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.

Cintractia limitata. [Distribution map].

2008 ◽  
Author(s):  
Keyword(s):  
New York ◽  
Tamil Nadu ◽  
New Caledonia ◽  
New South ◽  
Uttar Pradesh ◽  
The Philippines ◽  
Distribution Map ◽  
South Wales ◽  
New Distribution ◽  
Distribution In Europe

Abstract A new distribution map is provided for Cintractia limitata G.P. Clinton. Fungi: Basidiomycota: Anthracoideaceae. Main hosts: Cyperus spp. Information is given on the geographical distribution in Europe (France), Asia (Bangladesh, China, India, Bihar, Delhi, Karnataka, Madhya Pradesh, Maharashtra, Punjab, Tamil Nadu, Uttar Pradesh, Indonesia, Myanmar, Pakistan, the Philippines, Sri Lanka, Taiwan, Thailand), Africa (Congo, Cote d'Ivoire, Ghana, Guinea, Kenya, Malawi, Nigeria, Reunion, Sierra Leone, South Africa, Sudan, Tanzania, Togo, Uganda, Zambia, Zimbabwe), North America (Mexico, USA, Florida, New Jersey, New York), Central America and Caribbean (Belize, Costa Rica, Cuba, Dominica, Dominican Republic, El Salvador, Guatemala, Jamaica, Nicaragua, Panama, Puerto Rico, Trinidad and Tobago), South America (Argentina, Brazil, Rio de Janeiro, Colombia, Venezuela), Oceania (Australia, New South Wales, Northern Territory, Queensland, Victoria, Western Australia, New Caledonia, Papua New Guinea).

Arthropod community structures of rice ecosystems in the Philippines

1991 ◽  
Vol 81 (4) ◽  
pp. 407-416 ◽  
Author(s):  
K.L. Heong ◽  
G.B. Aquino ◽  
A.T. Barrion
Keyword(s):  
Abundant Species ◽  
Diversity Indices ◽  
Nilaparvata Lugens ◽  
The Philippines ◽  
Arthropod Community ◽  
Dominant Group ◽  
Cropping Patterns ◽  
Cyrtorhinus Lividipennis ◽  
Positive Correlations ◽  
Relative Differences

AbstractThe arthropod community associated with irrigated rice grown in five sites in Luzon Island, Philippines, was analysed using guild categories. Phytophages and predators were predominant in all sites. The phytophage species were mainly Homoptera and dominated by Nephotettix virescens (Distant), N. nigropictus (Stål) (Cicadellidae), and Nilaparvata lugens (Stål) and Sogatella furcifera (Horváth) (Delphacidae). Predators were mainly Heteroptera with Microvelia douglasi atrolineata Bergoth (Veliidae), Mesovelia vittigera (Horváth) (Mesoveliidae), and Cyrtorhinus lividipennis Reuter (Miridae) as the most abundant species. Spiders were the next dominant group with Pardosa pseudoannulata (Böesenberg & Strand) and three species of Tetragnatha the most common. Differences in species diversity between the sites were easily differentiated using diversity indices. The relative differences in arthropod abundance, species richness and diversity may be attributed to the median temperatures, cropping patterns, and diversity in crop stages and germplasm in the sites. Predator-Homoptera correlations were significant in all cases. High positive correlations were obtained for veliids, spiders and Cyrtorhinus lividipennis, in most sites.

scholarly journals Assessment of Wetland Water Quality and Avian Diversity of a Human-Modified Floodplain Wetland on River Yamuna

2013 ◽  
Vol 5 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Upma MANRAL ◽  
Faiyaz A. KHUDSAR
Keyword(s):  
Water Quality ◽  
Ecological Integrity ◽  
Uttar Pradesh ◽  
Diversity Indices ◽  
Organic Load ◽  
Ceratophyllum Demersum ◽  
Area Network ◽  
Rapid Urbanization ◽  
Untreated Wastewater ◽  
River Yamuna

Okhla Bird Sanctuary (OBS) is an Important Bird Area, which comes under the protected area network of Uttar Pradesh with one-third area lying in the state of Delhi (India). OBS has widest flood plains along the Delhi stretch of river Yamuna and is important in conserving the ecological wealth of floodplains of the river. Rapid urbanization and industrialization and discharge of untreated wastewater into the river have resulted in deteriorated water quality. The present study focused on assessment of water quality, aquatic flora and avifaunal diversity in the OBS. Water quality was analyzed following methods of APHA. For vegetation analysis, sub-merged and free-floating plants were scooped up from five randomly selected sites. Total bird counts were conducted for water birds and species richness, evenness and Shannon-Weaver species diversity indices were calculated. Results indicate that the organic load is very high in the wetland as evident from low levels of dissolved oxygen (2.26 ± 1.62 mg/l) and high Biological and Chemical Oxygen Demands (15.20 ± 3.75 mg/l, 44.60 ± 12.07 mg/l). Nine species of free-floating and submerged plants were recorded; Hydrilla verticillata, Vallisneria spiralis, Azolla pinnata and Ceratophyllum demersum dominated both deep and shallow water areas. 52 species of waterbirds including four near-threatened species viz., Anhinga melanogaster, Mycteria leucocephala, Threskiornis melanocephalus and Aythya nyroca were recorded. OBS provides opportunities for conservation in a metropolitan area, thus, appropriate measures should be taken to maintain its ecological integrity.

