Analysis Of Floral Characteristics Of Four Cultivars Biology Essay

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

This section deals with the discussion of the results obtained above. Structure-function relationships of the different parts of the four cultivars studied are discussed and different patterns and correlations if exist in the results are described and discussed. Finally, the findings of this project are compared to other research works done on Mangifera indica cultivars in order to find similarities and differences.

5.1 Analysis of floral characteristics

The differences in the flowers are the size itself of the flower, its color and differences in petals and reproductive structures. However, the similarity between the flowers is that they all exhibit bilateral symmetry. This brings into context the work carried out by Edward et al where he concluded that Mangifera indica cultivars have radially symmetrical flowers (Evans Edward et al, 2008). But in the study carried out by Bissoon M in 2009 whereby four cultivars of Mangifera indica from Mauritius were studied she found that the flowers were bilaterally symmetrical. All these studies prove that our mango cultivars are unique and different from cultivars abroad. Observations of the petals have shown that they contain ridges making a possible connection with nectar producing flowers and thus insect pollination. Similarly the observations made about the reproductive structures confirm the fact that wind pollination maybe uncommon as the pollen grains were not dry, light and abundant, in fact they were damp and present in small amount. Also, the fact that four of the cultivars studied showed that they possess stamens of the same length as the pistils; this suggests that self pollination may occurs. Moreover, Popenoe (1920) pointed out that mango flowers have none of the characteristics of a wind-pollinated flower, and he considered the mango to be an insect-pollinated plant. Furthermore, recent studies in India showed that plants caged to exclude all insects set no fruit, but a plant caged with a colony of honey bees where set a heavy crop. Singh (1961) confirmed this by reporting that over 65 percent of the perfect flowers were never pollinated- a strong indication that wind is not an effective pollinating agent.

5.2 Analysis of mango leaves characteristics

Observations and experiment carried out on mango leaves showed that the basic shape of mango leaves were Lanceolate although there are variations among the Lanceolate shape. This observation correlates with that of Edward G et al (Evans Edward et al) whereby he and his associates classified the leaves of the plants from Mangifera genus as Lanceolate in shape thus proving that the cultivars studied in this project namely; Aristide, Christian, Eugenie and Overseer Barkly are as well from the Mangifera genus. The color of the leaves correlates with most observation made by other researches whereby it has been noted that there is a variation in color from red in young leaves to green in mature leaves. In addition, with the statistical analysis carried out with the length of the leaves, where P was shown to be less than 0.05, it has been proved that significant differences exist between the lengths of the cultivars which are not so obvious at a first glance. Eugenie was found to possess the longest leaves while Christian has the shortest leaves. Significant differences also exist in width of the cultivars (P<0.05) whereby Christian possessed the narrowest leaves. Thus it can be concluded that the cultivar Christian possesses the smallest leaves among the four cultivars.

Concerning the secondary veins present in the leaves. It was seen that they were pinnately arranged. This observation correlates with the observation done by Bissoon M, where she too found that the leaves of Mangifera indica cultivars had pinnately arranged secondary veins. However, when comparing her statistical analysis of the number of veins present with mine, differences could be observed. While her cultivars studied had leaves which contained approximately the same number of veins, the cultivars studied in this project had leaves with significant differences in the number of veins they content meaning that the number of veins varied among the four cultivars. This has been proved by ANOVA test with a significant value of P being less than 0.05.

The stomatal analysis done with the four cultivars further concludes that the cultivars studied are very different from each other from a morphological viewpoint. The experiments done showed that mango leaves are hypostomatic having stomata confined only on the abaxial side (lower surface) of the leaves. With a P<0.05 at ANOVA test at 5%, the number of stomata present greatly differs from one cultivar to another. Cultivar Christian has been found to possess the smallest stomata and the highest density of stomata among the 4 cultivars. This makes it the one least adapted to reduce water loss during transpiration while Aristide is the most adapted. It is important to note that clear pictures of the stomata could not be obtained due to a lack of scanning electron microscope in the laboratory.

Tissue processing has enabled the study of the inner structures of the leaves. The different cell types comprising the midrib and its associated vascular bundles could be very well observed. It came out form these experiments that the inner anatomical structures of the leaves of the four cultivars were similar to each other. The four cultivars have the same type of epidermal, collenchyma, parenchyma, sclerenchyma and vascular tissue. However the number of vascular bundle present in the leaves of each cultivar differs validated with a P value of <0.05 with Christian possessing the highest number. Moreover it has been found that the shape of the midrib varies with each cultivar with cultivar Eugenie having the largest midrib.

