Allelopathic Effect of S. Macrophylla on the Growth of V. Radiata Seedlings

Allelopathic effect of S. macrophylla on the harvest-time of V. radiata seedlings Thea Philea I. Mostralesa, Greeny Joy A. Perucho, Rhoshela Vi C. Rendon, John Gregor A. Rono, Emmerson P. Rullog, Riffcord R-Denz M. Tabula Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City (a Thea Philea I. Mostrales, e-mail theaphilea. emailprotected com) ABSTRACT Swietenia macrophylla, or commonly cognise as the mahogany tree diagram in the Philippines, is an introduced species of the family Meliaceae that is commonly used for lumber and reforestation projects.However, establish on studies, it is shown that the mahogany tree has inhibitory effects that make a motion adjacent growing plants. This is made possible chemically and is referred to generally as allelopathy. This study aimed to determine is S. macrophylla had any adverse effects to the harvest-tide of plants in destination proximity to it. The researchers selected three mahogany trees and set six plots of differeing distances with each plot containing ten monggo seedlings.The results obtained indicate that there is no material difference between the outgrowth of monggo seedlings growing near the mahogany tree to that of monggo seedling growing near the control tree based on the analysis done on the seedlings height, weight and choice rate. Results also indicate that distance of the seedlings from the S. macrophylla has no effect on the intensity of inhibition of the growth of the V. radiata.The results obtained can be attributed to factors that include the texture of soil, fine-textures soil having been turn up to acquire a greater retention capacity of allelochemicals than coarse-textures soils. Also, allelopathic interactions include both promontory and inhibitory activities of phenolic allelochemicals and thus using seed germination as a assay parameter whitethorn be of belittled value. KEY WORDS Swietenia macrophylla, allelopathy, growth of monggo seedlings, inhibitory effect of mahogany, introduced species INTRODUCTIONBACKGROUND AND SIGNIFICANCE OF THE STUDY Swietenia macrophylla, commonly known in the Philippines as mahogany, is a member of the order Sapindales, under family Meliaceae. It is a large, fast-growing, semi-evergreen tree, popular for landscaping, especially in North American and Carribean countries, where it has a vulnerable circumstance as provided by CITES (Oldfield 1995), and for its strong wood for lumber. This tree was first introduced in the Philippines as early as 1907, and 1913 as part of the Mt. Makiling forest.It is currently used in the Philippines as a lumber tree and utilized in many reforestation projects. However, studies have shown that however beneficial S. macrophylla may be to the Philippine preservation and to its purlieu, it also displays adverse effects to the Philippine wild animation. As a recently introduced species, the said tree has been unable to produce a natural web of life around it ther e are no natural consumers of mahogany in the country, and as such, the area around the tree will non be populate by native fauna immediately.It is also suspected that mahogany leaves contain allelopathic compounds. In a study conducted by P. Thinley in 2002, it was shown that S. macrophylla leaves inhibited the growth of genus Pterocarpus indicus. Allelopathic compounds inhibit growth and development of separate plants when introduced to them. Allelopathy is the production of a authorized plant of such compounds and should not to be confused with competition, which may or may not involve allelopathy. Allelopathy is common in the plant kingdom, spread out in random fashion across orders. many plants are deemed invasive due to their allelopathic character and mahogany trees are not exempt. STATEMENT OF THE PROBLEM The study aimed to determine if S. macrophylla can adversely equal the growth of plants in close proximity to it and specifically sought to answer the following questio ns 1) Does mahogany affect the growth of newly planted seedlings based on the seedlings height and weight? 