SBR ID training

Diagnosticians

March 4^th, 2005

SPDN/NEPDN: 850-413-9245 1-5 pm Led by John McKemy, Carrie Harmon

Participants:

Clarissa Balbalian - MS, Jason Brock - GA, Rich Annaker, John Bowers, MD Maryland Dept of Ag;. Julie Beale; Mary Ann Hansen, Elizabeth Bush VA; Steve Vann AR; Sandra-Cornell, John Baneicki, WV; Nancy Gregory U. Delaware; John McKemy (APHIS); Richard Cullen, Richard Buckly-Rutgers; Paul Bachi and Don Hershman – U of K.; Rodney Waltbram WV; Meg Williamson; Jackie Mullen - AL; Rob Wick – Umass;

GPDN/NCPDN: 850-410-0967 2-4 pm Led by Carrie Harmon

Participants:

Gary Franc, WY. Needs a slide.

WPDN/all others: 850-921-6623 3-5 pm Led by Carrie Harmon

Participants: Tom Creswell, Larry Barnes, Natalie Goldberg, Ron Ykema AZ, Julie Jenkens UT, Shouhua Wabg - NV Dept of AG, Idaho dept of ag.

John McKemy: Looking at the slide, and the sheet that accompanied the slide. If you don’t have a slide, then the following link will be of use:

http://nt.ars-grin.gov/taxadescriptions/factsheets/index.cfm?thisapp=Phakopsorapachyrhizi If you click on the images, they link to larger images. John will lead us through the last 6 images. The last 4 images are urediniospores. Most folks received the slides and looked at them prior to the call.

Questions:

What do the paraphyses look like? An image of the paraphyses can be found on the page at the above link, the 5^th image from the bottom. They look similar to immature Puccinia teliospores. The presence of paraphyses, plus hyaline urediniospores, distinguish this as Phakopsora.

Urediniospores (last 4 images on the above website are urediniospores) are usually hyaline (colorless), but can range to brown or dark brown on kudzu.

How do these differ from other rusts? The 6^th image down is the underside of a soybean leaf. The rust pustules don’t look like regular pustules. These look like the openings of volcanoes. The morphology on soybeans and kudzu are much the same, even if the spores are a little darker. Images of the rust on other legumes may be available on the above website soon. The two species of Phakopsora look the same (except for teliospores, which are rarely seen).

Are there other rusts on soybeans? Not that John is aware of.

Are there tests on cowpeas, etc (other hosts)? Probably, but this is not known to John.

This can look like bacterial leaf spot. You will often get bacterial streaming with those.

Early lesions in a moist chamber can sporulate in a day or two. Even if you don’t see sporulation, you can use a moist chamber to induce it in a short amount of time.

From Paul: Tadashi Yorinori said 5 days post infection you can see flecks, then 10 days for sporulation.

What power handlens should be used? 15-20X. And experience matters.

John McKemy’s number: 301-504-5280 for further questions.

SPDN presentation is at http://spdn.ifas.ufl.edu/Identifying_Asian_Soybean_Rust_3-4-05%203MB.pps

This presentation covers macroscopic and micropic identification hints. Lots of photos from Brazil and Florida. The slides progress from field photos to microscopic images.

Carrie Lapaire Harmon 352-392-3631 xt 254 1453 Fifield Hall Department of Plant Pathology Gainesville FL 32611