of secondary roots had differences, the Victoria cultivar had 4.3 primary roots and the Biloxi cultivar had 12.65 secondary roots. The survival percent was major 95 % for all cultivars after the transplant. Limitations on study/implications: In some cultivars, the high concentrations of auxins inhibit rooting. Findings/conclusions: The proposed protocol let the rooting blueberry cuttings.Objetivo: Evaluar el efecto de ácido indolbutírico (AIB) en el enraizamiento de tres cultivares de arándano (Vaccinium corymbosum L.) Biloxi, Victoria y Ventura. Diseño/metodología/aproximación: Fue empleado un diseño completamente al azar con arreglo factorial 3 x 4. Estacas herbáceas de cultivares de arándano Biloxi, Victoria y Ventura, con 7 cm longitud y 2 mm de diámetro, fueron recolectadas a finales de abril de 2017. Las concentraciones de AIB utilizadas fueron 0, 1 000, 2 000 y 3 000 mg L-1. Las estacas se colocaron en sustrato de turba y perlita (50:50, v:v). Cuarenta días después se evaluó porcentaje de enraizamiento y de estacas muertas, número y longitud de raíces primarias, número de raíces secundarias, y porcentaje de sobrevivencia después del trasplante. Se realizó prueba de comparación de medias Tukey (0.05), excepto a los datos de porcentaje. Resultados: El cultivar con mayor porcentaje de enraizamiento promedio fue Victoria con 61%, también presentó el menor porcentaje de estacas muertas. Para las características de raíces evaluadas, solo existió diferencia para número de raíces primarias y secundarias; donde el cv. Victoria presentó 4.3 raíces primarias y el cv Biloxi 12.65 raíces secundarias. El porcentaje de sobrevivencia en todos los cultivares después del trasplante fue mayor al 95%. Limitaciones del estudio/implicaciones: En algunos cultivares, la concentración alta de auxinas inhibió el enraizamiento. Hallazgos/conclusiones: El protocolo propuesto permite el enraizamiento de estacas de arándano

Resposta fotossintética de citros a isolados de Citrus tristeza virus com potencial para proteção cruzada

The objective of this work was to evaluate the photosynthetic response of citrus varieties to the inoculation of isolates T30 and T3 of Citrus tristeza virus (CTV) characterized as having potential to provide cross‑protection against severe CTV isolates in citrus. Citrus plants of 'Campbell' orange, 'Persian' lime, and 'Key' lime were subjected to inoculations by both isolates by patch. Noninoculated plants were used as the control. Symptom expression, photosynthetic and transpiration rates, and stomatal conductance were evaluated by IRGA. Stomatal density and size were evaluated by epidermal impressions. The CTV isolates were also evaluated and molecularly characterized by RT-PCR and Sanger sequencing. 'Campbell' orange and 'Persian' lime plants remained asymptomatic after the inoculations. The inoculation treatments with both CTV isolates did not reduce photosynthetic capacity, transpiration rate, and stomatal conductance, in comparison with the control. Stomatal density and size varied according to the citrus species. T30 and T3 do not affect the photosynthetic responses of 'Campbell' orange and 'Persian' lime; therefore, these isolates have the potential to provide cross-protection to citrus varieties against severe isolates of CTV.O objetivo deste trabalho foi avaliar a resposta fotossintética de variedades de citros submetidas à inoculação dos isolados T30 e T3 de Citrus tristeza virus (CTV) caracterizados como tendo potencial para conferir proteção cruzada a citros contra isolados severos de CTV. Plantas de citros de laranja 'Campbell', limão 'Tahiti' e limão 'Galego' foram submetidas à inoculação de ambos os isolados por “patch”. Plantas não inoculadas foram utilizadas como controle. A expressão dos sintomas,  as taxas fotossintética e de transpiração, e a condutância estomática foram avaliadas por IRGA. A densidade e o tamanho estomáticos foram avaliados por impressões epidérmicas. Os isolados de CTV também foram avaliados e caracterizados molecularmente por RT-PCR e sequenciamento de Sanger. As plantas de laranja 'Campbell' e limão 'Tahiti' permaneceram assintomáticas após as inoculações. Os tratamentos de inoculação com ambos os isolados de CTV não reduziram capacidade fotossintética, taxas de transpiração e condutância estomática, em comparação ao controle. A densidade e o tamanho estomáticos variaram de acordo com a espécie. T30 e T3 não afetam as respostas fotossintéticas de laranja 'Campbell' e limão 'Tahiti'; portanto, estes isolados têm potencial para promover proteção cruzada a variedades de citros contra isolados severos de CTV

