How Mycorrhizal Fungi Improve Wheat Grain Yield in the Field

0:08 Thank you organizers for giving me the opportunity to talk about what we are doing in Noble Foundation. So today I'm going to talk about a unique fungi and how it promotes growth and so basically our model is to promote sustainable agriculture using low input or no input fertilizer and improving plant health and plant fitness.

0:43 So in first, why microbes in first place? So we all know that in our body we have hundreds and thousands of microbes and they actually help us in many ways. They help us to remain healthy, which most of the times we are not aware of. Similarly, like our body has our own microbes that help us to keep healthy, plants have their own microbes that help the plant to keep healthy. And more and more we rely on like chemical fertilizers, chemical inputs, we kind of lose these plants' natural microbes.

1:31 And as we more and more depend on medicines we kind of compromise with our natural immunity, natural defense systems to fight diseases. Similarly, plants lose these microbes with the over usage of chemicals, whether it is a fertilizer or pesticides or any forms.

2:01 So with this I begin about this unique fungi and so this unique fungi are root associated fungi and which has the ability to improve plant growth and some of you are aware that these type of associations we call as mycorr—

2:21 And this microa are two words joined together in which micos means fungi and Risa means root so basically these are root associated fungi and they helps in plant growth so this particular fungi which I'm going to talk about is unique in many aspects and one aspect is that these fungi are found kind of almost everywhere so far we have not found a place where these fungi does not exist and they have a very wide spectrum of association with plants.

3:00 So this fungi can make association with lower forms of plants higher forms of plants and even brasic AIS like you know which is traditionally known as non-micro risal so thus far we have not found any plant which has shown any kind of resistance to this a group of fungi.

3:30 We have tested this fungi with various types of crops and I put here three examples of monocots and three examples of dorts where we have seen that in greenhouse conditions and controlled plot experiments we have found that this fungi along with plants improve plant biomass in variety of levels so how a single fungi is able to colonize such a wide array of crops to understand that I present this small cartoon so basically if you look at this picture so there this is a cross-section of a root and this picture actually tells about how different types of micro risal fungi makes association with different types of plants so these are different.

4:37 These are actually fungi. These are the filaments of fungi which grows out of the roots and fetches nutrients from the soil. They can form this type of hairlike structure. They can form these type of spores, and inside the plants roots they form these type of structures where all the nutrient exchanges takes place. This can be of these type of hairlike structure and these type of dense packagings. Basically they collect nutrients from outside the roots and they transfer these nutrients inside the roots and then they move along the entire plants.

5:22 This is how it actually looks like in real situation. All these green colored things which you see, these are actually fungal structures heavily packed inside a single root cell. So this is Tall Fescue, this is Switchgrass, and this is winter wheat. And this is a single root cell. This is how they are packed inside. Basically this technique is called confocal microscopy. What we do is we take the picture of fungus with a green filter, then we take the picture of a plant root with a red filter, and we combine them together. This is how it looks like—a plant root which is packed with fungi. So basically this is the place where all the good things happen.

6:16 As you have heard from previous speakers, fungi cannot synthesize their own carbon because they are chlorophyllous. They do not have the ability to produce their carbon, while plants are photosynthetic, so they basically synthesize carbon.

6:37 The sunlight. Now why would such a relationship happen in spite of the fact that sometimes a plant will allow fungi to live inside its own body? And the reason is that both are actually getting a little bit of benefit. So in case of fungi, they are getting carbon from the plants, and in case of plants, they are getting all the macro and micronutrients from the fungi.

7:07 However, this is actually a cost-effective thing for the plants, which Kit said in his talk, that this is not free. Like plants have to pay a currency to maintain this fungi within their body. And if you add too much fertilizer, then plants do not allow or do not need this fungi to live within their body because it's simply put, like fertilizer are some kind of free food to these plants.

