Persistent Link:
http://hdl.handle.net/10150/198135
Title:
Update on Pink Bollworm Resistance to Bt Cotton in the Southwest
Author:
Dennehy, Timothy J.; Unnithan, Gopalan; Brink, Sarah A.; Wood, Brook D.; Carrière, Yves; Tabashnik, Bruce; Antilla, Larry; Whitlow, Mike
Affiliation:
University of Arizona, Tucson, AZ; Arizona Cotton Research and Protection Council, Phoenix, AZ
Issue Date:
May-2004
Publisher:
College of Agriculture, University of Arizona (Tucson, AZ)
Journal:
Cotton: A College of Agriculture and Life Sciences Report
Abstract:
Monitoring of Arizona pink bollworm (PBW), Pectinophora gossypiella, susceptibility to the Bt toxin Cry1Ac has been conducted annually since 1997. PBW were collected from cotton fields located throughout the Southwest in 2002, cultured in the laboratory, and tested for susceptibility to Cry1Ac using diet-incorporation bioassays. A total of 13 Arizona collections were successfully reared and bioassayed. Collections from California (6), New Mexico (1), and Texas (1) were also tested. Laboratory selection of pink bollworms collected from Arizona in 1997 and exposed to Cry1Ac in diet produced a strain capable of surviving on Bollgard® cotton. Subsequent studies showed that 10 g Cry1Ac/ml of insect diet was a reliable diagnostic concentration for detection of pink bollworm that were homozygous for resistance to Cry1Ac. On this basis, resistant PBW were detected in 2002 in only 2 out of 13 Arizona strains. The overall frequency of resistant PBW in 2002 for Arizona was 0.17% and ranged from 0.0 to 1.7%. One of six California collections evaluated had a single resistant survivor. No resistant pink bollworms were detected in the single New Mexico and Texas collections evaluated. Resistant PBW were significantly more abundant in Arizona in 2001 and 2002 than they were in 1998, 1999 or 2000. However, the frequency of resistant survivors in bioassays was low for 2001 and 2002, and markedly lower than in 1997. The Arizona Cotton Research and Protection Council evaluated the efficacy of Bt cotton in 2002 using adjacent pairs of Bt and non-Bt fields at 43 locations across Arizona. Pink bollworms were found in an average of 23.3% of these non-Bt boll fields. Bolls from Bt cotton fields yielded an average of 0.144% (range 0 to 1.300%) infested bolls. Of these, all but three of the pink bollworm recovered from Bt cotton plantings came from bolls that tested negative for Cry1Ac. We conclude from these findings that there is no indication that pink bollworm resistance to Cry1Ac was a problem at the locations sampled in 2002. Bt cotton continued to exhibit exceptional field performance in Arizona.
Keywords:
Agriculture -- Arizona; Cotton -- Arizona; Resistance management
Series/Report no.:
AZ1335; Series P-138

Full metadata record

DC FieldValue Language
dc.titleUpdate on Pink Bollworm Resistance to Bt Cotton in the Southwesten_US
dc.contributor.authorDennehy, Timothy J.en_US
dc.contributor.authorUnnithan, Gopalanen_US
dc.contributor.authorBrink, Sarah A.en_US
dc.contributor.authorWood, Brook D.en_US
dc.contributor.authorCarrière, Yvesen_US
dc.contributor.authorTabashnik, Bruceen_US
dc.contributor.authorAntilla, Larryen_US
dc.contributor.authorWhitlow, Mikeen_US
dc.contributor.departmentUniversity of Arizona, Tucson, AZen_US
dc.contributor.departmentArizona Cotton Research and Protection Council, Phoenix, AZen_US
dc.date.issued2004-05-
dc.publisherCollege of Agriculture, University of Arizona (Tucson, AZ)en_US
dc.identifier.journalCotton: A College of Agriculture and Life Sciences Reporten_US
dc.description.abstractMonitoring of Arizona pink bollworm (PBW), Pectinophora gossypiella, susceptibility to the Bt toxin Cry1Ac has been conducted annually since 1997. PBW were collected from cotton fields located throughout the Southwest in 2002, cultured in the laboratory, and tested for susceptibility to Cry1Ac using diet-incorporation bioassays. A total of 13 Arizona collections were successfully reared and bioassayed. Collections from California (6), New Mexico (1), and Texas (1) were also tested. Laboratory selection of pink bollworms collected from Arizona in 1997 and exposed to Cry1Ac in diet produced a strain capable of surviving on Bollgard® cotton. Subsequent studies showed that 10 g Cry1Ac/ml of insect diet was a reliable diagnostic concentration for detection of pink bollworm that were homozygous for resistance to Cry1Ac. On this basis, resistant PBW were detected in 2002 in only 2 out of 13 Arizona strains. The overall frequency of resistant PBW in 2002 for Arizona was 0.17% and ranged from 0.0 to 1.7%. One of six California collections evaluated had a single resistant survivor. No resistant pink bollworms were detected in the single New Mexico and Texas collections evaluated. Resistant PBW were significantly more abundant in Arizona in 2001 and 2002 than they were in 1998, 1999 or 2000. However, the frequency of resistant survivors in bioassays was low for 2001 and 2002, and markedly lower than in 1997. The Arizona Cotton Research and Protection Council evaluated the efficacy of Bt cotton in 2002 using adjacent pairs of Bt and non-Bt fields at 43 locations across Arizona. Pink bollworms were found in an average of 23.3% of these non-Bt boll fields. Bolls from Bt cotton fields yielded an average of 0.144% (range 0 to 1.300%) infested bolls. Of these, all but three of the pink bollworm recovered from Bt cotton plantings came from bolls that tested negative for Cry1Ac. We conclude from these findings that there is no indication that pink bollworm resistance to Cry1Ac was a problem at the locations sampled in 2002. Bt cotton continued to exhibit exceptional field performance in Arizona.en_US
dc.subjectAgriculture -- Arizonaen_US
dc.subjectCotton -- Arizonaen_US
dc.subjectResistance managementen_US
dc.identifier.urihttp://hdl.handle.net/10150/198135-
dc.relation.ispartofseriesAZ1335en_US
dc.relation.ispartofseriesSeries P-138en_US
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