Kesan Alelopati Chromolaena odorata (L.) R.M. King & H.Rob. dan Mikania micrantha Kunth ke atas rumpai dan sayuran terpilih
Studies have been: done to investigate the allelopathic effect of Chromolaena odorataand Mikania micrantha on the germination, growth and biochemical activities ofselected bioassay species (three weed species namely Eleusine indica, Cyperus iriaandAgeratum conyzoides and three vegetable crop species...
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| Format: | Thesis Book |
| Language: | Malay |
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| Summary: | Studies have been: done to investigate the allelopathic effect of Chromolaena odorataand Mikania micrantha on the germination, growth and biochemical activities ofselected bioassay species (three weed species namely Eleusine indica, Cyperus iriaandAgeratum conyzoides and three vegetable crop species namely Zea mays, Brassicachinensis and Cucumis sativus) in Malaysia. The experiments were done in thelaboratory and greenhouse to investigate the effect of aqueous leaf extract, leaf debrisand weed infested soil on the germination and growth of bioassay species. Threeconcentrations of aqueous leaf extract (12.5, 25 and 50 g/L) and leaf debris (2.5, 5.0and 10.0 g/500 g soil) were used in these experiments. Besides, the allelopathic effectof C. odorata and M. micrantha leaves were also investigated on the malondialdehyde(MDA) content, concentration of protein and the enzyme activities of peroxidase(POD) and catalase (CAT) in the bioassay species. Studies have also been done todetermine the effect of leaf leachate (sandwich method), leaf volatilization (dish packmethod) and root exudate (plant box method) of C. odorata and M. micrantha on thegermination and growth of bioassay species. Results showed that the growth of E.indica,A. conyzoides and B. chinensis were significantly inhibited by more than 90%of control when 50.0 g/L concentration of C. odorata and M micrantha aqueous leafextract were applied. As concentration increased, the germination rate of bioassayspecies decreased. Leaf debris of C. odorata and M micrantha significantlystimulated the growth of bioassay crop species especially B. chinensis. However? leafdebris of M. micrantha significantly inhibited the germination and by more than 50%of control the growth of C. iria and A. conyzoides at concentration of 10.0 g / 500 gsoil. Meanwhile, only the germination of B. chinensis was inhibited by 43% whengrown in weed infested soil. Based on these experiments, B. chinensis was highlyinhibited by C. odorata and M micrantha leaves compared to other species. Thecontent of MDA and the enzyme activities of catalase were increased by more than50%compared to control but the concentration of protein decreased by 38% of controlin the root part of B. chinensis when applied by 50.0 g/L concentration of C. odorataaqueous leaf extract. Studies also indicated that the leaf leachates of 50 mg of C.odorata and M micrantha inhibited the radicle length of B. chinensis by more than90% of control. Besides, the radicle length of B. chinensis was inhibited by 64% ofcontrol at the distance of 41 mm from the volatilization of C. odorata leaf.Meanwhile, the root exudates of C. odorata and M. micrantha inhibited the rootlength by 49% and 34% of control, respectively. Thus, allelopathic potential of C.odorata and M micrantha leaf were concentration dependent and also depended onthe bioassay species. Based on allelochemicals screening of volatile organiccompounds by HS-GC-MS, the leaf of C. odorata released a-pinene, gennacrene Dand B-pinene, whilst M micrantha leaf released gennacrene D, -himachalene into the environment. |
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| Physical Description: | xxiii, 228 leaves: ill. (some col.); 30 cm. |
| Bibliography: | Includes bibliographical references (p. 162-190) |