Screening a Diverse Soybean Germplasm Collection for Reaction to Purple Seed Stain Caused byCercospora kikuchii

Abstract

Purple seed stain (PSS), caused by Cercospora kikuchii, is a prevalent soybean disease that causes latent seed infection, seed decay, purple seed discoloration, and overall quality deterioration. The objective of this research was to screen soybean accessions from the United States Department of Agriculture germplasm collection for resistance to PSS. In total, 123 plant introductions (PI) from 28 different countries, representing maturity groups (MG) III, IV, and V, were screened. Incidence of Cercospora leaf blight (% CLB), visual PSS (% PSS), and seed infected by C. kikuchii (% C. kikuchii) in harvested seed were determined. In 2007, % C. kikuchii was 2 to 51% for MG III, 2 to 35% for MG IV, and 0 to 33% for MG V. In 2008, % C. kikuchii was 0 to 45% for MG III, 1 to 71% for MG IV, and 0 to 15% for MG V. In total, four and ten PI from MG III and IV, respectively, were identified as resistant to PSS in both years. Highly positive correlations were found for inoculated versus noninoculated treatments and for % PSS versus % C. kikuchii infection. The PSS-resistant PI identified in this study will be valuable to breeders in developing resistant cultivars.

Maximizing soybean yield by understanding planting date, maturity group, and seeding rate interactions in North Carolina

“…For instance, a study of 128 soybean plant introductions, including three MGs observed a difference in the amount of seed infected by Cercospora kikuchii (T. Matsumoto & Tomoy.) M. W. Gardner, the pathogen causing purple seed stain, in the different MGs, as a greater number of seed was infected in the MGs 3 and 4 than the MG 5 as this pathogen is more prevalent in southern growing regions where MG 5 cultivars are more frequently commercially produced (Alloatti et al, 2015). Although a diversity of MGs can be produced in the U.S. Southeast, as growers modify PDs to increase soybean yields, determining optimal MGs to use across a wide range of PDs is merited.…”

Evaluation of soybean genotypes for reaction to natural field infection by Cercospora species causing purple seed stain

“…Of 17 lines with different levels of resistance to PSS identified from this study, nine soybean genotypes (PI 417361, PI 504488, PI 88490, PI 346308, PI 416779, PI 417567, PI 381659, PI 417567, and PI 407749) were the previously reported lines with resistance to Phomopsis seed decay of soybean [38]. Among them, PI 417361 was also identified as a resistant line to PSS from the field tests in Arkansas in 2007 and 2008 [40]. All of these soybean lines could be useful in breeding programs for developing resistant soybean to both seed diseases.…”

“…Previous research reported a greater percentage of C . kikuchii seed infection in MG III and MG IV than MG V soybean genotypes [40]. It is likely due to the early soybean production system in Arkansas, where MG III and MG IV soybean cultivars are planted in late April to early May.…”

“…They represent maturity groups (MG) III, IV, and V including 36 plant introductions (PIs) and 6 cultivars with known reaction to PSD caused by Phomopsis longicolla [38, 39]. The PSS-resistant checks (PI 417361, PI 264555, and PI 407749) and susceptible checks (IA 3001, AP 350, and PI 417098) were selected based on previous tests in Arkansas [40]. Soybean cultivars SUWEON 97 and 5002T were used as cultivar checks.…”

Plant extract as a strategy for the management of seed pathogens: a critical review

“…M.W. Gardner causes seed discoloration (Alloatti et al, 2015). In soybean (Glycine max L.), Pythium Nees causes a purple spot (Upchurch & Ramirez 2010) and, when inside the embryonic tissues, it causes necrosis of cotyledons and vascular elements (Pathan et al, 1989).…”