Alex Centala, James Duong, and Amir Nahangi

ECTOMYCORRHIZAL FUNGUS (Glomus intraradices, Glomus mosseae, and Glomus aggregatum) AIDS IN THE GROWTH OF THE STRAWBERRY PLANT (Fragaria ananassa)

Department of Biological Sciences

Saddleback College

Mission Viejo, CA 92694

(added) Abstract

Many species of plants utilize symbiotic relationships with other organisms. mycorrhizae fungi are commonly a part of these relationships, and aid in plant growth as well as nutrient uptake. We tested the effects of a mixture of mycorrhizae fungi, species Glomus intradices, Glomus mosseae, and Glomus aggregatum, on the growth of the common garden strawberry plant, species Fragaria ananassa, chosen for its reputation as a plant that is inexpensive(new word choice-economical) and experiences rapid growth. Two groups of ten plants were tested over a four week testing period, one (group) with mycorrhizae fungi mixed with their soil, and the other (group) without. It was found that those with the fungal soil grew faster and thus experienced greater growth, along with a greater yield in strawberries, though the difference in strawberry yield was not found to be statistically significant. (Do not bold the whole abstract)

Introduction

(make sure your indents for each paragraph match up … around 5 spaces)The proposed study will investigate the effect of an mycorrhizal fungus (?) is this the plural form and proper English? group containing three species – Glomus intraradices, Glomus mosseae, and Glomus aggregatum – on the overall growth of strawberry plants. Mycorrhizal fungi forms mutually beneficial relationships with the roots of plants and are a great aid in the functioning of ecosystems (Van der Heijden 2009, Wilson 2001). The fungus is such a crucial factor in certain ecosystems that some plants have become dependent on it (Yücel, C., Özkan et 2009)( when you are citing multiple authors, you should put Yucel et al., 2009). While these plants supply the fungi with essential organic materials, the fungi aid the plants’ roots in uptaking more minerals and nutrients, allowing greater growth, due to the complex mycelia networks it produces (Campbell et al 2011). Other studies have shown that in the early stages of root development, Mycorrhizal fungi can be a major factor in growth rate (Janos 1980, Resendes et al 2008). The investigators are to test this symbiotic relationship on strawberry plants, (Fragaria ananassa), to see whether the fungi will accelerate growth, compared to plants without the aid of mycorrhizal fungi. The experiment will have a duration ( my grammar check said this should just be duration) of eight weeks, with measurements being taken every other day in order to track progress. Should this result in productive growth, these fungi could potentially be further tested as to whether or not they are safe, ethical, and viable to be used in the agriculture and distribution of strawberries and fruits alike.(PAST TENSE ONLY! You have already constructed this experiment, right?)

This experiment is looking to find how great of an effect the addition of mycorrhizal fungi will have on the growth of garden strawberries, Fragaria ananassa. Twenty sprouted strawberry plants will be obtained from Home Depot and divided into two groups. One bottle of twelve ounce Garden-Villa fungi will be purchased online from the Garden Villa website. Garden-Villa is a combination of three types of mycorrhizal fungus; Glomus intraradices, Glomus mosseae, and Glomus aggregatum. The day that the fungus is added to the group, all plants in both groups will be measured. Measurement will be taken from the bass(base) of the plant to the end of its longest point. For the next four weeks, the plants will be measured every two days. After the allotted time, the fungal group will be compared to the non-fungal group to determine the effect of the fungi on the growth of the experimental group of plants. Then a statistical analysis will be performed involving all the data acquired( you guys also stated that an ANOVA will be taken as well, along with the unpaired t-test… state up in the intro).

Materials and Methods

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The materials utilized in this research project consisted of Mycorrhizal fungi, strawberry plants, two 24x10x10 inch planters, Miracle Gro® brand potting soil, water, and measuring tape. The Mycorrhizal fungi were obtained through the “Garden Villa” company on Amazon.com for approximately $22 and consisted of a mixture of three species: Glomus intradices, Glomus mosseae and Glomus aggregatum. The twenty(added) strawberry plants (Fragaria ananassa) ( once you have stated the genus name for the plants, you do not have to state the common name again)were purchased from Home Depot for $3 per plant. The Miracle Gro® brand potting soil was also purchased from Home Depot. The planters were supplied by one of the researchers. Water was acquired through the tap( wil tap water affect this project if you were to substitute with filtered mineralized water?). The tape measure was supplied by a researcher.

