May in the News
|Dr. Chuck Brown and Dr. Debbie Inglis’ Visit to Neah Bay High School
Dr. Chuck Brown (USDA ARS Prosser, Potato Geneticist) and Dr. Debbie Inglis (Professor, Plant Pathology) recently visited biology students at Neah Bay High School, and presented lectures and laboratory exercises on Makah/Ozette potato and common potato diseases. Virus-free cuttings and tubers of this heritage potato were also distributed to the students and Makah tribal members. Makah/Ozette is believed to be a remnant potato variety introduced to the Olympic Peninsula by Spanish explorers during the 1700’s. The potato has been maintained and preserved by Makah tribal members since that time and used as a food item.
|Graduate Student Wins First Place in Paper Competition at International Workshop in Spain
Wonyong Kim , PhD student with Weidong Chen, USDA ARS and adjunct professor in the Department of Plant Pathology at Washington State University, Pullman, won the first place in the Bob Henson Student Paper Competition at the Third International Ascochyta Workshop held at Cordoba, Spain, April 22 to 26, 2012. His presentation was entitled “Identification of solanapyrone biosynthesis genes and generation of solanapyrone-deficient mutants in Ascochyta rabiei“, and was co-authored by W. Kim, H.O. Akamatsu, T.L. Peever, G.J. Vandemark and W. Chen. Eight students from seven countries participated in the competition.
|Congratulations to spring 2012 graduates, Segun Aukinbade and Dipak Sharma Poudyal for completing the requirements for the award of MS and PhD degrees, respectively.
Segun Akinbade’s MS dissertation was on genetic diversity viruses associated with apple green crinkle disease, carried out under the supervision of Dr. Ken Eastwell, Professor of Plant Patholgy and Director, Clean Plant Center for Northwest located at the IAREC, Prosser. The supervsory committee included, Drs. Lindsey du Toit, Dennis Johnson and Richard Larsen. Apple green crinkle disease (AGCD) is widespread in apple orchards worldwide, causing symptoms such as deformation and cracking of fruit. However, these clearly visible symptoms of the disease are only apparent in years with cooler spring temperatures (< 9.2oC). The mode of spread of AGCD suggests that a viral pathogen might be involved in the etiology. Field samples were indexed for the presence of Apple mosaic virus (ApMV), ACLSV, ASGV, ASPV, viroids (in the genus Apscaviroid) and phytoplasmas. Results from these analyses demonstrated that ACLSV, ApMV, viroids (entire genus Apscavirod) and phytoplasmas were not associated with AGCD. Genetic diversity analysis of the coat protein (CP) and replicase genes and triple gene block (TGBs) sequences of ASPV and ASGV were studied. Genetic diversity analysis of virus populations revealed that whereas ASGV populations were genetically conserved in both AGCD-symptomatic and asymptomatic trees, populations of ASPV were highly variable. Phylogenic analysis of CP sequences of ASPV revealed six major groups of sequence variants with two of six phylogroups comprised only of sequences from AGCD-symptomatic trees. These results point to the possible involvement of one or more of the ASPV variants, with or without ASGV, in the etiology of AGCD, and will direct future efforts to identify and characterize putative causal agent(s) of AGCD in symptomatic apple fruits.
Segun is a native of Nigeria and grew up in Ibadan, Nigeria. His love for science while in high school prompted him to register for a National Diploma in Science Laboratory Technology at the Federal Polytechnic, Ede, Nigeria. While studying at Ede, he visited the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria on an excursion tour and was amazed with the level of research in this institute. After his program, he joined IITA in 1995. While at IITA, he obtained Final Diploma (equivalent of baccalaureate degree) in Microbiology/Virology option from University of Ibadan, Ibadan, Nigeria and a Postgraduate Diploma in Crop Protection from University of Agriculture, Abeokuta, Nigeria.
Dipak Sharma Poudyal, completed the requirements for a PhD degree in plant pathology from Washington State University (WSU) under the supervision of Xianming Chen. His supervisory committee included Kulvinder Gill, Dennis A. Johnson, and Timothy D. Murray. Dipak’s PhD dissertation was titled “Prediction of disease damage, determination of pathogen survival regions, and characterization of international collections of wheat stripe rust”. Dipak conducted three studies in regional, national, and international scopes with a focus on the epidemiology of the disease. In the first study, he developed a series of models for predicting potential yield loss for the U.S. Pacific Northwest using historical climatic and disease data. In the second study, he determined the regions for over-seasoning of the stripe rust pathogen in the mainland U.S. using long-term means for temperature, relative humidity, rainfall, dew point, snow depth, and availability of plant hosts. In the third project, he determined virulences and molecular genotypes for more than 200 stripe rust isolates from 18 countries on 20 single resistance gene lines and 20 wheat differential genotypes and 17 SSR markers. His research showed common and unique virulences in different countries and two genetic groups with some of admix genotypes. Dipak’s research findings provided a better understanding of the virulence and genetic variation of the pathogen populations and should be useful for control of stripe rust using disease resistance. Dipak grew up in Chitwan, Nepal and received his BS in soil science in 1998 and MS in plant pathology in 2001 from Tribhuvan University, Nepal.