0:02  
Jim: Hello and welcome back to Plantopia. Plantopia is the plant health podcast of the American Phytopathological Society. And I'm the host Plantopia Jim Bradeen. I'm a professor of plant pathology and associate vice president at Colorado State University. And today, we're gonna have a really fun conversation with Carrie Harmon. So Dr. Carrie Harmon is an extension specialist, and a non tenure track full professor in the Department of Plant Pathology at the University of Florida Institute of Food and Agricultural Sciences. And I might refer to that later in the show it's UF i f as Carrie earned her BS degree in Plant and Soil Sciences at the University of Massachusetts and MS degree in plant pathology at Purdue University and a PhD in plant pathology at the University of Florida. And today, Carrie holds an extension and research appointment. Here he has built a very effective extension program focused on plant problem detection and diagnoses, improving methodologies for monitoring pests, and delivering desktop diagnoses to extension agents, pest control operators and master gardeners. And later in the show, we'll explain what a desktop diagnosis is. Since 2009, Carrie has served as the director of the UF I FAS extension plant Diagnostic Center in Gainesville, with a focus on supporting the work of extension faculty, agricultural professionals and diagnostic personnel. And she writes in her CV seven ports, three climate zones and the designation as a major producer of us ornamentals and fresh produce, make the state of Florida particularly vulnerable and probable as a place of introduction of new invasive species. Carrie has brought her extension and plant disease diagnostic talents to projects in six different countries, and trained diagnosticians from more than two dozen countries carry out the leaves research well aligned with their activities in the extension plant Diagnostic Center, including investigation of new detection and diagnostic methods for important emerging or high risk plant pathogens and diseases. Her research extension and diagnostic activities are well supported by external funding from national and regional sources. And very soon Carrie and her colleagues will publish a paper in a special focus issue of phyto frontiers that is focused specifically on plant diagnostics. This article is called standards of diagnostic validation recommendations for reference collections. And we're going to talk about that particular article. In today's episode, we will also talk about the national plant diagnostic network or the NPD n of which carries extension plant diagnostic centers apart. Carrie also teaches courses at the University of Florida, including a professional internship in the plant disease clinic for graduate students, a certificate class called plant disease management, and a course on plant disease diagnostics. And you can follow Carrie on Twitter at FPlantDr.  That's Florida plant doctore. Kerry, thank you so much for joining us here on Plantopia.

3:18  
Carrie: Thank you so much for inviting me. I'm excited to be part of this. 

3:21  
Jim: Yeah, I'm excited for this conversation too. I think it's gonna be a lot of fun in reading about your professional journey. One thing that really stands out is that your academic studies like mine were entirely in the plant sciences. How did you get started in plants? And how did you end up in plant pathology in particular,

