Ana Veruska Cruz da Silva

Diversity and genetic structure of jenipapo (Genipa americana L.) Brazilian accessions

Usually known as jenipapo, Genipa americana L. is a Rubiaceae Brazilian native species. It is an important species in the restoration of Brazilian riparian forests and is one of the most promising fruit trees for sustainable harvesting programs. In this study we provide the first data on the genetic diversity and structure of a Jenipapo Germplasm Bank using inter simple sequence repeat (ISSR) markers. We evaluated 160 accessions from wild populations, and the data generated from 12 ISSR primers were used to determine genetic variability via a model-based Bayesian procedure (Structure) and molecular variance analysis. In addition, Shannon index, genetic diversity and Jaccard coefficients were estimated. A total of 12 primers were used, which generated 123 polymorphic fragments. Four groups were formed from the analysis of the fragments, and the CR1-2 genotype was isolated, being more divergent than the other genotypes.

Sealing and explant types on the mangaba micropropagation

In micropropagation, especially for mangaba tree botanical variety of Northeastern Brazil, limiting aspects such as ethylene accumulation in the cultivation flask and loss of vigor in subcultures have been observed. This study was aimed at assessing the technical and scientific knowledge of the in vitro propagation of botanical mangaba tree variety and at improving the micropropagation protocol, establishing the in vitro cultivation time, the best type of flask sealing and explant at different micropropagation stages. For the establishment phase and for the first and second subcultures, the MS medium with 3% sucrose and 0.6% agar, supplemented with 1 mg L-1 IAA and 1 mg L-1 BA was used. Evaluations were performed at 30, 50 and 65 days of in vitro cultivation. The best types of flask sealing for the establishment phase were the PVC film and Para-film® and for the first subculture the Para-film® seal. In the second subculture the PVC film and Para-film® seals promoted the best growth. The median and basal nodal segments presented the best performance in the first subculture. No significant effect of explant type was observed in the second subculture. The ideal subculture interval in the establishment phase and the first and second subcultures is 50 days.

Temperatura e embalagem para abóbora minimamente processada

The present work aimed to evaluate the efficiency of different storage temperatures and packing materials for pumpkin fresh cuts. Pumpkin cuts of 5 × 10 cm were packed in polystyrene trays covered with polivynilchloride film or in vacuum high density polyethylene bags. The trays and bags were kept at 5 and 10 °C for 12 days. Soluble solids, total titratable acidity, pH, vitamin C, and color of pumpkin cuts were evaluated every 3 days. The different temperatures did not affect the storage of the pumpkins. However, packaging with PVC film allowed a longer conservation by keeping the pumpkin quality attributes up to the 9th day, except for the color which undergone minor alterations when stored within a vacuum pack.

Manitol para a conservação ex situ de coqueiro por crescimento mínimo

The objective of this work was to determine the mannitol concentration for in vitro germination and minimum growth of coconut (Cocos nucifera). The following accessions were used: Brazilian Red Dwarf Gramame (BRDG), Malaysian Yellow Dwarf (MYD), Brazilian Tall (BRA), Polynesian Tall (PYT), and Rennell Island Tall (RIT). Embryos were inoculated in an Y3 culture medium at different mannitol concentrations (0, 0.1, 0.2, 0.3, and 0.4 mol L-1). Inhibition of shoot development was verified at 0.1, 0.2, and 0.3 mol L-1, for MYD and BRDG, and at 0.1 and 0.2 mol L-1, for PYT, BRA, and RIT. Mannitol use is a promising strategy for minimum growth conservation.

Genetic variability in physic nuts cultivated in Northeastern Brazil

This research had as objective to characterize genetically individuals of physic nut cultivated in experimental areas in Sergipe, Brazil by means of RAPD molecular markers. Leaves of 40 individuals were collected and DNA was isolated using CTAB 2% method. Were used 30 primers RAPD for DNA amplification, and this data was used to estimate the genetic similarity among the pairs of individuals, using Jaccard coefficient, and group them out for the UPGMA method. Also, the genetic structure and diversity of the populations were assessed using AMOVA. Of the 100 fragments generated, 29 of were polymorphic. A similarity average of 0.54 among the individuals was found and the amplitude similarities varied from 0.18 to 1.00. One of them (U5) was unit clusters and formed by the most divergent individuals. AMOVA indicated that there is more variation within (63%) the population. In conclusion, it was possible verify genetic variability in physic nut using RAPD markers at these experimental areas.