2) Is there a pregnant difference between the growth of seedlings within the proximity of the mahogany tree to that of seedlings within the proximity of a different tree? ) Is there a operative difference between the pick rate of the seedlings within the proximity of the mahogany to that of seedlings within the proximity of a different tree? HYPOTHESIS The mahogany tree has no effect on the growth of newly planted seedlings. SCOPE AND LIMITATIONS OF THE STUDY The study aimed to determine the effect of the mahogany tree on the growth of monggo seedlings based solely on the seedlings weight and height after a specified amount of time.Other possible factors that might affect the growth of the seedlings like availableness of sunlight, presence of possible predators and competition with other plants in the vicinity were not included and was not accounted for in the analysis of t he data obtained. MATERIALS & METHODS The researchers used monggo (Vigna radiata) as the undecided plant. A frequent model plant for laboratory work in Philippine schools, V. radiata is known to be easily grown, requires little maintenance and is fast-growing, which makes it ideal for an investigate limited to a few weeks.Monggo seeds were allowed to germinate by soaking the seeds overnight. Three mahogany trees located along Beta Way in the University of the Philippines Diliman Campus were chosen based on their proximity to other trees. Since competition with other flora could affect the results, it was made sure that the mahogany trees were at least three meters away from the other trees. They were marked as T1, T2 and T3. An acacia tree, Samanea monkeypod, with similar conditions to the experimental trees, particularly to its proximity to other trees, was chosen as the control tree and was marked as T0.To standardize the perplexity of planting on each tree, angles of 200 east of north and 200 west of southern were used to mark radii of 3m each on the north and south side of the tree, respectively. The plots were cleaned and cleared of grass and other flora. Each radius was divided equally into three segments on each segment 10 monggo seeds were planted with a 10cm-interval per seed. Seeds planted on the north side were labelled as N1, N2 and N3 for segments positioned 1m, 2m and 3m away from the tree respectively.The labelling system was used for the south segments. The seeds were uprooted on the 9th day. Seedlings from the same segment were sort together. The heights of the seedlings were measured using a ruler from the apex of its leaves to the tip of the roots. To standardize the measurement of the height of the seedlings, the roots were cut off at the topographic point where the taproot has become soft and fibrous. The seedlings were then weighed using a top-loading balance. The averages of the height and weight of each segment were then determin ed. RESULTS AND DISCUSSIONSwietenia macrophylla is known to have inhibitory effects that affect adjacent growing plants. This is made possible chemically and is referred to generally as allelopathy. The term allelopathy was coined by Molisch in 1937 to refer to biochemical interactions between all types of plants, including microorganisms traditionally placed in the plant kingdom(Waller 1987). It is defined by Rice (1984) as any direct or indirect beneficial or injurious effect of one plant, including microorganisms, on the other by dint of release of chemicals to the environment.Phenolics, terpenoids, alkaloids, polyacetylenes, fatty acids, steroids and many other different secondary metabolites can act as allechemicals (Rice 1984 Waller 1987 Inderjit et al. 1995). However, the undefiled presence of these chemicals does not establish allelopathy, to demonstrate their involvement in allelopathy, it is important to establish 1)their direct release or indirect origin from plant-der ived materials in the environment and 2) that the chemicals are present in sufficient quantities and persist for a sufficient time in soil to affect plant species or microbes (Putnam & Tang 1986).Allelopathy is different to competition the latter defined as the removal or reduction of factors from the environment which are vital to survivability, by some other plant or microorganism sharing the same habitat. Allelopathic chemicals, or allelochemicals, are released by higher plants through several mechanisms. These are volatilization, exudation from roots, leaching from leaves or stem by rain,dew or fog, and from