{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/101188"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/101188","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Identification of fungal species causing powdery mildew on cucurbits, determination of the genetic and pathogenic variations of the fungi and their sensitivity to major powdery mildew fungicides","abstract":"Cucurbit species are members of the family Cucurbitaceae. Major cucurbit species grown in Illinois are Cucumis sativus (cucumber), Lagenaria sicerarias (gourd), C. melo (muskmelon), Cucurbita pepo (pumpkin), C. maxima and C. moschata (squash), and Citrullus lanatus (watermelon). Powdery mildew is an annually-occurring disease of cucurbits, which causes yield losses up to 50% in Illinois and worldwide. Podosphaera xanthii and Golovinomyces cichoracearum are known as the causal agents of cucurbit powdery mildew. No reported investigations have been conducted on the species identification of the agent of powdery mildew of cucurbits, genetic and pathogenic variation of the pathogen, or the fungicide-resistance of the fungus in the North Central Region (NCR). This research was conducted to: 1) identify species causing powdery mildew on cucurbits in Illinois and some other major cucurbit producing areas in the United States; 2) determine genetic and pathogenic variations among isolates of powdery mildew fungi on cucurbits; and 3) determine the sensitivity of cucurbit powdery mildew pathogens to commonly used powdery mildew fungicides, including DMI, QoI, SDHI, quinolines, and cyflufenamid fungicides. To identify the species of powdery mildew fungi, powdery mildew infected leaves of C. melo, C. sativus, C. maxima, C. moschata, C. pepo, and L. siceraria were collected from California, Illinois, Indiana, Iowa, Michigan, Pennsylvania, Texas, Washington, and Wisconsin. In addition, 10 DNA samples from Italy and 40 isolates from New York and Wisconsin of cucurbit powdery mildew fungi were obtained. After sequencing the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) for 119 isolates of powdery mildew causing fungi, only P. xanthii was identified. Distinct clustering of genetic variation based on geographical origins was found among the isolates. Also, significant variation (P < 0.0001) was found in pathogenicity among the 37 isolates tested. Our data showed reduced effectiveness of azoxystrobin, from the QoI group, for the control of cucurbits powdery mildew. Triflumizole (DMI group), penthiopyrad (SDHI group), quinoxyfen (quinolines group), cyflufenamid (unknown mode of action group of U6) all effectively controlled powdery mildew of pumpkin.","abstract_html":"Cucurbit species are members of the family Cucurbitaceae. Major cucurbit species grown in Illinois are Cucumis sativus (cucumber), Lagenaria sicerarias (gourd), C. melo (muskmelon), Cucurbita pepo (pumpkin), C. maxima and C. moschata (squash), and Citrullus lanatus (watermelon). Powdery mildew is an annually-occurring disease of cucurbits, which causes yield losses up to 50% in Illinois and worldwide. Podosphaera xanthii and Golovinomyces cichoracearum are known as the causal agents of cucurbit powdery mildew. No reported investigations have been conducted on the species identification of the agent of powdery mildew of cucurbits, genetic and pathogenic variation of the pathogen, or the fungicide-resistance of the fungus in the North Central Region (NCR). This research was conducted to: 1) identify species causing powdery mildew on cucurbits in Illinois and some other major cucurbit producing areas in the United States; 2) determine genetic and pathogenic variations among isolates of powdery mildew fungi on cucurbits; and 3) determine the sensitivity of cucurbit powdery mildew pathogens to commonly used powdery mildew fungicides, including DMI, QoI, SDHI, quinolines, and cyflufenamid fungicides. To identify the species of powdery mildew fungi, powdery mildew infected leaves of C. melo, C. sativus, C. maxima, C. moschata, C. pepo, and L. siceraria were collected from California, Illinois, Indiana, Iowa, Michigan, Pennsylvania, Texas, Washington, and Wisconsin. In addition, 10 DNA samples from Italy and 40 isolates from New York and Wisconsin of cucurbit powdery