Genetic diversity of sweet potatoes collection from Northeastern Brazil

The sweet potato, Ipomoea batatas (L.) Lam has its origin in Tropical America. In Sergipe State (Brazil), its production is very important, and to explore its potential in local agriculture in the State, the Embrapa Coastal Tableland created a collection with 52 accessions located in Umbauba City. Some accessions were from germplasm belonging to Embrapa vegetables and others from local farmers of Sergipe. Here, we provide the first data on the genetic diversity and structure of sweet potato collection of SPGB using random amplified polymorphic DNA (RAPD) markers. RAPD data were used to determine genetic variability via a model-based Bayesian procedure (structure) and molecular variance analysis (AMOVA). In addition, Shannon index, genetic diversity and Jaccard coefficients were also estimated. RAPD was efficient for the analysis of genetic diversity to identify groups and measure the genetic distance between accessions. The markers showed that the collection had a high level of polymorphism. By UPGMA, we separated three groups of genotypes and identified two reconstructed populations by structure software. Keywords: Ipomoea batatas , cultivars, accessions African Journal of Biotechnology , Vol. 13(10), pp. 1109-1116, 5 March, 2014

INFLUÊNCIA DE LUZ E SACAROSE NO CRESCIMENTO IN VITRO DE MANDIOCA

RESUMO: A mandioca e a unica especie do genero Manihot comercialmente produzida. A producao de mudas micropropagadas possui limitacoes, e entre estas esta o alto custo com energia utilizadas nas salas de crescimento, e na taxa de sobrevivencia das plantas na fase de aclimatizacao, porem a cultura de tecidos e uma ferramenta de multiplicacao rapida e obtencao de plantas sadias (cultura de meristema), pois o metodo de propagacao vegetativa acarreta problemas fitossanitarios como disseminacao de patogenos. Uma alternativa para diminuir gastos dessa tecnica seria a reducao de sacarose ao meio e inducao de enraizamento sob luz natural em casa de vegetacao. Sendo assim, o objetivo desse trabalho foi avaliar a influencia da luz e sacarose na sobrevivencia e desenvolvimento de mudas de mandioca micropropagada. As variedades BRS Formosa, Lagoao e BRS Verdinha, cultivadas em meio MS acrescido de diferentes concentracoes de sacarose (10; 20 e 30 g.L-1), e apos 30 dias em sala de crescimento, os frascos foram incubados em sala de crescimento e casa de vegetacao por 15 dias. Em cultivos envolvendo diferentes tipos de luz, BRS Formosa e Lagoao, alcancaram melhores medias sob luz natural e altas concentracoes de sacarose, enquanto que BRS Verdinha obteve melhor desenvolvimento em luz natural e baixa concentracao de sacarose.

Genetic Diversity of Accessions and First Generation Progeny of the Mangaba Genebank

Mangaba (Hancornia speciose Gomes—Apocynaceae) is an important fruit tree in Brazil and has an unexplored stock germplasm collection. Commercial varieties are unavailable and little is known about its potential as a source of genetic diversity for molecular breeding programs. Progeny tests may improve studies on commercial variability and facilitate genetic improvement of the species. Our aim was to evaluate the genetic diversity and structure of accessions and progeny from the Mangaba Genebank of Embrapa Coastal Tablelands. We estimated the genetic diversity of 96 individuals using 4 SSR markers. The mean observed heterozygosity was lower than expected, showing an excess of homozygotes, corroborated by the positive coefficient of endogamy. The genetic diversity indexes (Fst) and Nei’s unbiased genetic identity (GI) revealed, in general, moderate genetic diversity between accessions. The relationship between matrices and progenies showed that there may be a greater degree of genetic information sharing between the ABP1 and ABP2 accessions. The Bayesian analysis suggested the presence of two distinct groups of genotypes (K = 2). These results will assist future breeding programs and facilitate the conservation of mangaba.

Volatile Metabolomic Composition of Vitex Species: Chemodiversity Insights and Acaricidal Activity

The Vitex genus (Lamiaceae) produces a plethora of metabolites that include ecdysteroids and terpenoids, some of which have demonstrated insect repellent properties. The volatile composition of several members of this genus has not been chemically defined, as many taxa are endemic to remote ecosystems. In this study, leaves were collected from the northeast of Brazil from Vitex capitata, V. megapotamica, V. gardneriana, and V. rufescens plants and examined for their chemical profile via GC-MS/FID of essential oil extracts. The analyses showed a diversity of terpenoids. Of particular note were seven-member ring sesquiterpenes which were present in great abundance; a dendrogram showed clades separating by the production of bicyclogermacrene, aromadendrane and 5,10-cycloaromadendrane sesquiterpenoids for the four species. Comparison of volatile metabolite profiles to 13 other Vitex species showed strong similarities in the production of some monoterpenes, but varied by their production of larger terpenes, especially those with gem-dimethylcyclopropyl subunits on seven-member ring compounds. From this work, we suggest that the sesquiterpene skeleton with seven member rings is a good chemosystematic biomarker candidate for the Vitex genus. Separation using this biomarker was then validated using Inter-Simple Sequence Repeat profiling. Lastly, experiments examining the toxicity of these four oils against the coconut mite Aceria guerreronis showed that only the oil of V. gardneriana had strong acaricidal activity, with an LC50 of 0.85 mg/mL, thus demonstrating its potential for use as a natural pesticide.