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Title:	Genomic diversity of acacia mangium and acacia auriculiformis germplasms and commercial plantation seedlings using snp markers and health assessment of Acacia mangium
Authors:	Mandy Maid (P63259)
Supervisor:	Wickneswari Ratnam, Prof. Dr.
Keywords:	Mangium Acacia Forests and forestry -- Malaysia Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	2019
Description:	Acacia mangium and A. auriculiformis are tropical lowland species widely planted in plantation forests in humid tropical areas including Malaysia. In recent years, Acacia plantations throughout Asia showed signs of disease susceptibility particularly to root rot, fungal wilt, canker and dieback. SNP marker is a promising tool for detecting disease resistance genes, construction of genetic maps, mapping traits, genetic diagnosis and population structure analysis. The aims of this study were to determine the genomic diversity of A. auriculiformis and A. mangium natural germplasms and commercial plantation seedlings using SNP analysis; and to determine the incidences and severity of canker, wilt and dieback disease in A. mangium plantations in Sabah, Malaysia. Two hundred Acacia samples were genotyped using 230 SNPs on the lllumina Bead Xpress, and another 250 Acacia samples were genotyped using 132 SNPs on the Sequenom MassARRAY platform. Data generated from the genotyping platform was merged to determine genetic variation and population structure. A total of 4 (6.7 %) and 10 (15.6 %) putative FST outlier SNPs for A. auriculiformis and A. mangium respectively. Genetic variation within the population was greater compared to genetic variation between populations and between regions of A. auriculiformis and A. mangium. Heterozygosity of A. mangium natural populations (He = 0.28) was not significantly different from A. auriculiformis (He = 0.26) natural populations, nor with the commercial A. mangium seedlings (He = 0.28). New alleles were found at 30 SNP loci of the commercial A. mangium seedlings which contributed to the high heterozygosity. Genetic differentiation among populations (Gst) was higher compared to genetic differentiation among geographic regions (Gzt) for A. mangium (0.29 and 0.15 respectively) and A. auriculiformis (0.24 and 0.13 respectively). Cluster analysis showed two and three clusters within the A. mangium and A. auriculiformis natural populations respectively which corresponded to their geographic distribution. The A. mangium commercial plantation seedlings were genetically similar and grouped together with the PNG natural populations. Ganui and Padas commercial plantation seedlings were closely related to the Makapa, Lower Fly and Lake Murray W.P. PNG natural populations. The Bongkol commercial plantation seedlings were closely related to Upper Aramia Prov., Pongaki-Oriomo and Bituri W.P. PNG natural populations. Canker, wilt and dieback disease incidence and prevalence were on average less than 6 % and 20 % respectively at Ganui, Padas and Bongkol in Sabah. Based on fungal morphological and DNA sequence characterization, Hypoxylon monticulosum, Fusarium solani, F. polyphialidicum, F. fujikuroi, F. verticillioides and Bionectria sp. were identified as putative causal pathogens, and Lasiodiplodia theobromae and L. pseudotheobromae were verified as fungal pathogens of wilt, canker and dieback disease of A. mangium.,'Certification of Masters/Doctoral Thesis' is not available,Ph.D.
Pages:	344
Call Number:	SD397.M23M335 2019 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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