decomposition of residues that contain the allelochemicals. Low molecular weight allelochemicals such as those belonging to terpenes are dispersed by volatilization.Nonvolatile allelochemicals such as alkaloids store on plant surface and find their way to the soil by being leached by rainwater. Allelochemicals secreted through root exudation are of several classes. Some are alkaloids, coumarins, flavonoids, and many other types. Allelochemicals not directly secreted by the plant, in which some pigments are an example, but reach the soil by being released through the decomposition of the plant part that contains them (Leicach et al 2009). In the S. acrophylla, allelochemicals are released by the decomposition of leaf litter. S. macrophylla leaves are a source of tannins, which is evident on the ruby-red brown color of the dry leaves. Tannins are phenolic compounds that also function as an allelochemical. In February, mature S. macrophyllatrees shed their leaves, which will start to decompose on the ground and consequently release tannins from the cells. Aqueous extracts from the leaves of the S. macrophylla has been shown to retard the growth of Pterocarpus indicuss eedlings (Thinley 2002). Several hydrolysable and condensed tannins were identified as growth and germination inhibitors in dry fruit, growth retarders of nitrogen-fixing bacteria in sever al plants, and as reducers of seedling growth in several plants (Waller 1987). According to the data and the statistical analyses, the Swietenia macrophylla has no significant effect to the height, weight and survival of the fittest rate of the Vigna radiate seedlings compared to height, weight and survival rate of the seedlings planted near the Samanea saman. The inhibitory effects exhibited by the S. acrophylla may have been too little or inconsistent to cause a significant change on the growth of the seedlings throughout the duration of the experiment. The compared values of the height, weight and survival rate of seedlings planted near the S. macrophyllaand S. saman are shown in table 1, table 2, and table 3 respectively. The effectiveness of allelochemicals produced by S. macrophylla may have been affected by certain factors. Tannins have been shown to be bound by the humic material I of the soil and presumably inactivated (Waller 1987).The texture of soil has been proved to a ffect the effectiveness of allelochemicals, favouring fine-textured than coarse-textured soil, and secern indicates that the greater retention capacity of fine-textured soils for at least some allelochemicals may be important in the accumulation of physiologically active concentrations of these chemicals (Waller 1987). This may have been the factor that reduced the effects of the allelochemicals involved in our experiment, owing to the beta ways coarser soil composition. It is also proven that allelochemicals are decomposed in the soil, both abiotically or by microorganisms (Waller 1987).It is also observed that distance of the seedlings from the S. macrophylla has no effect on the intensity of inhibition of the growth of the V. radiata. The effect of distance to the height, weight and survival rate of the seedlings is seen in table 4, table 5 and table 6 respectively. This observation may have resulted from the mechanism in which the allelopathic tannins are dispersed. On the co me out of the study, the leaf litter covering the soil surrounding the tree also covered to plots, which meant that the plots may have received variable amounts of allelochemicals as these leached when rains fell.The type of experimentation done was also a factor in investigating the inhibitory effects of allelochemicals. Authors argue whether seed germination is an efficient test in finding out allelopathic potential of phenolic compounds seed germination is an important parameter for evaluating allelopathic potential of phenolic compounds (Rice, 1984 Waller, 1987), However, using seed germination as a bioassay parameter may be of little value (Stowe, 1979 Inderjit & Dakshini, 1995a). This is because allelopathic interactions include both promontory and inhibitory activities of phenolic allelochemicals.ACKNOWLEDGEMENTS The researchers would like to express their heartfelt gratitude to the following who contributed with