AVALIAÇÃO DE SUBSTRATOS PECTOCELULÓSICOS PARA O CULTIVO DE COGUMELOS COMESTÍVEIS DO GÊNERO PLEUROTUS SP. (AGARICALES)

Os fungos do gênero Pleurotus são bastante solicitados no mercado internacional tendo aplicações gastronômicas, ecológicas e medicinais. Neste trabalho foram avaliados o crescimento micelial (cm), a eficiência biológica (%), produtividade (%) e perda de matéria orgânica (%) de substratos pectocelulósicos, feitos com cascas de maracujá e banana, em comparação ao lignocelulósico de serragem (controle). Os substratos foram desidratados, esterilizados e umedecidos em água destilada. Em cada substrato foi colocado um inóculo (10mm) retirado de uma cultura já estabelecida de Pleurotus. Posteriormente os fungos foram incubados (45 dias) para crescimento à temperatura média de 29,2ºC e a 92,2% de umidade relativa. Foi aplicado o teste de ANOVA One-way para avaliar diferenças nos parâmetros analisados e comparar os diferentes substratos. Os substratos de casca de banana apresentaram maiores raios de crescimento micelial (4,55 ± 0,05 cm,

Effect of atmospheric warming and CO2 increase on genetic and biological parameters of tropical forage species Stylosanthes capitata (Vogel)

Em cenários de mudanças climáticas, é crucial a estimativa de parâmetros genéticos de espécies de plantas economicamente importantes, com o objetivo de prever sua capacidade de resposta e adaptabilidade. Nesta pesquisa avaliou-se o efeito do aumento da temperatura (+2 ºC) e da concentração atmosférica de CO2 (600 ppm) sobre a produção de sementes, germinação, diversidade genética, diferenciação genética e taxas de cruzamento da espécie Stylosanthes capitata, uma leguminosa forrageira de importância econômica para agro-pecuária brasileira. Utilizou-se o sistema de simulação de mudanças climáticas Trop-T-FACE (Temperature Free Air Controlled Enhancementand Free Air Carbon Dioxide Enrichment) no campus da USP/RP, com 4 repetições cada. Após semeadura e crescimento incial, as plantas foram submetidas a quatro tratamentos: [C] controle; [eCO2] aumento da concentração de CO2 atmosférico em 600 ppm; [eT] aumento da temperatura em 2°C e [eCO2+eT] sua combinação. No final do ciclo de reprodução, dez plantas adultas (matrizes) de cada tratamento foram coletadas e as sementes retiradas de suas inflorescências. Avaliou-se a porcentagem de vagens vazias, porcentagem de sementes inviáveis, número de sementes produzidas por inflorescência, o peso de 100 sementes (mg), a a germinabilidade (%) e o índice de velocidade de germinação (IVG). Para as análises genéticas, o DNA total foi extraído de amostras de tecido foliar (plantas matrizes) e de cotilédones frescos (progênies). Realizou-se a amplificação das famílias para 7 loci SSR polimórficos. A eletroforese e genotipagem foi realizada pel o sistema de eletroforese capilar GelBot. As análises foram realizadas nos softwares GenAlex, GenePop, GDA e MLTR. Diferenças entre tratamentos foram avaliadas pela ANOVA Fatorial 2x2 (p0,05). A maioria dos índices de diversidade genética e de fixação foram semelhantes entre gerações e tratamentos. Mas nas parcelas com aquecimento (eT) a heterozigosidade esperada foi reduzida (p 0,05), mostrando resiliência em seu sistema de cruzamento misto em as condições experimentais estudadas. O comportamento do polinizador, o número de flores por planta que promove a autogamia, bem como a possível degeneração dos grãos de pólen nos tratamentos de aquecimento, podem contribuir para os resultados observados. Esta pesquisa apresenta resultados inovadores úteis para orientar estratégias de preservação e melhoramento de germoplasma de S. capitata frente ao cenário iminente de mudanças climáticas.In climate change scenarios is crucial the estimation of genetic parameters of economically important plant species aiming to predict their responsiveness and adaptability. This research evaluated the effects of temperature increase (+2 ° C) and atmospheric CO2 concentration (600 ppm) on seed production, germination, genetic diversity, genetic differentiation and crossing rates of Stylosanthes capitata, a legume forage plant with economic importance for Brazilian agriculture. Trop-T-FACE (Temperature Free Air Controlled Enhancementand Free Air Carbon Dioxide Enrichment) climate change simulation system was used at the USP / RP campus, with 4 repetitions each. After sowing and initial growth, the plants were submitted to four treatments: [C] control; [eCO2] increase of atmospheric CO2 concentration to 600 ppm; [eT] temperature rise by 2 ° C and [eCO2 + eT] their combination. At the end of the breeding cycle, a total of ten adult plants (matrices) from each treatment (n=40) were collected and the seeds removed from their inflorescences. The percentage of empty pods, percentage of unfeasible seeds, number of seeds produced by inflorescence, weight of 100 seeds (mg), germinability (%) and germination speed index (IVG) were evaluated. For family\'s amplification, 16 progenies from each matrix plant were germinated in vitro (n=640). Total DNA was extracted from samples of leaf tissue (parent plants) and fresh cotyledons (progenies). Families were amplified to 7 polymorphic SSR loci. Electrophoresis and genotyping was performed by the GelBot capillary electrophoresis system. The analyzes were performed using GenAlex, GenePop, GDA and MLTR software. Differences between treatments were evaluated by 2x2 factorial ANOVA (p0.05). Most genetic diversity and fixation indices were similar across generations and treatments. But in the warmed plots (eT) the expected heterozygosity was reduced (p 0,05), showing resilience in its mixed crossing system under the studied experimental conditions. Pollinator behavior, the number of flowers per plant that promotes autogamy, as well as the possible degeneration of pollen grains in heating treatments, may contribute to the observed results. This research presents innovative results useful to guide strategies of preservation and improvement of S. capitata germplasm against the imminent scenario of climate change

