Caracterización morfológica y molecular de árboles de Umbu-cajá en la región nordeste del Brasil

The umbu-cajá (Spondias sp.) is a fruit specie native of the brazilian semiarid region with high potential for cultivation. The juicy pulp is used in the production of juices and nectars. The aim of this study was to characterize 18 individuals of umbu-cajá tree at three sites located in the Brazilian northeast municipalities of Mossoró/RN and Apodi/RN to identify individuals with superior attributes for fruit processing and/or in natura consumption The morphological, physical and physicochemical characterization of 20 fruits of each individuals were performed. Leaves of trees were used for molecular analyses with Inter Simple Sequence Repeats (ISSR) and Random Amplified Polymorphic DNA (RAPD) markers. It was possible to verify that there are phenotypic variability among the fruits of umbu-cajá trees.  The individuals of the same region were grouped in the same group. JZ5, JZ6 and MA6 individuals can be used for pulp processing, while JZ1, JZ2, JZ3 and JZ6 are adequate for in natura consumption. The molecular analyses showed polymorphism for the two molecular markers used. The ISSR marker generated the greatest polymorphism among the individuals. However, the RAPD marker made it possible to achieve a more consistent cluster, which is in agreement with the geographical distribution of these individuals. The use of morphological markers together with molecular markers constitutes an important tool for characterizing umbu-cajá individuals. Keywords: genetic resources, ISSR, RAPD, Spondias sp.Umbu-cajá (Spondias sp.) es una especie de fruto nativa de la región semiárida brasileña con alto potencial de cultivo. La pulpa jugosa se utiliza en la producción de jugos y néctares. El objetivo de este estudio fue caracterizar a 18 individuos de umbu-cajá en tres sitios ubicados en los municipios noreste de Mossoró / RN y Apodi / RN para identificar individuos con atributos superiores para procesamiento de frutas y / o consumo in natura. Se realizó la caracterización morfológica, física y fisicoquímica de 20 frutos de cada individuo. Las hojas de los árboles se utilizaron para los análisis moleculares mediante Secuencias Intergénicas Repetidas Simples (ISSR) y la Amplificación aleatoria de ADN polimórfico (RAPD). Se pudo verificar la existencia de variabilidad fenotípica entre los frutos de los árboles umbu-cajá. Los individuos de la misma región se agruparon en el mismo grupo. Los individuos JZ5, JZ6 y MA6 pueden usarse para el procesamiento de pulpa, mientras que JZ1, JZ2, JZ3 y JZ6 son adecuados para el consumo in natura. Los análisis moleculares mostraron polimorfismo para los dos marcadores moleculares utilizados. El ISSR generó el mayor polimorfismo entre los individuos. Sin embargo, el marcador RAPD permitió lograr un grupo más consistente, lo que está de acuerdo con la distribución geográfica de estos individuos. El uso de marcadores morfológicos junto con marcadores moleculares constituye una herramienta importante para caracterizar individuos umbu-cajá. Palabras clave: ISSR, RAPD, recursos genéticos, Spondias sp

Alterações físicas, fisiológicas e químicas durante o armazenamento de duas cultivares de sapoti

The objective of this work was to evaluate the physical, physiological and chemical changes during storage of two sapodilla cultivars (Manilkara sapota L.). Fruits were picked and evaluated at the physiological maturation point, and stored at temperature of 26±2ºC and 55±5% relative humidity. Respiration activities and ethylene production were daily evaluated, while the loss of mass, firmness, pulp color, total titratable acidity, pH, soluble solids content, total sugar and senescence were determined in the 0, 2, 4, 6, 8, 10 and 12 days of storage. Fruits of BRS-228 cultivar had respiration activities, ethylene production picks and senescence retarded when compared to BRS-227 cultivar. Fruits of BRS-228 maintained larger firmness, soluble solids and total sugar contents and smaller loss of mass than BRS-227. The cultivar BRS-228 presents higher postharvest storage potential than BRS-227.O objetivo deste trabalho foi avaliar alterações físicas, fisiológicas e químicas, durante a maturação de duas cultivares de sapoti (Manilkara sapota L.), relacionando-as às taxas respiratórias e de liberação de etileno. Os frutos foram colhidos no estádio de maturidade fisiológica, avaliados no dia da colheita e armazenados em temperatura de 26±2ºC e umidade relativa de 55±5%. A atividade respiratória e a produção de etileno foram determinadas diariamente; perda de massa, firmeza, acidez total titulável, pH, sólidos solúveis, açúcares solúveis totais e senescência foram avaliados nos tempos de 0, 2, 4, 6, 8, 10 e 12 dias de armazenamento. A cultivar BRS-228 teve pico respiratório, produção de etileno e senescência retardada em relação à cultivar BRS-227. A cultivar BRS-228 manteve maior firmeza, maiores teores de sólidos solúveis e açúcares solúveis totais, e menor perda de massa do que a cultivar BRS-227. A cultivar BRS-228 apresenta maior potencial de conservação pós-colheita do que a cultivar BRS-227

