Molecular DNA Markers In Parentage Identification And Clonal Genetic Structure Of Cryptocoryne ×Purpurea Ridl. Nothovar. Purpurea Hybrid Populations
| dc.contributor.author | Rusly, Rosazlina | |
| dc.date.accessioned | 2017-02-03T01:34:49Z | |
| dc.date.available | 2017-02-03T01:34:49Z | |
| dc.date.issued | 2016-07 | |
| dc.description.abstract | Natural hybridization has been confirmed to occur frequently in Cryptocoryne Wydler and considered a source of taxonomic complexity in this genus. This research involved a combined study of DNA sequencing data (internal transcribed spacer (ITS) of nuclear ribosomal DNA and matK gene of chloroplast DNA) to identify the parentage of a putative Cryptocoryne hybrid from Peninsular Malaysia. Based on the morphological characters the plant was tentatively identified as Cryptocoryne ×purpurea Ridl. nothovar. purpurea; a sterile plant which has long been considered a hybrid, possibly from two related species; Cryptocoryne cordata Griff. var. cordata and Cryptocoryne griffithii Schott. The hybrid status and its putative parents was independently confirmed by the presence in hybrid individuals of an additive ITS sequence pattern from these two parental species. The hybrid plants shared the identical matK sequences from C. cordata var. cordata and C. griffithii, which indicated that both putative parental species had functioned as the maternal parent. Reciprocal hybridization between the two species seems to be symmetrical rather than unidirectional. This study also aimed at developing microsatellite markers using next generation sequencing (Roche 454 pyrosequencing) from the genomic DNA of C. cordata var. cordata. Eleven new polymorphic loci were successfully isolated and all loci departed significantly from Hardy-Weinberg Equilibrium. No null alleles and no significant linkage disequilibrium were detected across any pairs of loci. Cross species amplification was successful across a panel of eleven Cryptocoryne species. The high similarities of allele sizes between C. ×purpurea nothovar. purpurea, C. cordata var. cordata and C. griffithii supported the idea that C. cordata var. cordata and C. griffithii were the parents of C. ×purpurea nothovar. purpurea. This study investigated six natural populations of C. ×purpurea nothovar. purpurea to examine the clonal diversity and spatial genetic structure among populations using Amplified Fragment Length Polymorphism (AFLP) analysis. The level of clonal genetic diversity in C. ×purpurea nothovar. purpurea was low because of the apparent high sterility of the populations due to their hybrid origin. However, the occurrence of different genotypes in certain populations give an evidence of the frequency of hybrid formation events from different parental populations and also somatic mutations. Cluster analyses revealed two distinct groups with the majority of genetic variation distributed among- rather than within populations between regions and showed correlation between genetic distances with geographical distance. These findings demonstrate that this sterile clonal taxon can preserve substantial amounts of genetic variation. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/3659 | |
| dc.subject | Molecular DNA markers in parentage identification | en_US |
| dc.subject | and clonal genetic structure of cryptocoryne ×purpurea ridl. | en_US |
| dc.title | Molecular DNA Markers In Parentage Identification And Clonal Genetic Structure Of Cryptocoryne ×Purpurea Ridl. Nothovar. Purpurea Hybrid Populations | en_US |
| dc.type | Thesis | en_US |
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