Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: MOLECULAR ANALYSIS OF DEVELOPMENT TO IMPROVE COTTON FIBER

Location: Cotton Fiber Bioscience Research Unit

Title: Improving Cotton (Gossypium hirsutum L.) Plant Resistance to Reniform Nematodes by Pyramiding Ren1 and Ren2

Authors
item Fang, David
item Stetina, Salliana

Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 13, 2011
Publication Date: August 23, 2011
Citation: Fang, D.D., Stetina, S.R. 2011. Improving Cotton (Gossypium hirsutum L.) Plant Resistance to Reniform Nematodes by Pyramiding Ren1 and Ren2. Plant Breeding. 130:673-678.

Interpretive Summary: Reniform nematode (a worm that causes damage to plant roots) is a major pest of cotton in the mid-south area of the United States. It causes US cotton production losses estimated to exceed $100 million annually. Resistance genes, Ren1 and Ren2 from cotton relatives G. longicalyx and G. aridum, respectively, have been identified and transferred into cultivated cotton. Using plant materials containing either Ren1 or Ren2 gene as parents, we developed an F2 population of 184 progeny for genetic evaluation of nematode resistance. The response of F2 plants to nematode inoculation was evaluated in a growth chamber. Molecular markers BNL2662 and BNL3279 were analyzed to assist selection of proper parents and F1 plants, and to study the segregation of the resistance genes among the F2 progeny. Our results suggested that Ren1 and Ren2 were duplicate genes with Ren1 residing on chromosome 11, and Ren2 on chromosome 21. F2 plants containing either Ren1 or Ren2 had significantly fewer nematodes than the susceptible Upland cotton genotype. No significant difference in nematode resistance was found between plants containing Ren1 and those having Ren2, indicating that these two genes may have similar resistance mechanisms. Combining Ren1 and Ren2 further enhanced plant resistance to reniform nematodes.

Technical Abstract: Reniform nematode (Rotylenchulus reniformis) has become a major pest of cotton in the mid-south area of the United States. Resistance genes, Ren1 and Ren2 from Gossypium longicalyx and G. aridum, respectively, have been identified and introduced into Upland cotton (G. hirsutum). We developed an F2 population of 184 progeny plants by crossing Ren2 –containing plants with a LONREN-2 plant that had the resistance gene Ren1. The F2 plants were evaluated for their resistance to reniform nematodes in a growth chamber. Microsatellite markers BNL2662 and BNL3279 were analyzed to assist the selection of proper parental plants and F1 progenies, and to study the segregation of the resistance genes in the F2 population. Our results suggested that Ren1 and Ren2 were duplicate genes with Ren1 residing on chromosome 11 (A subgenome), and Ren2 on chromosome 21 (D subgenome). F2 plants containing either Ren1 or Ren2 had significantly fewer nematodes than the susceptible Upland cotton genotype. No significant difference in nematode resistance was found between plants containing Ren1 and those having Ren2, indicating that these two genes may have similar resistance mechanisms. Plants containing both Ren1 and Ren2 appeared to have higher resistance than those with just one of the genes, and pyramiding these two genes may be a valuable tool to cotton breeders when managing this pest.

Last Modified: 9/23/2014
Footer Content Back to Top of Page