Assessment of genetic relationships among rhododendron species, varieties and hybrids by RAPD analysis (original) (raw)
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Genetic Diversity and Relationship of Rhododendron Species Based on RAPD Analysis
2008
A total of 43 samples belonging to Rhododendron species were studied among 49 using RAPD analysis, they including 25 samples of 23 species in subgenus Hymenanthes, 18 samples of 18 species belong to subgenus Rhododendron and six samples of two species belong to subgenus Pseudorhodorastrum. An obtained 407 DNA fragments were amplified using 24 primers, among which 399 were polymorphic with 98.03%. The genetic Similarity Coefficient (GS) was ranging from 0.2623 to 0.9059. The dendrogram obtained by unweighted pair group method using an arithmetic average (UPGMA) showed that RAPD analysis could divided the samples into three subgenus based on morphological characters. Subgenus Hymenanthes had a closer relationship with subgenus Rhododendron than with subgenus Pseudorhodorastru, however subgenus Pseudorhodorastru can not be merged into subgenus Rhododendron. The obtained RAPD analysis results suggested that subgenus Hymenanthes was more primitive in phylogeny and subgenus Pseudorhodorastru was the evaluative group in morphological characters, while subgenus Rhododendron was a transitional group.
Genetic Analysis of Rhododendron Mutants Using Random Amplified Polymorphic Dna (Rapd)
Pak. J. Bot, 2011
The aim of our study was to consider the efficiency of randomly amplified polymorphic DNA (RAPD) analysis to show the differences between Rhododendron mutants and control plants. The mutant plantlets were selected due to their better In vitro shoot and root regeneration relative to control in both varieties. Six mutant plantlets from Alfred and seven mutant plantlets from Paars variety were selected from M 1 V 2 generations. These mutants were selected from plantlets which were irradiated with doses 5 and 10 Gy. They were grown up In vitro conditions. The dendrogram shows one big cluster and the others to be distinguished. Genetic variability induced with gamma ray and RAPD methods were used to detect mutations at the Rhododendron shoot culture. Our results show that Rhododendron mutants were district from controls.
Genome, 2010
Genomic in situ hybridization (GISH) has been proved to be the most effective and accurate technique for confirmation of hybrid character. The objective of our study was to adapt and optimize a GISH protocol for identification of donor chromatin in hybrids obtained by interspecific crosses between five Rhododendron taxa (R. aureum, R. brachycarpum, R. catawbiense 'Catharine van Tol', R. catawbiense 'Nova Zembla', and R. yakushimanum 'Koichiro Wada'). Positive results were obtained only when we used mitotic chromosome spreads prepared from anthers. The best differentiation of maternal and paternal chromosomes in hybrid genomes was obtained when 50 ng of probe was applied together with blocking DNA at a concentration of 3.0 mg/mL. The results demonstrate that GISH is a practical tool for detection of alien genomes and analysis of the constitution of the chromosomes in rhododendron hybrids.
Identification of 33 Chinese Rhododendron species using matK sequences and AFLP data
Acta horticulturae
The current assortment of pot azalea (Rhododendron simsii hybrids) has been created from a relatively narrow basis of collectors material brought from the far east. R. simsii, the main ancestor, originates from hilly areas in China, Thailand, Laos and Burma. However several other species from the Tsutsusi subgenus, from South-Asia and Japan might have contributed e.g. R. indicum, R. mucronatum, and R. scabrum. From the Kunming Institute of Botany (China) 33 seed lots from natural populations in mountain area?s with an altitude ranging from 250 to 3500 m were obtained. The majority of these Rhododendron species belong to the Tsutsusi subgenus; 8 are R. simsii. Per population 10 plants were analysed by AFLP using 3 primer combinations. They were compared to the breeders pot azalea genepool (70 plants, some with common pedigree and bud sports). AFLP was performed using the commercially available kit for fluorescent fragment detection on an ABI Prism 377 DNA Sequencer. The genetic diver...
