Evaluation of Colletotrichum gloeosporioides for biological control of Miconia calvescens in Hawaii

E. M. Killgore; L. S. Sugiyama; R. W. Barreto; D.E. Gardner

doi:10.1094/pdis.1999.83.10.964b

Home/Archive/USGS

USGS · 70178422

Evaluation of Colletotrichum gloeosporioides for biological control of Miconia calvescens in Hawaii

E. M. Killgore·L. S. Sugiyama·R. W. Barreto·D.E. Gardner

View original source ↗Export metadata ↓

Abstract

Miconia calvescens (Melastomataceae), from the Neotropics, is a noxious forest weed in Hawaii. We evaluated an isolate of Colletotrichum gloeosporioides that causes leaf spots on Miconia spp. in Brazil for its potential in biological control. Hawaii has no native Melastomataceae genera but does have members of 12 introduced genera.

Explore related subjects

Plant Disease Article

Source-reported bounding extent: 18.917466° to 22.23317° latitude; -160.24961° to -154.809379° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

E. M. Killgore, L. S. Sugiyama, R. W. Barreto, D.E. Gardner. 1999. Evaluation of Colletotrichum gloeosporioides for biological control of Miconia calvescens in Hawaii. https://doi.org/10.1094/pdis.1999.83.10.964b

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS1995

Heterogeneity in pepper isolates of cucumber mosaic virus

Twenty-four cucumber mosaic cucumovirus (CMV) field isolates from pepper crops in Cali-fornia were characterized and compared by nucleic acid hybridization subgrouping, virion electrophoresis, and biological effects in several hosts. Isolates, belonging to subgroup I or subgroup II, were found that induced severe symptoms in mechanically inoculated bell pep-pers. Only two isolates, both from subgroup II, were mild. A group of 19 isolates collected from a single field were all in subgroup II and appeared identical by virion electrophoresis, but they exhibited varying degrees of symptom severity in peppers. As a more detailed indicator of heterogeneity, these 19 isolates were examined by RNase protection assays to delect sequence variation in the coat protein gene region of their genomes. The patterns of bands observed were complex and a high degree of genomic heterogeneity was detected between isolates, with no apparent correlation to symptomatology in bell pepper.

Plant Disease↗

USGS1993

A rapid inoculation technique for assessing pathogenicity of Fusarium oxysporum f. sp. niveum and F. o. melonis on Cucurbits

A continuous-dip inoculation technique for rapid assessment of pathogenicity of Fusarium oxysporum f. sp. niveum and F. o. melonis was developed. The method, adapted from a similar procedure for determining pathogenicity of Colletotrichum magna (causal agent of anthracnose of cucurbits), involves constant exposure of seedlings and cuttings (seedlings with root systems excised) of watermelon and muskmelon to conidial suspensions contained in small scintillation vials. Disease development in intact seedlings corresponded well to disease responses observed with the standard root-dip inoculation/pot assay. The continuous-dip inoculation technique resulted in rapid disease development, with 50% of watermelon cuttings dying after 4–6 days of exposure to F. o. niveum. A mortality of 30% also was observed in watermelon cuttings exposed to conidia of F. o. melonis, as opposed to only a 0–2.5% mortality in seedlings with intact roots. Disease response was similar with muskmelon seedlings and cuttings continuously dip-inoculated with F. o. melonis isolates. However, no disease symptoms were observed in muskmelon seedlings or cuttings inoculated with F. o. niveum. Four nonpathogenic isolates of F. oxysporum did not cause disease symptoms in either watermelon or muskmelon cuttings and seedlings when assayed by this technique. The proposed method enables a rapid screening of pathogenicity and requires less time, labor, and greenhouse space than the standard root-dip inoculation/pot assay. The reliability of the continuous-dip inoculation technique is limited, however, to exposure of intact seedlings at a concentration of 1 × 10 6 conidia per milliliter; the method is not accurate at this range for excised seedlings.

Plant Disease↗