College of Agriculture & Natural Resources Department of Horticulture

Horticulture MS student, Kaz Christian, was one of ten MSU students chosen to present her research (on Malus coronaria / Sweet Crabapple), at the recent Ignite Talks MSU. The chosen students gave 5-minute presentations (one big idea, in 20 or fewer slides that auto-advance every 15 seconds!) on a variety of topics related to their research projects and experiences here at MSU.  Kaz’s topic explored the status of a wild relative of commercial apples, which is native to Michigan but endangered.

Video

https://youtu.be/i7sPlwI8als?t=1628

Transcript

Thank you all for being here today. My name is Kaz Christian, and I will be presenting on the struggles of our native apple and state flower: Sweet Crabapple or Malus coronaria which, I admit, is a mouthful so let's affectionately call our apple Sweety for this presentation. To begin I want to touch on the importance of the apple industry in Michigan. First Michigan produces the second most apples in the US, for growers they bring in 430 million dollars and represent 71% of all fruit income in the state.  This industry provides jobs to around 850 family ran apple orchards. To start the discussion of Sweety, I thought I would share some fun facts with you all. It is 1 of 4 native apples in all of North America, it attained the name Sweet Crabapple due to the rose scent of its flowers, and Sweety specifically is our official state flower. Sweety also has the potential to serve an important role to the industry as well. Sweety has a very long shelf life and resilience. As well, its bloom time is a lot later than commercial and other apples meaning it avoids the Spring frost, which can be fiscally devastating to farmers. For example, in 2023 farmers in New York lost on average 20% of their apple crop to an especially bad early frost, with some losing 95%. As well, resilience helps to prevent spoilage before and after storage which can save money for growers. However, we strongly believe that Sweety is in decline. Right now, this is through anecdotal evidence like the lack of saplings and new tree growth, but also in how difficult it has been even locating the trees. Still, we need hard evidence, and so we have some goals we are working towards. These goals, which I will deep dive more into in the next slides, include donating seed to science through the USDA, seeing if hybridization is occurring with these trees, and noting how much habitat loss they’ve faced and how that is affecting Sweety’s populations. To begin we will focus on the USDA which funds our research. The USDA has an apple collection of 6,079 accessions. These apples are available to not just people in academia like a lot of us, but also to producers and scientists around the world for their work. We will be giving them the seeds we gather to keep in Geneva. A lot of the records we have found when analyzed on Google Earth have led to parking lots, farmer’s fields, or roads indicating that the tree has since been destroyed through human development. Before discussing our next theory, hybridization, I thought it would be useful to explain the genetics. So, let's talk about apple babies! Humans have pairs of chromosomes, but plants don’t like to be normal. Their chromosomes can come in sets of three or four, or even more. For Sweety it is most commonly triploid or tetraploid. Sterility in plants can arise when chromosome mismatch happens during breeding. So, if our crabapple is getting it on with other apples in its environment this could be problematic if they aren’t compatible. Feral apples for example are escaped apples from commercial farms that have made their homes in the same forests as our native apple and are potentially making baby apples with them. The first step to testing any of this is finding the trees. We use three methods to locate Sweety in the wild: We look at plant libraries called herbaria, we use crowdsourcing websites like iNaturalist, and we go out into natural spaces and look the ol’ fashioned way with our eyeballs. These plant libraries in addition to physical samples often have location data like coordinates and habitat to help people find the plant again if needed. However, these records are often older, with most herbaria samples being before 1950. Meaning that for us the tree we need is most likely dead. Now before we get into crowdsourcing, I thought it might be useful for you all to see what Sweety looks like in the wild; They have small green fruit, their leaves are sort of triangle shaped with lobing and spiky edges, their bark has long thorns, and their flowers are pinkish. Now keeping what I just said in mind, here are actual iNaturalist submissions by the public claiming to be Sweety. These submissions are all misidentified: They have red fruit, leaves have no lobes, etcetera. This type of submission is very common. Only about 12% of Sweeties are successfully ID’ed on iNaturalist. If any of you wanted to try and make that statistic a little less bleak, I thought it might be cool to tell you how to find this illusive apple yourselves. They are best to find at the beginning of spring, as they leaf out early; they prefer to be on the edges of deciduous forests; and lastly, they, like the introvert in us all, prefer to be in undisturbed areas. For our own hunting, we try to stick to National Forest land. This is because the USDA needs the trees to be available for future collecting. I included a map of National forests in Michigan to better show where we can look. Now with this info, you may be wondering what have we found? Here is a map showing the locations of trees so far in the state: Red are areas already collected from, green are trees found through exploration, the teal are places we have not yet confirmed a tree, blue are confirmed but not collected, and purple are places no tree was found. Let’s do a quick summary to wind down: Herbaria records are often too old, crowdsourcing data is often unreliable, and for exploration larger groups are essential for finding the tree. This takes me to my last point, which is the need for more reliable help! You all are now better equipped, if you so wish, to help actual research by going out and becoming tree finders yourselves. The first source is to submit your findings and the second is to refresh your knowledge. So, if any of you ever wanted to contribute to our science feel free to use these resources and submit your own records of this vital native tree.  Thank you!