scholarly journals Effect of Crop Rotation on the Survival of Phytophthora capsici in Michigan

Plant Disease ◽  
2003 ◽  
Vol 87 (7) ◽  
pp. 841-845 ◽  
Author(s):  
K. H. Lamour ◽  
M. K. Hausbeck
Keyword(s):  
Crop Rotation ◽  
Genetic Similarity ◽  
Fragment Length Polymorphism ◽  
Aflp Marker ◽  
Phytophthora Capsici ◽  
Limiting Factor ◽  
Clonal Lineage ◽  
Time Period ◽  
Economic Control ◽  
Infested Site

Phytophthora capsici is a limiting factor for some vegetable producers in Michigan despite crop rotation and fungicide applications. Our objective was to assess the effect of crop rotation on the survival of P. capsici at a naturally infested site in Michigan planted to cucumbers in 1998, corn in 1999 and 2000, and tomatoes in 2001. Isolates were characterized for compatibility type (CT), mefenoxam sensitivity, and amplified fragment length polymorphism (AFLP) marker profiles, and compared with isolates recovered from other locations in Michigan during the same time period. The A1:A2 CT ratio was 1:1, and approximately 60% of the isolates recovered in both years were intermediately sensitive or insensitive to mefenoxam. The majority of the isolates (89%) had unique AFLP fingerprints, and no members of the same clonal lineage were recovered among years. Isolates from this location were more similar to each other than to isolates from other locations in Michigan, and it was not possible to distinguish isolates based on the year of isolation. Genetic similarity analyses indicate that isolates from this location are part of a genetically distinct outcrossing population. These data indicate that P. capsici persisted as oospores for the 2 years between cucumbers and tomatoes, and that crop rotation and mefenoxam are not likely to provide economic control.

scholarly journals Investigating the Spatiotemporal Genetic Structure of Phytophthora capsici in Michigan

2001 ◽  
Vol 91 (10) ◽  
pp. 973-980 ◽  
Author(s):  
K. H. Lamour ◽  
M. K. Hausbeck
Keyword(s):  
Fragment Length Polymorphism ◽  
Aflp Marker ◽  
Phytophthora Capsici ◽  
Group Method ◽  
Analysis Of Molecular Variance ◽  
Arithmetic Average ◽  
Pair Group ◽  
Average Cluster ◽  
Over Time ◽  
F Statistics

Phytophthora capsici isolates were recovered from pepper and cucurbit hosts at seven locations in Michigan from 1998 to 2000. Isolates were characterized for compatibility type (CT), mefenoxam sensitivity (MS), and amplified fragment length polymorphism (AFLP) marker profiles. In total, 94 AFLP bands were resolved. Individual populations were highly variable. Within populations, 39 to 49% of the AFLP bands were polymorphic and estimated heterozygosities ranged from 0.16 to 0.19. Of the 646 isolates fingerprinted, 70% (454) had unique AFLP profiles. No clones were recovered between years or locations. Pairwise F statistics (ΦST) between populations from different locations ranged from 0.18 to 0.40. A tree based on unweighted pair-group method with arithmetic average cluster analysis indicates discrete clusters based on location. Isolates from the same location showed no clustering based on the year of sampling. Analysis of molecular variance partitioned variability among (40%) and within populations (60%). The overall estimated ΦST was 0.34 (SD = 0.03). A1/A2 CT ratios were ≈1:1, and MS frequencies were similar between years for the two locations sampled over time. These data suggest that P. capsici persists in discrete outcrossing populations and that gene flow among locations in Michigan is infrequent.

scholarly journals The Dynamics of Mefenoxam Insensitivity in a Recombining Population of Phytophthora capsici Characterized with Amplified Fragment Length Polymorphism Markers

2001 ◽  
Vol 91 (6) ◽  
pp. 553-557 ◽  
Author(s):  
K. H. Lamour ◽  
M. K. Hausbeck
Keyword(s):  
Length Polymorphism ◽  
Fragment Length ◽  
Selection Pressure ◽  
Fragment Length Polymorphism ◽  
Phytophthora Capsici ◽  
Amplified Fragment Length Polymorphism ◽  
Aflp Markers ◽  
Period 2 ◽  
Time Period ◽  
Fixation Indices