7:44 So fungi, when the plants get these free foods, they really don't want to work hard and they don't want any kind of this type of friends. But when you keep the fertilizer dose to a limited amount or low or no fertilizer, then they actually look out for these friends, which actually can go out into the soil and bring all these good nutrients and give it back to the plants. And in long term, this is actually a win-win situation for everybody because over the years, if you keep on adding fertilizer to the soil, you actually compromise with the soil health more and more. Fertilizer you add, you compromise with the diversity of.

8:32 Microorganisms present in the soil compromise with the soil's porosity and there is no end to it. On the contrary, if you rely on this type of good and beneficial microbes, it's kind of you are using Nature's own method to keep these plants healthy, to keep our soil healthy.

8:57 With this I talk about a case study where we have used winter wheat and we have tested how this fungi which helps plants to grow better and in field conditions.

9:19 So we all know these things like why wheat is important. Wheat provides like 20% of all calories consumed by the people worldwide and world's population is ever increasing. Basically, if we want to keep the cost of production low, we need to have a sustainable method where we can feed this ever increasing population in a more sustainable manner.

9:51 So basically we need a method which we can sustain over years. I'm not talking of 5 years, 10 years. I'm talking of much more beyond that.

10:03 Now I have told you about this beautiful fungi which can provide lot of benefits to the plants. Now we need to have a method how we can use this fungi to go to the field and inoculate crops in the field. Now there are a lot of methods available to do that. So here we tested different types of methods to how to deliver this fungi into the soil. One method we tried is we have used wheat straw and we put fungi in this wheat straw and see if it grows.

10:48 Choose wheat straw because it is cheap and it is readily available, it is easy to manipulate. And another method which we used is called root organ culture. What we do in this method actually, we grow only the roots. We call this as transformed roots. Basically these roots without any shoot, without any, they can grow in a green, in the laboratory conditions. And in this method what we add, we add this fungi—these filamentous cottony things—we add this fungi into these roots and we grow them in the laboratory conditions. And we try, then we put it back into the field.

11:33 Another method is like growing little plants in a controlled environment and adding fungi to the roots. And finally, which about which I'm going to talk about today, using these clay particles—these are basically what you commonly call as starface—so use these starface and add fungi to the surface of the starface and put the starface into the soil to deliver the fungi.

12:01 So out of all these four methods which we have tested, we found this the last one, which we the starface coated with fungi, as the most efficient one. And I will spend a little more about how we actually use this technology for mass production of this fungi for field trials.

12:25 So what we do actually, we grow fungi in bottles along with those clay particles—the picture which you have seen just in the previous slide. And once these particles are coated completely coated with fungi, we take them out.

12:46 Put it in some synthetic media in the laboratory conditions and we see the fungi are actually coming out so this is an indication that this small clay particles are actually coated with fungi and they are still alive so this is the same individual clay particle with a bigger size so this is a clay particle which does not have a fungal coating on its surface and this is a clay particle which have this fungal coating on its surface so these white cottony things which you see these are actually fungi coated on the surface and when we look deep down under an electron microscopy where we magnify it by thousand times we can see this small hairy things present all over on the surface.

13:40 Now so far in this we know that these clay particles can be coated with fungi and in this coating they are still alive and they can grow again out of these particles but how how we use this thing to actually infect a plant so what we do in our lab is actually we use these small tubes and we fill up these small tubes with these tiny particles and each of these particles are coated with fungi then we grow a plant on inside this and as this root system goes down they actually get comes in contact with this each and every individual clay particle and fungi from this clay particle enters the root system and this is how the fungi from the clay particle can enter the root and successfully colonize the plants so this is another picture to for.

16:59 In association with the tarace can actually release micro and micronutrients which will be helpful for the plants to grow. So this is an example how this fungi increases the plant health. So this is wheat, winter wheat in these small tubes which I have shown you before, and look at the root length in presence of fungi and in absence of fungi. So this is how this unique fungi helps. They actually accelerates the plant's growth in a much shorter time. So they produces bigger roots which helps in greater nutrition acquisition, greater water use efficiency, and this is how it helps the plants to grow.