Enzyme activities and pectin breakdown of sapodilla submitted to 1-methylcyclopropene

O objetivo deste trabalho foi investigar a influência do 1-metilciclopropeno (1-MCP) nas atividades das enzimas hidrolíticas da parede celular e nas mudanças na degradação da pectina durante o amadurecimento de sapoti (Manilkara zapota cv. Itapirema 31). Frutos de sapotizeiro foram tratados com o inibidor da ação do etileno, 1-MCP, na concentração de 300 nL L-1, por 12 horas e armazenados sob atmosfera modificada, à temperatura de 25±2ºC, por 23 dias. A firmeza, conteúdo de pectina total e solúvel e enzimas da parede celular foram avaliados durante todo o período de armazenamento. O 1-MCP a 300 nL L-1 por 12 horas retardou significativamente o amolecimento de sapoti por 11 dias a 25ºC. O tratamento com 1-MCP afetou a atividade das enzimas pectinametilesterase e poligalacturonase e inibiu o aumento da atividade beta-galactosidase por 8 dias, e, conseqüentemente, resultou em menor solubilização das substâncias pécticas. A beta-galactosidase parece ser relevante no amolecimento de sapoti e responsável pela modificação das pectinas e das xiloglucanas ligadas as microfibrilas de celulose.The objective of this work was to investigate the influence of 1-methylcyclopropene (1-MCP) at 300 nL L-1 on activities of cell wall hidrolytic enzymes and pectin breakdown changes which Sapodilla (Manilkara zapota cv. Itapirema 31) cell wall undergoes during ripening. Sapodilla were treated with ethylene antagonist 1-MCP at 300 nL L-1 for 12 hours and then, stored under a modified atmosphere at 25ºC for 23 days. Firmness, total and soluble pectin and cell wall enzymes were monitored during storage. 1-MCP at 300 nL L-1 for 12 hours delayed significantly softening of sapodilla for 11 days at 25ºC. 1-MCP postharvest treatment affected the activities of cell wall degrading enzymes pectinmethylesterase and polygalacturonase and completely suppressed increases in beta-galactosidase for 8 days, resulting in less pectin solubilization. Beta-galactosidase seems relevant to softening of sapodilla and is probably responsible for modification of both pectin and xyloglucan-cellulose microfibril network

Effect of salt stress on muskmelon (Cucumis melo L.) seeds

Cucumis melo is one of the most appreciated and consumed vegetables in the world, however, producing areas have been suffering from increased salinity in irrigation water. Therefore, accesses of melon, from the germplasm bank of the Federal Rural Semi-Arid University (UFERSA), were tested for salinity and the physiological responses of the seedlings were evaluated. For the 24 accesses of C. melo, salinity of 0.06 and 3.45 dS m-1 was applied. For this, four subsamples of 25 seeds per access were used, which were seeded in polystyrene trays having as a substrate washed and sterilized sand, initially moistened at 50% field capacity. The design was completely randomized in a factorial scheme (two salinity levels and 24 accesses). Salinity affected the physiological quality (germination and mean germination time) of melon seeds, germinating on average 62%, with an average germination time of 4 days, mean height of 10.5 cm and reduction of dry matter accumulation. The saline treatment increased the EC of the soil saturation extract, indicating the presence of stress. The accesses that presented intolerance to salinity were: A35, A24, A41, A31, A09, A28 and A43. The moderately tolerant accesses were: A16, A19, A15, A17, A34, A25, A27, A18, A42. The salinity tolerant accesses were: A45, A08, A37, A50, A14, A36, A07, A39 which may serve as a basis for genetic improvement