Mycorrhizae fungi and strawberry plants were acquired (Mycorrhizae fungi were obtained through “Garden Villa” on Amazon.com – the fungus was a mixture of species Glomus intradices, Glomus mosseae and Glomus aggregatum; 20 strawberry plants were purchased at Home Depot)( didn’t you just state this in the first paragraph? Instead of restating it exactly how it should have been stated in the first paragraph, you guys might want to say” with these twenty strawberry plants and the mycorrhizae fungi mixed, we conducted the experiment by splitting the plants into two groups…”. The strawberry plants were then split into two groups of ten, one to be placed in the control group planter and the other to be placed in the experimental planter. Each of two 24x10x10 inch planters were filled with Miracle Gro® brand potting soil. The soil of the control planter was left alone, while the soil of the experimental planter was mixed with the Mycorrhizae fungus mixture. Both plots of soil were soaked with equal amounts of water and each of the two groups were then planted and left to settle for 3 days. These planters were kept in one of the researcher’s back yards (in Ladera Ranch, California), where the two groups could experience the same natural fluctuations in sunlight and temperature (to remove possible confounds or extraneous variables)( what was the temperature faced outside? Did it rain? Did the experiment face any type of downfall because of the temperature change?). After this period, plants were watered and growth was recorded every other day over the course of four weeks. Plant feeding took place in the form of the addition of six fluid ounces per plant (every two days as previously stated), administered at the base of each plant( was this for both groups?). Data collection took place in the form of measurements of the length of the plant (in cm( spell centimeters out)) from its base to the end of its longest vine and in the form of its yield in strawberries (numbers of strawberries on each plant). Data analysis consisted of three statistical tests: a one-factor ANOVA for the lengths of the strawberry plants’ longest vines, another one-factor ANOVA to analyze the growth rates of the two groups, and a one-tailed, unpaired t-test for number of strawberries yielded by each group. The ANOVA tests were used on the basis that the lengths of plant vines were taken and compared over time, while the t-test was appropriate in that it was used solely to compare the ending quantities of produced strawberries between the two plant groups.

Results

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The null hypothesis (being that there is no difference in the growth of Fragaria ananassa with the addition of Glomus intraradices, Glomus Mosseae, and Glomus Aggregatum to the rooting system) has been rejected and the alternative hypothesis (that the growth of the experimental fungal will be greater than that of the control) has been accepted. A single variable ANOVA statistical analysis was run upon the average plant base to leaf length of both groups to find a p-value of 0.012314. Since this p value is less than 0.05 we can firmly reject our null hypothesis and accept the alternative hypothesis.

Date / Fungal Base to Longest Leaf Length Average (cm) / Non-fungal Base to Longest Leaf Length Average (cm)
25-Oct / 15.18 / 15.17
27-Oct / 15.80 / 15.52
29-Oct / 16.21 / 15.88
31-Oct / 16.56 / 16.05
2-Nov / 16.88 / 16.08
4-Nov / 17.32 / 16.22
6-Nov / 17.75 / 16.41
8-Nov / 18.05 / 16.85
10-Nov / 18.45 / 17.08
12-Nov / 19.05 / 17.29
14-Nov / 19.35 / 16.48
16-Nov / 19.37 / 16.43

Table 1: Table of the average base to longest leaf length of fungal group and non-fungal group against date.

( your table caption is the same format as a figure caption and should include more info on the tests, you can also include the data that is obviously stated as your variables per time and measure)

Figure 1: Scatter plot of the average plant length (measured in cm from base to longest leaf) of fungal group and controlled group versus time (two day increments). Single variable ANOVA shows that there is a significant difference in the groups (p=0.012314 / p<0.05).

