Evidence for Recombination in Magnaporthe Grisea Rice Pathogens: A Case Study from the Indian Himalayas

2000 ◽  
pp. 243-247
Author(s):  
R. S. Zeigler ◽  
J. Kumar ◽  
R. J. Nelson ◽  
H. Leung
Keyword(s):  
Magnaporthe Grisea ◽  
Rice Pathogens ◽  
Indian Himalayas

scholarly journals Sexually Fertile Magnaporthe grisea Rice Pathogens in Thailand

Plant Disease ◽  
1999 ◽  
Vol 83 (10) ◽  
pp. 939-943 ◽  
Author(s):  
Poonsak Mekwatanakarn ◽  
Wichai Kositratana ◽  
Tawatchai Phromraksa ◽  
R. S. Zeigler
Keyword(s):  
Mating Type ◽  
Male Fertility ◽  
Magnaporthe Grisea ◽  
Female Sterility ◽  
Diverse Populations ◽  
Type Distribution ◽  
Northern Regions ◽  
Rice Pathogens ◽  
Central Thailand

Sexual fertility and mating type distribution of Magnaporthe grisea field isolates collected in Thailand were analyzed from sites previously found to harbor diverse populations of the pathogen. Three hundred forty-one single conidium isolates of M. grisea collected from five sites in north, northeast, and central Thailand were evaluated for in vitro sexual fertility and mating type by pairing with strains of known mating type. Most isolates (67%) were infertile when crossed with the hermaphrodite tester strains; but fertile isolates of each mating type that yielded viable ascospores were detected in all sites from the northeastern and northern regions. MAT1-2 predominated over MAT1-1 in bioassay mating type. Male fertility (female sterility) predominated in fertile MAT1-1 (50 to 75%) and MAT1-2 (50 to 85%) isolates from all locations in Thailand; however, hermaphroditic and/or female fertile isolates were also detected in all but one site. Fertility, as determined by perithecia density, was low (<10 perithecia cm-2) for most isolates, although a few produced in excess of 20 perithecia cm-2.

Energy and economic analysis of traditional versus introduced crops cultivation in the mountains of the Indian Himalayas: A case study

Energy ◽  
2007 ◽  
Vol 32 (12) ◽  
pp. 2321-2335 ◽  
Author(s):  
Sunil Nautiyal ◽  
H. Kaechele ◽  
K.S. Rao ◽  
R.K. Maikhuri ◽  
K.G. Saxena
Keyword(s):  
Economic Analysis ◽  
Indian Himalayas

scholarly journals Compromise Programming Based Model for Augmenting Food Production with Minimum Water Allocation in a Watershed: a Case Study in the Indian Himalayas

2014 ◽  
Vol 28 (15) ◽  
pp. 5247-5265 ◽  
Author(s):  
Pradeep Dogra ◽  
V. N. Sharda ◽  
P. R. Ojasvi ◽  
Shiv O. Prasher ◽  
R. M. Patel
Keyword(s):  
Water Allocation ◽  
Food Production ◽  
Compromise Programming ◽  
Indian Himalayas

Analyzing Social Networks to Examine the Changing Governance Structure of Springsheds: A Case Study of Sikkim in the Indian Himalayas

2018 ◽  
Vol 63 (2) ◽  
pp. 233-248
Author(s):  
Sudeshna Maya Sen ◽  
Aprajita Singh ◽  
Navarun Varma ◽  
Divya Sharma ◽  
Arun Kansal
Keyword(s):  
Social Networks ◽  
Governance Structure ◽  
Indian Himalayas

Evolution and Organization of a Highly Dynamic, Subtelomeric Helicase Gene Family in the Rice Blast Fungus Magnaporthe grisea

Genetics ◽  
2002 ◽  
Vol 162 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Weimin Gao ◽  
Chang Hyun Khang ◽  
Sook-Young Park ◽  
Yong-Hwan Lee ◽  
Seogchan Kang
Keyword(s):  
Gene Family ◽  
Magnaporthe Grisea ◽  
Gene Families ◽  
Mapping Technique ◽  
Telomeric Region ◽  
Cloning And Sequencing ◽  
Fungal Evolution ◽  
Helicase Gene ◽  
Rice Pathogens ◽  
Almost All

Abstract Sequence analysis of a 13-kb telomeric region in O-137, a rice pathogenic isolate of Magnaporthe grisea, uncovered a novel gene, designated TLH1 (telomere-linked helicase 1). The TLH1 gene is a member of a gene family, and the sequences flanking this gene family have also been amplified. Genetic mapping showed that most members of the TLH gene family are tightly linked to the telomeres. A physical mapping technique, termed RecA-mediated Achilles’ heel cleavage, and cloning and sequencing of two additional telomeres of O-137 associated with the TLH gene family confirmed that most members of the TLH gene family are located within 10 kb from the telomeric repeat. A survey of M. grisea strains from diverse hosts revealed that the gene family is ubiquitously present among rice pathogens, but is absent from almost all isolates of hosts other than rice. The gene family appears to be highly dynamic, undergoing frequent deletion/amplification events. Given the presence of similar helicase gene families in chromosome ends of Saccharomyces cerevisiae and Ustilago maydis, the initial association of helicase genes with fungal telomeres might date back to very early stages of the fungal evolution.