3:39  
Carrie: It was kind of a funny story. I didn't actually start out in plants. I started out pre med at the University of Massachusetts. I thought I was gonna go into surgery, I found it super exciting. I loved the technology behind it. I loved having an immediate impact on potentially on someone's health and that their family. And that's where I was headed. So I was taking all Gen Ed type courses. And partway through my freshman year actually, I witnessed a few things that during a shadowing events for surgery, and I thought wow, I don't know if I can deliver bad news. I didn't realize that I that it's not all rainbows and roses, that sometimes the outcome is not awesome. And watching a doctor go out to a family and have to deliver really not great news. My heart sank and I thought I was going to be ill and I realized I could probably not do that. While I was retooling and refiguring. I realized that for years I've been tearing out from magazines, pictures of gardens, articles on plants, and then I absolutely loved looking at plants talking about plants, growing plants. And so I switched over to Plant and Soil Sciences and thought at this point I think I want to run a garden center, and maybe landscaping company or something when I graduate and this was all during my BS. My last semester during my Bachelor's at UMass. I took Gail Schumann's course, quite frankly, she was a professor at UMass. She has moved since then. And I had an honour section with her. So myself and three other students, undergrad students got to have her time, not just in class, but then an hour with her every week, just us and got to talk about plant pathology. And it was so cool. I loved the laboratory sections. I love the conversations. I loved the stories about things like the Irish potato famine, and these massive things I never How did I not know about plant pathology before this? Since then, of course, I've talked to lots of plant pathologist and we all talk about how plant pathology is a found discipline that very few people are kids and say I want to be a plant pathologist because nobody really knows what that is. But I found it or it found me. And after I graduated with my BS, I did run a grant garden center out on Cape Cod for almost two years. And turns out what I really loved is every time a client came in, and we talked about what was going to work in their yard, what wasn't working for plants, for them, the troubleshooting and problem solving. I loved it. And so I applied to grad schools, I visited several and could have been happy at many of them. But I ended up at Purdue. It felt like home. The department was a wonderful place for me for my master's I worked in the USDA ARS serial Disease Laboratory under Dr. Larry dunkel, who is an incredible mentor. And I just, I've never looked back, I could talk about plant diagnostics and disease all day. I love it. I love figuring out how does the plant respond? How does the pathogen get there? Why does it turn into a big disease? Or what when doesn't it turn into a big disease? Why didn't it get worse? What do we do about it? How do we make sure that our food is safe that our country has what it needs for fiber and fuel now with biofuels and that it's profitable for people to maintain a farm. These are the things that keep me going. After my master's, I ended up at the University of Florida, I was hired in actually to help direct the southern plant diagnostic network, which is the southeast portion of this big national diagnostic network as it was just starting up. And I did that for several years. And Dr. Jeff Jones, who's a bacteriologist in this department, was often asking me, why wasn't I just gonna go ahead and do my PhD and why I'm working constantly, I love what I do. Why don't really I don't have the time right now. And then I was asked in 2009, to start directing the plant Diagnostic Clinic at the time, it was just called the clinic. And it was just the clinical aspect, which is where we run plant samples for people figure out what's going on with their plants and what tell them what they can do about it, to manage the plant problem. And Jeff said, again, you really ought to have your PhD. Why don't you start, I'll be your advisor, if you want, I'll work with you, you can do it a little at a time. And the University of Florida has got a great program called the employee education program or eat, which at times, that's exactly what I was saying is I got waist deep in this eat, what have I got myself into. So it took me a few years, it took me four years after having a master's already to get my PhD done. Thanks to Jeff being a great mentor, and willing to let me really work on the things that were relevant to my job as the director of the plant diagnostics Center, which I was still building at the time building on these other pieces and training and education that made it more than just a clinic. And then I did, I made it, it wasn't it was a lot of work. But because I was working in something I love apparently that academic maturity over time of refining what it is I wanted to do, made the PhD possible. And I've been doing that ever since it has not changed my job per se, because I'm still the director of the plant diagnostics center. I still interact with grad students and mentor them. I have plenty of my own now which I would not have had any probably upper level grad students as a Masters even though I was part of the graduate faculty already because Dr. plant medicine students often asked me to be on because of my my diagnostic chops, I guess. So I kind of had a roundabout route. I didn't go full academics. I've been out in the field. I've been in USDA, and it all still comes back to why isn't the plant growing? Well, let's figure that out that troubleshooting piece. It's still all about what I do on the side, back as a grad student and As an undergrad, I like working on cars. I, you know, broke students drive a beater car, you got to be able to fix it. And I liked doing that. Well, now, I don't have beater cars anymore. I'm very fortunate to have a car that's dependable. But I still love knowing how stuff works. What do you do when it breaks? How do you fix it, and Plant Pathology and plant diagnostics specifically continues to support that piece of my personality.

10:28  
Jim: Wow, that's, that's incredible. And you clearly are passionate about what you do, very excited to, to have you in the field of plant pathology, I can see that the breadth of experience that you've had, as a professional really has helped you hone your skill set and, and brought you to this point in time, which is really exciting. It also strikes me that your initial passion, early in your academic career, your plans to, to pursue medical medical studies, really to change lives that, that passion. And I think you've been the diagnostic approach clearly translates well to what you're doing today. So thank you so much for sharing that story is super inspiring. And you've mentioned diagnostics and clearly very passionate and very impactful in diagnostics. When I was reading your introduction at the top of the show, I mentioned desktop diagnoses. What is a desktop diagnosis?