Idioscopus clypealis (mango leafhopper).

2021 ◽  
Author(s):  
R Ganeswaran
Keyword(s):  
Population Size ◽  
Indian Subcontinent ◽  
Uttar Pradesh ◽  
The Philippines ◽  
Yield Reduction ◽  
Bud Break ◽  
Flowering Stage ◽  
Flower Bud ◽  
Economic Injury ◽  
The Mean

Abstract Mango leafhoppers are major pests in the Indian subcontinent. The major damage caused is at the flowering stage and several studies have highlighted the reduction of yield which may be between 20 and 100% depending on population size. Verghese and Rao (1987) examined the critical infestation stages of I. clypealis in Uttar Pradesh, India. The mean density of cicadellids was 0.54-20.64 per panicle in 1983 and 0-6.03 per panicle in 1984. In both years, the peak population occurred when the fruit was pea sized. At the post-bloom stage a population of two adults per panicle was sufficient to cause yield reduction. It is suggested that the critical infestation stages are at post-bloom, when the fruit is marble sized, and 1 month before harvest, with corresponding critical population levels of two adults, 6-21 nymphs and 4-11 hoppers per panicle. In the Philippines, Corey et al. (1989) found that the economic injury levels for I. clypealis on two croppings of mangoes averaged 4.21, 4.30, 4.45 and 4.55 adults per panicle at 2, 10, 18 and 26 days, respectively, after flower bud break for the first cropping, and 4.79, 4.88, 5.06 and 5.18 adults per panicle for the second cropping.

scholarly journals A Set of Standard Differential Blast Isolates (Magnaporthe grisea (Hebert) Barr.) from the Philippines for Rice (Oryza sativa L.) Resistance

2008 ◽  
Vol 42 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Mary Jeanie TELEBANCO-YANORIA ◽  
Tokio IMBE ◽  
Hiroshi KATO ◽  
Hiroshi TSUNEMATSU ◽  
Leodegario A. EBRON ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Magnaporthe Grisea ◽  
Oryza Sativa L ◽  
The Philippines

scholarly journals Genetic Structure of Magnaporthe grisea Populations Associated with St. Augustinegrass and Tall Fescue in Georgia

2005 ◽  
Vol 95 (5) ◽  
pp. 463-471 ◽  
Author(s):  
L. P. Tredway ◽  
K. L. Stevenson ◽  
L. L. Burpee
Keyword(s):  
Genetic Structure ◽  
Tall Fescue ◽  
Host Species ◽  
Magnaporthe Grisea ◽  
Haplotype Diversity ◽  
Diversity Indices ◽  
Sample Population ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms

Amplified fragment length polymorphisms (AFLPs) were used to estimate phylogenetic relationships within Magnaporthe grisea and determine the genetic structure of M. grisea populations associated with tall fescue and St. Augustinegrass in Georgia. Sixteen clonal lineages were identified in a sample population of 948 isolates. Five lineages were isolated from tall fescue (E, G1, G2, G4, and H), with lineage G4 comprising 90% of the population. Isolates from tall fescue were closely related to those from perennial ryegrass, weeping lovegrass, and wheat. Two M. grisea lineages were isolated from St. Augustinegrass (C and K), with lineage C comprising 99.8% of the population. Populations from crabgrass were dominated (98%) by lineage K, but also contained a single lineage C isolate. Haplotype diversity indices ranged from 0.00 to 0.29 in tall fescue populations and from 0.00 to 0.04 in St. Augustinegrass populations. Selection due to host species was the primary factor determining population structure according to analysis of molecular variance; host cultivar and geographical region had no significant effect. The host range of M. grisea lineages from turfgrasses was determined in growth chamber experiments and supports the prominent role of host species in determining the genetic structure of M. grisea populations from turfgrasses in Georgia.

Phenotypic diversity of soybean (Glycine max (L.) Merr.)accessions in the Philippines for utilization

2016 ◽  
Author(s):  
Hidelisa De Chavez ◽  
Teresita Borromeo ◽  
Nic Oswald Borines ◽  
Renerio Jr Gentallan
Keyword(s):  
Coat Color ◽  
Phenotypic Diversity ◽  
Germplasm Collection ◽  
Principal Component ◽  
Diversity Indices ◽  
Morphological Characters ◽  
The Philippines ◽  
Soybean Germplasm ◽  
Plant Growth Habit ◽  
Qualitative Characters

