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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #253436
Title: Fine mapping QMi-C11 a major QTL controlling root-knot nematodes resistance in Upland cotton

Author
item SHEN, XINLIAN - University Of Georgia
item HE, YAJUN - University Of Georgia
item LUBBERS, EDWARD - University Of Georgia
item Davis, Richard
item NICHOLS, ROBERT - Cotton, Inc
item CHEE, PENG - University Of Georgia

Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2010
Publication Date: 9/1/2010
Citation: Shen, X., He, Y., Lubbers, E.L., Davis, R.F., Nichols, R.L., Chee, P.W. 2010. Fine mapping QMi-C11 a major QTL controlling root-knot nematodes resistance in Upland cotton. Journal of Theoretical and Applied Genetics. 121:1623-1631.

Interpretive Summary: The identification and utilization of a high-level of host plant resistance is the most effective and economical approach to control root-knot nematode in cotton. In a previous study, we identified a genetic region (a quantitative trait locus or QTL) responsible for a significant amount of the resistance to root-knot nematode in the Upland cotton line M-120 RNR, which derived its nematode resistance from Auburn 623 RNR germplasm. The nematode resistance QTL was found to be located near one end of Chromosome 11 between the two DNA markers CIR069 and CIR316, which bracket a region measuring 12.9 cM. In this study, to construct a fine map to more precisely define the location of the resistance QTL, a bulked segregation analysis was performed using two DNA pools derived from a cross between a resistant and a susceptible parent with one pool consisting of individuals with DNA in the suspect QTL region from the susceptible parent and the other pool consisting of DNA from the resistant parent. From a survey of 1152 DNA markers (AFLP primer combinations), nine markers closely linked to the target region were identified. By screening an additional 1221 individuals (F2 plants developed from the initial mapping population), the Mi-C11 nematode resistance locus was shown to be located in a 3.6 cM region flanked by the SSR marker CIR069 and the AFLP marker E14M27-375. These results more precisely identify the location of the Mi-C11 nematode resistance locus and provide the basis for map-based isolation of the nematode resistance gene in M-120 RNR.

Technical Abstract: The identification and utilization of a high-level of host plant resistance is the most effective and economical approach to control root-knot nematode (Meloidogyne incognita). In an earlier study, we identified a major quantitative trait locus (QTL) for resistance to root-knot nematode in the M-120 RNR Upland cotton line (Gossypium hirsutum L.) of the Auburn 623 RNR source. The QTL is located in a 12.9 cM interval flanked by the two SSR markers CIR069 and CIR316 on the distal segment of Chromosome 11. To construct a fine map around the target region, a bulked segregation analysis was performed using two DNA pools consisting of five individuals, with each being homozygous for the two parental alleles. From a survey of 1152 AFLP primer combinations, nine AFLP markers closely linked to the target region were identified. By screening an additional 1221 F2 individuals developed from the initial mapping population, the Mi-C11 locus was delimited to a 3.6 cM interval flanked by the SSR marker CIR069 and the AFLP marker E14M27-375. These results further elucidate the genetic fine structure of the Mi-C11 locus and provide the basis for map-based isolation of the nematode resistance gene in M-120 RNR.