Location: Crops Pathology and Genetics Research
Project Number: 2032-21220-006-05
Start Date: Sep 17, 2012
End Date: Sep 16, 2017
We will utilize High Resolution Computed Tomography (HRCT- a type of CAT scan) in combination with light and scanning electron microscopy to complete the project objective. Live vines and excised woody stems and roots will be scanned with HRCT at the Advanced Light Source (ALS) facility at Lawrence Berkeley National Lab using beamline 8.3.2. We will supplement this work with imaging efforts using a neutron beam at the McClellan Nuclear Research Center at UC Davis. Resultant datasets will be analyzed at each facility and in the McElrone and Walker labs using AVISO software and powerful PCs dedicated to this work. We will continue to compare the vascular anatomy of grapevine varieties that exhibit Pierces’s Disease (PD) susceptibility, tolerance, and resistance. Accessions of Vitis girdiana and V. arizonica from ARS scientist's collection from the southwestern US will be used for this purpose and will be compared to Lenoir and Blanc du Bois varieties exhibiting PD resistance in TX growing regions. ARS scientist and colleagues recently used HRCT scans of the grapevine vascular system to identify previously unknown structures in the vascular system that have an impact on the plant's ability to prevent pathogen and embolism spread. Examining the internal progression (or lack thereof) of disease development in susceptible, resistant, and tolerant cultivars will provide significant insights into potential breeding targets and possible management strategies. This approach has been used recently by our group to begin to study grapevine trunk canker pathogens as well. Post doc(s) will drive related efforts in related efforts to explore how different grapevine accessions/rootstocks respond to drought with specific focus on utilizing HRCT to visualize embolism spread and repair among the plant materials, and differences in uptake potential of roots using neutron radiography. Supplemental funds will allow the continuation of this work on several fronts, and will enable our team to combine the power of HRCT and neutron radiography, which will allow us to visualize root shrinkage and recovery from drought and specific locations of uptake along the length of these woody roots. During the funding period, personnel will also conduct trial runs to test whether HRCT is a viable technique for studying root pests/pathogens in live, intact plants. Target patho-systems could include: root knot and lesion nematodes, trunk canker pathogens, Agrobacterium and Phytophthora. This will build off our efforts with Dr. Baumgartner on trunk canker pathogens and efforts to visualize nematodes inside purple nutsedge tubers.