Leaf Blight of Onions in Barbados Caused by Xanthomonas campestris

Paulraj, Litta; O'Garro, Leonard W.

doi:10.1094/pd-77-0198

Cited by 29 publications

(9 citation statements)

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“…Xanthomonas leaf blight of onion has since been reported in Barbados (26), the continental United States (17,22,30,32), Japan (19), Réunion Island (27,28), and South Africa (35). X. axonopodis pv.…”

mentioning

confidence: 99%

Management of Xanthomonas Leaf Blight of Onion with Bacteriophages and a Plant Activator

2007

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Xanthomonas leaf blight of onion (Allium cepa), caused by Xanthomonas axonopodis pv. allii, continues to be a challenging and yield-threatening disease in Colorado and other regions of onion production worldwide. Studies were conducted to develop management strategies for this disease that are equally effective and more sustainable than the current practices of making multiple applications of copper bactericides. Mixtures of bacteriophages and the plant defense activator, acibenzolar-S-methyl, were evaluated under field and greenhouse conditions for their abilities to reduce Xanthomonas leaf blight severity. Bacteriophage populations in the phyllosphere of onion were monitored over time. Bacteriophage populations persisted on onion leaves for at least 72 to 96 h under field and greenhouse conditions, respectively. Under field conditions at one location, biweekly or weekly applications of bacteriophages reduced disease severity by 26 to 50%, which was equal to or better than weekly applications of copper hydroxide plus mancozeb. Acibenzolar-S-methyl also successfully reduced disease severity by up to 50% when used alone preventatively or followed by biweekly bacteriophage applications. Reductions in disease severity generally were not associated with improvements in onion bulb size or yield. Integration of bacteriophage mixtures with acibenzolar-S-methyl appears to be a promising strategy for managing Xanthomonas leaf blight of onion, and could reduce grower reliance on conventional copper bactericide applied with ethylenebisdithiocarbamate fungicides.

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confidence: 99%

Management of Xanthomonas Leaf Blight of Onion with Bacteriophages and a Plant Activator

2007

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“…allii (Xaa) merupakan penyakit penting yang dapat menyerang berbagai jenis bawang (Roumagnac et al, 2004). Gejala ditemukan pada daun berupa bintik kecil kebasahan yang kemudian meluas menjadi coklat kehitaman, gejala ini kemudian menyatu menyebabkan terjadinya gejala mati pucuk serta hawar pada daun-daun yang lebih tua (Paulraj & O'Garro, 1993). Kerusakan akibat gejala penyakit dapat menurunkan hasil dan kualitas umbi (mencapai 100%) bila kondisi lingkungan mendukung dengan suhu dan curah hujan yang tinggi (Schwart & Gent, 2006).…”

Section: Pendahuluanunclassified

Aktivitas Enzim Peroksidase Bawang Merah Yang Diintroduksi Dengan Bakteri Endofit Dan Tahan Terhadap Penyakit Hawar Daun Bakteri (Xanthomonas Axonopodis Pv. Allii)

