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RAPD
About: RAPD is a research topic. Over the lifetime, 15960 publications have been published within this topic receiving 360391 citations.
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TL;DR: The analysis of plants of two sugarcane varieties cultivated in vitro from meristems showed that variety RB83-5486 was more unstable than variety SP80-185, and there was no direct association with the stage of subcultivation.
Abstract: The RADP (Random amplified polymorphic DNA) technique was used to detect tissue-culture-induced variations in sugarcane. Plants of the Brazilian variety RB83-5486 propagated via rhizomes and via meristem cultures were studied. The polymorphism rate for 98 RAPD loci was 6.93% when the plants derived from meristems. Besides, in order to evaluate the influence of the number of subcultures on the generation of somaclonal variation, field-grown RB83-5486 plants derived from 10 meristems were studied after five subcultivations. Although different rates of polymorphism were observed, there was no direct association with the stage of subcultivation. The analysis of plants of two sugarcane varieties cultivated in vitro from meristems showed that variety RB83-5486 was more unstable than variety SP80-185.
80 citations
TL;DR: In this article, the authors investigated the genetic variation among 12 populations of the American chestnut (Castanea dentata) and found that approximately 10% of the allozyme diversity resided among populations.
Abstract: Genetic variation among 12 populations of the American chestnut (Castanea dentata) was investigated. Population genetic parameters estimated from allozyme variation suggest that C. dentata at both the population and species level has narrow genetic diversity as compared to other species in the genus. Average expected heterozygosity was relatively low for the population collected in the Black Rock Mountain State Park, Georgia (He = 0.096 +/- 0.035), and high for the population in east central Alabama (He = 0.196 +/- 0.048). Partitioning of the genetic diversity based on 18 isozyme loci showed that ~10% of the allozyme diversity resided among populations. Cluster analysis using unweighted pair-group method using arithmetric averages of Rogers' genetic distance and principal components analysis based on allele frequencies of both isozyme and RAPD loci revealed four groups: the southernmost population, south-central Appalachian populations, north-central Appalachian populations, and northern Appalachian populations. Based on results presented in this study, a conservation strategy and several recommendations related to the backcross breeding aimed at restoring C. dentata are discussed.
80 citations
TL;DR: In order to identify mycorrhizal fungi during their symbiotic phase, a nonpolymorphic RAPD band identified as marker for some isolates of Glomus mosseae was purified from agarose gels and cloned in a bluescript vector.
Abstract: Mycorrhizal fungi are usually identified on the basis of the morphological characters shown by fruit bodies, spores, vegetative mycelia or symbiotic structures. The development of molecular techniques provides a valuable and alternative approach to identify mycorrhizal fungi, especially when it is difficult to gather a sufficient number of data on morphological features. Short arbitrary oligonucleotides were used as primers for the amplification of genomic DNA extracted from spores of arbuscular fungi. The RAPD fingerprints showed banding patterns which allowed us to distinguish between species and even isolates within Glomales. In order to identify mycorrhizal fungi during their symbiotic phase, a nonpolymorphic RAPD band identified as marker for some isolates of Glomus mosseae was purified from agarose gels and cloned in a bluescript vector. The fragment was sequenced and specific primers (PO-M3) were designed for the mycorrhizal fungus. They specifically and successfully amplified the DNA not only from G. mosseae spores, but also from roots of pea, clover, leek and onion plants when they were colonized by G. mosseae isolates.
79 citations
TL;DR: RAPD data are useful particularly when pedigree information is incomplete, there has been substantial selection within breeding populations, and a high proportion of alleles are identical in state but not by descent.
Abstract: Previous studies of peach germplasm using pedigree information and isozyme polymorphism data have shown limited diversity in the U.S. gene pool. To further investigate the genetic diversity among peach cultivars grown in different regions of the United States, 94 RAPD markers were used to estimate the genetic distances among 136 cultivars. Of the 12 clusters formed in a dendrogram, the 90 U.S. cultivars and breeding lines and most of those from Europe and Latin America grouped to only three clusters, while the 23 peach entries from India, Pakistan, Russia, Okinawa, and China, as well as the almond cultivar used as an outgroup, were distributed among the other nine clusters. Therefore, the genetic diversity within temperate U.S. peach germplasm is quite limited, and to expand the variability, additional germplasm should be obtained, especially from Asia. Comparison of genetic similarity based on inbreeding coefficients with similarity coefficients based on the RAPD data produced a correlation of 0.395, which is comparable to values in similar investigations in other crops. Thus, similar conclusions can be drawn from these two sources of information. RAPD data are useful particularly when pedigree information is incomplete, there has been substantial selection within breeding populations, and a high proportion of alleles are identical in state but not by descent.
79 citations
TL;DR: The correlation data indirectly suggest that natural selection appears to be the major determinant of both RAPD and allozyme diversities both being correlated with environmental stress.
Abstract: Genetic variability in RAPDs (Randomly Amplified Polymorphic DNA) was studied in 104 genotypes of wild barley, Hordeum spontaneum from 21 populations sampled in Israel, Turkey and Iran, seven population from each country. The band (= loci) frequencies were calculated for each population and correlated with ecogeographical variables. In general, high RAPD genetic diversity indices were associated with stressful environments, either with hot or cold steppes and deserts. Interpopulational genetic distances showed no association with the geographic distance between the populations' provenance. Significant Spearman rank correlations between RAPD band frequencies and ecogeographical parameters of provenance occured. Frequencies of RAPD bands were significantly correlated with the principal component factors of allozymes. The correlation data indirectly suggest that natural selection appears to be the major determinant of both RAPD and allozyme diversities both being correlated with environmental stress.
79 citations