Evandro Henrique Schinor

Genetic transformation of Citrus sinensis with Citrus tristeza virus (CTV) derived sequences and reaction of transgenic lines to CTV infection

Transgenic Citrus sinensis (L.) Osb. plants, cvs. Valencia and Hamlin, expressing Citrus tristeza virus (CTV) derived sequences were obtained by genetic transformation. The gene constructs were pCTV-CP containing the 25 kDa major capsid protein gene (CTV-CP), pCTV-dsCP containing the same CTV-CP gene in an intron-spliced hairpin construct, and pCTV-CS containing a 559 nt conserved region of the CTV genome. The transgenic lines were identified by PCR and the transgene integration was confirmed by Southern blot. Transgene mRNA could be detected in most transgenic lines containing pCTV-CP or pCTV-CS transgene. The mRNA of pCTV-dsCP transgene was almost undetectable, with very light bands in most analyzed plants. The transgene transcription appears to be closely linked to the type of gene construct. The virus challenge assays reveals that all transgenic lines were infected. However, it was possible to identify propagated clones of transgenic plants of both cultivars studied with a low virus titer, with values similar to the noninoculated plants (negative control). These results suggested that the transgenic plants present some level of resistance to virus replication. The higher number of clones with low virus titer and where mRNA could not be detected or was presented in a very light band was found for pCTV-dsCP-derived transgenic lines.

Produtividade de laranjeira Folha Murcha enxertada em limoeiro Cravo sob adensamento de plantio

) para cada espacamento proposto. No espacamento mais adensado (6,5×2,0 m), as plantas apresentaram menor volume de copa; em contrapartida, maior produtividade da laranjeira Folha Murcha foi observada nesse tratamento. Houve queda de producao nos anos mais avancados de cultivo, independentemente da densidade de plantio. O espacamento 6,5×2,0 acarreta alta produtividade para laranjeira Folha Murcha, tornando a tecnica do adensamento apta a adocao pelo citricultor. Palavras-chave: Citrus sinensis, Citrus limonia, densidade de plantio, sistema de producao, produtividade. Yield of Folha Murcha sweet orange grafted on Rangpur lime under high density planting Abstract The Brazilian citrus production comes through changes in technological standard, specially the high density of plantations. Within this context, was implemented in 1982, the experiment for evaluation of five plant spacings (2.0, 3.0, 4.0, 5.0 and 6.0 meters) to Folha Murcha sweet orange grafted on Rangpur. The test was conducted without irrigation, settling the line spacing of 6.5 meters. Complementing the data obtained in the years of deployment and stabilization of the orchard (1982 to 1993), are presented and discussed in this paper results of assessments carried between the 12 th and 22 nd years of cultivation (1994-2004). It was calculated canopy volume from the data of height and diameter of the plants in 1995. In addition, evaluated the production of fruits per plant and yield (t ha -1 ) for each spacing proposed. In the high density (6.5×2.0 m) the plants had lower canopy volume, on the other hand increased yield of the Folha Murcha sweet orange was observed in this treatment. There was production fall, in the final years of cultivation, regardless of plant density. The 6,5×2,0 m spacing leads to high productivity of Folha Murcha sweet Orange, making high density an apt technique to the adoption by the citrus producer.

Avaliação da mancha preta dos citros em diferentes variedades de laranjeira doce

The citrus black spot - CBS (Guignardia citricarpa Kiely) has been responsible for great losses in Brazil, where all commercial varieties of sweet orange are susceptible. Given the economic losses that this disease causes to the brazilian citrus industry, this study aimed to evaluate the susceptibility of sweet orange varieties with late harvest to CBS. A total of 36 varieties were evaluated in Cordeiropolis city, and 35 located at Conchal city, in two years (2007 and 2008), both in Sao Paulo State, Brazil, in randomized block design assays with three replications. By using a diagrammatic scale specific to the CBS, the severity of CBS was quantified between the months from June to November (2007 and 2008), data was used to calculate the area under disease progress curve. All varieties were susceptible to CBS, however Imperial and Valencia Palida Israel were less susceptible than the others at both locations.