11:32  
Carrie: Thanks for asking that. It's a term I've kind of developed with my program here as a way to bring diagnosis to the field. I can't be everywhere, no diagnostician can, we don't even have enough extension specialists to always get out to the field, and really some of triage, so maybe I should back up. Let's talk about what diagnostics is. So that I can it also helps to connect that early desire to be in medicine, with my current sort of being in plant medicine. And and that troubleshooting the How does it work piece. So a diagnostic lab plant diagnostic lab, there's one in every state at least one. And all the land grant universities, those are your big flagship agriculturally focused universities and every state, they've all got one. Some of them are little, basically built into a couple of closets or a single room. Some of them are like mine, pretty big, quite substantial impact on the whole state. And in fact, our state actually has multiple diagnostic labs. The diagnostic aspect is still the same. It's about figuring out what the plant problem is. So if you're more familiar with the human and most of us would be right being humans, we're familiar with either going to an emergency room, hopefully you're not real familiar with that, or walking into a doctor's office. And that first thing you need to do is explain what's going on what brought you there. We do that too. And that process is called triage. It's, what's the problem? In that triage process is also developing a hypothesis, a big word that just means, what's the problem? What do I think the problem is, so that I can explore and get to the root of the issue? We do that too, here. So right now we're the emergency room, and doctor's office for plant health. That's what a diagnostic lab a plant diagnostic lab is. But we have a second piece that most doctors offices don't. And that is we've got the lab piece. So not only like in an emergency room or a hospital where the doctor orders tests. To investigate that hypothesis. We ordered the test tube, but we also do the tests. So our diagnosticians, unlike a medical practitioner really have to understand what the test is, how to do it, how to build the pieces of it, and how to interpret it. In the medical field, there's just so much that being a good diagnostician is kind of hard as a medical practitioner, even though in medicine, there's only one host humans, whereas in the plant field, we've got 1000s of hosts all kinds of different plants that could be affected by hundreds of 1000s of different organisms. So the diagnostic side, we've got to be able to do the tests, decide which test to run because we can't afford to do every test. That is another difference between human medicine and plant medicine. And that is that a single plant sample may represent hundreds of 1000s, or even millions of dollars in plants, or it might represent a $40 investment at all, or homeowners yard. And so we can't run 1000s of dollars in tests just to come up with what it is. We really have to narrow things down and use the most applicable test to get to the answer that we need. That will actually create some kind of management some kind of prescription for the client to do. And so in that way, we're also like the doctor in that we write a prescription. The only piece we're not is the pharmacy. Our labs don't tell you exactly what to apply. We tell you what the possibilities are, that would be effective. And so we're making some of those, we're interpreting that medical side for plants. So desktop diagnosis, takes the lab out of this, and allows me to talk to those in the field about how can you narrow it down? How do you develop some kind of hypothesis and narrow it down, to be able to take some kind of initial management or know that you're going to have to send a sample to the lab, it's a way for me to bring cost effective decision management skills to the field. Because I can't be there to advise them in person, by the day just don't have enough of me. And cloning technology is not quite there yet. Right? So this allows, the way that I teach it is, first you have to decide if it's biotic or abiotic. Is it something from the environment or frankly, what we humans did, which is, you know, kind of biotic. It's a living thing. But that's not what we mean. Or is it an insect, a disease? A nematode, something like that. So that's the first step recognizing symptom patterns, what does it look like in the field or in the landscape or on the golf course? So that you can decide did it happen overnight, and it's affecting all the plants, so it's probably a biotic or environmental like, a freeze, or a lightning strike. Or an improperly though this is rare, and improperly applied chemical, something applied, and it was too hot, and it burned to the plant something like that. And then we because I'm a disease person, I think about all right, how about now we have to decide you've decided it's biotic because only affecting one type of plant and that happened over time, fine. Is it a bug? Or is it a disease? And we go through? How would you sort of what can you use like a Hanlon, so a magnifier, because you don't have a lab, what's the next tool you can use to make that next decision. And at that point, just being able to decide if it's bug or insect, they can make some initial management decisions, which may just be it's not a disease, or it's not a pathogen, I don't have to apply an insecticide, I might end up with a fungicide. When we get down to whether it's fungal, viral, or bacterial. So we've decided it's probably a disease, but it's not an insect, or we don't know which disease, that's when they might need to call my lab, at least send me pictures. And that's when people say digital diagnosis. That's that piece that's sending me pictures by text or by Twitter, or on our Facebook page or through email, and saying, Hey, this is what's going on. Here's the background on watering and what we've done recently, here's how fast it developed. And here's what it looks like. What is your hypothesis? Do you think I need to send you a sample, what I'm trying to do with desktop diagnosis is get them to the point where they don't have to send me a sample every time they can make initial management decisions that are maintain profitability for the business, reduce exposure. So they're not applying chemicals when they don't need to, like they've decided it's a fungus. So there's no insecticide application needed. So it's good, putting them more in the driver's seat, and enabling them to make good management decisions. That's desktop diagnosis. And desktop diagnosis doesn't necessarily always happen in the office of the pest control operator, or, or, you know, the nursery manager, it might be in their truck. It might be in their office, it might be in the greenhouse, but desktop was a way for me to, to indicate that it was not lab based.