Date / Fungal Growth Average (cm) / Non-fungal Growth Average (cm)
25-Oct / 0.62 / 0.35
27-Oct / 0.41 / 0.36
29-Oct / 0.35 / 0.17
31-Oct / 0.32 / 0.03
2-Nov / 0.44 / 0.14
4-Nov / 0.43 / 0.19
6-Nov / 0.30 / 0.44
8-Nov / 0.40 / 0.23
10-Nov / 0.60 / 0.21
12-Nov / 0.30 / 0.08
14-Nov / 0.02 / 0.05

Table 2: Table of the change in the average base to longest leaf length of the fungal group and the non-fungal group against date. Table caption goes above the table, not below like a figure

Figure 2: Scatter plot of the change in the average base to longest leaf length of fungal group and controlled group over time. Linear regression lines with equations and R2 values are also displayed. Single variable ANOVA shows that there is a significant difference between the growth of the experimental group and the that the change in the average base to longest leaf length of the experimental group is consistently greater than that of the controlled. controlled group. Comparison of linear regression lines shows

Figure 3: Column graph of the mean number of berries produced in the fungal group and the controlled group. Two sample t-test assuming equal variance shows that there is no significant difference in the number of strawberries produced by the experimental, fungal, group and the controlled, non-fungal, group. (p=0.075475 / p<0.05) one tailed unpaired t-test.( explain what the p value is… i.e. This test is a one tailed, unpaired t-test with a p-value measured at 0.075475, which shows no significant difference because the p-value is less than 0.05)

Discussion

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Our tests have indicated that strawberry plants that are planted with strictly ectomycorrhizal fungi located around the roots will grow at a faster rate than those without the fungus. Figure 1 is a pictorial representation of the averages in Table 1, and depicts the average plant length (from the base of the plant to its longest leaf in centimeters) versus time, where measurements took place in two day increments. Visual examination of the graph will show a clear separation of the two groups as the average plant length of the fungal group moves above that of the non-fungal, control group. A single factor ANOVA test indicated a significant difference between the two groups of average plant lengths (p value of 0.012314). This indication of difference brought about by the ANOVA test along with an examination of the nature of the graph leads to the conclusion that ectomycorrhizal fungi do improve the growth of strawberry plants.

Figure 2 plots the data from Table 2 against( new word choice?) time. Examination of the linear regression lines in Figure 2 show that the amount of growth that was recorded for the experimental fungal group was consistently above that of the controlled, non-fungal group. A single factor ANOVA was also run upon the two groups, measuring change in average plant length over time. Through this, it was found that there was a significant difference between them (p=0.00965). Noting this, along with the clear difference in linear regression lines, where that of the fungal group is much higher than that of the non-fungal group, it can be said that the fungal group’s growth is thus significantly greater than that of the control. This is likely due to the accelerated uptake of nutrients provided by the complex mycelia networks created by the ectomycorrizal fungi (Cambell et al 2011).

As also shown by Figure 2, the growth rates have negatively sloped linear regression lines associated with them, consistent with research previously performed, which showed more rapid growth changes immediately after fungal addition, as opposed to later in the study (Janos 1980, Resendes et al 2008).(add commas after the author and before the year)

The numbers of berries that each group yielded, experimental and controlled, were also taken into account to further assess the effect of addition of ectomicorrhizal fungi upon the strawberry plants’ growths. A one tailed unpaired t-test indicated that there was no significant difference in the number of berries produced between the two groups (p value of 0.075475). However it is worth recognition that this p value is very close to required alpha of 0.05, meaning the data is close to significant. The fact that the experimental group was the only to actually yield strawberries at all is something that should also be taken into consideration( extra space not needed), regardless of the fact that very few were produced. This supports the idea that the fungi benefit the ecosystem as a whole because of their ability to help the plant produce more fruit, therefore allowing for a greater reproductive capacity as well as providing more food for the local consumer, ultimately adding to the food chain. This supports research previously done by Van der Heijden in 2009, which found that mycorrizae fungi play an important part in some ecosystems. When considering the fact that the strawberry plants in the control group lacked strawberries entirely, it isn’t unreasonable to image these fungi as being a vital component of certain communities. It could be said that without the help of a mycorrhizae fungus, the host plant would not be able to create fruit and therefore reproduce and contribute to the community as well, if at all (Yücel et all 2009). This additionally plays along with previous studies that have found that mycorrhizal fungi improve not nly growth, but the flowering of plants as well (Wilson et al 2001).