The Effect of Hormones on Pea Seedlings: Growth and Development Study

This report investigates the effects of three plant hormones – Indole Acetic Acid (IAA), Gibberellic Acid (GA), and Kinetin – on the growth and development of pea seedlings (Pisumsativum). The study involved applying these hormones, along with a control (distilled water), to 15-day-old pea seedlings and recording their heights and the number of leaf pairs before and after treatment. ANOVA tests were performed to analyze the data and determine the significance of the hormone treatments. The results indicated that Gibberellic acid showed the maximum increase in height in leaf treatment, and all hormones were equally important in root treatment. In leaf treatment, IAA showed the most effect on the increase in the number of leaf pairs, while in root treatment, all hormones were equally important. The study concluded that hormone selection is important for root treatment but not as critical for leaf treatment. The report includes tables and figures summarizing the results, along with a discussion of the findings and a detailed methodology section.

Running Head: PLANT GROWTH AND DEVELOPMENT
The Effect of IAA, Gibberellic Acid and Kinetin on Growth of Intact Pea Seedlings
Name of the Student
Name of the University
Author Note

1PLANT GROWTH AND DEVELOPMENT
Abstract
In this research, the growth of pea seedlings on applications of different hormones has to be
tested. Three different hormones have been applied to 15-day old pea seedlings along with
distilled water and their heights and number of leaf pairs have been recorded before and after the
application of the hormones. The increase in the heights and the number of leaf pairs have been
measured and ANOVA test has been run to check the significant differences in the heights after
application of different types of hormones.

2PLANT GROWTH AND DEVELOPMENT
Table of Contents
1.0 Introduction................................................................................................................................3
2.0 Results........................................................................................................................................3
3.0 Discussion................................................................................................................................11
4.0 Method and Materials..............................................................................................................12
References......................................................................................................................................13
Appendix........................................................................................................................................14

3PLANT GROWTH AND DEVELOPMENT
1.0 Introduction
The plant that has been used in this study is pea (Pisumsativum). This crop has been
studied since the age of Gregor Mendel (Bateson, William and Gregor). The plant has green pods
and those pods contain dry seeds inside. These seeds are in high demand as they are cooked both
as a pulse as well as vegetables. This crop has a very high nutritious value and contains proteins,
vitamins A and K, carbohydrates, phosphorus and calcium.
Three hormones are used to develop this pea crop. They are Gibberellic acid (GA), Indole
Acetic Acid (IAA) and Kinetin. Gibberellic acid is a hormone which is usually found in plants
and fungi. This acid helps in the growth and elongation of plant cells (Iqbal, Muhammad and
Muhammad). Indole Acetic Acid is also a plant hormone which is usually produced in the tips of
the leaves and in young leaves of a plant. IAA signals of essential molecules that are required for
the growth and development coordination for the major components of plants (Tabatabaei et al.).
One type of cytokinin is kinetin which is also a type of plant hormone. This hormone helps in
promoting the cell division of plants (Bandivadekar et al.).
2.0 Results
To test the difference in the mean increase in heights of the pea seedlings after
application of the three hormones Indole Acetic acid, Kinetin and Gibberellic acid, ANOVA test
has to be done. Similarly, to test the difference in the standard error of the mean increase in
heights of the pea seedlings after application of the three hormones Indole Acetic acid, Kinetin
and Gibberellic acid, ANOVA test has to be performed. To perform these ANOVA tests, the
following hypothesis can be framed:

4PLANT GROWTH AND DEVELOPMENT
Null Hypothesis (H01): The mean increase in height of plants has no difference on application of
different types of hormones for leaf treatment.
Alternate Hypothesis (HA1): The mean increase in height of plants has significant differences
on application of different types of hormones for leaf treatment.
The results of the ANOVA test for the hypothesis H01 is given in table 1 and 2.
Table 1: Summary for mean increase in heights after leaf treatment
Groups Count Sum Average Variance
Water 9 25.60 2.84 0.06
IAA 9 29.18 3.24 0.06
Kinetin 9 28.24 3.14 0.14
GA 9 84.60 9.40 0.61
Table 2: Results of ANOVA test for mean increase in heights after leaf treatment
Source of Variation SS df MS F P-value F crit
Between Groups 270.861 3 90.287 412.350 0.000 2.901
Within Groups 7.007 32 0.219
Total 277.868 35

