 Welcome everyone to this week's hater talk. This is another great week where we have the opportunity to hear and learn another distinguished and good researcher that we can work with and so this week we have Dr. Gary Seacour from IndieSU and as you can see at the slide here showing up that he's going to talk about what we know about Dickie so far. We've been working on this for a number of years and look forward to his presentation. And so don't forget, if you have questions, there's a Q&A box at the bottom you can type your answer into or your question into and you can answer it. When he gets done with his presentation and you may also raise your hand and let us know if you want to talk and we can allow you to talk. So whichever works best for you, feel free or there's also the chat box to that you can even send him, you know, send questions into. Anyway, without further ado, let's go ahead and get this week's hater talk started and take away Gary. Good morning, everyone. I like Andy's comment. Maybe we should do something a little different today. You guys stop in the type in the question or the answer, and I'll try to guess the question. There used to be a show like that on TV. But anyway, good morning. I'm happy to be distinguished. Thank you for that Andy. So I'm going to talk about kind of what we know about Dickie so far just give an update of of our project on Dickie. So I'll start with a little history and then go through some of the findings we've got and then have time for questions at the end, I hope. So thanks for attending. In 2017, the USDA and if I awarded our group two and a half million dollars to look at management of soft trot and black leg of potatoes. The title of it is that integrating next generation technologies for black leg and soft trot management in the USA. And the main driver of this, this grant that we received was because there was a widespread outbreak of Dickie causing some field losses of table and chipping potatoes, particularly in the eastern US that's where the disease first started and that's where the most of the most serious losses were and where it was the most frequent, all up and down forward all the way from Maine down to Florida really and it was causing losses in stand because of seed decay and black leg from some of those seed pieces that decayed, not completely resulting in black leg and of course the plants died later. The pathogen that was causing this, this stand and black leg loss was Dickie dienthiccola. And that was that pathogen is new to the US. It used to be called Erwinia chrysanthemum I was very uncommon. It's been here for about 20 years. They changed the name to Dickie dienthiccola. That pathogen was new to the US and increased in the incidents and the seriousness of, of soft trot and black leg in the US. This proposal and this project was widely supported by growers by industry and by other stakeholders. We received four years of funding year four ends in October of this year. We have an option to do a one year extension, which we probably will do, because there's obviously some unfinished projects, main objectives, improve detection identification, using some molecular technology, epidemiology and spread. We also have a range of systems using omics like genomics and proteomics and metal omics metabolomics and screening for host resistance and of course management is a main key factor and what's the impact of economic development, the economic impact of decay infection on potato fields. These are myself Amy Charkowski in Colorado, Jay Howe and main and Chris McIntosh in Idaho. We have 10 additional scientists that you can see here throughout the US that are involved in this project as research scientists I don't need to, you can read those I don't need to see their names are to say their names. And then we have an advisory board from farms commodity groups and industry. Again, you can see their names here. Some of them like Don Sklarzake is semi retired John Norgaard is retired. The other is semi retired. So some of the people are in transition for our advisory board, but suffice it to say we've got a pretty good advisory board for this project as well. One of the things, one of the principle foci of this project is detection of the bacteria in seed lots or detection of infected seed lots, because Dickie and Pecto are both seed borne diseases they're not soil borne diseases they're poor competitors. They do not have any endos spores for long term survival. So the main sorts of infection is infected. Or a post harvest test is necessary to detect Dickie in the seed, because Dick well late in the season, Dickie infection is usually early in the season with stand losses and early season black leg, and it does not cause much soft rot decay in harvested potatoes. So we in order to. So the inspectors can't see doesn't cause decay and storage so we have to test the seed lots to determine which seed lots at Dickie which do not. So part of this is development of a seed lot testing. So our scientific community has developed a protocol to detect Dickie and seed. This is kind of we have to use a PCR test. We