18:30  
Jim: Yeah, so that really provides an amplification of your abilities and impact across the state. That's, that's exciting. You mentioned a moment ago that diagnosticians need really broad skill sets. Could you elaborate on some of the the methodologies that are used in diagnostics?

18:49  
Carrie: Well, it's always changing, just like human medicine? That's a great question. Because we're always trying, especially with the National plant diagnostic network, this project to support plant diagnostics across the country. We're always looking at how do we ensure proficiency. So that means make sure people are good at what they do. And support that development, so that we're staying on the cutting edge, but maybe not the bleeding edge of, of our technology, what tools are appropriate for use in plant health? What tools are appropriate for an individual lab and their clients? Those are the decisions that get made in part with the institution where the diagnostic lab is, but on the whole, we're using within the national plant diagnostic network. And in my own program, we use a combination of in person traditional hands on like workshops, to train people in new methods, but also we're doing something with a learning management system. And if anything, we can say there's anything positive that came out of the COVID times it was that we all had to pivot right to some kind of digital way. To deliver and receive information. So in the national plant diagnostic network, I'm going to call it the NPD. N from now on, even though I don't like acronyms, but NPD n is a lot easier to say, within the NPD. And we've invested in a system called a learning management system, a big phrase, that just means an electronic place where we can all gather sort of like an online institution for teaching and training. And in that we're putting, sort of downloading all the good mechanisms for testing that we know is diagnosticians so that we can share it more broadly. It's also a way for diagnosticians to check in with each other and say, what's working for you, I'm looking at, I need to get better about viruses and virus detection, because for some reason, we seem to be getting more virus issues and the samples coming in. That's when a diagnostician wants to be able to reach out to others and say, Well, what tools are you using that I have the capacity in my institution in my lab to adopt, because we can't all be experts in anything and everything kind of like in human medicine, right, you don't go to the same doctor for a foot problem, a bone problem and a brain problem, you don't go to the same doctor, if you're pregnant, that you would go to if you're having a skin issue, we have some specialization in plant pathology, as well. And the tests that we use are kind of based around the organisms we need to detect. And frankly, in plant medicine, we can't do everything, either any more than we can with human medicine. So within NPD, and we're looking at ways to support those labs that have developed some specific expertise or have an industry or client group focus, and advertise or promote and support their specialization in that thing. So that we don't all have to be experts in everything. But we'll all know who's got that expertise when we need it, or when we want to learn it. So there are two mechanisms we're using to make sure that diagnosticians can communicate about these things, and also that our industry and other clients like APHIS, know, when who's got the expertise when they need it. So say during a disease emergency and brand new thing has been detected, and it's got major impact implications, or there's an industry that needs suddenly needs a new kind of testing them. This is a big issue right now and say, seed health testing, viruses that are moving around in this seed trade and to support safe trade and seed and profitability for our growers. We need to have mechanisms for detecting and preventing the movement of certain things. One of the ways we're supporting the decision making process, or what test to use, or what test to adopt or learn about is part of our partnership with the diagnostic assay validation network. Another acronym, we're going to call it the DAV, and this is another like NPN, USDA funded project. So that means we're supported with grant money to do a specific thing and a certain amount of time. The DA, bn is brand new. And one of the big outputs of that is going to be a tool, a dashboard that supports registries or like libraries, experts, which labs can run, which tests the methods that those labs run? And for the diagnostic assay validation. The big piece here is, how validated is it? What types of validation? How do we know that we can trust the results of those tests? diagnosticians, we need this so much, but many of the research papers that are produced with a, with a an eye to making it that method or a diagnostic use method, don't include those pieces. So we don't necessarily always know how sensitive it is, how specific it is. And really importantly, what do we do for positive controls so that we know if we get a positive, it's a true positive. Or if we get a negative with our test, we can trust that the organism is not there. Those two things, real positives, real negatives. And the trust in those results, is why the NPD n is always looking at making sure we're encouraging our diagnosticians to be aware of and accurately and we use Well, the tests available to us. And the DA VN is the piece that we've been missing that we don't within NPD and we just don't have the resources to be able to do all of that. Hopefully, the DAV n will get a nice mix of acronyms. But we'll also have the support for the knowledge and the decision making that we need to apply the best method for the specific situation, whether it's one plant in a in one homeowner yard, or it represents millions of dollars in a new ornamental.