5PLANT GROWTH AND DEVELOPMENT
A B C D E F G H I
0.0
2.0
4.0
6.0
8.0
10.0
12.0
Mean Increase in Height (Leaf Treatment)
Water IAA Kinetin GA
Trays
Increase in Height (in cm)
Figure 1: Mean Increase in heights after leaf treatment
From the graph in figure 1 it can be seen that the increase in height is maximum with the
application of gibberellin to the leaf treatment of pea seedlings.
Null Hypothesis (H02): The mean increase in height of plants has no difference on application of
different types of hormones for root treatment.
Alternate Hypothesis (HA2): The mean increase in height of plants has significant differences
on application of different types of hormones for root treatment.
The results of the ANOVA test for the hypothesis H02 is given in table 3 and 4.
Table 3: Summary for mean increase in heights after root treatment
Groups Count Sum Average Variance
Water 9 29.20 3.24 0.06
IAA 9 26.96 3.00 0.04
Kinetin 9 29.28 3.25 0.04
GA 9 28.99 3.22 0.06
Table 4: Results of ANOVA test for mean increase in heights after root treatment
Source of Variation SS df MS F P-value F crit
Between Groups 0.408 3 0.136 2.767 0.058 2.901

6PLANT GROWTH AND DEVELOPMENT
Within Groups 1.574 32 0.049
Total 1.982 35
A B C D E F G H I
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Mean increase in Height (Root Treatment)
Water IAA Kinetin GA
Trays
Increase in heights (in cm)
Figure 2: Mean Increase in heights after root treatment
From the figure 2, it can be seen clearly that all the hormones are equally important for
the increase in the height of the pea seedling in case of root treatment. The variation is least in
case of application of water.
Null Hypothesis (H03): The mean increase in the number of leaf pairs of plants has no difference
on application of different types of hormones for leaf treatment.
Alternate Hypothesis (HA3): The mean increase in the number of leaf pairs of plants has
significant differences on application of different types of hormones for leaf treatment.
The results of the ANOVA test for the hypothesis H03 is given in table 5 and 6.
Table 5: Summary for mean increase in number of leaf pairs after leaf treatment
Groups Count Sum Average Variance
Water 9 32.96 3.66 0.14

7PLANT GROWTH AND DEVELOPMENT
IAA 9 48.83 5.43 0.67
Kinetin 9 31.60 3.51 0.12
GA 9 37.17 4.13 0.19
Table 6: Results of ANOVA test for mean increase in number of leaf pairs after leaf treatment
Source of Variation SS df MS F P-value F crit
Between Groups 20.429 3 6.810 24.342 0.000 2.901
Within Groups 8.952 32 0.280
Total 29.381 35
A B C D E F G H I
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
Mean increase in number of leaf pairs (Leaf Treatment)
Water
IAA
Kinetin
GA
Trays
Increase in number of leaf pairs
Figure 3: Mean Increase in number of leaf pairs after leaf treatment
From figure 3, it can be seen clearly that the effect of indole acetic acid is the most in the
increase in number of pairs of leaves of pea after leaf treatment.
Null Hypothesis (H04): There is no significant difference in the number of leaf pairs of the plants
after root treatment on application of different types of hormones.
Alternate Hypothesis (HA4): There is no significant difference in the number of leaf pairs of the
plants after root treatment on application of different types of hormones.