mildew fungi were obtained. After sequencing the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) for 119 isolates of powdery mildew causing fungi, only P. xanthii was identified. Distinct clustering of genetic variation based on geographical origins was found among the isolates. Also, significant variation (P &lt; 0.0001) was found in pathogenicity among the 37 isolates tested. Our data showed reduced effectiveness of azoxystrobin, from the QoI group, for the control of cucurbits powdery mildew. Triflumizole (DMI group), penthiopyrad (SDHI group), quinoxyfen (quinolines group), cyflufenamid (unknown mode of action group of U6) all effectively controlled powdery mildew of pumpkin.","abstract_has_math":false,"creators":["Xiang, Yiwen"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Crop Sciences","degree_department":null,"school":null,"contributors":["Babadoost, Mohammad","Miller, Andrew","Brown, Patrick","Domier, Leslie","Eastburn, Darin"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-09-04T20:36:44Z","date_published":"2018-09-04T20:36:44Z","updated_at":"2026-07-22T22:24:38Z","subjects":["powdery mildew","cucurbit","genetic variations","fungicide"],"languages":["en"],"rights":["Copyright 2018 Yiwen Xiang"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/101188","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Babadoost, Mohammad","Miller, Andrew","Brown, Patrick","Domier, Leslie","Eastburn, Darin"]},{"key":"dc:creator","label":"Author","values":["Xiang, Yiwen"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2018-09-04T20:36:44Z","2020-09-05T09:15:29Z","2018-04-18","2018-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Crop Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["powdery mildew","cucurbit","genetic variations","fungicide"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2018 Yiwen Xiang"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/101188"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Cucurbit species are members of the family Cucurbitaceae. Major cucurbit species grown in Illinois are Cucumis sativus (cucumber), Lagenaria sicerarias (gourd), C. melo (muskmelon), Cucurbita pepo (pumpkin), C. maxima and C. moschata (squash), and Citrullus lanatus (watermelon). Powdery mildew is an annually-occurring disease of cucurbits, which causes yield losses up to 50% in Illinois and worldwide. Podosphaera xanthii and Golovinomyces cichoracearum are known as the causal agents of cucurbit powdery mildew. No reported investigations have been conducted on the species identification of the agent of powdery mildew of cucurbits, genetic and pathogenic variation of the pathogen, or the fungicide-resistance of the fungus in the North Central Region (NCR). This research was conducted to: 1) identify species causing powdery mildew on cucurbits in Illinois and some other major cucurbit producing areas in the United States; 2) determine genetic and pathogenic variations among isolates of powdery mildew fungi on cucurbits; and 3) determine the sensitivity of cucurbit powdery mildew pathogens to commonly used powdery mildew fungicides, including DMI, QoI, SDHI, quinolines, and cyflufenamid fungicides. To identify the species of powdery mildew fungi, powdery mildew infected leaves of C. melo, C. sativus, C. maxima, C. moschata, C. pepo, and L. siceraria were collected from California, Illinois, Indiana, Iowa, Michigan, Pennsylvania, Texas, Washington, and Wisconsin. In addition, 10 DNA samples from Italy and 40 isolates from New York and Wisconsin of cucurbit powdery mildew fungi were obtained. After sequencing the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) for 119 isolates of powdery mildew causing fungi, only P. xanthii was identified. Distinct clustering of genetic variation based on geographical origins was found among the isolates. Also, significant variation (P < 0.0001) was found in pathogenicity among the 37 isolates tested. Our data showed reduced effectiveness of azoxystrobin, from the QoI group, for the control of cucurbits powdery mildew. Triflumizole (DMI group), penthiopyrad (SDHI group), quinoxyfen (quinolines group), cyflufenamid (unknown mode of action group of U6) all effectively controlled powdery mildew of pumpkin.