of the pigment | Color of the pigment |
| Chlorophylls (a and b) | Green |
| Carotene | Orange |
| Xanitophyll | Yellow |
| Phaeophytin-a | OLIVE BROUN or GREY |
Table 2. Raw data.
| Number of | Light intensity (lux) |
| plant | |
| 0 | 0,273 | 0,041 | 84, 98 | 41,89 | 0,0000 |
| 20,5 | 0,579 | 0,056 | 90,33 | 41,76 | 0,0496 |
| 27,5 | 0,332 | 0,033 | 90,06 | 36,33 | 0,1462 |
| 89,5 | 0,181 | 0,018 | 90,06 | 19,81 | 0,1769 |
| 142 | 0,511 | 0,047 | 90,80 | 41,33 | 0,0697 |
| 680 | 0,338 | 0,043 | 87,28 | 29, 33 | 0,1557 |
| 1220 | 0,301 | 0,034 | 88,70 | 18,64 | 0,1939 |
Calculation of amount of chlorophyll in plants basing on the results of titration
H2 SO4 + C56 O5 N4 Mg => C56 O5 N4 H + MgSO4
Concentration of H2SO4 is 0,01 M
C - concentration
V - volume n - quantity of substancy m - mass
Mr - molar mass
For light intensity equal to 20,5 lux. n = V (in dm3)? C
2? 10-3? 0,01 = 2? 10-5 n = m / Mr => m = n? Mr m = 2? 10-5? 832 = 1,664? 10-2 grams mass of plant mass of chlorophyll
1,68 grams - 0,08335 grams of chlorophyll
1 gram - x grams of chlorophyll
Hence there are 0,0496 grams of chlorophyll.
Table 5. The correlation between mean length of plants and mean dry biomass.
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Table 6. The correlation between mean length and mass of chlorophyll per 1 g of plant.
Site | Mean length, cm | Rank (R1) | Mass of chl. In 1 g | Rank (R2) | D (R1-
R2) | D ^ 2 | | 1 | 41,89 | 1 | 0,0000 | 7 |-6 | 36 | | 2 | 41,76 | 2 | 0,0496 | 6 |-4
| 16 | | 3 | 36,33 | 4 | 0,1462 | 4 | 0 | 0 | | 4 | 19,81 | 6 | 0,1769 | 2 | 4 | 16 | | 5
| 41,33 | 3 | 0,0697 | 5 |-2 | 4 | | 6 | 29, 33 | 5 | 0,1557 | 3 | 2 | 4 | | 7 | 18,64 | 7
| 0,1939 | 1 | 6 | 36 | | | | | | | | | |
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Table 7 . The correlation between mean dry biomass and mass of chlorophyll per 1 g of plant.
Site | Mean dry biomass, g | Rank (R1) | Mass of chl. In 1 g | Rank (R2) | D
(R1-R2) | D ^ 2 | | 1 | 0,041 | 4 | 0,0000 | 7 |-3 | 9 | | 2 | 0,056 | 1 | 0,0496 | 6 |-5
| 25 | | 3 | 0,033 | 6 | 0,1462 | 4 | 2 | 4 | | 4 | 0,018 | 7 | 0, 1769 | 2 | 5 | 25 | | 5
| 0,047 | 2 | 0,0697 | 5 |-3 | 9 | | 6 | 0,043 | 3 | 0,1557 | 3 | 0 | 0 | | 7 | 0,034 | 5
| 0,1939 | 1 | 4 | 16 | | | | | | | | | | | | | | | | | | Rs =-0, 57 | | | | | |
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Several tendencies can be clearly seen.
For the first, with the increase of light intensity mean length of plants is decreasing, but there are exceptions. For light intensity 142 lux the value of mean length is approximately equal to the values ??of length for light intensities 0 lux and 20,5 lux. If exclude this data it is also seen that for light intensity equal to 680 lux mean length is also slightly falling out from the main tendency - decreasing from 19.81 cm.
The second tendency is increase of mass of chlorophyll per 1 gram of plant biomass with the increase of light intensity. But the values ??of mass of chlorophyll of those plants under light intensities 142 lux and 680 lux are falling out from the main tendency. The first and the second ones are too small - approximately equal to the value corresponding to 20.5 lux light intensity and to 89.5 lux respectively. This may happen because not all the seeds of Cicer arietnum were of the same quality, because it is impossible to guarantee that more than 250 seeds in one box have the same high quality. At the mean time it was expected that starting from the light intensity more than 680 lux the amount of chlorophyll in plants will decrease, because the value of destructed chlorophyll with be bigger than the value of newly formatted. But the experiments showed that the amount of chlorophyll was constantly increasing even when the light intensity level exceeded the point 1220 lux. This could happen because light intensity equal to 1220 lux is not so extremely high that the amount of total chlorophyll in plants will start decreasing.
Also it is clearly seen that there are no correlations between light intensity and values ??of wet and dry biomass.
Basing on these arguments the sudden decrease of the amount of chlorophyll in plants placed on light intensity equal to 142 lux was likely to be insignificant and could not be considered as a trend.
But it is impossible to forget such important factor as plant hormones that affect the growth and development of plants. There are five generally accepted types of hormones that influence plant growth and development.
They are: auxin, cytokinin, gibberellins, abscic acid, and ethylene. It is not one hormone that directly influences by sheer quantity. The balance and ratios of hormones present is what helps to influence plant reactions. The hormonal balance possibly regulates enzymatic reactions in the plant by amplifying them.
Due to results of my investigation it is seen that my hypothesis didn't confirm fully (for example, comparing the diagram 1 and diagram 7), because I proposed that when light intensities will be very high , mass of chlorophyll in plant will start decreasing and due to my observations it didn't happen. I should say that the only reason I can suggest is that I haven't investigated such extremely high light intensities, so that chlorophyll start destructing. But if we will not pay attention to that fact the other part of my hypothesis was confirmed and mass of chlorophyll in plants increased with the increase of light intensity. Furthermore I didn't estimate amount of plant hormones and so didn't estimate their influence on results.
Questions for further investigation:
1. Investigating very high light intensities.
2. Implementation of colorimetric analysis.
3. Paying attention to estimation of plant hormones level.
Those questions should be further investigated in order to get clearer picture and more accurate results of the dependence of the amount of chlorophyll in plants on the light intensity, knowing the fact that the amount of chlorophyll has a tendency to decrease at extremely high light intensities. So this statement needs an experimental confirmation and as in this investigation conditions with extremely light intensity were not created in further investigations they have to be created.
Implementation of colorimetric analysis is also very important thing, because it gives much more accurate results comparing with the titration method. The colorimetric method suggests that as different pigments absorb different parts of light spectrum differently, the absorbance of a pigments mixture is a sum of individual absorption spectra. Therefore the quantity of each individual pigment in a mixture can be calculated using absorbance of the certain colors and molecular coefficients of each pigment. This was proposed by DA Sims, and JA Gamon (California State University,
USA)  with the reference on Lichtenthaler (1987).
There are several results in my work, that are falling out from the main tendencies. It may seem that such results may occur due to different percentage of water in plants, but when I was calculating mass of chlorophyll in 1 gram of plant I was using only values ??of mean dry biomass so it couldn't affect