Recent findings from Michigan suggest that recombination may play a role in the survival and evolution of sensitivity to the fungicide mefenoxam in populations of Phytophthora capsici on cucurbit hosts. In 1998, 63 mefenoxam insensitive isolates were recovered from a squash field in which mefenoxam had been applied. Additional isolates were recovered from untreated squash fields planted at this location in 1999 (200 isolates) and the spring of 2000 (34 isolates). Isolates from 1998 and 1999 were characterized using fluorescent amplified fragment length polymorphism (AFLP) markers and all isolates were screened for compatibility type and mefenoxam sensitivity. In 1998 and 1999, 92 and 71% of the isolates, respectively, had unique multilocus AFLP genotypes with no identical isolates recovered between years. Seventy-two identical AFLP markers were clearly resolved in both the 1998 and 1999 sample sets, and fixation indices for the 37 polymorphic AFLP loci indicate little differentiation between years. There was no decrease in the frequency of resistant isolates during the 2 years without mefenoxam selection. We conclude that oospores play a key role in overwintering and that the frequency of mefenoxam insensitivity may not decrease in an agriculturally significant time period (2 years) once mefenoxam selection pressure is removed.

scholarly journals Identification of Molecular Markers Linked to the Trait of Natural Astringency Loss of Japanese Persimmon (Diospyros kaki) Fruit

2001 ◽  
Vol 126 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Shinya Kanzaki ◽  
Keizo Yonemori ◽  
Akira Sugiura ◽  
Akihiko Sato ◽  
Masahiko Yamada
Keyword(s):  
Fragment Length Polymorphism ◽  
Aflp Marker ◽  
Bulked Segregant Analysis ◽  
Rflp Analysis ◽  
Breeding Population ◽  
Diospyros Kaki ◽  
Dominant Allele ◽  
Japanese Persimmon ◽  
Efficient Selection ◽  
Selection Of

Japanese persimmon (Diospyros kaki Thunb.) cultivars are classified into four types depending upon the nature of astringency loss of the fruit. Among them, the pollination-constant and nonastringent (PCNA) type is the most desirable for fresh fruit consumption due to the trait of stable loss of astringency on the tree with fruit development. Lack of tannin accumulation is the main cause of natural astringency loss in PCNA-type fruit, and is qualitatively inherited. The PCNA trait is recessive to the non-PCNA trait. In this study, we investigated amplified fragment length polymorphism (AFLP) markers for the trait of natural astringency loss of PCNA-type fruit using bulked segregant analysis (BSA) for efficient selection of PCNA type plants in a breeding population. A total of 128 primer combinations were tested and one AFLP marker was found to be linked to the dominant allele controlling the trait for astringency. This marker, EACC/MCTA-400, was absent in all of the PCNA-type plants tested, whereas it was present in about half of the non-PCNA-type plants tested. However, RFLP analysis using this marker enabled the detection of the other dominant allele, and all PCNA-type plants could be distinguished from the non-PCNA-type plants. Application of this marker system will be useful for the selection of PCNA-type plants in persimmon breeding.

scholarly journals AFLP MARKER IN GENETIC DIVERSITYASSESSMENT OF FIG (Ficus carica L.) POPULATIONS IN KURDISTAN REGION – IRAQ.

2021 ◽  
Vol 52 (4) ◽  
pp. 859-867
Author(s):  
Hussein & Jubrael
Keyword(s):  
Genetic Similarity ◽  
Genetic Relatedness ◽  
Aflp Marker ◽  
Genetic Distances ◽  
Similarity Coefficient ◽  
Kurdistan Region ◽  
Aflp Data ◽  
Different Populations ◽  
Cultivar Improvement ◽  
Similarity Matrices

In this study, the genetic relatedness of 12 cultivars of fig from different populations in Kurdistan region- Iraq were analyzed using eleven AFLP primers pairs combinations by using the technology of molecular analysis the DNA. Genetic similarity matrices were produced for the AFLP data to calculate genetic distances among their cultivars. Genetic similarity coefficient ranged from 0.1261 to 0.3905. The lowest genetic similarity was observed between Kola and Gala Zard (0.1261). The Hejeera Rash and Shela cultivars were most similar ones with a coefficient of 0.3905. Clustering based on AFLP data for the 12 fig cultivars was identified at the 0.32 similarity level. In the developed dendogram two main groups were found, the first one combined Ketek and Shela together, while the second group contained two sub group Shingaly and Benatty combined together, while in the other sub group cluster three other sub-group were identified. The results of this study may help in the formulation of appropriate strategies for conservation and cultivar improvement in figs, for which limited knowledge of the genetic diversity is available.

