Pusat Pengajian Sains Kajihayat - Tesis
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Browsing Pusat Pengajian Sains Kajihayat - Tesis by Subject "September 2024"
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- PublicationCharacterisation And Pathogenicity Of Fungi Causing Sooty Blotch And Flyspeck (Sbfs) Disease Of Mango (Mangifera Indica L.) In Peninsular Malaysia(2024-09)Tham, Khai XinThe sooty blotch and flyspeck (SBFS) disease complex, caused by multiple fungal species, leads to black smudges and clusters of black spots on various fruits, including mango, impacting their marketability as fresh fruit. Although not previously reported in Malaysia, field visits in 2018 found similar SBFS disease symptoms on mango in various orchards in Perak. Therefore, this research aimed to: 1. Isolate and identify SBFS fungi on mango collected from Perak, Pahang, and Perlis based on morphological and molecular approaches; 2. Assess the phylogenetic relationship among the SBFS fungal isolates; 3. Determine the pathogenicity of the SBFS fungi isolated from mango. A total of 87 mango fruit showing SBFS disease symptoms were collected, and the number of SBFS colonies on each mango (CPM) and the percentage area of SBFS infection were determined. Subsequently, 2106 mango peel samples were obtained and subjected to isolation. Morphological characterization resulted in the identification of 33 pure cultures belonging to SBFS fungal genera, such as Zasmidum, Peltaster, Exophiala, Pseudocercospora, and Ochroconis. The DNA sequencing of the internal transcribed spacer (ITS) and large subunit (LSU) confirmed 18 representative isolates as distinct species, including Z. citrigriseum, Z. aporosae, Peltaster-like species, ‘Pseudopeltaster’, E. bergeri, E. spinifera, Pseudocercospora species, and O. cordanae. Phylogenetic analyses using maximum parsimony (MP) and maximum likelihood (ML) approaches indicated that the SBFS fungal complex on mango was related to both known SBFS members globally and non-SBFS taxa.
- PublicationEfficacy And Autodissemination Of Aedestech Mosquito Home System (Amhs) On Aedes Mosquitoes In Laboratory And Small-scale Field Study(2024-09)Universiti Sains MalaysiaOvitrap deployment stands as a viable strategy for Aedes mosquito control. This study evaluated the efficacy of an autodissemination ovitrap called AedesTech Mosquito Home System (AMHS), which incorporates pyriproxyfen. This study encompassed laboratory trials and a small-scale field study. The objective of the field study was to comprehensively assess the impact of AMHS on Aedes, non-target insects, and dengue infection rates in mosquitoes. Within the laboratory trials, these investigations unfolded across two species of mosquitoes: Aedes albopictus and Aedes aegypti. Three distinct facets were explored in the laboratory trials: the influence of an attractant on the oviposition, the effect of trap positioning on oviposition, and the selection of oviposition sites. The field study conducted in Asoka Apartment, Pulau Pinang, unfolded in three successive periods: baseline study, effectiveness study, and autodissemination study. Concurrently, the accuracy of the AedesTech Mobile App (ATA) was scrutinized. The laboratory results indicated the Mosquito Home Aqua (MHAQ) solution with attractant consistently attracted Ae. aegypti effectively (Welch's ANOVA, F(2,68.66)=5.22,p=0.01). However, its efficacy with Ae. albopictus was suboptimal compared to other treatments (Two-way ANOVA, F=0.16,df=2,p>0.05), highlighting the need for considering additional attractants. Notably, the placement of AMHS exhibited no discernible impact on its attractiveness for both mosquito species (T-test,p>0.05), underscoring the flexibility in trap deployment.
