Journal of Nematology (2004) 36, p. 313 (Colgrove et al.)

A.L. Colgrove and T.L. Niblack (2004)
An analysis of development of field populations and inbred lines of Heterodera glycines, the soybean cyst nematode, on resistant soybean
Journal of Nematology 36 (3), 313-313
paper presented at the Society of Nematologists 43rd Annual Meeting, Estes Park, Colorado 7-11 August 2004
Abstract: The soybean cyst nematode is responsible for major economic losses to soybean producers. Resistant soybean varieties are used in attempts to reduce Heterodera glycines population densities and limit yield loss. Bioassays such as Hg-type and race tests are performed to monitor H. glycines population development on resistant soybeans. Assessment of virulence in field populations facilitates management decisions and increases understanding of H. glycines population development and soybean resistance. The lack of diversity and durability of resistant soybean genotypes are problems confronted by soybean producers. In Illinois, varieties developed from plant introduction (PI) 88788, the most commonly used source of resistance, have become less effective due to adaptation by H. glycines populations. Soybean lines with the highly resistant PI 437654 source of resistance should be exploited. However, some populations are now virulent on varieties developed from soybean lines such as Cyst-X (that have PI 437654 as the source of resistance). A paucity of knowledge of the nature of soybean resistance and how deployment of resistant cultivars may affect population development currently exists. Therefore, female indices from more than 1000 race and HG-type tests on field populations and inbred lines were obtained and analyzed. Initial tests indicate highly significant correlations (p < 0.001) for parasitism on PI 88788, PI 209332 and PI 548316 and for parasitism on PI 548402, PI 90763, and PI 89772. Previous reports indicate a similarity of resistance mechanisms in these two "groups" of soybean genotypes. As adaptation of field populations to deployed sources of resistance occurs, the effectiveness of resistant cultivars derived from soybean genotypes within these groups will be brought into question.
Database assignments for author(s): Terry L. Niblack

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Heterodera glycines	Soybean (Glycine max)	U.S.A. (mid N)