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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #254748
Title: Yield drag associated with resistance to Meloidogyne incognita in high-yielding cotton germplasm.

Author
item Davis, Richard
item CHEE, P.W. - University Of Georgia
item LUBBERS, E.L. - University Of Georgia

Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 7/13/2010
Publication Date: 9/1/2010
Citation: Davis, R.F., Chee, P., Lubbers, E. 2010. Yield drag associated with resistance to Meloidogyne incognita in high-yielding cotton germplasm. Journal of Nematology. 42(3):42.

Interpretive Summary:

Technical Abstract: In plant breeding, accidental incorporation of deleterious DNA near a desirable gene is called linkage drag; if it reduces yield, it is called yield drag. Yield drag is best documented by comparing near isogenic lines with and without the DNA containing the desired gene to minimize other genetic differences. In a back-cross breeding program to improve the yield and fiber quality of cotton germplasm with resistance to M. incognita, near-isogenic lines with and without resistance were selected. In greenhouse tests, the resistant isoline (GA120R1B3) reduced reproduction of M. incognita by 95% compared to the susceptible isoline (GA120S1A1). The isolines and the susceptible recurrent parent (PD94042) used in creating the isolines were evaluated for yield drag in a field study with 8 replications. Although they are not isogenic lines, the source of resistance (M-120 RNR) in GA120R1B3 also was tested along with its susceptible recurrent parent (Coker 201). The study was conducted in a field with very low to nil populations of M. incognita, and the field was fumigated with 1,3-dichloropropene prior to planting to evaluate plants in the absence of nematode parasitism. No galling was found during this study. Yield of M-120 RNR (1776 kg/ha) did not differ (P = 0.05) from Coker 201 (1673 kg/ha). This suggests that yield drag may not have occurred with M-120 RNR. However, yield of GA120R1B3 (2087 kg/ha) was less than the yield of either GA120S1A1 (2356 kg/ha) or PD94042 (2405 kg/ha), which did not differ from each other. Although yield and quality of GA120R1B3 are improved compared to its resistant parent (M-120 RNR), yield drag may have been introduced. Yield drag may be more readily observed as yield potential increases. Additional breeding should be able to break this linkage drag thereby further improving yield of this resistant germplasm line.