An increasing trend of soybean production and consumption has been seen in the Philippines. To assess the potential of the soybean germplasm for utilization, diversity of the Philippine soybean collection was established. High diversity was marked on 17 out of 29 qualitative characters, which include plant growth habit, leaf blistering and flower standard color. Phenotypic diversity indices (H’) of 92 soybean accessions averaged at 0.62. This aside, traits identical to a variety of soybean with superior characters were all present in the soybean germplasm collection. Using simple matching similarity coefficient, cluster analysis separated the different accessions into 12 distinct clusters at 62% similarity. Categorical Principal Component Analysis (CATPCA) showed that two independent components accounted for 35.36% of the total variation of the qualitative morphological characters. Factor loadings for each component showed the morphological characters, such as pubescence color, flower wing color, and seed coat color, that were contributing to the high projections in the two principal components. Accessions with vigorous seedlings were also observed. With the marked trait diversity, the soybean collection could be potentially used directly and for breeding purposes. Consequently, to uncover further the potential of our genetic resources at hand, the remaining germplasm accessions at NPGRL should be characterized and evaluated

scholarly journals Pathogenic Variation in the Pearl Millet Blast Pathogen Magnaporthe grisea and Identification of Resistance to Diverse Pathotypes

Plant Disease ◽  
2013 ◽  
Vol 97 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Rajan Sharma ◽  
H. D. Upadhyaya ◽  
S. V. Manjunatha ◽  
K. N. Rai ◽  
S. K. Gupta ◽  
...  
Keyword(s):  
Pearl Millet ◽  
Magnaporthe Grisea ◽  
Blast Resistance ◽  
Uttar Pradesh ◽  
Yield Potential ◽  
Sources Of Resistance ◽  
Pathogenic Variation ◽  
Fodder Yield ◽  
Improvement Programs ◽  
Serious Disease

Blast, also known as leaf spot, caused by Pyricularia grisea (teleomorph: Magnaporthe grisea), has emerged as a serious disease affecting both forage and grain production in pearl millet in India. Pathogenic variation was studied in a greenhouse using 25 M. grisea isolates collected from four major pearl-millet-growing states in India (Rajasthan, Haryana, Maharashtra, and Uttar Pradesh) on 10 pearl millet genotypes (ICMB 02444, ICMB 02777, ICMB 06444, ICMB 93333, ICMB 96666, ICMB 97222, ICMB 99444, 863B, ICMR 06222, and ICMB 95444). Differential reactions to the test isolates were recorded on ICMB 02444, ICMB 93333, ICMB 97222, 863B, and ICMR 06222. The 25 isolates were grouped into five different pathotypes based on their reaction types (virulent = score ≥ 4 and avirulent = score ≤ 3 on a 1-to-9 scale). For the identification of resistance sources, a pearl millet mini-core comprising 238 accessions was evaluated under greenhouse conditions against five M. grisea isolates (Pg118, Pg119, Pg56, Pg53, and Pg45) representing the five pathotypes. Of 238 accessions, 32 were found to be resistant to at least one pathotype. Resistance to multiple pathotypes (two or more) was recorded in several accessions, while three accessions (IP 7846, IP 11036, and IP 21187) exhibited resistance to four of the five pathotypes. Four early-flowering (≤50 days) blast-resistant mini-core accessions (IP 7846, IP 4291, IP 15256, and IP 22449) and four accessions (IP 5964, IP 11010, IP 13636, and IP 20577) having high scores (≥7) for grain and green fodder yield potential and overall plant aspect were found to be promising for utilization in pearl millet improvement programs. Identification of five pathotypes of M. grisea and sources of resistance to these pathotypes will provide a foundation for breeding for blast resistance in pearl millet in India.

scholarly journals Analysis of the Structure of the AVR1-CO39 Avirulence Locus in Virulent Rice-Infecting Isolates of Magnaporthe grisea

2002 ◽  
Vol 15 (1) ◽  
pp. 6-16 ◽  
Author(s):  
Mark L. Farman ◽  
Yukiko Eto ◽  
Tomomi Nakao ◽  
Yukio Tosa ◽  
Hitoshi Nakayashiki ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Magnaporthe Grisea ◽  
Repetitive Element ◽  
Rice Cultivar ◽  
The Philippines ◽  
Hybridization Signal ◽  
Left Hand ◽  
Right Hand ◽  
French Guyana ◽  
The Right

The AVR1-CO39 gene that came from a Magnaporthe grisea isolate from weeping lovegrass controls avirulence on the rice cultivar CO39. AVR1-CO39 was not present in the genome of the rice-infecting M. grisea isolate Guy11 from French Guyana, suggesting that the gene had been deleted. Molecular analysis of the deletion breakpoints in the AVR1-CO39 locus revealed the presence of a truncated copy of a previously unknown retrotransposon at the left-hand border. At the right-hand border was a truncated copy of another repetitive element that is present at multiple locations in the genome of Guy11. The structures of avr1-CO39 loci were further examined in 45 rice-infecting isolates collected in Brazil, China, Japan, India, Indonesia, Mali, and the Philippines. Most isolates showed no hybridization signal with the AVR1-CO39 probe and had the same locus structure as Guy11. Some isolates from Japan showed a signal with the AVR1-CO39 probe, but the region specifying avirulence activity was rearranged. These findings suggest that widespread virulence to ‘CO39’ among rice-infecting M. grisea isolates is due to ancestral rearrangements at the AVR1-CO39 locus that may have occurred early in the evolution of pathogenicity to rice.

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