24:56  
Jim: That's great. There's a lot I want to know about in PDN, but one Question I want to ask before we get there is what advice you have for students who are interested in diagnostics and plant diagnostics in particular, sounds as though the University of Florida has specific courses that students may enroll in, what options exist at other institutions or nationwide?

25:20  
Carrie: I really glad you brought this up. Because I really feel strongly that we need to be supporting not only the development of the next generation of scientists, although that's really at its core, but also mentoring our early career scientists and our students to find their niche. When I when we started talking, you know, we were, I was describing kind of how weird my path was to get to where I am. We need to make plant science and diagnostics in general, more widely known, because, in the end, the application of those sciences is wider than just plant health. I have had several grad students and undergrads come through my program, and get training in my lab, not as grad students. But as hourly workers, just working in the diagnostic lab, and getting some feel for the methods we use the research we do. And the process of diagnostics, I keep going back to the medical side, because several of my students have taken their training and diagnostics, and gone on to med school. And that's where they're finding success now. So they've reversed what I did, right, I started on the med track and went plant, they started in plant and went Med and the process of diagnostics. It's really just a process of troubleshooting. And it applies to almost any science. So I like the idea that we can use plant sciences, to encourage science, to encourage students in whatever direction is going to be a good fit for them, giving them the chance to play with these tools that they're going to use in almost any science and get to do it with samples potentially in a lab like mine, or any of the other diagnostic labs be able to try those out in a pretty low risk situation, right. They're not dealing with human pathogens, they're dealing with plant pathogens. The other thing is, there are courses at almost every land grant university that's got a plant science program of some sort. Through singular focus plant pathology departments, there are fewer and fewer of those, they're merging with say entomology or plant sciences in general, it's still fine, it's still plant science, we're still supporting the science. But at the University of Florida, we've got a couple of things that maybe make it special if I could promote, you know, just what we do here because I know it so well, not because it's the only place there are lots of land grant universities with really good plant pathology programs. So I would say if someone is interested, they think in plant sciences or diagnostics for anything, animal or human medicine, try out the plant science and the plant diagnostic courses. At an undergrad level, you're looking at an introductory plant pathology course and lots of our plant pathology departments across the country also have some really broad based like plants, plagues and people where we talk about plant diseases, their impact on human life, things like the Irish potato famine, and how I plant disease made a really big impact on human movement, emigration, and human health. We also at the University of Florida have a few specific courses. So obviously my diagnostics course, there are a few institutions across the country that have diagnostics, specific courses. Mine is online only as a build up to the internship course, which is hands on only some plant pathology departments have a plant diagnostics course that is both lecture and lab. So you get to do the techniques and learn about them at the same time, like a traditional lab course. And then u f has one other thing and that is the doctor of plant medicine program. There are two of these in the country. The other one is Dr. Plant Health at Nebraska. And these are broad based professional degrees, their doctoral level, but no research. They're applied. So these are practitioners sort of like if you were to go to school for an MD or dentistry degree, it's a practitioner degree. So they are trained in Weed Science, soil science, Plant Pathology, entomology and nematology. So that they can go into regulatory plant pathology or scouting crops for any pest and plant problem or running a production facility. They have a really broad application. What they don't have in that one is a research component because they have to take so many courses and they have so many internships. The room for research isn't there. So if you really want to do research You're looking at a masters or a PhD program, which is going to focus you on research, and building new tools and finding out new things about how plants and pathogens interact. So I'd say at the grad level, undergrad level, so many options for getting a taste for a deep dive.