the expiration of this research * First of all, to the Almig hty God, to whom the researchers dedicate this research study. * To their families and friends who served as their inspirations and the source of very much needed support. * Ms. Lillian Jennifer Rodriguez, for her support and guidance and for lending us pinko ribbons for our experiment. * Mr. James LaFrankie, for his contribution to the success of this research study. CONTRIBUTION OF INDIVIDUAL AUTHORSThea Philea Mostrales abstract of data, abstract of paper, SP proper Greeny Joy Perucho Introduction and Methodology of paper, SP proper Rhoshela Vi Rendon Analysis of data, tables, SP proper John Gregor Rono Results and discussion of paper, SP proper Emmerson Rullog Introduction and Methodology, SP proper Riffcord R-Denz Tabula Results and discussion, SP proper REFERENCES Leicach, S. R. , Sampietro D. A. , Narwal, S. S. , Allelochemicals theatrical role in Plant Environment Interaction, Studium Press 2009 Plant phenolics in allelopathy. The Botanical Review. New York Botanic al Garden. 996. HighBeam Research. 4 April 2013 The IUCN Red List of Threatened Species. International Union for Conservation of Nature and Natural Resources. 4 April 2013 Thinley P. 2002. Negative interaction between large leaf mahogany (*Swietenia macrophyllaKing) and some indigenous tree secies in lowland forest of Mt. Makiling allelopathy, a possible cause? Unpublished B. S. Forestry Thesis, UPLB-CFNR. Waller, G. R. , Allelochemicals Role in Agriculture and Forestry, American Chemical Society, Washington, D.C. 1987 TABLES Table 1. Independent Samples T-test of the Height of Monggo Plants at 0. 05 significance level Levenes Test for play offity of Variances t-test for Equality of averages F Sig. t df Sig. (2-tailed) rigorous Difference Std. Error Difference 95% Confidence Interval of the Difference Lower Upper height Equal variances assumed . 167 . 704 . 737 4 . 502 1. 000428290 1. 357522153 -2. 768657448 4. 769514028 Equal variances not assumed . 737 3. 900 . 503 1. 000428290 1. 357522153 -2. 807242567 4. 808099147 Table 2.Independent Samples T-test of the Weight of Monggo Plants at 0. 05 significance level Levenes Test for Equality of Variances t-test for Equality of Means F Sig. t df Sig. (2-tailed) Mean Difference Std. Error Difference 95% Confidence Interval of the Difference Lower Upper weight Equal variances assumed . 344 . 589 -. 445 4 . 679 -. 006665782 . 014968143 -. 048224010 . 034892446 Equal variances not assumed -. 445 3. 819 . 680 -. 006665782 . 014968143 -. 049013784 . 035682220 Table 3. Independent Samples T-test of the Survival ramble of Monggo Plants at 0. 5 significance level Levenes Test for Equality of Variances t-test for Equality of Means F Sig. t df Sig. (2-tailed) Mean Difference Std. Error Difference 95% Confidence Interval of the Difference Lower Upper weight Equal variances assumed . 344 . 589 -. 445 4 . 679 -. 006665782 . 014968143 -. 048224010 . 034892446 Equal variances not assum ed -. 445 3. 819 . 680 -. 006665782 . 014968143 -. 049013784 . 035682220 Table 4. ANOVA of the Height of Monggo Plants at 0. 05 significance level Sum of Squares df Mean Square F Sig. Between Groups 14. 889 2 7. 44 4. 598 . 062* Within Groups 9. 715 6 1. 619 Total 24. 604 8 *no significant difference Table 5. ANOVA of the Weight of Monggo Plants at 0. 05 significance level Sum of Squares df Mean Square F Sig. Between Groups . 003 2 . 001 1. 960 . 221* Within Groups . 005 6 . 001 Total . 008 8 *no significant difference Table 6. ANOVA of the Survival Rate of Monggo Plants at 0. 05 significance level Sum of Squares df Mean Square F Sig. Between Groups . 011 2 . 005 . 487 . 637* Within Groups . 065 6 . 011 Total . 076 8 *no significant differenceTable 7. Average Height, Weight, and Survival Rate of Monggo Plants Tree Distance from tree (m) Height (cm) Weight (g) Survival Rate T0 1 16. 67 0. 2361 0. 9 2 15. 49 0. 2347 0. 95 3 13. 15 0. 2074 0. 95 T1 1 16. 21 0. 2255 1. 0 2 17. 02 0. 2567 0. 75 3 16. 73 0. 2380 0. 75 T2 1 13. 00 0. 1688 0. 8 2 18. 99 0. 2553 0. 85 3 16. 55 0. 2340 1. 0 T3 1 14. 22 0. 1884 0. 95 2 16. 86 0. 1928 0. 9 3 15. 07 0. 2183 0. 9 T0 = controlled tree S. saman T1 = 1st replicate of S. macrophylla T2 =2nd replicate of S. macrophylla T3 = 3rd replicate of S. macrophylla