recommend stem end cores in groups of 25 per sample so 16 groups of 25 stem end cores that's 400 samples. Plus, we know that Dickie is also in the lentils. So we collect 25 peel samples per sample as well. And the peels are one to two inches long north to south as nor guard says. And then we, we smash those samples or test those samples, the peels and stem end cores together. And we use PCR tests using either pill ad primers or DFDR primers for Dickie. And then we can sequence a PCR product to identify the particular species of Dickie at the present, but the primary one is dying tickle that's that's the primary target that we're after. Amy Tarkowski is the source of reference isolates for our testing. We've done some multi lab testing of DNA. And we know that we have about a 98.6% accuracy so that's good. We did a test in November of 2019 with inoculated mini tubers with Pecto and Dickie and both or neither. And we sent those to nine different labs as a ring test to look at the accuracy of our detection procedure. We had 100% accuracy in that day. So we're pretty confident that this seed lot testing procedure or protocol that we've developed developed actually does work pretty well. But the problem we have is we only have limited results to predict the amount of field disease, based on what we find in the seed lot testing results. That's become a very hard nut to crack and we're still working on that. We can't, we can't predict how much will be in the field, based on what we find in the seed, because the environmental factors that will impact the development of disease. So this is some data that we just put together of looking at the incidence of infection by PCR testing of 316 potato seed lots collected in the US from 2017 to 2021. And you can see across the bottom of the table or the chart is that years with testing, and on the X axis on the left hand side is the percent positive. So we're looking at the number of lots we tested in the blue is the lots, and in the gold is the samples that were tested. In 2017, for instance, we tested 67 lots 16.8% were positive. We tested 1057 samples. 5.5 were positive. And so on for each of the years and you can see that the, the number of lots that were positive range pretty much between 10 and 15% and the number of samples in those years range between about one and 5%. So that's been pretty consistent. Except I know somebody's going to ask the question, what happened in 2019, when we had 46% of the lots positive for Dickia. I think what happened is we did we first found Dickia like 2016. By the time those lots went from generation one to generation two to generation three to generation four for commercial, there was a high number of seed lots. And with continued testing, we were able to get rid of those seed lots. And now we're back to our normal low levels of seed lots. And we're still testing this year. So the results from 2021 are as of March 1 of this year. But it looks like we have a pretty, pretty good test pretty even distribution of seed lots over the over that time period from 17 to 21. So in addition to some screening, we tested one large seed lot in 2020 with 42 diverse seed lots 472 samples, zero positives. So it looks like we're making headway of getting rid of infected seed lots are diagnostic lab at NDSU has tested 94 lots. So far this year, none of them have been positive. There's kind of good news that we're making headway on using seed lot testing to eliminate infected seed lots. It does seem that Dickia as a cause of seed decay and blackleg is declining and importance, but pectobacterium continues to be important, and especially the emergence of pectobacterium parmenterii. So this appears to be a more serious cause of storage software. It seems to be pretty aggressive. It seems to be really important storage software, especially in the eastern US. Okay. So there are some practical aspects of this seed testing results. We work with a large farming operation and tested a number of samples from them using our standard procedure. 1.2% of the samples tested positive for Dickia in 2019. The range was from zero to 16 of 16 samples, 12, about half of the seed lots for free of Dickia. And in the field, the 100% sample to 16 of 16 had less than a 50% stand. So we know that the higher the infection level in a seed lot, the greater the stand up to 50%. Here's some anecdotal grower observations from that study that this group rejected a highly infected seed lots. Okay. And in general, they observed that any seed lot that has three of the 16 samples positive is considered a problem. Okay. So they will have to work with that seed lot or planted in a special location or an area where Dickia is not common. Anyway, it's considered a problem they need to deal with it. In two states have the highest incidence. One of the states was completely clean and did not have any dick at all. And that that that state was North Dakota. So you grows North Dakota the produce seed, keep going to church, you got a good deal going on we didn't find any seed lots with with Dickia from North Dakota. The two samples seem to be more