- PublicationMicropropagation Of Fig (Ficus Carica) Cv.japanese Btm 6(2024-09)Lee, Yong JunFicus carica L., commonly known as the fig tree and belonging to the Moraceae family, is cultivated in subtropical and Mediterranean regions worldwide. This fruit-bearing tree is rich in natural fibre, minerals, and vitamins. However, conventional propagation methods, such as grafting, hardwood cutting, and air layering, are inefficient for establishing viable plant stocks in Malaysia. The primary factor to this inefficiency is the suboptimal rooting efficiency associated with these conventional propagation techniques. However, experiments have shown that vermicast can enhance root induction, improving the survival rate of plantlets in these methods. Therefore, vermicast can be as an option to help with root induction."Vermicast, a byproduct of organic matter decomposition by earthworms, is known for its advantageous impact on plant growth in agriculture. This study aims to establish methods for the micropropagation of Ficus carica cv. Japanese BTM 6 and to evaluate the regeneration effects of vermicast solution on in vitro shoot cultures. Sterile nodal segment explants were subjected to treatments involving various types and concentrations of organic additives, including potato, banana, and coconut water. The induced shoots were further treated with different combinations and concentrations of cytokinins (meta-topolin, BAP, 2ip, zeatin, and TDZ) and auxins (IAA, IBA, NAA) to promote shoot multiplication. Additionally, the induced shoots were assessed for their response to varying concentrations of vermicast solution (ranging from 5% to 30%) in terms of in vitro shoot and root regeneration. Plantlets with roots were acclimatized with different potting mix and vermicast as the acclimazation media with and without vermicast solution during watering.
- PublicationUnveiling Limestone Orchid Hotspots In The Karst Hills Of Northern Peninsular Malaysia(2024-09)Bakar, Shahrul Nizam AbuA significant knowledge gap remains regarding the diversity of orchids in the limestone hills of northern Peninsular Malaysia, especially in Kedah and Perak. Addressing this knowledge gap requires thorough comprehensive assessments and proper documentations of orchid diversity and endemism in this unique karst habitat. To fulfill this, 10 field assessments have been carried out between Mac 2021 to November 2022 to five selected limestone hills in Kedah and Perak state boundary, aimed to assess the diversity of limestone orchids and their species richness, evaluating the threats facing by the orchids and their natural habitat, determining areas with high diversity hotspots, and proposing new conservation status for the rare and endangered orchid species with restricted distribution and small population size. A total of 134 orchid species represented in 68 genera have been recorded from Gunung Batu Putih, Gunung Pong, Gunung Baling, Gunung Pulai and Gunung Fakir Terbang. From the five limestone hills, Gunung Batu Putih was known to have the most richest and diverse orchid species with a total of 105 species from 58 genera (H’ = 4.504 and D = 0.9875), followed by Gunung Pong with 103 species from 57 genera (H’ = 4.471 and D = 0.9867), Gunung Baling with 93 species from 50 genera (H’ = 4.366 and D = 0.9853), Gunung Pulai with 90 species from 49 genera (H’ = 4.296 and D = 0.9838) and lastly Gunung Fakir Terbang with 67 species from 29 genera (H’ = 3.88 and D = 0.9756). From the account, 36 species are recognized as new records to Kedah and three species as new records to Peninsular Malaysia, namely Anoectochilus sanguineus P.T.Ong & P.O’Byrne, Bulbophyllum meson J.J.Verm., Schuit. & de Vogel and Luisia brachystachys (Lindl.) Blume. Three species endemic to Peninsular Malaysia were gathered in this study which are Anoectochilus sanguineus, Cheirostylis goldschmidtiana Schltr. and Phalaenopsis appendiculata Carr. This study has also revealed the relationships between the diversity of orchids and the influences of certain environmental factors. Only soil pH and relative humidity (RH) were found to be positively correlated with orchid’s species richness. The analysis on species distribution data has shown that Gunung Batu Putih to have the highest number of hotspot areas followed by Gunung Pong, Gunung Baling, Gunung Pulai and Gunung Fakir Terbang. New conservation status have been proposed to the selected rare and endangered orchids, which four species were proposed as Critically Endangered (CR) (Aerides krabiensis, Anoectochilus albolineatus, Goodyera hispida and Phalaenopsis appendiculata), and four as Endangered (EN) (Anoectochilus sanguineus, Cheirostylis goldschmidtiana, Paphiopedilum niveum and Spathoglottis hardingiana).