Genetic-Relationships as Assessed by Molecular Markers and Cross-Infection Among Strains of Colletotrichum gloeosporioides

1994 ◽  
Vol 42 (1) ◽  
pp. 9 ◽  
Author(s):  
HL Hayden ◽  
KG Pegg ◽  
EAB Aitken ◽  
JAG Irwin

Morphological characterisation allows isolates of Colletotrichum gloeosporioides, Colletotrichum musae and Colletotrichum acutatum to be identified only to species level. Pathogenicity tests and random amplified polymorphic DNA (RAPD) markers distinguished a mango biotype of C. gloeosporioides from eight other isolates of C gloeosporioides obtained from five different fruit species. Using these procedures, it was also possible to distinguish C. acutatum and C. musae both from each other, and from the C. gloeosporioides isolates. In cross-infectivity studies, isolates of C. gloeosporioides displayed a wide host range with the exception of isolates from mango, which were highly virulent on mango only. Teleomorphic isolates of C. gloeosporioides were clustered together by RAPD analysis. This work has demonstrated the existence of a biotype of C. gloeosporioides which shows specialisation to mango.

1998 ◽  
Vol 46 (1) ◽  
pp. 143
Author(s):  
Agnieszka M. Poplawski ◽  
John A. G. Irwin ◽  
John M. Manners

Genetic markers that distinguish fungal genotypes are important tools for genetic analysis of heterokaryosis and parasexual recombination in fungi. Random amplified polymorphic DNA (RAPD) markers that distinguish two races of biotype B of Colletotrichum gloeosporioides infecting the legume Stylosanthes guianensis were sought. Eighty-five arbitrary oligonucleotide primers were used to generate 895 RAPD bands but only two bands were found to be specifically amplified from DNA of the race 3 isolate. These two RAPD bands were used as DNA probes and hybridised only to DNA of the race 3 isolate. Both RAPD bands hybridised to a dispensable 1.2 Mb chromosome of the race 3 isolate. No other genotype-specific chromosomes or DNA sequences were identified in either the race 2 or race 3 isolates. The RAPD markers hybridised to a 2 Mb chromosome in all races of the genetically distinct biotype A pathogen which infects other species of Stylosanthes as well as S. guianensis. The experiments indicate that RAPD analysis is a potentially useful tool for obtaining genotype- and chromosome-specific DNA probes in closely related isolates of one biotype of this fungal pathogen.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 546e-546 ◽  
Author(s):  
Mark W. Farnham ◽  
Jiang Lu ◽  
Julie M. Villand

DNA markers can assess close genetic relationships between individuals of a crop as when one variety is developed (i.e., “essentially derived”) from another. An acceptable threshold, based on empirical results, should be established for a crop to indicate what constitutes an “essentially derived” variety in the absence of clear pedigree information. Empirical data could help settle infringements of intellectual property rights, but appropriate data are not being generated for most crops. Thus, our objectives were to characterize genetic relationships among broccoli varieties “essentially derived” from known parents using random amplified polymorphic DNA (RAPD) markers as a measure of genotype and to provide an empirical basis for threshold levels in this crop. Six F1 broccoli hybrids and three inbred lines (doubled-haploids) developed from each of the hybrids (24 entries) were evaluated by RAPD analysis. RAPD assays were conducted using 23 different oligonucleotide 10-mers. Of 179 RAPD bands scored, 94 were polymorphic among the entries. Similarity indices were computed from RAPD data, and a multi-dimensional scaling (MDS) plot was constructed. Similarity indices for all pairwise comparisons ranged from 0.40 to 0.90. `High Sierra' and it's derived lines were the most closely related group with indices from 0.81 to 0.90. With `High Sierra', `Sultan', and `Marathon', the three derived lines were more closely related to their respective parental hybrids than were any other entries. The hybrids `Futura', `Everest', and `Viking' were more genetically similar to other entries than to their derived lines. A threshold level based on data from `High Sierra', `Marathon', `Sultan', and their derived lines would not identify “essentially derived” lines developed from other hybrids.


