scholarly journals Genetic Diversity and Mating Type Distribution of Tuber melanosporum and Their Significance to Truffle Cultivation in Artificially Planted Truffiéres in Australia

2012 ◽  
Vol 78 (18) ◽  
pp. 6534-6539 ◽  
Author(s):  
C. C. Linde ◽  
H. Selmes
Keyword(s):  
Genetic Diversity ◽  
Mating Type ◽  
Allelic Diversity ◽  
Tuber Melanosporum ◽  
Mating Types ◽  
Content Type ◽  
Truffle Cultivation ◽  
Host Trees ◽  
Tuber Brumale ◽  
Source Populations

ABSTRACTTuber melanosporumis a truffle native to Europe and is cultivated in countries such as Australia for the gastronomic market, where production yields are often lower than expected. We assessed the genetic diversity ofT. melanosporumwith six microsatellite loci to assess the effect of genetic drift on truffle yield in Australia. Genetic diversity as assessed on 210 ascocarps revealed a higher allelic diversity compared to previous studies from Europe, suggesting a possible genetic expansion and/or multiple and diverse source populations for inoculum. The results also suggest that the single sequence repeat diversity of locus ME2 is adaptive and that, for example, the probability of replication errors is increased for this locus. Loss of genetic diversity in Australian populations is therefore not a likely factor in limiting ascocarp production. A survey of nursery seedlings and trees inoculated withT. melanosporumrevealed that <70% of seedlings and host trees were colonized withT. melanosporumand that some trees had been contaminated byTuber brumale, presumably during the inoculation process. Mating type (MAT1-1-1 and MAT1-2-1) analyses on seedling and four- to ten-year-old host trees found that 100% of seedlings but only approximately half of host trees had both mating types present. Furthermore, MAT1-1-1 was detected significantly more commonly than MAT1-2-1 in established trees, suggesting a competitive advantage for MAT1-1-1 strains. This study clearly shows that there are more factors involved in ascocarp production than just the presence of both mating types on host trees.

scholarly journals A PCR-based Assay for Distinguishing between A1 and A2 Mating Types of Phytophthora capsici

2017 ◽  
Vol 142 (4) ◽  
pp. 260-264
Author(s):  
Ping Li ◽  
Dong Liu ◽  
Min Guo ◽  
Yuemin Pan ◽  
Fangxin Chen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating Type ◽  
Phytophthora Capsici ◽  
Mating Types ◽  
Sequence Repeat ◽  
Chain Reaction ◽  
Plant Parasite ◽  
Dna Fragment ◽  
Polymerase Chain ◽  
Microsatellite Diversity

Sexual reproduction in the plant parasite Phytophthora capsici Leonian requires the interaction of two distinct mating types, A1 and A2. Co-occurrence of these mating types can enhance the genetic diversity of P. capsici and alter its virulence or resistance characteristics. Using an intersimple sequence repeat (ISSR) screen of microsatellite diversity, we identified, cloned, and sequenced a novel 1121-base pair (bp) fragment specific to the A1 mating type of P. capsici. Primers Pcap-1 and Pcap-2 were designed from this DNA fragment to specifically detect the A1 mating type. Polymerase chain reaction (PCR) using these primers amplified an expected 997-bp fragment from known A1 mating types, but yielded a 508-bp fragment from known A2 mating types. This PCR-based assay could be adapted to accurately and rapidly detect the co-occurrence of A1 and A2 P. capsici mating types from field material.

scholarly journals Genetic Diversity and Differentiation inPhoma betaePopulations on Table Beet in New York and Washington States

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1487-1497 ◽  
Author(s):  
Lori B. Koenick ◽  
Niloofar Vaghefi ◽  
Noel L. Knight ◽  
Lindsey J. du Toit ◽  
Sarah J. Pethybridge
Keyword(s):  
Genetic Diversity ◽  
New York ◽  
Mating Type ◽  
Gene Diversity ◽  
Management Strategies ◽  
Allelic Diversity ◽  
Genotypic Diversity ◽  
Reproduction Mode ◽  
Inoculum Source ◽  
Seed Crops