Much comparison could not be made with other cultivars as midribs of Mangifera indica cultivars have been rarely experimented.

5.3 Analysis of mango fruits

The most striking difference between the four cultivars was their fruits. The fruits are the most important feature to characterize the four cultivars because they have distinct characteristic. The first feature studied was the shape whereby Christian and Eugenie were more or less of the same shape and Aristide and Overseer Barkly had varying oblong shape. For the peel color it was noted that all cultivars had to reach that common transition yellow color before reaching their distinct color at maturation. By statistical analysis, the mean length, width and weight of the different cultivars were found to be very significantly different form each other with a P value of <0.05 for all the three features. The percentage of pulp present and the fiber content was determined and these also vary from cultivars to cultivars. No other studies were made on these cultivars; hence much comparison to other related works could not be made.

Analysis of the seeds further complemented the study and showed that the four cultivars studied possess characteristic feature. The cultivars contain very different seeds in terms of their weight, length and width (P<0.05). The amount of fibers and venation also was found to vary. These are the salient features which enable the classification of the cultivar at a glance and thus allow easy identification of the cultivars. In this project the study of the maximum features available of the fruits were done to obtain good criteria for the characterization of the cultivars as compared to Bissoon M where thickness of the skin, the pulp percentage content and the flesh texture were not mentioned in her study.

5.4 Analysis of stem structure

Cutting of the stem by free hand sectioning method has provided an easy and quick way to analyze the internal structures of the stem. Vascular bundles in the stem of the four cultivars are similar and present no differences in structure except for the compactness of the vascular bundles. The bundles are arranged in a collateral way and in a ring like in most dicot plants. However the free hand sectioning reduced the visibility of the form, shape and size of the inner cells as the sections cut were relatively thick as compared to sections cut by a microtome.

Hence, finally it can be said that the four cultivars studied namely: Aristide, Christian, Eugenie and Overseer Barkly have contrasting feature to distinguish them from each other and other Mangifera indica species. Thus they can be claimed as our national heritage belonging only to or country and thus are endemic species.

6. Conclusions

The aim of this study is to characterize morphologically four locally available Mangifera indica cultivars pertaining to Mauritius. This project’s results, has enable the characterization of the four cultivars endemic to Mauritius namely; Aristide, Christian, Eugenie and Overseer Barkly.

Morphological and Micromorphological analysis of the salient features like the flowers, leaves, fruits and stem have provided enough similarities and differences to compare and contrast them and hence claimed them as our national heritage. The features were studied by various experiments like tissue processing and embedding in wax, free hand sectioning and taking measurements and record observations.

This study has enables the observation in detail of the flowers of the four cultivars. It has been shown that the flowers exhibit bilateral symmetry and that mango flowers do not rely much on wind pollination since they do not possess characteristic features of a wind pollinated plant but that of an insect pollinated plant.

During this study, it has been found that leaves of Mangifera indica cultivars are of Lanceolate shape and are hypostomatic having stomata only on the abaxial side. These two features have made possible the correlation of this study with that of James C and Evan E whereby they both concluded that the shape of the leaves is of Lanceolate type. It has also been observed that the features of the leaves studied vary much among the four cultivars studied.

Furthermore, the fruits studied were characteristic of the cultivars whereby their color, shape, structure and pulp texture were each of significant difference except for their width which were approximately the same. These unique characteristics have allowed the characterization of the cultivars endemic to our island as no resemblance has been found to cultivars abroad.

Finally, this project shows that morphological analysis can be an easy, cheap and essential tool for characterizing species based on their characteristic features like; flowers, leaves, fruits and stem. This project in which the characterisation of four locally available cultivars were carried out can present a new beginning to the classification and characterization of the rest of the cultivars present in Mauritius noting that Mauritius have more than 50 cultivars of Mangifera indica and thus complementing the list of mangoes classified as our national heritage. Furthermore, this work can be a taken as a continuation of the work done by Bissoon M whereby four other different cultivars were studied and the work done by Seeruttun S who studied only the fruits of different cultivars locally available.