scholarly journals Characterizing the Sphaceloma Fungus, Causal Agent of Superelongation Disease in Cassava

Plant Disease ◽  
2000 ◽  
Vol 84 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Elizabeth Alvarez ◽  
Martha L. Molina

The fungus Sphaceloma manihoticola causes superelongation disease in cassava, a starchy root crop grown widely in the tropics. Isolates were collected from infected plants grown in six localities of Colombia. Morphological analyses of the fungus showed that colony growth and color are not stable characteristics over time. Pathogenicity studies, using the susceptible cassava variety M Col 22 and the resistant M Ven 77, showed that M Col 22 was tolerant of 29% of pathogen isolates studied and had an intermediate reaction to 71%. Variety M Ven 77 also showed tolerance of 16.2% of the isolates, had an intermediate reaction to 80.6%, and was susceptible to 3.2%. Significant cultivar × isolate interactions indicated pathogenic specialization. This study is the first to describe this pathogen's molecular characteristics. A homogeneous and reporducible band of about 545 bp was obtained with polymerase chain reaction which, when digested by restriction enzymes, showed an equal pattern of bands for all isolates. The isolates thus belonged to one species. Random amplified polymorphic DNA analysis revealed intraspecific genetic diversity. By better understanding the pathogen, we can apply more appropriate disease management strategies, such as selection of germ plasm tolerant of superelongation disease.

1999 ◽  
Vol 41 (5) ◽  
pp. 291-295 ◽  
Author(s):  
Abdel-Hamid Zaki ABDEL-HAMID ◽  
Jeanne Blanco de MOLFETTA ◽  
Vania FERNANDEZ ◽  
Vanderlei RODRIGUES

Susceptibility of snails to infection by certain trematodes and their suitability as hosts for continued development has been a bewildering problem in host-parasite relationships. The present work emphasizes our interest in snail genetics to determine what genes or gene products are specifically responsible for susceptibility of snails to infection. High molecular weight DNA was extracted from both susceptible and non-susceptible snails within the same species Biomphalaria tenagophila. RAPD was undertaken to distinguish between the two types of snails. Random primers (10 mers) were used to amplify the extracted DNA by the polymerase chain reaction (PCR) followed by polyacrylamide gel electrophoresis (PAGE) and silver staining. The results suggest that RAPD represents an efficient means of genome comparison, since many molecular markers were detected as genetic variations between susceptible and non-susceptible snails.


2021 ◽  
pp. 3224-3228
Author(s):  
Budi Utomo ◽  
Rimayanti Rimayanti ◽  
Indah Norma Triana ◽  
Amaq Fadholly

Background and Aim: The genetic improvement of cattle through livestock section is based on quantitative, qualitative, and molecular characteristics. This study examined polymorphisms of the melanocortin-4 receptor (MC4R) and leptin genes as a reference for the selection of superior breeds in Madrasin cattle. Materials and Methods: The leptin and MC4R genes of Madrasin cattle were amplified using polymerase chain reaction (PCR); then, restriction fragment length polymorphism of the leptin gene was performed using the restriction enzyme BsaA1, at site 2793 with ACGT point position. Results: The leptin gene was divided into three bands, namely, AA with one fragment (522 bp), CG with two fragments (441 bp and 81 bp), and AG with three fragments (522 bp, 441 bp, and 81 bp). The MCR-4 gene was divided into three bands, namely, 493 bp, 318 bp, and 175 bp. Conclusion: The MC4R and leptin genes can act as molecular markers for growth traits in Madrasin cattle and can be used to genetically optimize and improve growth. The GG allele of the MC4R gene and the AA allele of the leptin gene can be used in Madrasin cattle.


2012 ◽  
Vol 58 (8) ◽  
pp. 953-964 ◽  
Author(s):  
Sara Christianson ◽  
Joyce Wolfe ◽  
Hafid Soualhine ◽  
Meenu K. Sharma