Virulence and Molecular Diversity in the Kabatiella zeae Population Causing Maize Eyespot in China

Plant Disease ◽  
2020 ◽  
Vol 104 (12) ◽  
pp. 3197-3206
Author(s):  
Nan Chen ◽  
Shuqin Xiao ◽  
Jiaying Sun ◽  
Lu He ◽  
Miaomiao Liu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Diversity ◽  
Fragment Length Polymorphism ◽  
Genotypic Diversity ◽  
Limiting Factor ◽  
Aflp Analysis ◽  
Limited Information ◽  
Pathogen Population ◽  
Nomenclature System ◽  
Differential Hosts

Maize eyespot, caused by Kabatiella zeae, has become a major yield-limiting factor in maize planting areas in northeast China. Limited information is available on pathotypes, virulence, and the genetic diversity of the K. zeae population. We analyzed virulence and genetic diversity of 103 K. zeae isolates collected from six provinces in China with differential hosts and the amplified fragment length polymorphism (AFLP) technique, respectively. To evaluate the virulence, 103 isolates were inoculated on nine differential hosts (maize inbred lines)—E28, Shen137, Qi319, B73, Danhuang34, Zi330, Mo17, Huangzaosi, and CN165—and grouped into 23 pathotypes and three virulence groups according to the coded triplet nomenclature system on differential hosts. AFLP analysis resolved the set of isolates into four genetic diversity clusters (DICE similarity values of 76%). Genetic variation of K. zeae among and between pathotypes revealed that the pathogen population had a high genotypic diversity. The correlation between pathotypes, virulence, and genetic diversity grouping was low. A correlation between AFLP groups and geographic locations was detected.

Comparison of Danish Isolates of Salmonella entericaSerovar Enteritidis PT9a and PT11 from Hedgehogs (Erinaceus europaeus) and Humans by Plasmid Profiling and Pulsed-Field Gel Electrophoresis

2000 ◽  
Vol 38 (10) ◽  
pp. 3631-3635 ◽  
Author(s):  
B. Nauerby ◽  
K. Pedersen ◽  
H. H. Dietz ◽  
M. Madsen
Keyword(s):  
Gel Electrophoresis ◽  
Fragment Length Polymorphism ◽  
Phage Type ◽  
Pulsed Field Gel Electrophoresis ◽  
Clonal Lineage ◽  
S1 Nuclease ◽  
Pulsed Field ◽  
Plasmid Profiling ◽  
Susceptibility Patterns ◽  
Pfge Profiles

During the years 1994 to 1998, 10 strains of Salmonella enterica serovar Enteritidis phage type 11 (PT11) and 6 PT9a strains were isolated from Danish hedgehogs, together with 7 strains that did not yield phage susceptibility patterns conforming with any known phage type (routine dilution no conformity [RDNC]). From 1995 to 1998, five Danish patients were reported infected with serovar Enteritidis PT11 and two with PT9a. All serovar Enteritidis PT11, PT9a, and RDNC isolates from hedgehogs and humans were analyzed by pulsed-field gel electrophoresis (PFGE), plasmid profiling, and restriction fragment length polymorphism (RFLP) of plasmids. By use of S1 nuclease and HindIII, the PT11 and PT9a isolates had identical plasmid profiles and RFLP patterns, which differed from the RDNC profiles. The PFGE profiles were identical for all serovar Enteritidis PT11 and PT9a strains from hedgehogs, four of five human strains of serovar Enteritidis PT11, and two human strains of serovar Enteritidis PT9a, irrespective of restriction enzyme, whereas the last human strain deviated slightly when NotI was used but not when XbaI or SpeI was used. The results indicate that serovar Enteritidis PT9a and PT11 are closely related and that PT11 and PT9a from Danish hedgehogs and humans belong to the same clonal lineage.

scholarly journals Occurrence and Characterization of a Phytophthora sp. Pathogenic to Asparagus (Asparagus officinalis) in Michigan

2008 ◽  
Vol 98 (10) ◽  
pp. 1075-1083 ◽  
Author(s):  
C. Saude ◽  
O. P. Hurtado-Gonzales ◽  
K. H. Lamour ◽  
M. K. Hausbeck
Keyword(s):  
Phylogenetic Analysis ◽  
Internal Transcribed Spacer ◽  
Mycelial Growth ◽  
Fragment Length Polymorphism ◽  
Distinct Species ◽  
Asparagus Officinalis ◽  
Polymorphism Analysis ◽  
Clonal Lineage ◽  
Storage Roots

A homothallic Phytophthora sp. was recovered from asparagus (Asparagus officinalis) spears, storage roots, crowns, and stems in northwest and central Michigan in 2004 and 2005. Isolates (n = 131) produced ovoid, nonpapillate, noncaducous sporangia 45 μm long × 26 μm wide and amphigynous oospores of 25 to 30 μm diameter. Mycelial growth was optimum at 25°C with no growth at 5 and 30°C. All isolates were sensitive to 100 ppm mefenoxam. Pathogenicity studies confirmed the ability of the isolates to infect asparagus as well as cucurbits. Amplified fragment length polymorphism analysis of 99 isolates revealed identical fingerprints, with 12 clearly resolved fragments present and no clearly resolved polymorphic fragments, suggesting a single clonal lineage. The internal transcribed spacer regions of representative isolates were homologous with a Phytophthora sp. isolated from diseased asparagus in France and a Phytophthora sp. from agave in Australia. Phylogenetic analysis supports the conclusion that the Phytophthora sp. isolated from asparagus in Michigan is a distinct species, and has been named Phytophthora asparagi.

