Amplified Fragment Length Polymorphism Fingerprinting of 16 Banana Cultivars (Musa cvs.)

Banana is one of the most important subtropical crops. The genetic system, however, is relatively unknown and is complicated by specific interhybridization, heterozygosity, and polyploidy, which are common in most clones. These factors make identification of closely related banana cultivars difficult, particularly when sterile. Amplified fragment length polymorphism (AFLP) analysis using eight primer combinations was carried out on 16 banana cultivars. Results showed that AFLP could be used to distinguish the different cultivars by their unique banding patterns. Unique AFLP molecular markers were detected for 12 banana cultivars, which can be used to develop specific probes for identification purposes. The cluster analysis also revealed the need for a link between genotype studies using molecular techniques and the current system of classification of Musa cultivars based purely on morphological traits.     

Novel alleles of 31-bp VNTR polymorphism in the human cystathionine β-synthase (<Emphasis Type="Italic">CBS</Emphasis>) gene were detected in healthy Asians

A 31-bp variable number of tandem repeats (VNTR) polymorphism of the cystathionine β-synthase (CBS) gene was earlier reported in Caucasians of predominantly European descent and Indo-Caucasoid populations.We report here for the first time, the detection of allele 20, which was absent in Caucasian and Indo-Caucasoid populations, as a common allele present in Singaporean Chinese (6.25%), Indians (11.7%), and Malays (11.5%). Hence, allele 20 might be a specific allele for Asian populations. A relatively common allele 19 found in the Caucasian and Indo-Caucasoid populations (10.4%–10.6%) was absent in the Asian samples of this study. Therefore, allele 19 might be a specific allele for the Caucasian populations. A novel and rare allele 13, which was not reported before in the Caucasian and Indo-Caucasoid populations, was found in 0.5% of Singaporean Chinese as genotype 13/17 heterozygotes. The presence of alleles 13 and 20 were verified by DNA sequencing. There were five new genotypes (13/17, 16/20, 17/20, 18/20 and 20/20) not reported before in the Caucasian and Indo-Caucasoid populations, detected in this study. Nine genotypes (15/18, 16/18, 16/21, 17/19, 18/19, 18/21, 19/19, 19/21 and 21/21) which were present in the Caucasian and/or Indo-Caucasoid populations were absent in this study. Our results showed that CBS 31-bp VNTR polymorphism has a distinct genetic difference in allele and genotype frequencies between the European Caucasians, Indo-Caucasoid and Asian populations.     

A Study of Genetic Variation and Relationships within the Bamboo Subtribe Bambusinae using Amplified Fragment Length Polymorphism

Taxonomic and systematic studies of the woody bamboos are traditionallybased on floral morphology, which can cause problems in identificationdue to the lack of, or infrequent, flowering. Limited studieshave been conducted using molecular techniques to overcome thisproblem. In this study, we used amplified fragment length polymorphisms(AFLPs) to conduct a study of four genera of bamboos (Bambusa,Dendrocalamus, Gigantochloa andThyrsostachys ) in the subtribeBambusinae. AFLP analysis using eight primer combinations wascarried out on 15 species of bamboo. Results showed that AFLPsdistinguish the different species by their unique banding patterns.Unique AFLPs were detected in 13 of the 15 species examined.The six Bambusa species examined separated into two clusters.The sixGigantochloa species studied formed a discrete clusterdiverging from one of the Bambusa clusters, whileThyrsostachyswas less similar to the Bambusa clusters. The similarity indexbetween B. lako and G. atroviolacea was the highest, suggestingthat B. lako is more appropriately included within the genusGigantochloarather than the genus Bambusa. The two Dendrocalamus speciesexamined were very different with D. brandisii clustering withinone of the Bambusa clusters and D. giganteus appearing as avery distant species. These results support the contention thatcritical study of the genus Dendrocalamus is required. The useof AFLPs for identification of particular bamboo species, aswell as for the study of relationships within the subtribe,will be useful for industrial purposes and for systematic studies.Copyright 2000 Annals of Botany Company Bamboo, Bambusinae, Bambusa, Gigantochloa, Dendrocalamus, Thyrsostachys, AFLP, diversity, AFLP markers     

Intergeneric and Interspecific Relationships in Araceae tribe Caladieae and Development of Molecular Markers using Amplified Fragment Length Polymorphism (AFLP)

Since amplified fragment length polymorphism (AFLP) analysishas proved useful in distinguishing cultivars of Caladium, itwas used to assess the status of species of Caladium vs. Xanthosoma,both in tribe the Caladieae, and to reassess the position ofHapaline in the same tribe. AFLP analysis using three primercombinations was carried out on four species of Caladium(C.bicolor, C. humboldtii, C. lindenii and C. schomburgkii). Resultsshowed that AFLP can distinguish between the different speciesby their unique and different banding patterns. AFLP analysisconfirmed that C. humboldtii is a species distinct from C. bicolorand that C. lindenii is a true Caladium species and does notbelong to Xanthosoma. UPGMA cluster analysis showed that C.bicolor and C. schomburgkii are most similar and that C. humboldtiiis closer to the C. bicolor / C. schomburgkii cluster comparedwith C. lindenii. Genetic relationships between Caladium, Xanthosoma,Hapaline, Alocasia and Protarum were also examined by AFLP analysisusing eight primer combinations. Several useful molecular markerswere specific either to Caladium orXanthosoma , so that AFLPcan be used to distinguish species of these two genera. Geneticanalysis of the genera examined confirms that the Caladieaeand Colocasieae tribes are distinct and that Hapaline fallswithin the tribe Caladieae and that Protarum is most distantfrom all the genera examined. Copyright 2000 Annals of BotanyCompany Araceae, Caladium, Xanthosoma, Hapaline, Alocasia, Protarum, AFLP DNA fingerprinting, diversity, AFLP markers