Abstract Detail

Ecology/Pathology

Rojas, Alejandro [1], Urrea, Keiddy [2], Rothrock, C.S. [2], Chilvers, Martin [1], Rupe, John [2].

Effect of crop rotation and baiting temperature on the diversity of Oomycetes associated with root diseases of soybean.

Diversity of oomycetes and their association with field crops has been studied to assess their impact as disease causal agents. The approaches have included traditional isolation on semi-selective media and/or baiting techniques.  However, the isolation or baiting method can potentially introduce biases due to differences in species growth rate, media preference and incubation temperature. Sampling depth with culture based methods is also limited, due to time and resources required for such approaches.  The primary oomycete genera associated with soybean, rice and other field crops include Pythium, Phytophthora and Phytopythium. In this study we examined the effect of crop rotation (soybean-soybean or soybean-rice) on the diversity of oomycetes at three locations in Arkansas, and we examined the effect of temperature on infection of soybean by baiting soil with soybean seedlings at 20°C or 30°C. From the traditional baiting technique a total of 25 oomycete species were identified, species such as Pythium irregulare, Pythium paroecandrum and Pythium sylvaticum were widespread among all the samples, but their abundance changed among locations, crop rotation treatments and baiting temperatures. According to the isolation methods, the rice-soybean rotation and baiting at 20°C had the greatest diversity of oomycete species. We also compared the traditional baiting and isolation technique with a community profile approach using targeted amplicon sequencing.   Species abundance and diversity appears to be influenced by rotation, and baiting temperature influences the diversity of species recovered.

1 - Michigan State University, Plant, Soil and Microbial Sciences, 578 Wilson Rd, 104 CIPS, East Lansing, MI, 48824, USA
2 - University of Arkansas, Plant Pathology, 495 N. Campus Drive, Plant Sciences Building 212 , Fayetteville, AR, 72701, USA

Keywords:
Oomycetes
Root pathogens
biodiversity.

Presentation Type: Offered Paper - Paper
Session: 5
Location: Room 103 AB/Kellogg Hotel and Conference Center
Date: Monday, June 9th, 2014
Time: 1:45 PM
Number: 5004
Abstract ID:150
Candidate for Awards:Graduate Student Oral Presentation Award