18:00 So now when you took this small piece of root and look under the microscope you can see all those green things. These are all fungi present all along these roots, and this is just a much closer look of this fungi, how they are present inside.

18:18 So far we were able to successfully develop a method where we can quote this unique fungi in a medium and which can successfully infect plants of our choice. Now our next goal is we wanted to know that if this actually helps across the four different cultivar of a plant. So for this experiment we choose wheat as our choice of crop, which choose wheat because in Noble Foundation wheat is one of the four important pillar crops we are currently investigating.

19:01 So what we did actually in laboratory conditions we grow three different cultivat of wheat. We got these cultivat from OSU and this is control.

19:14 Meaning that these plants are without fungi and these sets are with fungi so you can clearly see the difference between the presence and absence of fungi and in three different cultivars.

19:31 Thus far we were able to convince ourselves that this fungi can improve biomass of wheat under laboratory conditions but our next step is that we wanted to know that if it is really true in field conditions.

19:47 For that we did an experimental design we went out to the field and we did this for 2 years so we chose two field locations here in Ardmore. One field location we call it as NF1 which is NF2, they are all in and around Ardmore and we chose three different cultivars of wheat: NFX 25, Duster, and NFX 28. And three treatments with fungi. One is Cina, in which means that we treated these plants with fungi. Control in which we treated these plants with clay particles without containing any clay particle and the third one is absolute control where we give nothing to the plants.

20:40 So we run this experiment for two years in two different field conditions so I just want you to concentrate on this green bars. Green bars are those plants which are treated with fungi. Yellow bars are those where these plants are treated with clay particle without any fungi and the red bars are those where absolutely no treatment was given so what we found is that for this cultivar NFX25 we see an enormous enhanced in grain yield with respect to.

21:21 Treatment and whereas in Duster we do not see any difference in grain, whereas in N28 we see a biomass enhancement in one field but not in the other. And the same thing here in the next two graphs you see the impact of different cultivar with response to the fungal treatment.

21:49 So it is the same data with a different perspective. The previous one was grain yield in terms of weight and this one is grain yield in terms of number of grains. And here also as you can see those green bars in cultivar NFX 25 we see an improved grain yield due to the fungal treatment and in Duster you do not see any grain yield. Whereas in N28 you see a grain yield in one field conditions but in other not in other field conditions.

22:28 Lastly we look at a thousand grain data. This is something commonly wheat breeders do and here we do not see any significant impact of this fungi in terms of grain yield. So what it means actually when you use this fungi for improving wheat grain yield it helps in increasing the grain yield but it does not change the grain size. So there is no change in the morphology of the grain per se, which is good because we do not want the fungi to change the shape and size of wheat. That's not a desirable trait.

23:17 So the final take home message out of this experiment is that when we use this fungi with the help of the delivery mechanism that we have developed it can

23:31 Increase the grain yield by almost 50% and this is irrespective of any kind of cultivar which we have tested. However, it does not have any impact on grain size or grain shape. And so basically we have seen that one cultivar the grain yield was improved in two different field conditions. In one cultivar we do not see any grain improvement. And in a third cultivar we see improvement in one field condition but not in the others.

24:11 So what it actually means is we do not have a single solution for all problems or we do not have a single solution for all different crops and all different soil conditions. So we have to treat situations case by case. If you see this fungi improving plant health in one condition, that may not be true for a different condition or a different crop. So this is very natural and we have to consider we do not have a single rule of thumb. When you use a beneficial fungi, it improves plant health. You have to adapt these good microbes for a particular soil condition, for a particular crop.

24:58 So with this I end my talk. And this is our lab. Kelly Kraven is our group leader and unfortunately we missed him because he has gone for another conference in San Diego. And this is all our lab members. All my research is founded by the US Department of Energy and Noble Foundation. And with this I am happy to the questions.