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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #316975
Title: Differential effects on nematode development of two QTLs for resistance to Meloidogyne incognita in cotton

Author
item DA SILVA, MYCHELE - University Of Georgia
item KUMAR, PAWAN - University Of Georgia
item JI, PINGSHENG - University Of Georgia
item CHEE, PENG - University Of Georgia
item Davis, Richard

Submitted to: American Phytopathology Society
Publication Type: Abstract Only
Publication Acceptance Date: 6/7/2015
Publication Date: 9/15/2015
Citation: Da Silva, M.B., Kumar, P., Ji, P., Chee, P.W., Davis, R.F. 2015. Differential effects on nematode development of two QTLs for resistance to Meloidogyne incognita in cotton [abstract]. American Phytopathology Society. 105:54.13.

Interpretive Summary:

Technical Abstract: QTLs qMi-C11 and qMi-C14 impart resistance to Meloidogyne incognita in cotton. Breeders had backcrossed both QTLs into Coker 201 (C201; susceptible) to create M-120 RNR (M-120; highly resistant), and we crossed C201 and M-120 to create near isogenic lines with either qMi-C11 or qMi-C14. Previous work suggests different modes of action for qMi-C11 and qMi-C14. To document individual and combined effects of the QTLs, C201 (neither QTL), M-120 (both QTLs), CH11 isoline (qMi-C11), and CH14 isoline (qMi-C14) were inoculated with M. incognita (one plant/pot, 4000 J2s/pot, 7 replications, completely randomized design). After 38 days, roots were weighed, M. incognita eggs were harvested, the number of galls was counted, and roots were stained to observed nematode developmental stages (J2, swollen J2 [SJ2], J3, J4, and Female [F] as percentage of total nematodes). Root weight did not differ among genotypes. QTLs were effective alone or combined: C201 had more nematodes becoming F than M-120, CH11 or CH14 (51% vs. 9%, 3%, and 12%). More nematodes remained J2 in M-120 (41%), CH11 (58%) and CH14 (27%) than in C201 (9%). CH14 had more J3 than CH11 (26% vs. 10%) and CH14 and C201 had more total nematodes and larger galls than CH11 and M-120, suggesting that CH11 affects nematode development earlier than CH14. This study confirms that both qMi-C11 and qMi-C14 impart resistance to M. incognita and that qMi-C11 and qMi-C14 have different effects on nematode development.