related to a farm source and variety, and there is no variety specificity in other words, we don't find any resistant varieties or any differences in varieties. So not all strains of dienticola are can be detected by this general test using the primers that we have. So we've had to identify some additional tests you can see in these publications. So it identifies some dienticola lots that are not detected. So for instance, this strain that went from Wisconsin to deck, Texas, different in the strange from Maine, and it lacks the, the, the site for the DIA, DIA primer so it escapes detection. So we use this PCR assay. So we're aware of that we need to be careful that we don't get new strains it's kind of like, kind of like our friend COVID, we get new strains, they may not be be detected, like the vaccine may not work. So we do have some genetic variability, starting to show up in some of these strains of Dickia. We also want to know how Dickia spreads. We know we can inoculate Dickia by infiltration or needle puncture. We did a trial in Florida, North Dakota inoculating seed. We had significant differences in reduction of stand in Florida, but not in North Dakota and I think the environment in Florida and the moisture was much more favorable for disease than it was in North Dakota. One of the things we asked, what does the concentration of Dickia and the seed tuber impact seed decay? In other words, if there's a lot of bacteria in the seed versus a little amount of bacteria, does that impact seed decay? And this is the thesis work of Cal Larson. He inoculated seed with different, or with increasing concentrations of Dickia from 10 to the four to 10 to the nine. So 10 to the four is 10,000. And we planted those in Florida and North Dakota. We did not find a significant difference in emergent plantarite yield, tuber infection by Dickia. So we conclude that the concentration of Dickia has minimal impact on disease or growth of the potatoes. So really, concentration of Dickia does not seem to be important. But another trial, just Dickies spread in the field. And we had two trials in Florida and Oaks North Dakota. This was the thesis work of Blake Griner. We've got his master's degree here. And we inoculated seed with Dickia by vacuum infiltration. And we surrounded those by not inoculated seed that was tested and shown to be free of Dickia. So the red illustrates the planting, the red illustrates the infected seed piece, and it was surrounded on all four sides illustrated in blue of seed free of Dickia. Okay. And we let the net growth grew full season long. We did not have stand or black leg during the season, but we collected tubers from progeny tubers of each site surrounding the positive plant and tested those for PCR by tested those for Dickia by PCR. So we collected four tubers from each of the each of the plants surrounding each of these seed pieces. Okay. The infection rate by PCR was 33% in Florida and 13% in North Dakota. This is pretty comparable to a similar trial done in Netherlands by Vanderwolf that he found infection of 27%. So we know that Dickia can move from the infected seed piece to the progeny tubers in in the soil moisture. Okay. So we collected those Dickie infected tubers the next year had a 94% stand in Florida 99% stand in North Dakota. So we also know that Dickia can infect those progeny tubers without symptoms, they can be infected and not show symptoms the next year, and we assume that that bacteria is moving in the soil moisture. And that's how Dickia can spread between seed lots can infect without causing any symptoms. So the third trial we did for spread is Dickia spread by seed cutting. Okay, and my colleague Steve Johnson whose photo is here, observed that Dickia wasn't transmitted during seed potato handling and cutting. We did some trials in 1718 and 19 a plot trial and 17 by mixing Dickia inoculated seed with healthy seed, and then handled cut and planted those potatoes together but we handled and cut them together but planted them separately. That's what we observed for the amount of disease in the field. In 2017 2017 it was a plot trial in Florida. We did not see any stand loss no spread to healthy seed. The growers said, Well, that was a plot trial what happens if you do it on a commercial level. So we did a commercial trial in Florida 200 pounds of seed inoculated with diet and tickle a mixed with commercial mix with 2500 pounds of healthy seed and commercially cut. We did not see a stand loss in that healthy planted seed. But when we planted the inoculated seed we had a 90% stand loss. Okay. So we didn't have any spread there. Again, we did a replicated trial in 2019 in Florida and Maryland, mixing healthy seed and inoculated seed. No blacklegger seed decade either site. It was found by PCR testing of cores and peels from 240 progeny tubers in Maryland. Okay, so we tested the seed. We didn't see disease we didn't see spread of the bacteria into that into the project progeny into the, the cut seed during that cutting and handling. And we saw no difference in yield and grade. Now this study had just been published in the