Regina Ceres Torres da Rosa

Efeitos do uso de Crotalaria juncea e carbofuran em fitonematóides ectoparasitos de cana-de-açúcar

A study was done on the effects of Crotalaria juncea and carbofuran on ectoparasite nematodes of sugarcane (Saccharum sp.) planted in soil naturally infested by Helicotylenchus dihystera, Criconemella ornata, Paratrichodorus minor, and Trichodorus sp. The stydy compared the use of C. juncea for one year, with incorporation, with one application of the systemic nematicide carbofuran at time of planting sugarcane var. SP79-1011. Evaluations were based upon soil nematode population densities throughout the first year of cropping. The nematode populations showed low number of specimens, being slighly influenced by the crotalaria incorporation and carbofuran application. Nematode population level remained low, during plant development, with low increment, in general, after 90 days of planting. The behavior of the C. ornata population in function of the time in plots treated with crotalaria or carbofuran was described by the equations Y = 100,56524 + 0,01504X - 0,00003032X2 (R2 = 0,5605**) or Y = 10 0,62059 + 0,01394X - 0,00002786X2 (R2 = 0,6416**), respectively. On sugarcane treated with carbofuran the increase of Trichodorus sp. population followed the quadractic model Y = 13,16667 - 0,10904X + 0,00065711X2 (R2 = 0,6916**).

Caracterização patogênica, fisiológica e morfológica de Pseudocercospora musae

The pathogenic, physiological and morphological characterization of eight Pseudocercospora musae isolates were studied. To determine pathogenicity, the isolates were inoculated on banana (Musa spp.) leaves, using two methods. The most efficience in the reproduction of the symptoms was observed in the wound method where all isolates showed pathogenicity, while without wounds, only P-2 and P-4 isolates presented the ability to enter and colonize the host tissue. For the physiological characterization, the behavior of the eight isolates was studied in six culture media and three pH levels, during seven days of incubation at 25 °C, and alternated light. Coconut, potato dextrose agar, and oat media induced higher mycelial growth, while potato dextrose agar, MPA, V-8 juice and Czapek promoted higher production of conidia. The isolates of P. musae grew well at pH 4,5, and the sporulation was favoured at pH 6,5. The cultural characteristics of the isolates showed little variation in topography, coloration, and pigmentation of the colony, according to the medium and pH level used. The morphological characterization showed little, but not significant, variation in size and conidial length/width ratio.

Doenças fúngicas em cultivos de plantas ornamentais temperadas da região Agreste do Estado de Pernambuco, Brasil

This study aimed to evaluate genetic variability using the internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) and the phylogeny of five Beauveria bassiana: IPA145, IPA148, IPA223, IPA225 and IPA226, obtained from different hosts and geographical origin from the Biological Control Laboratory of the Agronomic Institute of Pernambuco - IPA. The ITS region was amplified using primers ITS1 and ITS4, where an amplicon with average size of 800 bp was observed and sequenced. The DNA sequences of Beauveria isolates were compared with sequences in the database (GenBank). The results show that all isolates, except IPA145, were presented as a monophyletic group. IPA145 showed a genetic identity of 99% with Cordyceps bassiana and B. bassiana. IPA148 was the most genetically distant from the others, with less than 40% similarity. Most of the Beauveria isolates studied proved to be phylogenetically distinct.

Pestalotiopsissp. causing the fall of folioles in Parkia pendula in Brasil

Pestalotiopsis sp. causing the fall of folioles in Parkia pendula in Brasil This paper reports the occurrence of Pestalotiopsis sp. causing the fall of leaflets in visgueiro (Parkia pendula) seedlings in the State of Pernambuco, Brazil, in 2005. This is the first time that Pestalotiopsis sp. is reported in visgueiro in Brazil. O visgueiro (Parkia pendula Benth) arvore da familia Mimosaceae, ocorre em terra firme, nas matas primarias ou secundarias, na Regiao Amazonica, sul da Bahia, norte do Espirito Santo, Pernambuco e Alagoas. Sua madeira e utilizada na carpintaria e marcenaria, para caxotarias e outros. Usada para o plantio em areas degradadas e de preservacao permanente, gracas ao seu rapido crescimento em ambientes abertos, e na arborizacao de pracas publicas e parques (Lorenzi, Arvores Brasileiras: manual de identificacao e cultivo de plantas arboreas nativas do Brasil, 1992; Ribeiro et al., Flora da reserva Ducke: guia de identificacao das plantas vasculares de uma floresta de terrafirme na Amazonia Central, 1999). Mudas de visgueiro provenientes do municipio do Cabo de Santo Agostinho-PE foram enviadas ao Laboratorio de Fitossanidade da Empresa Pernambucana de Pesquisa Agropecuaria – IPA, apresentando manchas escuras nas bordas dos foliolulos que progrediam tornando-os escuros e secos com posterior queda do foliolo (Figura 1 A e B). O material foi analisado em microscopio esterioscopico e optico, onde, apos o preparo de lâminas, foram observados conidios do fungo pertencente ao genero Pestalotiopsis. Foliolulos infetados foram submetidos a assepsia, em seguida transferidos para meio de cultura de BDA, onde se desenvolveu um fungo com micelio branco apresentando pontuacoes negras (Figura 1 C). Em lâminas semipermanentes observou-se conidios fusiformes, com quatro septos, celulas das extremidades hialinas e as medianas de coloracao castanha, com um a tres apendices (Figura 1 D). Foram medidos 100 conidios que apresentaram 31,25 – 18,75 (25,04) x 6,25 – 3,81 (5,64) i m. Posteriormente, o fungo foi inoculado em mudas sadias de visgueiro, numa concentracao de 1,75 x 10 conidios.ml, e mantidos em câmara umida durante 48 h, em condicoes de laboratorio, na sede do IPA. Oito dias apos, reisolou-se dos tecidos inoculados o mesmo fungo observado anteriormente, comprovando o postulado de Koch. FIG. 1Sintomas de queda de foliolos em visgueiro (Parkia pendula) causados por Pestalotiopsis sp. (A e B); colonia em meio BDA (C) e conidio do patogeno (D).