Distribution of Pratylenchus spp. and Heterodera glycines in Michigan and combined reproduction on Peking and PI 437654 soybean

Authors: Schumacher, Lesley; BIRD, GEORGE - Michigan State University

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2025
Publication Date: 3/3/2025
Citation: Schumacher, L.A., Bird, G.W. 2025. Distribution of Pratylenchus spp. and Heterodera glycines in Michigan and combined reproduction on Peking and PI 437654 soybean. Plant Health Progress. https://doi.org/10.1094/PHP-10-24-0101-RS.
DOI: https://doi.org/10.1094/PHP-10-24-0101-RS

Interpretive Summary: The focus of this research was to assess distribution of two nematodes—soybean cyst nematode and lesion nematode—in Michigan soybean production. These two nematode species are responsible for yield loss in soybeans, which is a valuable crop in worldwide food production. Upon survey completion, we sought to investigate the interaction of these two nematodes on two soybean cyst nematode-resistant cultivars (PI 437654 and Peking) vs. susceptible to see if lesion nematode enhanced soybean cyst nematode development in two greenhouse trials. The Michigan Soybean Promotion Committee grower database was used to randomly select 5% of Michigan soybean growers and these growers were approached for soil sampling to determine if the two nematodes were present on their farms. Overall, soybean cyst and lesion nematode were both widely distributed throughout soybean-producing counties, with levels of infestation at 48% and 44%, respectively. This amounted to 36 of the 45 sampled counties being positive for soybean cyst nematode and 39 of the 45 sampled counties being positive for lesion nematode. In the greenhouse trials, lesion nematode enhanced soybean cyst nematode development regarding soybean cyst nematode females in roots, females in soil, males in roots, and viable units (i.e., eggs and juveniles) in soil for both PI 437654 and Peking cultivars, but with inconsistent results between trials. However, on the susceptible cultivar, there were no instances in which lesion nematode enhanced soybean cyst nematode development. Two previously unidentified soybean cyst nematode-positive counties were added to the official soybean cyst nematode distribution map as a result of this work. Such information is valuable to growers trying to maximize their yields under nematode pressure, including choosing appropriate sources of resistance.

Technical Abstract: Soybeans are a major field crop cultivated around the world. Two common nematode endoparasites, Heterodera glycines (soybean cyst nematode, SCN) and Pratylenchus spp. (lesion nematode, LN), damage soybeans and frequently occur together in soybean fields. A 2010-2011 randomly selected site survey was conducted in Michigan to determine the extent of SCN and LN soil infestations in soybean-producing counties. The Michigan Soybean Promotion Committee grower database was used to randomly select five percent of Michigan soybean farms (n=548) from soybean-producing counties. Of the 45 counties sampled in 2010 and 2011, 36 were positive for SCN and 39 were positive for LN. The occurrence of SCN averaged among the counties was 48%, whereas the average occurrence of LN was 44%. Additionally, soybean cultivars derived from the PI 88788 source of SCN resistance are common, and prior research showed that the presence of Pratylenchus penetrans (penetrans lesion nematode, PLN) enhanced SCN development on PI 88788. Another goal of this research was to determine if PLN enhances SCN development on soybean cultivars from two other sources of resistance, Peking and PI 437654. Two greenhouse trials were conducted to evaluate the effects that PLN had on SCN reproduction on susceptible (control), Peking, and PI 437654 cultivars. The SCN inoculation rate was 2000 eggs and juveniles per conetainer for both trials while the PLN inoculation rate was 250 PLN per conetainer in trial 1 and 500 PLN per conetainer in trial 2. Three assays for SCN were used: females in roots/soil, second-stage juveniles (J2) in roots/soil, and males in roots/soil. For PLN, all life stages in roots and soil were enumerated. Both SCN and PLN were able to complete development on each cultivar. There was no difference (P>0.05) in SCN development between PLN and non-PLN infested plants for the susceptible cultivar. There were some instances where the presence of PLN increased SCN population densities on both Peking and PI 437654 in each trial. In trial 1, this included significantly (P<0.05) greater SCN females in roots on Peking and SCN males in roots on PI 437654 in PLN-infested conetainers than non-PLN conetainers. In trial 2, this included greater SCN J2 in soil on Peking and SCN females in roots and soil on PI 437654 in PLN-infested conetainers than non-PLN conetainers. Overall, the interactions between SCN and PLN were inconsistent on the three cultivars tested.