scholarly journals Characterization of Isolates of Phytophthora infestans from Southern and Southeastern Brazil from 1998 to 2000

Plant Disease ◽  
2003 ◽  
Vol 87 (8) ◽  
pp. 896-900 ◽  
Author(s):  
Ailton Reis ◽  
Christine D. Smart ◽  
William E. Fry ◽  
Luiz A. Maffia ◽  
Eduardo S. G. Mizubuti
Keyword(s):  
Restriction Fragment Length Polymorphism ◽  
Phytophthora Infestans ◽  
Mating Type ◽  
Fragment Length Polymorphism ◽  
Southeastern Brazil ◽  
Mating Types ◽  
Clonal Lineage ◽  
Metalaxyl Resistance ◽  
Restriction Fragment Length

The population of Phytophthora infestans in Brazil was first characterized 12 years ago. In this research, isolates of P. infestans from potato (n = 184) and tomato (n = 267) collected in southern and southeastern Brazil were characterized to provide more detailed analysis of the current structure of the population. All 451 isolates were analyzed for mating type, and subsets of the isolates were analyzed for allozymes, restriction fragment length polymorphism fingerprint, mtDNA haplotypes, and metalaxyl resistance. Tomato isolates were all of A1 mating type, mtDNA Ib, and US-1 genotype or some variant within this clonal lineage. Of the potato isolates, 82% were A2 mating type, mtDNA IIa, BR-1 genotype, which is a new lineage of P. infestans. All A2 isolates were found on potato, whereas 91% of the A1 isolates were from tomato. A1 and A2 isolates were never found in the same field. The frequency of resistance to metalaxyl was higher in isolates from tomato (55%) than in isolates from potato (38%). After more than a decade of coexistence of isolates of the A1 and A2 mating types, the population was highly clonal, dominated by the BR-1 and US-1 clonal lineages.

scholarly journals Genetic diversity among asexual and sexual progenies of Phytophthora capsici detected with ISSR markers

2021 ◽  
Vol 57 (No. 4) ◽  
pp. 271-278
Author(s):  
Ping Li ◽  
Dong Liu
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Similarity ◽  
Phytophthora Capsici ◽  
Issr Markers ◽  
Similarity Coefficients ◽  
Sexual Progeny ◽  
Sexual Offspring ◽  
Issr Primers

The population structure of Phytophthora capsici among asexual and sexual progenies was analyzed using ISSR. Thirty asexual progenies of one parent and three sexual populations were assayed for genetic diversity using 5 ISSR primers and DNA from 120 offspring of P. capsici was amplified. In total, 71 reproducible ISSR fragments were obtained, of which 100% were polymorphic, revealing high polymorphism among the isolates. Among them, the percentages of polymorphism of sexual and asexual progeny isolates were 100.00 and 77.46%, respectively. Genetic similarity coefficients among all the isolates ranged from 0.54 to 0.73. The sexual offspring population showed much more variability than the asexual offspring population with 76.26% variability attributed to diversity within populations as compared with 23.74% among populations. This research reveals that the sexual progeny population of P. capsici contributes more genetic diversity than that of asexual progeny population.

scholarly journals Von der Nachhaltigkeit als Beschränkung zur nachhaltigen Entwicklung als Programm | From Sustainability as a Limiting Factor to a Sustainable Development as a Policy

2000 ◽  
Vol 151 (12) ◽  
pp. 497-501 ◽  
Author(s):  
Anton Schuler
Keyword(s):  
Sustainable Development ◽  
20Th Century ◽  
19Th Century ◽  
Production Capacity ◽  
17Th Century ◽  
Limiting Factor ◽  
Time Period ◽  
Calculation Parameter ◽  
The 19Th Century

The development of sustainability is presented on the basis of quotations from German forestry literature published from the 17th century up until now. At the beginning of this time period, the demand for sustainability was limited to the exploitation of the increment. However, in the 19th century,the conservation of the site's production capacity was included and ‹sustainability› was backed up by arguments such as the forest’s role within the forest economy. In the 20th century,sustainability developed from a mere calculation parameter to a behavioural norm with regard to all interventions dealing with forest and ecosystems.

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