New Disease Reports (2010) 20, 37.

First report of anthracnose and fruit mummification of olive fruit (Olea europaea) caused by Colletotrichum acutatum in Brazil

H.S.S. Duarte 1, P.G.C. Cabral 1, O.L. Pereira 1*, L. Zambolim 1, E.D. Gonçalves 2, J. Vieira Neto 2, E.M. Zambolim 1 and V. Sergeeva 3

*oliparini@ufv.br

Show affiliations

Accepted: 26 Jan 2010

The olive tree is an arboreal species belonging to the family Oleaceae with recognized importance in the production of olive oils and olives. In December 2008, typical lesions of anthracnose, with mature fruit mummification (Figs. 1, 2) were observed in olive tree fields in Maria da Fé, in the state of Minas Gerais, Brazil . A fungus was isolated directly on potato dextrose agar (PDA) from conidia collected from pink to orange masses on infected fruit. A typical fruit sample was deposited in the local herbarium (VIC 31209). The isolate showed a pink colony on PDA, producing sporodochia with a mass of hyaline amerospores with pointed ends. Based on these morphological characteristics the fungus was identified asColletotrichum acutatum, which has been reported to cause anthracnose on olives trees in other countries and most recently in Australia (Sergeeva et al., 2008). In Brazil , C. acutatum is reported to cause disease on fruit of apple, citrus, strawberry, peach, plum, nectarine, medlar, and on yerba-mate (Kimati et al., 2005).

Identity was confirmed by extracting the DNA of a monoconidial isolate, OLP 570, and amplifying the ITS region of the rRNA by polymerase chain reaction with primer ITS4 and specific primers for C.acutatum(CaInt2; Sreenivasaprasad et al., 1996) and C.gloeosporioides (CgInt; Mills et al., 1992). Isolates of C.acutatum(DAR78874 and DAR78876) and C.gloeosporioides(DAR78875) obtained from Australian olives trees were used as positive controls. TheprimersITS4 and CaInt2 amplified a single DNA product of 490 bp, as expected for C. acutatum(Fig. 3). Pathogenicity was confirmed by placing a 40-mm disk of PDA colonized with OLP 570 on 40 olive fruits that were either intact or slightly wounded. Non-colonized PDA disks were used as negative controls. The inoculated fruits were transferred to Gerbox-type boxes with high humidity and kept in a growth chamber at 25º C. Typical anthracnose symptoms were observed only on the slightly wounded inoculated fruit (Fig. 4) four days post-inoculation with subsequent fruit mummification after a further three days.This is the first report of C. acutatumcausing anthracnose and mummification of olive fruit in Brazil .

Figure1+
Figure 1: Anthracnose symptom and mature mummified fruit of olives at the field condition
Figure 1: Anthracnose symptom and mature mummified fruit of olives at the field condition
Figure2+
Figure 2: Healthy mature green olive fruit (left) and mummified dried mature fruits (right), showing an abundant mass of pink to orange conidia produced on acervuli
Figure 2: Healthy mature green olive fruit (left) and mummified dried mature fruits (right), showing an abundant mass of pink to orange conidia produced on acervuli
Figure3+
Figure 3: Electrophoresis profile of amplified DNA by PCR using the ITS4 primer together with specific primers for C. acutatum (CaInt2) and C. gloeosporioides (CgInt). Samples of the genomic DNA of C. acutatum (DA78874 and DA78876) and of C. gloeosporioides (DA78875) isolated in olive from Australia were used as controls. OLP 570 represents the isolate of C. acutatum from olives in Brazil.
Figure 3: Electrophoresis profile of amplified DNA by PCR using the ITS4 primer together with specific primers for C. acutatum (CaInt2) and C. gloeosporioides (CgInt). Samples of the genomic DNA of C. acutatum (DA78874 and DA78876) and of C. gloeosporioides (DA78875) isolated in olive from Australia were used as controls. OLP 570 represents the isolate of C. acutatum from olives in Brazil.
Figure4+
Figure 4: Anthracnose symptoms on artificially inoculated wounded olive fruits and the beginning of mummification
Figure 4: Anthracnose symptoms on artificially inoculated wounded olive fruits and the beginning of mummification

Acknowledgements

Authors Duarte, Cabral, Pereira and Zambolim thank the CNPQ and Gonçalves and Vieira Neto thank FAPEMIG for financial support.


References

  1. Kimati H, Amorim L, Rezende JAM, Bergamin Filho, A, Camargo LEA, 2005. Manual de Fitopatologia-Doenças das Plantas Cultivadas. São Paulo, Brazil: Agronômica Ceres Ltda.
  2. Mills PR, Sreenivasaprasad S, Brown AE, 1992. Detection and differentiation of Colletotrichum gloeosporioides isolates using PCR. FEMS Microbiology Letters 98, 137-144.
  3. Sergeeva V, Spooner-Hart R, Nair NG, 2008. First report of Colletotrichum acutatum and C. gloeosporioides causing leaf spots of olives (Olea europaea) in Australia. Australasian Plant Disease Notes 3, 143-144.
  4. Sreenivasaprasad S, Sharada K, Brown AE, Mills PR, 1996. PCR-based detection of Colletotrichum acutatum on strawberry. Plant Pathology 45, 650-655.

This report was formally published in Plant Pathology

©2010 The Authors