Sensory acceptance and postharvest quality of a new hybrid of citrus: TMxLP 16

Planting new types of sweet orange is an interesting alternative for the Brazilian citrus growers as this domestic market continues to grow. Thus, the aim of this study was to evaluate the acceptance and storage of a new hybrid between Murcott tangor and Pêra sweet orange, TMxLP 16. The treatments tested were: storage of fruits with and without wax, at room temperature (21 ± 2 °C and relative humidity (RH) = 60 ± 5%) and at cold temperature (10 ± 2 °C and RH = 90 ± 5%). Before storage samples were sensory tested for acceptance. Physicochemical qualities of the fruit and juice [mass, seeds, juice yield, acidity, soluble solids and ratio of soluble solids to titratable acidity (SS/TA)] were performed, before and after storage. The TMxLP 16 hybrid has an appropriate mass required for sale per fruit, a suitable juice yield, and early-mid season maturation, with high sensory acceptance, all characteristics which meet the standards required by the Brazilian consumer market. The results of this investigation showed that fruit stored at room temperature lost considerable weight. These results indicate a trend towards a loss of quality in fruits stored under ambient conditions and not coated with wax, which reaffirms the need for the use of refrigeration and waxy coverage for postharvest conservation of citrus fruits in natura.

Porta-enxertos alternativos para cultivo de laranja Valência na região sudoeste do estado de São Paulo

1 Faculdade de Ciências Agronômicas, Universidade Estadual Paulista “Júlio de Mesquita Filho” – UNESP, Botucatu, SP, Brasil 2 Centro de Citricultura Sylvio Moreira, Instituto Agronômico – IAC, Cordeirópolis, SP, Brasil 3 Polo Regional Sudoeste Paulista – Capão Bonito, Agência Paulista de Tecnologia dos Agronegócios – APTA Regional, Capão Bonito, SP, Brasil 4 Centro de Ciências Agrárias, Universidade Federal de São Carlos – UFSCar, Araras, SP, Brasil 5 Instituto de Biociências de Botucatu, Universidade Estadual Paulista “Júlio de Mesquita Filho” – UNESP, Botucatu, SP, Brasil

Qualidade pós-colheita de um híbrido do tipo Ponkan de maturação tardia

O estudo de tangerinas e hibridos e de grande importância, tendo em vista o pequeno numero de variedades plantadas comercialmente e o amplo mercado que esse tipo de fruta pode atingir. O presente trabalho teve como objetivo avaliar a aceitacao sensorial do hibrido TMxTP 9, proveniente do cruzamento entre tangor Murcott (TM) com tangerina Ponkan (TP), possibilitando a ampliacao do quadro varietal desse grupo citrico. Foram avaliadas as caracteristicas fisicoquimicas (massa, tamanho, numero de sementes, cor, acidez, vitamina C, solidos soluveis, ratio e rendimento de suco) e sensoriais (cor, sabor, aroma, textura, tamanho, descasque, firmeza). Um total de 50 provadores, nao treinados, realizou o teste de aceitacao sensorial atraves da escala hedonica estruturada de nove pontos para a aceitabilidade e escala estruturada de cinco pontos para intencao de compra. Os resultados obtidos na avaliacao sensorial apresentaram indices de aceitabilidade superiores a 50, ou seja, os frutos do hibrido TMxTP 9 tiveram 78% de aceitacao, o que indica que a variedade em questao agradou ao paladar dos consumidores brasileiros, sendo sua intencao de compra ainda mais satisfatoria, 84% dos provadores comprariam o produto. Conclui-se, portanto, que os frutos analisados estao aptos para a comercializacao, visto que apresentaram um bom resultado sensorial, com alta intencao de compra e aceitacao.