Resti¹,

Habazar²,

Putra³

et al. 2016

JURNAL HAMA DAN PENYAKIT TUMBUHAN TROPIKA

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Peroxidase enzyme activity of the introduced shallots with endophytic bacteria and resistant to bacterial leaf blight (Xanthomonas axonopodis pv. allii). Bacterial leaf blight caused by Xanthomonas axonopodis pv. allii is an important disease in shallots. We have earned six isolates of endophytic bacteria, which have the ability to induce systemically resistance to shallots. One mechanism in induce resistance in plants is a change in the plant defense enzyme activity such as peroxidase. The purpose of this study was to calculate the peroxidase enzyme activity of shallots crop is being introduced with endophytic bacteria and is able to induce resistance to Xanthomonas axonopodis pv. allii. This research was conducted by introducing six isolates of endophytic bacteria on shallot bulbs and planted in greenhouse. Shallots crop that was 14 days old then inoculated with the bacterium Xanthomonas axonopodis pv. allii and incubated until symptoms appear. Peroxidase enzyme activity was calculated on the roots and leaves of shallots are 0, 1, 2, 4, 6, 8, 10, 15, and 30 days after inoculation (dai). The results showed an increase in the peroxidase enzyme activity of shallots crop is being introduced by endophytic bacteria compared to the control. Isolates ULG1E2 (Serratia marcescens PPM4) was isolate with the highest peroxidase enzyme activity both in the roots and leaves are 0,051 ìm/ ml.Key words: endophytic bacteria, Shallot, peroxidase enzyme, Xanthomonas axonopodis pv. allii ABSTRAK Aktivitas enzim peroksidase bawang merah yang diintroduksi dengan bakteri endofit dan tahan terhadap penyakit hawar daun bakteri (Xanthomonas axonopodis pv. allii). Penyakit hawar daun bakteri yang disebabkan oleh Xanthomonas axonopodis pv. allii merupakan penyakit yang penting pada pertanaman bawang merah. Penulis telah mendapatkan enam isolat bakteri endofit, yang memiliki kemampuan mengimbas ketahanan tanaman bawang merah secara sistemik. Salah satu mekanisme dalam pengimbasan ketahanan pada tanaman adalah perubahan aktivitas enzim pertahanan tanaman seperti peroksidase. Tujuan penelitian ini adalah menghitung aktivitas enzim peroksidase dari tanaman bawang merah yang diintroduksi dengan isolat bakteri endofit dan mampu mengimbas ketahanannya terhadap Xanthomonas axonopodis pv. allii. Penelitian ini dilakukan dengan mengintroduksikan enam isolat bakteri endofit pada umbi bawang merah dan ditanam di rumah kaca. Tanaman bawang merah yang berumur 14 hari kemudian diinokulasi dengan bakteri Xanthomonas axonopodis pv. allii dan diinkubasi sampai muncul gejala. Aktivitas enzim peroksidase dihitung pada akar dan daun tanaman bawang merah yang berumur 0, 1, 2, 4, 6, 8, 10, 15, dan 30 hari setelah inokulasi (hsi). Hasil penelitian menunjukkan terjadinya peningkatan aktivitasenzim peroksidase pada tanaman bawang merah yang diintroduksi bakteri endofit dibandingkan dengan kontrol. Isolat ULG 1 E 2 (Serratia marcescens PPM4) merupakan isolat dengan aktivitas enzim peroksidase tertinggi baik pada akar maupun daun yaitu 0,051µm/ml. Kata kunci...

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“…This bacteria is difficult to control because the pathogen survives in soil, seed-borne, sprinkler, agricultural equipment and infects some genus of weeds without symptoms (Roumagnac et al, 2004; and a few other Allium species (Paulraj and O'Garro, 1993), although some strains are reportedly pathogenic to leguminous hosts such snap bean (Phaseolus vulgaris), lima bean (Phaseolus lunatus), soybean (Glycine max), winged bean (Psophocarpus tetragonolobus), moth bean (Vigna aconitifolia) and field pea (Pisum sativum) .…”

Section: Introductionmentioning

confidence: 99%

Screening of Rhizobacteria From Onion Rhizosphere Can Induce Systemic Resistance to Bacterial Leaf Blight Disease on Onion Plants

Ernita¹,

habazar²,

jamsari³

et al. 2018

Preprint

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In modern cultivation processes indiscriminate use of pesticides and fertilizers, has led to substantial pollution of soil, air and water. So, there is an urgent need to solve the problem. Rhizobacteria are bacteria that colonize plant roots, and these bacteria are known to stimulate growth and thereby reduce incidence of plant disease by direct and indirect mechanisms. A total of 136 rhizobacteria isolates were isolated from different rhizosphere soils in central areas of production of onions in Indonesia. These isolates were screened for their capability to enhance growth and protect onions against bacterial leaf blight disease-caused by Xanthomonas axonopodis pv.allii. The results showed that ten isolates can enhance growth and protect onions against bacterial leaf blight diseases. Five isolates were isolated from West Sumatra, four isolates from Java and one isolated from North Sumatra. All isolates produced indol-3-acetic acid with different concentrations. Molecular identification of ten isolates belong to Bacillus sp, Pseudomonas sp, Stenotrophomonas sp and Serratia sp.

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Leaf Blight of Onions in Barbados Caused by Xanthomonas campestris

Cited by 29 publications

References 0 publications

Management of Xanthomonas Leaf Blight of Onion with Bacteriophages and a Plant Activator

Management of Xanthomonas Leaf Blight of Onion with Bacteriophages and a Plant Activator

Aktivitas Enzim Peroksidase Bawang Merah Yang Diintroduksi Dengan Bakteri Endofit Dan Tahan Terhadap Penyakit Hawar Daun Bakteri (Xanthomonas Axonopodis Pv. Allii)

Screening of Rhizobacteria From Onion Rhizosphere Can Induce Systemic Resistance to Bacterial Leaf Blight Disease on Onion Plants

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