30:18  
Jim: Exciting, it's fun to think of all the opportunities that are out there. Now, you you've mentioned the national plant diagnostic network, or NPD, n. And it sounds as though that's a very important asset to support plant disease clinics or plant diagnostic clinics across the nation. I'd like to take a step back and ask you what is an PDN? And where did this thing come from?

30:46  
Carrie: Thanks, I should have started there, right as soon as I dropped that acronym. So the national plant diagnostic network is built by connecting diagnostic labs like mine all across the country. It started in 2002, as the USDA, what's now NIFA used to be called CS Reese, which is the research education and extension component of the USDA. So federal program, set money aside to build the national plant diagnostic network in response to a recognition that not only was our whole infrastructure, so this is after 9/11. Not only did we have big risks, kind of on transportation and all over, but also agriculture could be at risk. So then, then PDN was built to help put eyes out everywhere and preparedness. Sort of like connecting all the human hospitals or all the vet hospitals, making sure that people are trained to look for things that are new, and know what to do if they detect something that might be a new problem or becoming a new problem. So it's a really an infrastructure grant project. So the NPN is supported through what are called cooperative agreements. What that is, is it's a four or five year, it's a multi year agreement between USDA, all these institutions all across the country, all these universities and a couple of state departments of ag. To do this thing, we have a very specific set of tasks. And one of those is really readiness. How do you be prepared for everything that could be unknown. So it's, it's sort of just as we need hospitals and human clinics to always be staffed with good doctors have the equipment they need. Ambulances know how to get there, and people know how to call them and know where their hospital and their clinics are, right? The end. PDN is the plant version of that. It's built on the extension system, which has been around since the 1800s. And it's, it's still supporting moving knowledge from the government and from academics or universities, to where it needs to be used for the benefit of citizens. And so it's just connecting those labs up so they don't have to work by themselves. They now have a support network that helps to build that infrastructure, continue it and keep us abreast of new, say, new pathogens that we need to be on the lookout for or new methods to detect the things that are already here. How do we keep an eye on what's going on? Well, you've got to have a national network to do that. And USDA for 20 years now has been recognizing that the NPN needs to continue to exist. Serving and continuing plant health expertise one sample at a time or surge during an a plant emergency at a time. It's sort of like USDA funding is providing the national insurance policy, keeping the practitioners at the ready, just like insurance and Medicare and Medicaid help to keep hospitals open and doctors offices always ready when you need them.

34:02  
Jim: It's really well said I've been in positions of leadership now at two different institutions and have worked really closely with colleagues in plant disease clinics or playing diagnostic clinics. And I really do think that the clinics, certainly the practitioners, and the NPD network is sort of an unsung hero in agriculture plays a very, very important role in helping us respond to plant health challenges. And I understand that you have been part of a team that has organized a special issue of the journal. This relates to DAG, plastics. So tell us a bit more about what we can see in vital frontiers.