2004 ◽  
Vol 94 (5) ◽  
pp. 446-453 ◽  
Author(s):  
C. L. Xiao ◽  
S. J. MacKenzie ◽  
D. E. Legard

Colletotrichum crown rot of strawberry in Florida is caused primarily by Colletotrichum gloeosporioides. To determine potential inoculum sources, isolates of Colletotrichum spp. from strawberry and various noncultivated plants growing in the areas adjacent to strawberry fields were collected from different sites. Species-specific internal transcribed spacer primers for C. gloeosporioides and C. acutatum were used to identify isolates to species. Random amplified polymorphic DNA (RAPD) markers were used to determine genetic relationships among isolates recovered from noncultivated hosts and diseased strawberry plants. Selected isolates also were tested for pathogenicity on strawberry plants in the greenhouse. In all, 39 C. gloeosporioides and 3 C. acutatum isolates were recovered from diseased strawberry crowns, and 52 C. gloeosporioides and 1 C. acutatum isolate were recovered from noncultivated hosts. In crown inoculation tests, 18 of the 52 C. gloeosporioides isolates recovered from noncultivated hosts were pathogenic to strawberry. Phylogenetic analysis using RAPD marker data divided isolates of C. gloeosporioides from noncultivated hosts into two separate clusters. One cluster contained 50 of the 52 isolates and a second cluster contained 2 isolates that were homothallic in culture. Isolates from strawberry were interspersed within the cluster containing the 50 isolates that were recovered from noncultivated hosts. The results are not inconsistent with the hypothesis that C. gloeosporioides isolates obtained from strawberry and noncultivated hosts adjacent to strawberry fields are from the same population and that noncultivated hosts can serve as potential inoculum sources for Colletotrichum crown rot of strawberry.


ISRN Agronomy ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Ferdaous Guasmi ◽  
Walid Elfalleh ◽  
Hédia Hannachi ◽  
Khadija Fères ◽  
Leila Touil ◽  
...  

Random amplified polymorphic DNA (RAPD) and intersimple sequence repeat (ISSR) were assayed to determine the genetic diversity of 80 barley specimens from South Tunisia. The ISSR primers showed variation in the percentage of polymorphism, band informativeness (Ib), and resolving power (Rp). The percentage of polymorphism is 66.67%, the average Ib ranged from 0.24 to 0.39, while Rp ranged from 0.74 to 1.16. In RAPD analysis, three primers yielded a total of 17 scorable bands, which are all polymorphic. The three polymorphic primers exhibited variation with regard to average band informativeness (AvIb) and resolving power (Rp). RAPD and ISSR marker systems were found to be useful for the genetic diversity among the barley specimens. The two dendrograms obtained through these markers show different clustering of 80 barely specimens, but we noted that some clusters were similar in some cases. A poor correlation () was found between both sets of genetic similarity data, suggesting that both sets of markers revealed unrelated estimates of genetic relationships. Therefore, the ISSR and RAPD molecular markers show two genetic grouping of studied barely specimens.


Plant Disease ◽  
1999 ◽  
Vol 83 (2) ◽  
pp. 108-113 ◽  
Author(s):  
Craig M. Sandlin ◽  
James R. Steadman ◽  
Carlos M. Araya ◽  
Dermot P. Coyne

Five isolates of the bean rust fungus Uromyces appendiculatus were shown to be specifically virulent on bean genotypes of Andean origin. This specificity was demonstrated by the virulence of five pairs of isolates on a differential set of 30 Phaseolus vulgaris landraces. Each isolate pair was from a different country in the Americas and consisted of one Andean-specific isolate and one nonspecific isolate. Of the differential P. vulgaris landraces, 15 were of Middle American origin and 15 were of Andean origin. The Andean-specific rust isolates were highly virulent on Andean landraces but not on landraces of Middle American origin. Rust isolates with virulence to Middle American landraces were also generally virulent on Andean material; no truly Middle American-specific isolates were found. Random amplified polymorphic DNA (RAPD) analysis of the rust isolates also distinguished the two groups. Four of the Andean-specific rust isolates formed a distinct group compared to four of the nonspecific isolates. Two of the isolates, one from each of the two virulence groups, had intermediate RAPD banding patterns, suggesting that plasmagomy but not karyogamy occurred between isolates of the two groups.


Genome ◽  
2000 ◽  
Vol 43 (4) ◽  
pp. 724-727 ◽  
Author(s):  
Wenguang Cao ◽  
G Scoles ◽  
P Hucl ◽  
R N Chibbar

The genetic relationships among the five groups of hexaploid wheat: common, spelta, macha, vavilovii, and semi-wild wheat (SWW) are not clear. Random amplified polymorphic DNA (RAPD) analysis was used to assess phylogenetic relationships among these five morphological groups of hexaploid wheat. RAPD data were analyzed using the NTSYS-PC computer program to generate Jaccard genetic similarity coefficients. A dendrogram based on RAPD analysis grouped 15 accessions into five distinct clusters. These results are in agreement with those based on morphological classification, suggesting that common wheat is most closely related to SWW, followed by spelta, vavilovii, and macha.Key words: RAPD, macha, spelta, vavilovii, semi-wild wheat, phylogenetic relationships.


