REGISTRATION OF RN96425, RN96527, AND RN96625-1 NEMATODE-RESISTANT COTTON GERMPLASM

Authors: COOK, C - SYNGENTA; Robinson, Arin

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/2005
Publication Date: 8/24/2005
Citation: Cook, C.G., Robinson, A.F. 2005. Registration of RN96425, RN96527, and RN96625-1 nematode-resistant cotton germplasm. Crop Science. 45:1667-1668.

Interpretive Summary: There are many kinds of microscopic worms called nematodes that feed on the roots of cotton and other crops, debilitating the plants and markedly decreasing yields. The direct losses to U.S. cotton farmers caused by nematodes each year are estimated by the National Cotton Council to exceed $300,000,000. The reniform nematode and the root-knot nematode are the two most important nematodes on cotton in the U.S. Two varieties of cotton are resistant to the kinds of root-knot nematodes found in some fields, but not in others, and all varieties suffer considerable damage when grown in soil where the reniform nematode is present in high numbers. In this study, three high yielding cotton breeding lines were developed that are resistant to the root-knot nematode and highly tolerant to the reniform nematode. This means that when they are planted in a field where the root-knot nematode is present, they will grow well and the nematode populations in the soil will drop. On the other hand, when they are planted in a field where there are reniform nematodes, plants also will grow well and produce large cotton yields but the nematode population will not drop, or not very much. Thus, cotton breeders can use these breeding lines to quickly develop high-yielding new varieties that will be useful both to farmers with root-knot nematodes and to those with reniform nematodes. Farmers with root-knot nematodes could use them to obtain excellent yields while reducing nematode populations so that sensitive crops can be grown the following year, and farmers with reniform nematodes would be able to produce a profitable cotton crop that year even though reniform nematode populations remain high.

Technical Abstract: Three cotton (Gossypium hirsutum L.) germplasm lines, RN96425, RN96527, and RN96625-1, were released because they possess valuable traits that confer resistance to the southern root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood Race 3], field tolerance to the reniform nematode (Rotylenchulus reniformis Linford & Oliveira), and good productivity and fiber quality. The lines were developed jointly by the USDA-ARS, Syngenta Seeds, Inc., and the Texas Agricultural Experiment Station and released in 2004.