Phoma betae is an important seedborne pathogen of table beet worldwide that is capable of causing foliar, root, and damping-off diseases. Ten microsatellite and mating type markers were developed to investigate the genetics of P. betae populations in table beet root crops in New York and in table beet seed crops in Washington, from where table beet seed is predominantly sourced. The markers were used to characterize 175 isolates comprising five P. betae populations (two from New York and three from Washington), and they were highly polymorphic with an allelic range of 4 to 33 and an average of 11.7 alleles per locus. All populations had high genotypic diversity (Simpson’s complement index = 0.857 to 0.924) and moderate allelic diversity (Nei’s unbiased gene diversity = 0.582 to 0.653). Greater differentiation observed between populations from the two states compared with populations within the same state suggested that an external inoculum source, such as windblown ascospores, may be homogenizing the populations. However, most genetic diversity (87%) was among individual isolates within populations (pairwise index of population differentiation = 0.127; P = 0.001), suggesting that local within-field inoculum source(s), such as infested field debris or infected weeds, may also be important in initiating disease outbreaks. Standardized index of association, proportion of compatible pairs of loci, and mating type ratio calculations showed evidence for a mixed reproduction mode in all populations. These findings could be useful in designing more effective management strategies for diseases caused by P. betae in table beet production.

scholarly journals Evidence for Sexual Recombination in Didymella tanaceti Populations, and Their Evolution Over Spring Production in Australian Pyrethrum Fields

2019 ◽  
Vol 109 (1) ◽  
pp. 155-168 ◽  
Author(s):  
Tamieka L. Pearce ◽  
Jason B. Scott ◽  
Stacey J. Pilkington ◽  
Sarah J. Pethybridge ◽  
Frank S. Hay
Keyword(s):  
Genetic Diversity ◽  
Mating Type ◽  
Sampling Period ◽  
Genotypic Diversity ◽  
Tan Spot ◽  
Late Winter ◽  
Linkage Equilibrium ◽  
Mating Types ◽  
Isolation Frequency ◽  
Sexual Recombination

Tan spot, caused by Didymella tanaceti, is one of the most important foliar diseases affecting pyrethrum in Tasmania, Australia. Population dynamics, including mating-type ratios and genetic diversity of D. tanaceti, was characterized within four geographically separated fields in both late winter and spring 2012. A set of 10 microsatellite markers was developed and used to genotype 774 D. tanaceti isolates. Isolates were genotypically diverse, with 123 multilocus genotypes (MLG) identified across the four fields. Fifty-eight MLG contained single isolates and Psex analysis estimated that, within many of the recurrent MLG, there were multiple clonal lineages derived from recombination. Isolates of both mating types were at a 1:1 ratio following clone correction in each field at each sampling period, which was suggestive of sexual recombination. No evidence of genetic divergence of isolates of each mating type was identified, indicating admixture within the population. Linkage equilibrium in two of the four field populations sampled in late winter could not be discounted following clone correction. Evaluation of temporal changes in gene and genotypic diversity identified that they were both similar for the two sampling periods despite an increased D. tanaceti isolation frequency in spring. Genetic differentiation was similar in populations sampled between the two sampling periods within fields or between fields. These results indicated that sexual reproduction may have contributed to tan spot epidemics within Australian pyrethrum fields and has contributed to a genetically diverse D. tanaceti population.

scholarly journals Frequency and Genetic Diversity of theMAT1Locus of Histoplasma capsulatum Isolates in Mexico and Brazil

2013 ◽  
Vol 12 (7) ◽  
pp. 1033-1038 ◽  
Author(s):  
Gabriela Rodríguez-Arellanes ◽  
Carolina Nascimento de Sousa ◽  
Mauro de Medeiros-Muniz ◽  
José A. Ramírez ◽  
Cláudia V. Pizzini ◽  
...  
Keyword(s):  
Mating Type ◽  
Internal Transcribed Spacer ◽  
Histoplasma Capsulatum ◽  
Geographical Origin ◽  
Soil Samples ◽  
The Other ◽  
Clinical Samples ◽  
Mating Types ◽  
Content Type ◽  
Type Strains