scholarly journals Seed source variation affects the growth, biomass, carbon stock, and climate resilience potential: A case study of Celtis australis in Indian Himalayas

2021 ◽  
Vol 26 ◽  
pp. e01469
Author(s):  
Raj Kumar ◽  
Harsh Mehta ◽  
Arvind Kumar ◽  
Ajay Kumar Bhardwaj ◽  
Rajesh Kaushal ◽  
...  
Keyword(s):  
Carbon Stock ◽  
Seed Source ◽  
Biomass Carbon ◽  
Climate Resilience ◽  
Source Variation ◽  
Celtis Australis ◽  
Indian Himalayas

scholarly journals Population Structure and Dynamics of Magnaporthe grisea in the Indian Himalayas

Genetics ◽  
1999 ◽  
Vol 152 (3) ◽  
pp. 971-984
Author(s):  
J Kumar ◽  
R J Nelson ◽  
R S Zeigler
Keyword(s):  
Magnaporthe Grisea ◽  
Uttar Pradesh ◽  
Diversity Indices ◽  
The Philippines ◽  
Single Locus ◽  
Differential Survival ◽  
Repeated Sampling ◽  
Copy Dna ◽  
Population Structure And Dynamics ◽  
Indian Himalayas

Abstract The population genetics of Magnaporthe grisea, the rice blast pathogen, were analyzed in a center of rice diversity (the Uttar Pradesh hills of the Indian Himalayas) using multilocus and single-, or low-copy, DNA markers. Based on DNA fingerprinting with the multilocus probe MGR586 and single-locus probes, 157 haplotypes clustered into 56 lineages (at ≥70% MGR586 band similarity, each with unique single-locus profiles) and high diversity indices were detected among 458 isolates collected from 29 sites during 1992–1995. Most valleys sampled had distinct populations (73% of the lineages were site specific) with some containing one or a few lineages, confirming the importance of clonal propagation, and others were very diverse. Widely distributed lineages suggested that migration occurs across the region and into the Indo-Gangetic plains. Repeated sampling at one site, Matli, (170 isolates, 1992–1995) yielded 19 lineages and diversity significantly greater than that reported from similar samples from Colombia and the Philippines. Analysis of allelic associations using pairwise comparisons and multilocus variance analysis failed to reject the hypothesis of gametic phase equilibrium. The Matli population shifted from highly diverse in 1992 to almost complete dominance by one lineage in 1995. Such population dynamics are consistent with recombination followed by differential survival of clonal descendants of recombinant progeny. At another site, Ranichauri, population (n = 84) composition changed from 2 to 11 lineages over 2 yr and yielded additional evidence for equilibrium. Sexually fertile and hermaphrodite isolates of both mating types were recovered from rice in both Matli and Ranichauri. We demonstrate that Himalayan M. grisea populations are diverse and dynamic and conclude that the structure of some populations may be affected to some extent by sexual recombination.

Spatial Distribution of Rainfall in Indian Himalayas – A Case Study of Uttarakhand Region

2007 ◽  
Vol 22 (10) ◽  
pp. 1325-1346 ◽  
Author(s):  
Ashoke Basistha ◽  
D. S. Arya ◽  
N. K. Goel
Keyword(s):  
Spatial Distribution ◽  
Indian Himalayas

scholarly journals Determination of Rainfall Thresholds for Landslide Prediction Using an Algorithm-Based Approach: Case Study in the Darjeeling Himalayas, India

Geosciences ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 302 ◽  
Author(s):  
Togaru Surya Teja ◽  
Abhirup Dikshit ◽  
Neelima Satyam
Keyword(s):  
Warning System ◽  
Land Loss ◽  
Landslide Occurrence ◽  
Power Law Equation ◽  
The Relationship ◽  
Automated Tool ◽  
Indian Himalayas ◽  
Darjeeling Himalayas

Landslides are one of the most devastating and commonly recurring natural hazards in the Indian Himalayas. They contribute to infrastructure damage, land loss and human casualties. Most of the landslides are primarily rainfall-induced and the relationship has been well very well-established, having been commonly defined using empirical-based models which use statistical approaches to determine the parameters of a power-law equation. One of the main drawbacks using the traditional empirical methods is that it fails to reduce the uncertainties associated with threshold calculation. The present study overcomes these limitations by identifying the precipitation condition responsible for landslide occurrence using an algorithm-based model. The methodology involves the use of an automated tool which determines cumulated event rainfall–rainfall duration thresholds at various exceedance probabilities and the associated uncertainties. The analysis has been carried out for the Kalimpong Region of the Darjeeling Himalayas using rainfall and landslide data for the period 2010–2016. The results signify that a rainfall event of 48 hours with a cumulated event rainfall of 36.7 mm can cause landslides in the study area. Such a study is the first to be conducted for the Indian Himalayas and can be considered as a first step in determining more reliable thresholds which can be used as part of an operational early-warning system.

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