Response to nematicide by cotton genotypes varying in reniform nematode resistance

Abstract

Reniform nematode (RN, Rotylenchulus reniformis Linford & Oliveria) is a parasite that reduces and limits cotton (Gossypium hirsutum L.) yields. At present, nematicides and crop rotations are the most effective management tool for producers. Our study investigated the use of six composite breeding lines that have quantitative trait loci (QTLs) for RN resistance and the interaction effect of a nematicide under high RN pressure. The study compared these genotypes in both a non-RN field and a RN-infected field under a Velum Total (active ingredients fluopyram and imidacloprid) treatment at Tennessee Valley Research and Extension Center near Belle Mina, AL. In both years, the breeding lines outyielded commercial controls and the parental lines in RN infested field with and without Velum Total. Five out of the six breeding lines contained both chromosome 21 (Ren barb1 and Ren barb2) resistant QTLs, which reduced RN egg numbers (P < .05) and produced higher yields than the commercial checks. These lines can be considered moderately resistant to RN. The remaining line contained one QTL Ren barb1 , produced good yield, and is considered tolerant, despite the fact that it had high RN egg numbers. However, adding a nematicide treatment did increase yields in all material tested. Therefore, further work at increasing resistance from other genetic sources is needed to completely eliminate nematicide use.

Rotation of Cotton (Gossypium hirsutum) Cultivars and Fallow on Yield and Rotylenchulus reniformis

“…The use of this excellent source of R. reniformis resistance (McCarty et al, 2013) was facilitated by the development of SSR markers associated with the resistance on chromosome 21 (Gutierrez et al, 2011). Cotton breeding lines with reniform nematode resistance that had been developed from crosses with GB713 yielded higher than susceptible commercial cotton varieties in R. reniformis infested field trials (Koebernick et al, 2021). The commercially available cultivars have not only obtained resistance to R. reniformis, but also to M. incognita (2-gene resistance), and in addition contain six transgenic traits (three Bt genes and three herbicide tolerant genes), making a total of at least nine genes that must be selected in addition to acceptable yield and fiber quality traits.…”

Transcriptome Analysis of Resistant Cotton Germplasm Responding to Reniform Nematodes

“…This approach will require long rotational cycles to significantly lower the nematode population and therefore crop rotation is not always feasible due to the economic and resource constraints associated with cotton production [1,11]. Growing resistant Upland cotton cultivars or combining the application of nematicides with the use of resistant cultivars has been reported as an effective management strategy [1,11,[17][18][19]. McCulloch et al (2021) reported that resistant cultivars significantly suppress the reniform nematode population resulting in a 26% seedcotton yield increase compared to susceptible controls [20], whereas Koebernick et al (2021) reported 8-20% yield increase using a resistant cultivar with a nematicide application during planting [17].…”

Management of Reniform Nematode in Cotton Using Winter Crop Residue Amendments Under Greenhouse Conditions

“…Reniform nematode ( Rotylenchulus reniformis , RN) is one of the most important pathogens in the southeast United States ( Jones et al, 2013 ) and is considered one of the most significant plant-parasitic nematodes affecting cotton ( Gossypium hirsutum ) in the region ( Robinson, 2007 ). Reniform nematode limits production, alters growth, and defers flowering, while the size and number of cotton bolls, as well as lint quality, are reduced ( Koebernick et al, 2021 ). Yield losses caused by RN can reach 50% ( Dyer et al, 2020 ).…”