ABSTRACTTheMAT1-1andMAT1-2idiomorphs associated with theMAT1locus ofHistoplasma capsulatumwere identified by PCR. A total of 28 fungal isolates, 6 isolates from human clinical samples and 22 isolates from environmental (infected bat and contaminated soil) samples, were studied. Among the 14 isolates from Mexico, 71.4% (95% confidence interval [95% CI], 48.3% to 94.5%) were of theMAT1-2genotype, whereas 100% of the isolates from Brazil were of theMAT1-1genotype. EachMAT1idiomorphic region was sequenced and aligned, using the sequences of the G-217B (+ mating type) and G-186AR (− mating type) strains as references. BLASTn analyses of theMAT1-1andMAT1-2sequences studied correlated with their respective + and − mating type genotypes. Trees were generated by the maximum likelihood (ML) method to search for similarity among isolates of eachMAT1idiomorph. AllMAT1-1isolates originated from Brazilian bats formed a well-defined group; three isolates from Mexico, the G-217B strain, and a subgroup encompassing all soil-derived isolates and two clinical isolates from Brazil formed a second group; last, one isolate (EH-696P) from a migratory bat captured in Mexico formed a third group of theMAT1-1genotype. TheMAT1-2idiomorph formed two groups, one of which included twoH. capsulatumisolates from infected bats that were closely related to the G-186AR strain. The other group was formed by two human isolates and six isolates from infected bats. Concatenated ML trees, with internal transcribed spacer 1 (ITS1) -5.8S-ITS2 andMAT1-1orMAT1-2sequences, support the relatedness ofMAT1-1orMAT1-2isolates.H. capsulatummating types were associated with the geographical origin of the isolates, and all isolates from Brazil correlated with their environmental sources.

scholarly journals Creation of Stable Heterothallic Strains ofKomagataella phaffiiEnables Dissection of Mating Gene Regulation

2017 ◽  
Vol 38 (2) ◽  
Author(s):  
Lina Heistinger ◽  
Brigitte Gasser ◽  
Diethard Mattanovich
Keyword(s):  
Gene Regulation ◽  
Mating Type ◽  
Cell Formation ◽  
Methylotrophic Yeast ◽  
Diploid Cell ◽  
Mating Types ◽  
Inverted Repeat Region ◽  
Position Effects ◽  
Content Type ◽  
Diploid Cells

ABSTRACTThe methylotrophic yeastKomagataella phaffii(Pichia pastoris) is homothallic and has been reported to switch mating type by an ancient inversion mechanism. Two mating-type (MAT) loci include homologs of theMATaandMATα transcription factor genes, with the expression from one locus downregulated by telomere position effects. However, not much is known about mating gene regulation, since the mixture of mating types complicates detailed investigations. In this study, we developedK. phaffiistrains with stable mating types by deletion of the inverted-repeat region required for mating-type switching. These heterothallic strains retain their ability to mate with cells of the opposite mating type and were used to further elucidate mating gene regulation. Functional analysis ofMATmutant strains revealed the essential role ofMATa2andMATα1in diploid cell formation. Disruption ofMATa1orMATα2did not affect mating; however, in diploid cells, both genes are required for sporulation and the repression of shmoo formation. The heterothallic strains generated in this study allowed the first detailed characterization of mating gene regulation inK. phaffii. They will be a valuable tool for further studies investigating cell-type-specific behavior and will enable in-depth genetic analyses and strain hybridization in this industrially relevant yeast species.

scholarly journals ECOLOGICAL AND GENETIC ADVANCES IN THE CULTIVATION OF TUBER SPP.

2017 ◽  
Vol 40 (4) ◽  
pp. 371-377
Author(s):  
Alessandra Zambonelli ◽  
Pamela Leonardi ◽  
Mirco Iotti ◽  
Ian Hall
Keyword(s):  
Tuber Melanosporum ◽  
Mating Types ◽  
Fruiting Body Formation ◽  
Important Advance ◽  
Body Formation ◽  
Truffle Cultivation ◽  
The Past ◽  
Tuber Species ◽  
Tuber Spp

Recent advances on the ecology and genetics of true truffles (Tuber spp.) are reported and their impact on truffle cultivation is discussed. New insights have been gained on truffle soil ecology and interrelationships of truffles with associated microorganisms in the soil. For instance, some bacteria seem to play a key role in truffle fruiting body formation and maturation. However, the most important advance in truffle genetics over the past 20 years has been the sequencing of the Tuber melanosporum genome and the discovery that truffles, like other Pezizalean fungi, are heterothallic. This finding has had a significant impact on research on truffles and many studies have been devoted to better understanding the distribution of the mating types in soil in natural and cultivated truffières. The characterization of the mating type idiomorphs of several Tuber species has led to the possibility of selecting mycelial strains for truffle cultivation in particular sites.