Scientia Horticulturae, 2000
Genetic relationships among specimens of the 15 currently recognized species in Rhododendron L. section Pentanthera G. Don were derived from sequence comparisons of the internal transcribed spacer (ITS) region. Sequences of the entire ITS region including ITS1, ITS2, and the 5.8S subunit were generated by direct sequencing of polymerase chain reaction (PCR) ampli®ed fragments. Rhododendron vaseyi A. Gray, Rhododendron section Rhodora (L.) G. Don was used as an outgroup. Aligned sequences of the 16 taxa resulted in 688 characters. The region contained 38 variable sites and eight phylogenetically informative characters. A bootstrap analysis was performed and a dendrogram was constructed with MEGA. Divergence values among the taxa were extremely low ranging from 0.00 to 3.51%, providing support to traditional views of section Pentanthera as a group of very closely related species. #
Botanical Journal of the Linnean Society, 2008
Rhododendron (Ericaceae) is a large woody genus in which hybridization may play an important role in evolution and speciation, particularly in the Sino-Himalayan region, where many interfertile species often occur sympatrically. Natural hybridization between Rhododendron delavayi Franch. (= R. arboreum ssp. delavayi) and Rhododendron decorum Franch., which belong to different subsections of subgenus Hymenanthes, was investigated. Material of R. delavayi and R. decorum and their putative hybrids was collected from the wild. On the basis of morphology, chloroplast DNA, nuclear ribosomal DNA, and AFLP profiles, hybrids and parental species were identified. Hybridization occurred in both directions, but was asymmetrical, with R. delavayi as the major maternal parent in the hybrid zone. Most of the hybrids possessed intermediate phenotypes, and amongst the 15 hybrids detected were six F1s, two F2s, one first-generation backcross to R. delavayi, and two first-generation backcrosses to R. decorum. This indicates that, if Rhododendron underwent rapid radiation in this region, it did so in spite of permeable species barriers.
Origin of the Rhododendron kaempferi related species and cultivars estimated by SSR analysis
Acta Horticulturae, 2019
More than 30 native evergreen azalea species have been recognized in Japan, from which many cultivars have been produced since the Edo era (1603-1867). Rhododendron kaempferi var. kaempferi Planch. (= R. kaempferi) is classified in subsection Tsutsusi and widely distributed in mountains and suburban forests throughout Japan. There are several native species and cultivars closely related to R. kaempferi. Our previous study revealed that the origin of R. transiens and R. × hannoense are considered as interspecific hybrids of R. kaempferi and other evergreen azalea species and cultivars. Recently, we also applied SSR analysis to other R. kaempferi related species and cultivars such as R. komiyamae and R. kaempferi var. mikawanum. Cluster analysis showed that R. komiyamae and R. kaempferi var. mikawanum were related to R. kaempferi and not related to other evergreen azalea species, which means they originated from R. kaempferi and not from hybridizing with other azalea species. From the results of SSR analysis using R. kaempferi and its related species and cultivars, we propose three models of establishment of R. kaempferi related species and cultivars: 1) natural mutation, 2) interspecific hybridization between wild species, and 3) hybridization between wild species and cultivars.
…, 2007
Morphological analysis historically has been used to determine parentage of unknown hybrids. This can be difficult when potential parents have similar appearance, as in the case of three azaleodendron cultivars, Rhododendron L. 'Fragrans', 'Fragrans Affinity', and 'Fragrant Affinity'. These cultivars are similar in name and appearance, and all are purported hybrids of R. catawbiense Michx. or R. ponticum L. and R. viscosum (L.) Torr. Amplified fragment length polymorphism (AFLP) analysis was conducted to determine whether the cultivars are synonyms or distinct clones and to elucidate the parental species. The three cultivars, suspected to be hybrids between taxa in subgenera Hymenanthes (Blume) K.Koch (evergreen rhododendrons) and Pentanthera (G.Don) Pojarkova (deciduous azaleas), and related taxa from each subgenus were evaluated using 31 AFLP primer combinations. Genetic similarity, calculated using Jaccard's coefficient, among the hybrids ranged from 53% to 71%, indicating that they are distinct cultivars and not a single clone. Genetic similarity was highest between the hybrids and R. ponticum among the evergreen rhododendrons, and R. viscosum among the deciduous azaleas. A dendrogram generated using the genetic similarity matrix grouped taxa into their respective subgenera, with the three cultivars nested intermediately between subgenera but more closely with subgenus Hymenanthes and particularly R. ponticum, suggesting it is the evergreen rhododendron parent. Furthermore, principle components grouped R. ponticum more closely with the hybrids and there were 18 AFLP fragments unique to R. ponticum and the hybrids. However, no unique AFLP bands were shared exclusively among the hybrids and the purported deciduous azalea parent, R. viscosum, suggesting that the original azalea parents may have been hybrids.