Genome ◽  
1995 ◽  
Vol 38 (2) ◽  
pp. 201-210 ◽  
Author(s):  
F. N. Wachira ◽  
R. Waugh ◽  
W. Powell ◽  
C. A. Hackett

Camellia sinensis is a beverage tree crop native to Southeast Asia and introductions have been made into several nonindigenous countries. No systematic assessment of genetic variability in tea has been done anywhere. In this study, random amplified polymorphic DNA (RAPD) analysis was used to estimate genetic diversity and taxonomic relationships in 38 clones belonging to the three tea varieties, assamica, sinensis, and assamica ssp. lasiocalyx. Extensive genetic variability was detected between species, which was partitioned into between and within population components. Seventy percent of the variation was detected within populations. Analyses based on band sharing separated the three populations in a manner consistent with both the present taxonomy of tea and with the known pedigrees of some clones. RAPD analysis also discriminated all of the 38 commercial clones, even those which cannot be distinguished on the basis of morphological and phenotypic traits.Key words: genetic diversity, RAPDs, Camellia sinensis.


Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 289
Author(s):  
Minju Kim ◽  
Jun-Cheol Moon ◽  
Songmun Kim ◽  
Kandhasamy Sowndhararajan

Bak-ri-hyang (Thymus quinquecostatus Celak.) is an important medicinal and aromatic plant in Korea. T. quinquecostatus population and is always mixed with other thyme cultivars during cultivation and marketing. Hence, this study aimed to determine the genetic variability and the essential oil composition of three Korean native thyme, T. quinquecostatus cultivars collected from the Wolchul, Jiri, and Odae mountains, in comparison with six commercial thyme cultivars (T. vulgaris), to distinguish Bak-ri-hyang from other thyme cultivars. The composition of essential oils obtained from nine individuals was analyzed by gas chromatography–mass spectrometry (GC–MS). The random amplified polymorphic DNA (RAPD) analysis was accomplished using 16 different primers. The GC–MS analysis revealed that Wolchul, creeping, golden, and orange cultivars belong to the geraniol chemotype. Whereas the Odae, lemon, and silver cultivars belong to the thymol chemotype. Further, linalool was the most abundant component in carpet and Jiri cultivars. The RAPD analysis demonstrated that all thyme cultivars showed characteristic RAPD patterns that allowed their identification. In total, 133 bands were obtained using 16 primers, and 124 bands were polymorphic, corresponding to 93.2% polymorphism. Cluster analysis of RAPD markers established the presence of clear separation from nine thyme cultivars. The highest dissimilarity and similarity coefficient of the RAPD markers were 0.58 and 0.98, respectively. According to the RAPD patterns, the nine thyme cultivars could be divided into two major clusters. Among three Korean cultivars, the Wolchul and Odae cultivars were placed into the same cluster, but they did not show identical clustering with their essential oil compositions. The findings of the present study suggest that RAPD analysis can be a useful tool for marker-assisted identification of T. quinquecostatus from other Thymus species.


Author(s):  
Indu Rialch ◽  
Rama Kalia ◽  
H. K. Chaudhary ◽  
B. Kumar ◽  
J. C. Bhandari ◽  
...  

Ten morpho-agronomic traits and 80 random amplified polymorphic DNA (RAPD) molecular markers were used to survey genetic diversity in 25 chickpea genotypes. Analysis of variance revealed significant variability among different genotypes for morpho-metric traits. The cluster analysis done using morpho-metric traits grouped 25 genotypes into seven and six clusters in Environment I (Env. I) and Environment II (Env. II), respectively. Three genotypes viz., ICCV-96904, HPG-17, ICCV-95503 and L-HR-1 belonging to diverse clusters were identified divergent and may use in heterosis breeding programme. Of 80 random RAPD markers, 25 were found polymorphic. Three major clusters were identified using 25 polymorphic RAPD markers. The genetic similarity coefficient among genotypes ranged from 0.57 to 0.91. The average polymorphic information content (PIC) for 25 RAPD markers ranges from 0.12 to 0.40. D2-statistic, RAPD analysis and study of genotypes performance revealed sufficient genetic diversity among chickpea genotypes which would be useful in future breeding programme.


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