Nontuberculosis mycobacteria (NTM) are an important cause of human disease and infections. Though less notorious than tuberculosis, these infections are clinically significant and have been associated with outbreaks in various settings. To accommodate outbreak investigations for the numerous species of NTM, we evaluated a DiversiLab repetitive-sequence-based PCR (rep-PCR) kit for genotyping of mycobacteria. This kit was used to genotype both rapidly and slowly growing mycobacteria and was compared with other PCR-based genotyping methods, including random amplified polymorphic DNA (RAPD) analysis, hsp65 gene sequencing, and mycobacterial interspersed repetitive unit – variable number of tandem repeat (MIRU–VNTR) analysis. Compared with RAPD analysis, rep-PCR achieved better reproducibility in testing. When compared with hsp65 gene sequencing and MIRU–VNTR for Mycobacterium avium , rep-PCR provided results that agreed with these less discriminatory genotyping methods but provided a higher level of discrimination for situations such as outbreak investigations. We also evaluated the kit for its ability to identify closely related rapidly growing NTM. While rep-PCR was informative in some cases, a much larger library of isolates would be necessary to truly evaluate it as an identification tool. Overall, rep-PCR was able to provide improved reproducibility over RAPD and a discriminatory genotyping method for the isolates evaluated in this study.


Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Kemal Kazan ◽  
John M. Manners ◽  
Don F. Cameron

The inheritance of random amplified polymorphic DNA (RAPD) markers generated via the polymerase chain reaction amplification of genomic DNA sequences in an F2 family of an interspecific cross between Stylosanthes hamata and S. scabra was investigated. An initial comparison between the parental species, S. hamata cv. Verano and S. scabra cv. Fitzroy, demonstrated that 34% of detected RAPD bands were polymorphic. Of 90 primers tested, 35 showed relatively simple and reliably scorable polymorphisms and were used for segregation analysis. Sixty F2 individuals were scored for the segregation of 73 RAPD markers and 55 of these markers fit a 3:1 ratio. Segregation of eight other RAPD markers deviated significantly from a 3:1 ratio. There was no bias in the inheritance of RAPD markers regarding parental origin of the segregating RAPD markers. Linkage analysis revealed 10 linkage groups containing a total of 44 RAPD loci. Another 10 RAPD markers (7 of maternal origin) that were polymorphic between the parents did not segregate in the F2 population. One of the maternally inherited RAPD bands hybridized to chloroplast DNA. Analysis of RAPD loci by DNA hybridization indicated that mainly repeated sequences were amplified. These data indicate that RAPDs are useful genetic markers in Stylosanthes spp. and they may be suitable for genetic mapping.Key words: genetic mapping, molecular markers, polymerase chain reaction, Stylosanthes hamata, Stylosanthes scabra.


Genome ◽  
1993 ◽  
Vol 36 (6) ◽  
pp. 1029-1031 ◽  
Author(s):  
Juan Manuel González ◽  
Esther Ferrer

Random amplified polymorphic DNA analysis was performed by applying a set of 13 arbitrary 10-mer primers to 19 Hordeum species and subspecies. High levels of variation in fragment pattern were observed both within and among species with most of the primers used. Genetic similarities between accessions and species were calculated from the fragment patterns. The resulting phenograms confirmed previous relationships among the Hordeum species.Key words: random amplified polymorphic DNA, polymerase chain reaction, polymorphism, Hordeum.


1994 ◽  
Vol 45 (7) ◽  
pp. 1319 ◽  
Author(s):  
WR Lawson ◽  
RJ Henry ◽  
JK Kochman ◽  
GA Kong

A cross-section of sunflower genotypes grown in Australia including commercial cultivars (Suncross 40R, Hysun 33, Hysun 45CQ, Advance, DK3873), breeding lines (Sunfola, S37- 388, PhRR3, HA-R2, MC29, MC69, S37-388RR), wild sunflower varieties (H. annuus, H. argophyllus), a distantly related species (Tithonia diversifolia), and a hexaploid/diploid cross (H. tuberosus L.x H. annuus L.) were assessed for genetic diversity using RAPD (Random Amplified Polymorphic DNA) analysis. A considerable amount of polymorphism was revealed. Of the total of 158 markers amplified, 133 were polymorphic for at least one pair-wise comparison within the 16 genotypes. Overall, 33% dissimilarity was detected, with an average of 27% dissimilarity revealed among the hybrids and breeding lines, which exhibited 38% dissimilarity to the wild varieties H. annuus and H. tuberosus, and 51% dissimilarity to Tithonia and H. tuberosus x H, annuus. PCR of the 5S ribosomal RNA gene spacer region did not reveal any polymorphisms among the cultivated and breeding lines, but did distinguish between H. tuberosus and the other wild species. This survey of a selection of sunflower genotypes indicates that the genetic base of domesticated sunflower may be quite wide. These results suggest that RAPD methodology will provide an efficient tool for the analysis of the sunflower genome, in particular in breeding programs.