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2020-05-01","The student, Yiwen Xiang, accepted the attached license on 2018-04-18 at 10:51.","The student, Yiwen Xiang, submitted this Dissertation for approval on 2018-04-18 at 10:58.","This Dissertation was approved for publication on 2018-04-18 at 12:00.","DSpace SAF Submission Ingestion Package generated from Vireo submission #12342 on 2018-08-31 at 17:20:27","Made available in DSpace on 2018-09-04T20:36:44Z (GMT). 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Major cucurbit species grown in Illinois are Cucumis sativus (cucumber), Lagenaria sicerarias (gourd), C. melo (muskmelon), Cucurbita pepo (pumpkin), C. maxima and C. moschata (squash), and Citrullus lanatus (watermelon). Powdery mildew is an annually-occurring disease of cucurbits, which causes yield losses up to 50% in Illinois and worldwide. Podosphaera xanthii and Golovinomyces cichoracearum are known as the causal agents of cucurbit powdery mildew. No reported investigations have been conducted on the species identification of the agent of powdery mildew of cucurbits, genetic and pathogenic variation of the pathogen, or the fungicide-resistance of the fungus in the North Central Region (NCR). This research was conducted to: 1) identify species causing powdery mildew on cucurbits in Illinois and some other major cucurbit producing areas in the United States; 2) determine genetic and pathogenic variations among isolates of powdery mildew fungi on cucurbits; and 3) determine the sensitivity of cucurbit powdery mildew pathogens to commonly used powdery mildew fungicides, including DMI, QoI, SDHI, quinolines, and cyflufenamid fungicides. To identify the species of powdery mildew fungi, powdery mildew infected leaves of C. melo, C. sativus, C. maxima, C. moschata, C. pepo, and L. siceraria were collected from California, Illinois, Indiana, Iowa, Michigan, Pennsylvania, Texas, Washington, and Wisconsin. In addition, 10 DNA samples from Italy and 40 isolates from New York and Wisconsin of cucurbit powdery mildew fungi were obtained. After sequencing the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) for 119 isolates of powdery mildew causing fungi, only P. xanthii was identified. Distinct clustering of genetic variation based on geographical origins was found among the isolates. Also, significant variation (P < 0.0001) was found in pathogenicity among the 37 isolates tested. Our data showed reduced effectiveness of azoxystrobin, from the QoI group, for the control of cucurbits powdery mildew. Triflumizole (DMI group), penthiopyrad (SDHI group), quinoxyfen (quinolines group), cyflufenamid (unknown mode of action group of U6) all effectively controlled powdery mildew of pumpkin.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2020-05-01","The student, Yiwen Xiang, accepted the attached license on 2018-04-18 at 10:51.","The student, Yiwen Xiang, submitted this Dissertation for approval on 2018-04-18 at 10:58.","This Dissertation was approved for publication on 2018-04-18 at 12:00.","DSpace SAF Submission Ingestion Package generated from Vireo submission #12342 on 2018-08-31 at 17:20:27","Made available in DSpace on 2018-09-04T20:36:44Z (GMT). No. of bitstreams: 2 XIANG-DISSERTATION-2018.pdf: 2429228 bytes, checksum: 8dda097bb17d3611d65a3b076136ee19 (MD5) LICENSE.txt: 4208 bytes, checksum: bfc82804d8fe9edde1d6e0519d4b3d17 (MD5) Previous issue date: 2018-04-18","Embargo set by: Seth Robbins for item 107272 Lift date: 2020-09-04T20:37:00Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","Embargo set by: Seth Robbins for item 107272 Lift date: 2020-09-04T20:42:08Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 107272 on 2020-09-05T09:15:29Z."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/101188"],"dc:language":["en"],"dc:rights":["Copyright 2018 Yiwen Xiang"],"dc:subject":["powdery mildew","cucurbit","genetic variations","fungicide"],"dc:title":["Identification of fungal species causing powdery mildew on cucurbits, determination of the genetic and pathogenic variations of the fungi and their sensitivity to major powdery mildew fungicides"],"dc:type":["text"],"thesis:degree_discipline":["Crop Sciences"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:38Z"}