Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2003
Publication Date: 9/15/2003
Citation: Brown, C.R., Mojtahedi, H. 2003. Breeding potato for resistance to meloidogyne species and tobraviruses. Journal of Nematology. 35:328.
Technical Abstract: The increased cultivation of potato in warmer and tropical production areas necessitated a search for resistance to Southern Root Knot Nematode (SRN). No useful resistance among cultivated materials was identified. Extensive surveys of wild species identified a number of resistant candidates. The wild species S. sparsipilum has proven to be a good source that has been introgressed into advanced breeding material. Resistance from S. sparsipilum appeared to be highly heritable. Melodiogyne chitwoodi, Columbia root-knot nematode (CRN), described first in 1980, has come to dominate root-knot research efforts in certain traditional production areas including the Netherlands and the Western United States. Resistance to CRN was not available in cultivated materials, but was found in S. bulbocastanum, S. hougasii, and S. fendleri. Inheritance studies have determined monogenic dominant resistance in both S. bulbocastanum and S. hougasii. The genomic location of resistance in both species has been mapped to homologue 11. In contrast, there are numerous varieties and advanced breeding materials presenting resistance to Tobravirus tobacco rattle virus (TRV) vectored by Trichodorid nematodes. Although apparently not simply inherited, resistance to TRV is heritable enough to be readily bred into progeny of resistant parents. Transgenic resistance to TRV, utilizing a 'pathogen derived resistance' approach has been researched by several groups. Partial levels of resistance have had the undesirable concomitant attributes of being strain-specific or providing resistance to TRV by mechanical inoculation to foliage but not by nematode transmission to tubers. Different strategies of transgenic resistance obviously need to be examined. The introduction of these two types of natural resistance either singly or combined, to new commercial varieties would reduce the burden of soil fumigation that is a particularly heavy cost in the Pacific Northwest of the U.S.