Diagnostic fingerprints ISSR/SSR for tropical leguminous species Stylosanthes capitata and Stylosanthes macrocephala

Stylosanthes capitata Vogel and Stylosanthes macrocephala M.B.Ferreira & Sousa Costa are two forage leguminous species of agronomic importance for animal husbandry in tropical environments. The physical mixture of both species (80 % S. capitata and 20 % S. macrocephala) comprises the commercial cultivar “Estilosantes Campo Grande”. However, proximity of fields for seed production may contaminate seed lots, compromising seeds quality. The combined use of dominant and co-dominant molecular markers is an appropriate strategy to certificate genetic purity and perform diversity studies of cultivars. In this research, a set of ISSR (Inter-Simple Sequence Repeat polymorphic DNA) and SSR (Simple Sequence Repeat polymorphic DNA) molecular markers were standardized to characterize S. capitata and S. macrocephala species and evaluate the genetic purity of commercial samples. Four ISSR markers (UBC 2, 864, 885, 886) and SSR marker SC18-01 G4B showed precise species-specific electrophoretic fingerprints for both species. Electrophoretic patterns of ISSR molecular markers should be displayed first to confirm the sample identification. The structure analysis showed that the less contaminated sample was S. capitata with 97 % of its genetic composition assigned to a single genetic cluster vs. 95 % for S. macrocephala. S. capitata has greater genetic diversity (ISSRHe:0.292; SSRHe:0.57) than S. macrocephala (ISSRHe:0.285; SSRHe:0.16); however, this difference was only significant with SSR molecular markers. As these genetic resources have considerable ecological, agronomic and economic importance, tools for accurate species identification and genetic studies are essential for further seed multiplication, as well as for improvement and conservation of cultivar

Elevated CO2 and warming affect pollen development in a tropical legume forage species

Global climate change is expected to have impacts on the physiological, phenological, and morphological traits of plants. However, the vulnerability of tropical plant reproductive processes in response to climate change events has been poorly studied. Here, we assess if warming and elevated CO2 compromise the pollen characteristics of Stylosanthes capitata Vogel, a tropical legume forage species. This work was conducted in a Trop-T-FACE (combined Free-Air Temperature Controlled Enhancement and Free-Air Carbon Dioxide Enrichment) facility, where we exposed the plants to four treatments: C (Control-ambient atmospheric carbon dioxide concentration [CO2] and ambient temperature); eCO2 (increase in [CO2] to 600 ppm and ambient temperature); eT (canopy temperature increase by 2°C and ambient [CO2]); and eCO2+eT, a combination of both treatments. We analyzed pollen morphology of samples taken from the different treatments through light microscopy (LM) and scanning electron microscopy (SEM). In addition, pollen viability was analyzed through colorimetry. Based on the histological LM analysis, the tapetum cells of pollen sacs showed early degeneration under eT (72%) added to hypertrophy under eCO2 (67%) and eCO2+eT (90%) treatments. SEM images showed compaction of pollen exine and less distinguishable pollen apertures in the treated plots (eCO2, eT, and eCO2+eT), possibly, by the early death of the tapetum cells. These morphological abnormalities may hinder the viability of pollen grains, as observed especially in the eCO2+eT treatment (%V=64%) that was the lowest in comparison with the Control (71%) and the other treatments (eCO2 = 69%, eT = 67%). These results indicate that during the reproductive cycle of S. capitata pollen sacs and pollen grains are vulnerable to warming, elevated CO2, and their combined effects.Fil: Alzate Marin, Ana Lilia. Universidade de Sao Paulo; BrasilFil: Pádua Teixeira, Simone. Universidade de Sao Paulo; BrasilFil: Correia da Rocha Filho, Léo. Universidade de Sao Paulo; BrasilFil: Bonifácio Anacleto, Fernando. Universidade de Sao Paulo; BrasilFil: Marlys Sá Rivas, Priscila. Universidade de Sao Paulo; BrasilFil: Abramo Barrera San Martin, Juca. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Martinez, Carlos Alberto. Universidade de Sao Paulo; Brasi