scholarly journals Tuber melanosporum: mating type distribution in a natural plantation and dynamics of strains of different mating types on the roots of nursery-inoculated host plants

2010 ◽  
Vol 189 (3) ◽  
pp. 723-735 ◽  
Author(s):  
Andrea Rubini ◽  
Beatrice Belfiori ◽  
Claudia Riccioni ◽  
Sergio Arcioni ◽  
Francis Martin ◽  
...  
Keyword(s):  
Mating Type ◽  
Host Plants ◽  
Tuber Melanosporum ◽  
Mating Types ◽  
Type Distribution

scholarly journals Differential Gene Expression between Fungal Mating Types Is Associated with Sequence Degeneration

2020 ◽  
Vol 12 (4) ◽  
pp. 243-258 ◽  
Author(s):  
Wen-Juan Ma ◽  
Fantin Carpentier ◽  
Tatiana Giraud ◽  
Michael E Hood
Keyword(s):  
Differential Expression ◽  
Differentially Expressed Genes ◽  
Mating Type ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Gc Content ◽  
Differentially Expressed ◽  
Mating Types ◽  
Sexual Antagonism ◽  
Recombination Suppression

Abstract Degenerative mutations in non-recombining regions, such as in sex chromosomes, may lead to differential expression between alleles if mutations occur stochastically in one or the other allele. Reduced allelic expression due to degeneration has indeed been suggested to occur in various sex-chromosome systems. However, whether an association occurs between specific signatures of degeneration and differential expression between alleles has not been extensively tested, and sexual antagonism can also cause differential expression on sex chromosomes. The anther-smut fungus Microbotryum lychnidis-dioicae is ideal for testing associations between specific degenerative signatures and differential expression because 1) there are multiple evolutionary strata on the mating-type chromosomes, reflecting successive recombination suppression linked to mating-type loci; 2) separate haploid cultures of opposite mating types help identify differential expression between alleles; and 3) there is no sexual antagonism as a confounding factor accounting for differential expression. We found that differentially expressed genes were enriched in the four oldest evolutionary strata compared with other genomic compartments, and that, within compartments, several signatures of sequence degeneration were greater for differentially expressed than non-differentially expressed genes. Two particular degenerative signatures were significantly associated with lower expression levels within differentially expressed allele pairs: upstream insertion of transposable elements and mutations truncating the protein length. Other degenerative mutations associated with differential expression included nonsynonymous substitutions and altered intron or GC content. The association between differential expression and allele degeneration is relevant for a broad range of taxa where mating compatibility or sex is determined by genes located in large regions where recombination is suppressed.

scholarly journals Deletion of the Schizophyllum commune Aα Locus: The Roles of Aα Y and Z Mating-Type Genes

Genetics ◽  
1996 ◽  
Vol 144 (4) ◽  
pp. 1437-1444
Author(s):  
C Ian Robertson ◽  
Kirk A Bartholomew ◽  
Charles P Novotny ◽  
Robert C Ullrich
Keyword(s):  
Mating Type ◽  
Sexual Development ◽  
Schizophyllum Commune ◽  
Mating Types ◽  
Developmental Pathway ◽  
Mating Type Gene ◽  
Mating Type Genes ◽  
Regulatory Loci ◽  
Type Gene

The Aα locus is one of four master regulatory loci that determine mating type and regulate sexual development in Schizophyllum commune. We have made a plasmid containing a URA1 gene disruption of the Aα Y1 gene. Y1 is the sole Aα gene in Aα1 strains. We used the plasmid construction to produce an Aα null (i.e., AαΔ) strain by replacing the genomic Y1 gene with URA1 in an Aα1 strain. To characterize the role of the Aα genes in the regulation of sexual development, we transformed various Aα Y and Z alleles into AαΔ strains and examined the acquired mating types and mating abilities of the transformants. These experiments demonstrate that the Aα Y gene is not essential for fungal viability and growth, that a solitary Z Aα mating-type gene does not itself activate development, that Aβ proteins are sufficient to activate the A developmental pathway in the absence of Aα proteins and confirm that Y and Z genes are the sole determinants of Aα mating type. The data from these experiments support and refine our model of the regulation of A-pathway events by Y and Z proteins.

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