Plant Disease ◽  
1998 ◽  
Vol 82 (2) ◽  
pp. 218-222 ◽  
Author(s):  
K. Kageyama ◽  
H. Uchino ◽  
M. Hyakumachi

The hyphal swelling (HS) group of Pythium species and P. ultimum were studied for cultural and morphological characteristics, restriction fragment length polymorphisms of the amplified internal transcribed spacer (ITS) region in nuclear rDNA, and random amplified polymorphic DNA (RAPD) analysis of genome DNA. The shape of sporangia was spherical to subspherical or lemoniform and averaged 18.1–23.0 μm. All isolates could grow at 5 to 35°C, and the rate at the optimal temperature, 30°C, was 29–34 mm/24 h. The size of the ITS region amplified by polymerase chain reaction and the banding patterns after digestion with the restriction enzymes showed no variation between the HS group and P. ultimum. No difference in banding patterns was shown between the HS group and P. ultimum by RAPD analysis with each of three primers. Isolates examined were from Japan, and results should be confirmed from other regions.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Eui Jeong Doh ◽  
Seung-Ho Paek ◽  
Guemsan Lee ◽  
Mi-Young Lee ◽  
Seung-Eun Oh

SeveralArtemisiaspecies are used as herbal medicines including the dried aerial parts ofArtemisia capillaris, which are used as Artemisiae Capillaris Herba (known as “Injinho” in Korean medicinal terminology and “Yin Chen Hao” in Chinese). In this study, we developed tools for distinguishing betweenA. capillarisand 11 otherArtemisiaspecies that grow and/or are cultured in China, Japan, and Korea. Based on partial nucleotide sequences in the internal transcribed spacer (ITS) that differ between the species, we designed primers to amplify a DNA marker forA. capillaris. In addition, to detect otherArtemisiaspecies that are contaminants ofA. capillaris, we designed primers to amplify DNA markers ofA. japonica,A. annua,A. apiacea, andA. anomala. Moreover, based on random amplified polymorphic DNA analysis, we confirmed that primers developed in a previous study could be used to identifyArtemisiaspecies that are sources of Artemisiae Argyi Folium and Artemisiae Iwayomogii Herba. By using these primers, we found that multiplex polymerase chain reaction (PCR) was a reliable tool to distinguish betweenA. capillarisand otherArtemisiaspecies and to identify otherArtemisiaspecies as contaminants ofA. capillarisin a single PCR.


1995 ◽  
Vol 75 (1) ◽  
pp. 221-224 ◽  
Author(s):  
Jean-Guy Parent ◽  
Danièle Pagé

Random amplified polymorphic DNA analysis was used to identify and differentiate the 13 strawberry cultivars of Quebec's certification program. DNA extracts from leaves of field plants were analyzed. Young and apparently healthy leaves were chosen to ensure a good quality of DNA. A selection of only two primers, in a test combination, was sufficient to attain the anticipated result. Key words: Strawberry (Fragaria spp.), random amplified polymorphic DNA, RAPD, cultivar identification


Genome ◽  
1996 ◽  
Vol 39 (6) ◽  
pp. 1051-1061 ◽  
Author(s):  
Daniel Verhaegen ◽  
Christophe Plomion

Two single-tree linkage maps were constructed for Eucalyptus urophylla and Eucalyptus grandis, based on the segregation of 480 random amplified polymorphic DNA (RAPD) markers in a F1 interspecific progeny. A mixture of three types of single-locus segregations were observed: 244 1:1 female, 211 1:1 male, and 25 markers common to both, segregating 3:1. Markers segregating in the 1:1 ratio (testcross loci) were used to establish separate maternal and paternal maps, while markers segregating in the 3:1 ratio were used to identify homology between linkage groups of the two species maps. An average of 2.8 polymorphic loci were mapped for each arbitrary decamer primer used in the polymerase chain reaction. The mean interval size beween framework markers on the maps was 14 cM. The maps comprised 269 markers covering 1331 cM and 236 markers covering 1415 cM, in 11 linkage groups, for E. urophylla (2n = 2x = 22) and E. grandis (2n = 2x = 22), respectively. A comparative mapping analysis with two other E. urophylla and E. grandis linkage maps showed that RAPDs could be reliable markers for establishing a consensus species map. RAPD markers were automatically and quantitatively scored with an imaging analyzer. They were classified into four categories based on their optical density. A fragment intensity threshold is proposed to optimize the selection of reliable RAPD markers for future mapping experiments. Key words : genetic linkage map, Eucalyptus urophylla, Eucalyptus grandis, random amplified polymorphic DNA, RAPD, automated data collection.


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