American Potato Journal, or the American Journal of Potato Research that shows old I am American Potato Journal. And it's, this has been published and it's, it's January of 2021 in the American Potato Journal, volume 9864 to 71. If you want to look at this study in greater detail. So looking at pathogen diagnostics and population structure. Okay, Brian Swingle in New York. In 2016 and 17, found that that black leg in New York was equally caused by the Anticola or Dickia and Pectobacterium. And the Dickia had very little genetic diversity, which is consistent with a recent introduction. So that shows that it might have been introduced recently. Pectobacterium are much more diverse, consistent with a long term endemic population that's been around for a long time. And they've done genome sequencing of Pectobacterium and Dickia di Anticola. So those have been we know that we know the, the genome sequence of those. And you can see he looked at one called Pectobacterium maceratum. So this is the new Pectobacterium. Okay. So he looked across in Oregon, looked at the distribution of keratovirum and Dickia in Oregon. Okay, so he found keratovirum atrocepticum parmenterii, which was not previously reported in Oregon and only a little bit of Dickia only 3% of the black leg there. So he looked at this population in Maine and showed that the population is a little bit different than the European populations. And southern states don't have the exact population as Maine. He also showed that there was an interaction between our friend di Anticola and our friend Pectobacterium parmenterii. And this severity is greater with co infection and either one alone. So there's some synergism going on between Dickia and Pectobacterium that makes disease worse. And he found that there are three clades of di Anticola in the northeastern US. And the cause of that outbreak, which we've always said has been started in Maine. Maybe is an associated with one of these new strains that was derived five form by mutation. So we still don't know whether this new Dickia came as an introduction from say Europe or it was derived or it was caused by a mutation. So we've got two lines of evidence for that, if you will. We're also screening germ clouds for resistance. We're doing traditional testing of processing varieties using tuberonoculation. And you can see that in this population from you potatoes USA that we have a lot of variability in susceptibility but we don't have resistance. But this is not a really good test to use, because Dickia is not a good Dickia is not a good tuber pathogen but Pectobacterium certainly is. And we test for both Dickia and Pectobacterium in our tests. And Susie Thompson as a graduate student and I'm helping to co-advise Eduardo Palete is looking at screening our NDSU germplasm for Dickia using pedioles, because remember, Dickia infects the plants in the field so we're using pedioles to screen for resistance for Dickia. So we're using replicated trials in the green in the new greenhouse to screen and he screen 287 genotypes to promising selections have been identified. So we are using these foam flower foam cubes and putting the pedioles in those fresh cut and measuring the amount of rot and wilt and discoloration in the leaves to screen for resistance. So it seems to be a pretty good method. On the basis of his work, we are finding some good resistance. We're also going to try screening tubers for resistance with Susie's population. Brian Swingle again in Cornell is screening us get a data gene bank bank, wild species for high levels of soft drought resistance. He's finding some resistance in Solana Microdotum. He's in, in progressing those into crossing to try to get some resistance. Adam Hoyberger at Colorado State is using some, remember I talked about omics, he's using some metabolomics to look for small molecules associated with resistant to Dickia. He's literally screen hundreds of molecules. And he's found some little molecules that for resistant wild potatoes that appeared to inhibit virulence. So these could be useful as markers for resistant for breeding for resistant potato variety. So we're making some progress there. And Melanie Philly of troll who's USDA Cornell is looking at defense response of potato plants to Dickia. And she's found in the green and you can read all of this but the green kind of summarizes that it's a class of genes called antimicrobial peptides that are hypothetically involved in resistance to soft rock pathogens. And so she's got a very basic research project. I'm looking for some of these antimicrobial pep peptide. So we get a lot of work going on a developing resistance or looking for resistance to Dickia. We're also trying to look for potential sources of Dickia. This is one of my favorite stories. There are 120 dahlia bulbs from a well known European mail order source in the Netherlands. Okay. For those tests of positive for Dickia. Okay, so I planted those at my house in Fargo, because the dahlia flowers are beautiful. And so we cultured and sequenced those. And it showed that it was Dickia chrysanthemum, which is now Dickia