Estudo da diversidade genética de Podosphaera xanthii através de marcadores AFLP e seqüências ITS

Abstract

Melon crop (Cu cu mis me lo L.) is a fruit la rgely cultivated in Brazil, especially in the Northwestern region, where it is produced mainly for export. Plants of the melon family, such as cucumber and pumpk in, ca n be severely a ffected by powdery mildew, cau sed by Podosphaera xanthii. This fungus has several physiological races and their correct identifica tion is important for ma na ging the disea se, since the use of resistant cultivars is the most effective method for its control. However, identification of races by the traditional method of inoculation in a differential series of melon varieties is laborious and error prone. Due to this, an alternative method would be the use of molecu la r ma rkers to qu ick ly determine the ra ce identity. The Naruzawa, E.S.; Dalla Vale, R.K.; Silva, C.M.; Camargo, L.E.A.. Genetic diversity of Podosphaera xanthii assessed by AFLP markers and ITS sequences. Summa Phytopathologica, v.37, n.2, p.94-100, 2011.Keywords: Powdery mildew, Cucumis melo, races, genetic diversity Palavras-chave adicionais: Cucumis melo, raças, diversidade genética. RESUMOO meloeiro (Cucumis melo L.) é uma frutífera largamente cultivada no Brasil, principa lmente no nordeste brasileiro, onde é produ zida principa lmente pa ra a exportação. Pla ntas da família do meloeiro, como pepino e abóbora, podem ser severamente afetadas pelo oídio, causado por Podosphaera xanthii.. Este fungo apresenta diversas raças fisiológicas cuja correta identificação é importante para o manejo da doença, já que o uso de variedades resistentes é o método mais eficaz de seu controle. No entanto, a identificação destas raças por meio da prá tica tra dicional de inoculações em uma série diferencia dora de variedades de meloeiro é laboriosa e passível de erros. Devido a isso, um método alternativo seria o uso de ma rcadores moleculares para determinar de forma rápida a identidade das raças. O objetivo deste Naruzawa, E.S.; Dalla Vale, R.K.; Silva, C.M.; Camargo, L.E.A.. Estudo da diversidade genética de Podosphaera xanthii através de marcadores AFLP e seqüências ITS. Summa Phytopathologica, v.37, n.2, p.94-100, 2011.objective of this study was to analyze the variability among P. xanthii isolates previously classified into races through the AFLP technique and sequencing of the rDNA's ITS 5.8S region. With the AFLP markers a dendrogram was generated, where the isolates could not be grouped a ccording to their ra ces, geogra phic region or host. With this techniqu e, a high va ria bility among isola tes wa s verified, with maximum genetic similarity of 69% and minimum similarity of 23%. In contrast to the AFLP data, there was no sequence variation in the ITS 5.8 S region among isolates. T hus the AFLP data indicated that the isola tes have a heterogeneous genetic composition even thou gh this was not evidenced by the sequencing of the ITS region. estudo foi o de analisar a variabilidade entre isolados de P. xa nthii previamente classificados em raças através da técnica de AFLP e do seqüenciamento da região ITS 5.8S do r...

Journal of Plant Protection Research

“…Podosphaera xanthii is commonly found in tropical and subtropical regions, whereas Golovinomyces oron tii is primarily seen in temperate climates (Cohen et al 2004;Naruzawa et al 2011). Physiological races and pathotypes are well documented for both species (Lebeda et al 2016).…”

Morphological and molecular characterization of powdery mildew on watermelon plants in São Paulo state

“…P. xanthii is more frequent in Brazil, being adapted to regions of tropical and subtropical climates, whereas G. cichoracearum occurs in dry weather and more frequently in temperate regions (Naruzawa et al, 2011).…”

“…and watermelon are cultivated. It is more prominent in places with high temperatures and low humidity during the growing season, or under protected crop growing (Naruzawa et al, 2011).…”