Location: Crop Genetics ResearchTitle: Gossypium arboreum accessions resistant to Rotylenchulus reniformis identified Author
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/16/2016
Publication Date: 12/1/2016
Citation: Stetina, S.R., Erpelding, J.E. 2016. Gossypium arboreum accessions resistant to Rotylenchulus reniformis identified. Phytopathology. Vol. 106; S4.38.
Technical Abstract: Reniform nematode (Rotylenchulus reniformis) is a serious pest of upland cotton (Gossypium hirsutum) in the southeastern United States. Resistance does not exist naturally in G. hirsutum and there are no resistant cultivars available. To identify sources of reniform nematode resistance, 225 G. arboreum accessions from the US germplasm collection were evaluated for their reaction to the nematode in repeated growth chamber experiments. Due to growth chamber space constraints, accessions were divided into 3 sets for initial evaluation. Root infection was measured on 3 plants 4 weeks after inoculation with 1,000 nematodes. The 16 accessions supporting the fewest infections (A2-254, A2-272A, A2-272B, A2-294, A2-354, A2-362, A2-456, A2-483, A2-497, A2-514, A2-522, A2-553, A2-558, A2-568, A2-632, and A2-665) were evaluated again in confirmation tests lasting 8 weeks. The numbers of nematodes extracted from soil and eggs extracted from roots of 5 plants were combined and totals were analyzed (analysis of variance and differences of least squares means, P = 0.05). Susceptible controls G. hirsutum cultivar Deltapine 16 and G. arboreum accession A2-101 had 85,999 and 46,902 reniform nematodes, respectively; the resistant control G. arboreum accession A2-190 had 1,665 reniform nematodes, and only 136 reniform nematodes remained in fallow pots. All 16 accessions tested supported significantly smaller reniform nematode populations than the susceptible controls, ranging from 10,883 to 707 individuals. Nine accessions (A2-254, A2-272B, A2-294, A2-362, A2-456, A2-497, A2-514, A2-558, and A2-665) supported reniform nematode populations comparable to the resistant control, and accession A2-354 had significantly fewer reniform nematodes than the resistant control. Cotton breeders would benefit from introgressing the resistance from these newly-identified resistant accessions into their upland cotton improvement programs.