Using host resistance to control cotton parasitic reniform nematode

Authors: Feng, Chunda; Stetina, Salliana; ERPELDING, JOHN - US Department Of Agriculture (USDA)

Submitted to: Book / Chapter / eBook
Publication Type: Book / Chapter
Publication Acceptance Date: 6/3/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cotton is the primary source of natural fiber for the textile industry worldwide. The US is a leading cotton producer and the largest exporter for the international cotton market, representing about US$ 7 billion annually. Reniform nematode is root feeding microscopic worm that is an increasing threat for US cotton production, currently causing about 1% yield loss, equivalent to approximately US$100 million loss annually. Several approaches are applied for management of this microscopic worm. Nematicides are effective in providing protection for cotton seedlings, but there are environmental concerns in addition to the cost. Rotation with non-host crops will reduce nematode populations, but long rotational cycles are required to suppress the recovery of the nematode population, therefore it is not a preferred choice for growers. Growing resistant cultivars would be the most effective and sustainable strategy for long-term management of this pest. However, the widely grown upland cotton is susceptible to reniform nematode. Resistance to reniform nematode found in a few varieties of Pima cotton has been transferred to upland cotton. Resistance to this nematode was more frequently observed in diploid cotton species (with two sets of chromosomes); however, specialized breeding approaches are required to transfer resistance genes to upland cotton (with four sets of chromosomes). Our research focuses on introgression of resistance from diploid cotton species to upland cotton, better understanding the genetics of resistance, and developing genomic tools that can be applied for studying the genetics of resistance and breeding resistant cultivars.

Technical Abstract: Cotton is the primary source of natural fiber for the textile industry worldwide. The US is a leading cotton producer and the largest exporter in the international cotton market, representing approximately seven billion dollars total value annually. Reniform nematode Rotylenchulus reniformis is an increasing threat to US cotton production, which causes about 1% yield loss to the total production (equivalent to hundreds of millions of dollars). In some southeast states, such as Alabama, Louisiana, and Mississippi, reniform nematode is becoming the most important disease for cotton production; the yield loss caused by this parasite is about 5% to 9% in these states and could reach up to 50% in some heavily infested fields. Several approaches are applied to manage this important disease. Nematicides provide protection for cotton seedlings for a short period, but the nematode populations increase dramatically during cotton growing season. Rotation with non-host crops may reduce the populations of R. reniformis but is often not a choice due to some technical and economic constraints. Growing resistant cultivars would be the most effective and sustainable way to manage this parasite. However, resistance to R. reniformis was not found in the widely grown tetraploid upland cotton (Gossypium hirsutum) but found in a few genotypes of tetraploid G. barbadense and some diploid Gossypium species. The resistance of Gossypium to R. reniformis is controlled by a single gene or multiple genes. Genomic tools have been applied in studying the genetics of resistance and in breeding. Upland cotton varieties with improved resistance to R. reniformis have been developed using G. barbadense resistance sources. Our research focuses on introgression of resistance to R. reniformis from diploid Gossypium species to upland cotton.