Identification of zygotic and nucellar seedlings in polyembryonic mango cultivars

O objetivo deste trabalho foi avaliar a ocorrência de poliembrionia nas mangas 'Manila' e 'Ataulfo' e determinar se as plântulas cultivadas in vitro são zigóticas ou nucelares. A percentagem de poliembrionia foi calculada e o número de embriões em 100 sementes de cada cultivar foi determinado. 'Manila' apresentou 97% de poliembrionia com 3,4 embriões por semente, enquanto 'Ataulfo' teve 95% de poliembrionia com 3,2 embriões por semente. Posteriormente, 20 sementes de cada cultivar foram cultivadas in vitro, tendose analisado aquelas em que todos os embriões germinaram (12 sementes de 'Manila' e sete de 'Ataulfo'). O DNA foi extraído a partir de tecidos foliares das plântulas, e sua origem foi identificada com 14 iniciadores RAPD. Os marcadores polimórficos reconheceram o embrião de origem sexual em sete das nove sementes poliembriônicas de 'Manila' e em quatro das sete sementes de 'Ataulfo'. Além disso, nem todas as plântulas zigóticas foram produzidas por embriões pequenos localizados no micrófilo das sementes poliembriônicas.The objective of this work was to evaluate the occurrence of polyembryony in the mango cultivars Manila and Ataulfo, and to determine whether seedlings cultured in vitro are zygotic or nucelar. Percentage of polyembryony was calculated and the number of embryos in 100 seeds of each cultivar was recorded. 'Manila' exhibited 97% polyembryony with 3.4 embryos per seed, while 'Ataulfo' had 95% polyembryony with 3.2 embryos per seed. Later, 20 seeds of each cultivar were established in vitro, and it was analyzed those in which all embryos germinated (12 seeds from 'Manila' and 7 from 'Ataulfo'). DNA was extracted from seedling leaf tissue, and its origin was identified with 14 RAPD primers. The polymorphic markers recognized the seedlings of sexual origin in seven of nine 'Manila' polyembryonic seeds, and in four of seven 'Ataulfo' ones. Also, in polyembryonic seeds not all zygotic seedlings were produced by small embryos located at the micropyle

TRATAMIENTOS POST-COSECHA DE LA SEMILLA DE PAPAYO PARA MEJORAR LA GERMINACIÓN Y DESARROLLO DE LA PLÃNTULA

Tecnologías prácticas se requieren para preservar la viabilidad de las semillas en particular cuando su viabilidad no es duradera como la semilla de Carica papaya (papaya). Semillas de papaya fueron embebidas en agua o en soluciones de CaCl2 10-5 M, ácido salicílico 10-4 M y ácido giberélico 10-5 M e inoculadas con una suspensión de células bacterianas para determinar sus efectos en la germinación, desarrollo inicial de las plántulas, acumulación de biomasa y de clorofila. Las semillas embebidas en agua germinaron 40 % más y requirieron de dos días menos para que el 50 % de la semilla germinara en comparación con la semilla sin tratar; sin embargo, la semilla sin tratar generó plántulas de mayor longitud (9.2 cm) y más vigorosas. La semilla embebida en la solución combinada de calcio, ácido giberélico y ácido salicílico generó plántulas de mayor peso (biomasa fresca y seca) superando al control. La semilla embebida en solución de ácido giberélico seguido de la inoculación con células de Azospirillum brasilense tuvieron alta germinación (69 %), emergencia (47 %) y generaron plántulas de mayor altura, 19 % más que el testigo. Las diferencias en la acumulación de clorofila fueron mínimas

Citrus Polyembryony

Polyembryony is a type of sporophytic apomixis common in citrus species. Previous studies discovered that embryo traits relate to their sexual or asexual origin. Smaller embryos at the micropyle end are considered zygotic embryos, whereas larger embryos are nucellar. Early embryogenesis in the ovule of apomictic citrus promotes the development of nucellar embryos. The chalaza region inhibits the early development of the zygotic and nucellar embryos; thus, both embryos must grow at the micropyle end. Numerous researchers agree that highly polyembryonic cultivars produce nucellar seedlings more often as the zygotic embryos cannot survive field conditions. Thus, the selection of polyembryonic genotypes facilitates clonal propagation. This chapter analyzes the factors that affect polyembryony in citrus