8PLANT GROWTH AND DEVELOPMENT
The results of the ANOVA test for the hypothesis H04 is given in table 7 and 8.
Table 7: Summary for mean increase in number of leaf pairs after root treatment
Groups Count Sum Average Variance
Water 9 29.13 3.24 0.06
IAA 9 29.25 3.25 0.09
Kinetin 9 30.35 3.37 0.12
GA 9 27.17 3.02 0.37
Table 8: Results of ANOVA test for mean increase in number of leaf pairs after root treatment
Source of Variation SS df MS F P-value F crit
Between Groups 0.586 3 0.195 1.230 0.315 2.901
Within Groups 5.080 32 0.159
Total 5.665 35
A B C D E F G H I
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
Mean increase in Number of leaf pairs (Root Treatment)
Water
IAA
Kinetin
GA
Trays
Increase in the number of leaf pairs
Figure 4: Mean Increase in number of leaf pairs after root treatment
From the figure 4, it can be seen that all the three hormones and water are equally
important for the increase in the number of leaf pairs after root treatment. Importance cannot be
given to any one of the hormones for this type of treatment.

9PLANT GROWTH AND DEVELOPMENT
3.0 Discussion
The ANOVA test has been run to test all the hypothesis that has been stated above. For
the first hypothesis H01, the results of the ANOVA test are given in tables 1 and 2. It can be seen
from table 2 that the p value is 0.000 which is less than the level of significance (0.05 at 95
percent confidence interval). Thus, the null hypothesis (H01) is rejected. Therefore, it can be said
that the mean increase in heights do not differ on application of different hormones in leaf
treatment.
It can be seen from table 4 that the p value is 0.058 which is more than the level of
significance (0.05 at 95 percent confidence interval). Thus, the null hypothesis (H02) is accepted.
Thus, it can be said that the mean increase in heights differs significantly on application of
different types of hormones as well as water in case of root treatment.
It can be seen from table 6 that the p value is 0.000 which is less than the level of
significance (0.05 at 95 percent confidence interval). Thus, the null hypothesis (H03) is rejected.
Thus, it can be said that the mean increase in the number of leaf pairs of the plants on application
of different types of hormones along with water does not differ in case of leaf treatment.
It can be seen from table 8 that the p value is 0.315 which is more than the level of
significance (0.05 at 95 percent confidence interval). Thus, the null hypothesis (H04) is accepted.
Thus, it can be said that the mean increase in the number of leaf pairs of the plants on application
of different types of hormones along with water has significant differences in case of root
treatment.
Hence, it can be said that selection of hormones along with water is important in case of
root treatment as different hormones show different levels of growth. In case of leaf treatment,

10PLANT GROWTH AND DEVELOPMENT
selection of hormones is not that important as application of different hormones do not show
much difference in growth.
4.0 Method and Materials
In Cairn’s greenhouse, the three hormones Indole Acetic Acid, Gibberellic acid and
Kinetin along with distilled water has been applied to 15-day old pea seedlings in 4 different lab
sessions. The height and the number of leaf pairs were recorded before application of the
hormones and also 1 week after the application of the hormones.

11PLANT GROWTH AND DEVELOPMENT
References
Bandivadekar, Kavita, et al. "Use of Plant Auxins Produced by Bacteria in Plant Tissue Culture
and Seed Pre-treatment; A Possibility of Replacement of Synthetic Auxins." Int. J. Curr.
Microbiol. App. Sci 5.11 (2016): 126-131.
Bateson, William, and Gregor Mendel. Mendel's principles of heredity. Courier Corporation,
2013.
Iqbal, Muhammad, and Muhammad Ashraf. "Gibberellic acid mediated induction of salt
tolerance in wheat plants: growth, ionic partitioning, photosynthesis, yield and hormonal
homeostasis." Environmental and Experimental Botany 86 (2013): 76-85.
Tabatabaei, Samira, et al. "Indole-3-acetic acid (IAA) producing Pseudomonas isolates inhibit
seed germination and α-amylase activity in durum wheat (Triticumturgidum L.)." Spanish
Journal of Agricultural Research 14.1 (2016): 0802.