dionthicola. They were pathogenic to potato. Okay. There's also been reported as a sorts of Dickia in Australia, South Africa and New York. So dahlia is looked like those flower bulbs are a source of Dickia, because they can they are pathogenic to potato. And remember that Dickia is found in many ornamentals, especially in Florida, where they reuse their irrigation water, they recycle it that recycles the Dickia and Pectobacterium as well. It's also found in flower bulbs, broccoli, nettles, pineapple, and likely many more hosts. So Dickia, not only infects potatoes, but a lot of other crops as well. And those could be sources of Dickia and an oculom for potatoes. And I see how I was looked at surface water because they say is surface water a source of Dickia, because it is for Pectobacterium. So he's found Dickia aquarica. Okay, which is a new species, and Dickia Zia, and Dickia dionthicola have all been found in water and are all pathogenic to potato. You can see the testing he's done here with an oculation of tubers, and you can see the, the, the lesion size based on which species it is you can see aquarica and is is pathogenic to potatoes but we don't really know how important that is. And whether this is a source of infection for potatoes or not. So that that research is still ongoing. We've got our ag economists of course looking at the economic impact of data. We did replicated trials in four states in 2019 by planting infected seed mixed with infected and not infected seed at 05 1020% The data is done. We looked at stand black leg yielding grade and economic analysis with Chris McIntosh and Kate Fuller. Chris is at University of Idaho, Kate is at Montana State. We're repeating this trial in 2021 at four locations. Again, the most important thing is communication of soft rod black like Dickia to the industry. We've got an advisory board. We try to meet annually across this year we've had zooms, because we can't meet personally. And one of the things we hear from our advisory board is management. All that other good all the omics is good all the spread is good. How do we manage it they really want to know about management. We're trying to concentrate on management as much as we can. We used to have grower seminars live but now we've done a lot of zoom seminars and some of you have probably participated and then including this one. And Michigan State has even put out a YouTube. So here's some end thoughts that I have this kind of summarize where I think we are. Dickia is most frequently found in the eastern half of the US far less likely to be found in the Western US probably because it's drier. We do have a good standard assay for detecting Dickia and seed lots. We have a lot of seed cores and peel using a PCR test. Dickie is not spread by seed handling and cutting, at least in the trials we've done. It can spread to field by two adjacent tubers up to 33% in Florida. Dickia infection can be re remain latent and seed potato tubers, not result in disease expression after planting. This is a key issue because most of the seed is planted in cool areas where it doesn't express. So you can have infection a latent infection and seed potato tubers planted in a warm area say like Florida or Maryland, then you can get disease expression. So that's one of the take home lessons it's really important. Several labs are screening germplates of resistant to Dickia using different methods. There are all kinds of sources for Dickia as I talked about before, many that still need to be identified. And in my heart of hearts I'm still wondering where that initial infection comes because we can make many tubers free of Dickia and Pecto, where's that initial infection come from. That's really, it's a big question I really want to know. The micro-bacterium populations are changing. Our friend Parmentera is becoming more important and Dickia is declining as a disease of importance. A couple of families to talk about the Dickias and the Pecto. So I'm going to just talk about those quickly. There's one, two, three, four, five, six, seven species of Dickia so far. Dianticula is the one that's most important in the US. Aquaticus is the one found in water. This one, Fungzongdai is the first one of woody plants. So they can infect woody species as well. And of course our friend Solana, which is serious in Europe, it's pretty much disappeared. We don't have that in the US. Then there's a family called the Pectos, okay. Atroceptica, which causes black leg. KeraTauvera, which is a general soft rotter of fleshy fruits and vegetables. Bacillians, which is not too common, but also occurs in sugar beaded North Dakota, Minnesota. And here's our new friend Parmentera, which is the new series one in storage. We're finding new Pectos, driving us crazy. Here's Polaris, which is a new species found in Norway, and Maseratum, which is new that goes to cabbage and potato and Russia. And I'm sure that as the, the bacterial just get involved, we're going to find new members of both of these two families. So I will stop there. And that is the end of my presentation. And I'll be happy to answer questions.