RESUMEN
The genus Juniperus L. (Cupressaceae), an aromatic evergreen plant, consists of up to 68 species around the world. We classified five species of Juniperus found in Iran using molecular markers to provide a means for molecular identification of Iranian species. Plants were collected (three samples of each species) from two different provinces of Iran (Golestan and East Azarbayejan). The DNA was extracted from the leaves using a Qiagen Dneasy Plant Mini Kit. Amplification was performed using 18 ten-mer RAPD primers. Genetic distances were estimated based on 187 RAPD bands to construct a dendrogram by means of unweighted pair group method of arithmetic means. It was found that J. communis and J. oblonga were differentiated from the other species. Genetic distance values ranged from 0.19 (J. communis and J. oblonga) to 0.68 (J. communis and J. excelsa). Juniperus foetidissima was found to be most similar to J. sabina. Juniperus excelsa subspecies excelsa and J. excelsa subspecies polycarpos formed a distinct group.
Asunto(s)
Juniperus/genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Secuencia de Bases , Cartilla de ADN , IránRESUMEN
Random Amplified Polymorphic DNAs (RAPD) were used to estimate genetic distances and determine the correlation between genetic distance and hybrid performance of 29 tomato lines that were the parents in a diallel mating design. Among 97 observed bands, 69 showed polymorphism and were used for establishing genetic distances based on the Nei coefficient between parents. A UPGMA dendrogram and Multi-Dimensional Scaling (MDS) analysis based on Nei genetic distances clearly clustered each group, confirming the variation at a molecular level. Correlations between genetic distances of the parents and performances of hybrids were established for various quantitative traits. Significant correlations were found between RAPD markers estimated genetic distances and MPH, HPH, SCA for some traits. The low correlation between parental genetic distances and hybrid performances for some quantitative traits suggested that RAPD markers have low linkage to Quantitative Trait Loci (QTLs) or have inadequate genome coverage for these traits. The results indicated that RAPD markers can be used as a tool for determining the extent of genetic diversity among tomato lines, for allocating genotypes into different groups and also to aid in the choice of the superior crosses to be made among tomato lines, so reducing the number of crosses required under field evaluation.
Asunto(s)
Quimera , Marcadores Genéticos , Vigor Híbrido , Técnica del ADN Polimorfo Amplificado Aleatorio , Solanum lycopersicum/genética , Análisis por Conglomerados , Variación Genética , Polimorfismo Genético , Distribución AleatoriaRESUMEN
The secondarily homothallic life cycle of the white button mushroom that results in scarcity of uninucleate basidiospores (homokaryons) in its progeny, is the most important impediment for genetic improvement of the commercial strains. Identification of homokaryons for breeding programs of Agaricus bisporus (button mushroom) is, therefore, crucial. Verifying homokaryons through fruiting trial is time consuming and unreliable. In this study, ability of RAPD markers, compared to morphological characters for identification of homokaryon isolates, was investigated. Based on morphological characters, 42 isolates were screened and exposed to RAPD markers. The results showed that RAPD markers could discriminate homokaryons from heterokaryons, based on number of bands generated. The numbers of band in homokaryons were significantly less than those of heterokaryons. Results also showed that cluster analysis, based on average of band number generated, could separate homokaryon from heterokaryon isolates. It is suggested that RAPDs could be used to identify hyomokaryons from heterokaryons for breeding program of A. bisporus.
Asunto(s)
Agaricales/genética , ADN/genética , Marcadores Genéticos , Técnica del ADN Polimorfo Amplificado AleatorioRESUMEN
In current research, genetic relationships among rapeseed genotypes from several geographical origins including France, Canada, Germany, Iran, Hungary, Denmark, Australia and America were evaluated using RAPD markers. Among generated 86 bands, 80 different polymorphic bands were obtained using 9 random primers. Diversity Index (DI) or Polymorphism Information Content (PIC) was varied from 0.29 to 0.48, showed a relatively high potential of primers among studied genotypes. Dice similarity coefficient between genotypes was calculated using Nei and Li formula. Maximum (0.91) and minimum (0.42) similarity coefficients were observed between Bristol and Amber genotypes, consul and express, respectively. Cluster analysis based on dice similarity coefficient was also carried out. Base on the cluster analysis, genotypes were grouped into five main clusters. Results showed that genotypes with same geographical origin were genetically different. Therefore, geographical origins of genotypes cannot be used as a base to cross parent to obtain high heterosis and it must be carried out by exact genetic studies. Results confirmed that RAPD is a simple, cheap and fast method for evaluation of genetic diversity of Brassica napus.