34:44  
Carrie: I am so excited to talk about this phyto frontiers issue. So Fido frontiers in itself is a very different kind of journal. I'm excited about it because it encourages open access publishing, which means the articles are for any One to read, you don't have to be part of a university, you don't even have to be part of the US you can anyone can read it. And that open access open science is a, that's a big part of making sure that what we're doing, anybody can use. And I think that's really important for supporting our Agricultural Safety, and Plant Health. This special focus issue has been more than a year in the making. And I am so excited one, because it was a tremendous amount of work. We had dozens of articles submitted each one of those needed to be reviewed, or the science recommendations made to make sure that the writing is nice and clear. And it's related to diagnostics. And to assay validation. What that means is sort of back to what I was talking about earlier about being able to trust the results of our tests. So this new focus issue is sort of like when you get a like a big double issue, a special issue of a magazine that you love and go to for resources. That's what this is going to be it's a it's a pretty packed, focused issue. The reason it's called a focus issue is because it's not just a monthly or regular collection of whatever articles were submitted in that month. It's focused completely around diagnostics and assay validation. So I'm, I was super excited, I was on this team of CO editors, with a couple of other great professionals that are also helping to build the diagnostic assay validation network. We have six perspective articles, where we sort of lay out what are the aspects of assay validation? Why are they important? What's the point? You know, bring this really bring it home? To what what do I? Why do I need to know about this? Who cares? We have six perspectives on that. And one of those is one of the articles that you mentioned, which is recommendations for reference collections. So that when we're thinking about collections, and by collections, for those who are not really deep in plant pathology, we as scientists who work on plant pathogens often end up with cultures or pieces of these organisms that we've pulled out of the plants. And we've identified and now we know what it is, well, we collect those. So that we not like having, you know, salt shakers from every state, but kind of like that idea of a hobby. But this is to support our science, knowing what organisms are out there. And being able to define them well, allows us to develop methods that other people can use to also define those things when they find them in the plant samples that they end up with. That's what the diagnostic assays do. And that's why reference collections are so important, just for diagnostics, but in on the greater whole reference collections of all kinds are one super important for our science in general, it's a way for us to make sure that we have a record of what is out there. And who knows how to identify it. It's a it's for breeders to use so that they can create plants, that and breed for plants that are resistant to these diseases, or that grow well in a new place. So that we can continue to feed the future. These collections are in jeopardy everywhere, all around the world. Because as researchers retire or change jobs, there's nobody necessarily who can caretake that collection anymore. It's kind of like, you know, when your grandmother downsizes. And who's going to take on that salt and pepper collection? Well, you kind of got to find a home for it. The other reason is is maintaining these collections is not easy. Some of these organisms don't like to live in a petri dish, or can't live in a petri dish. And so you have to maintain it in plant tissue that requires really weird freezing or specialized storage, kind of like during COVID. Lots of samples were being stored at super cold freezers, well in the plant labs, we use those to and lots of other methods. So we're looking in the diagnostic assay validation network and the specific focus issue and article that you mentioned. We're looking at how do we across the N PDN, the APS colleagues, and even internationally, how can we make sure that when we have records of a collection, we we know what's in there, and how important it is so that people can use it for these other purposes like breeding and diagnostics. We can catalog where they are, and which ones are in jeopardy so that we can find resources to support them and transfer them and keep them. That's a being able to do that we've all got to speak the same language like we have. We need a catalogue of them. The US culture collection network is doing this as well, but they're doing it for way more than just That pathogens. So the standards that we're talking about are what can we add for little pieces of information about those culture collections to allow us to reference those specific for plant diagnostics?

40:13  
Jim: Yeah. So reference collection really is a tool for plant diagnostics, and really captures the genetic diversity of pathogen populations, right. So, so plant pathogen similar to you mentioned COVID. Of course, we're all very well aware that the virus that causes COVID has different strains, different versions of that, that's true to plant pathogens as well. So those reference collections really capture that broad diversity. And while we're looking forward to reading that paper, I should mention the title of that papers, standards of diagnostic validation recommendations for reference collections. It is already available on a first look that that is part of the bio frontiers journal and will be featured in this upcoming April focused issues. So we'll make sure there's a link to that, on the plan topia podcast at work landing page for this episode, too. So Carrie, thank you so much for your time and enthusiasm here. Do you have any parting comments for the listeners of plant topia?

41:19  
Carrie: Thanks so much for having me today. I really love to talk about plant diagnostics. And I would say for anybody listening to this podcast, that you can reach out to your plant clinic, or your plant pathology department and your local plant scientists because they're always excited just like I am to talk about what we do and how it can benefit you.

41:39  
Jim: Very, very well said and again, thank you for being on the show. We just heard from Dr. Carrie Harmon, and extension specialist and non-tenure track full professor at the University of Florida. And this has been another episode of the plan to be a Podcast, the podcast of the American Phytopathological Society. I'm your host, Jim Bradeen. Thanks so much for listening, and we'll talk soon

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