Influence of Isolation Method on Growth Rate Characteristics of Populations of Phytophthora cinnamomi

1977 ◽  
Vol 25 (5) ◽  
pp. 477 ◽  
Author(s):  
CJ Shepherd ◽  
RI Forrester
Keyword(s):  
Growth Rate ◽  
Phytophthora Cinnamomi ◽  
Isolation Method ◽  
Direct Plating ◽  
Eucalypt Forest ◽  
North Eastern

Direct plating and baiting methods were used to obtain 266 isolates of Phytophthova cinnamomi from eucalypt forest in north-eastern Victoria. Isolates derived by baiting grew faster than those from plating. Single zoospore progeny showed that many of those obtained by direct plating were probably heterocaryotic for determinants of growth rate, while those obtained by baiting exhibited significantly less variance among single zoospore progenies.

Temperature-Growth Relations and Genetic Diversity of A2 Mating-Type Isolates of Phytophthora cinnamomi in Australia

1974 ◽  
Vol 22 (2) ◽  
pp. 231 ◽  
Author(s):  
CJ Shepherd ◽  
BH Pratt
Keyword(s):  
Growth Rate ◽  
First Generation ◽  
Phytophthora Cinnamomi ◽  
Phytophthora Species ◽  
Temperature Growth ◽  
Field Isolates ◽  
Place Of Origin ◽  
Successive Generations ◽  
Cardinal Temperatures ◽  
Range Of Values

Determinations of cardinal temperatures for growth on various media of 50 Australian isolates of Phytophthova cinnamomi showed that growth did not occur outside the range 5-35°C. The range of temperatures at which growth optima occurred varied according to the isolate and medium used and encompassed the whole range of values reported by overseas authors. Growth rates of 361 isolates on corn meal agar at 25°C varied within the range 4.7-10.5 mm/day. There was no correlation between optimum temperature and whether isolates were slow- or fastgrowing or their place of origin. Fast-growing isolates (6-11 mm/day) were obtained from all States, but slower-growing isolates (<6 mm/day) were obtained only from southern and western regions of Australia. Populations from different regions of Australia exhibited different growth rate parameters. The variability of mycelial isolates in culture was studied by examining differences in growth rate among replicated parent, single-zoospore, single-zoosporangium and single terminal-hyphal isolates. Extensive variation was found among first generation single-zoospore progenies of field isolates, with lesser variation among progeny of single zoosporangia, terminal hyphal cultures and second and third generation zoospore derivatives. The origin of this variation is discussed and it is suggested that field isolates are heterokaryotic, since zoospores proved to be predominantly uninucleate. When various Phytophthora species were incubated at temperatures above those at which growth was possible and then returned to 25°C, their subsequent ability to resume growth depended on the particular time-temperature combination used. Considerable variation of response was found among a number of isolates of P. cinnamomi and, following the establishment of single zoospore isolates, the potential variability of field isolates was shown to persist through successive generations of zoospore propagation. It is suggested that a cytoplasmic mechanism of inheritance may be responsible for this variation.

Isolation Method (Direct Plating or Enrichment) does Not Affect Antimicrobial Susceptibility ofCampylobacterfrom Chicken Carcasses

2016 ◽  
Vol 37 (1) ◽  
pp. e12279 ◽  
Author(s):  
Scott R. Ladely ◽  
Richard J. Meinersmann ◽  
Jodie R. Plumblee ◽  
Paula J. Fedorka-Cray
Keyword(s):  
Antimicrobial Susceptibility ◽  
Isolation Method ◽  
Direct Plating

Earthworms in some Tasmanian forest soils in relation to bioturbation and soil texture profile

Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1231 ◽  
Author(s):  
M. D. Laffan ◽  
T. J. Kingston
Keyword(s):  
Forest Soils ◽  
Forest Type ◽  
Texture Profile ◽  
Earthworm Species ◽  
Eucalypt Forest ◽  
North Eastern ◽  
Earthworm Population ◽  
Subsurface Layers ◽  
Texture Contrast ◽  
Density And Biomass

Soil properties and earthworm population density were examined for 5 forest soils derived from Silurian-Devonian sandstones (Mathinna Beds) in north-eastern Tasmania. The soils occur along gradients of altitude, rainfall, and forest type; they include 2 with texture-contrast and 3 with gradational soil profile types. The density and biomass of the most abundant earthworm species Megascolex montisarthuri, and of all earthworm species combined, were found to be greater in gradational than in texture-contrast soils. A greater proportion of the earthworms in gradational soils than in texture-contrast soils was found to occur at soil depths exceeding 10 cm. The contrast was most pronounced between the 2 texture-contrast soils and the single gradational soil that occur under dry eucalypt forest. This paper explores the hypothesis that bioturbation of surface and subsurface layers by earthworms is an important mixing process that in gradational soils outweighs the counter tendency for soil particles to sort and thus form texture-contrast profiles.

Populations of Four Small Mammals in Radiata Pine Plantations and Eucalypt Forests of North-Eastern Victoria.

1978 ◽  
Vol 5 (3) ◽  
pp. 305 ◽  
Author(s):  
GC Suckling ◽  
A Heislers
Keyword(s):  
Small Mammals ◽  
Radiata Pine ◽  
Pine Plantations ◽  
Native Vegetation ◽  
Forest Types ◽  
Eucalypt Forest ◽  
North Eastern ◽  
Antechinus Stuartii ◽  
Rattus Fuscipes ◽  
Eucalypt Forests

[See also FA 39, 2088] A 2-yr trapping study was made on (a) Rattus fuscipes, (b) Antechinus stuartii, (c) Mus musculus and (d) A. swainsonii in mature eucalypt forest, a narrow stream-side strip of eucalypt forest, and in 3 pine plantations, 8, 22 and 42 yr old. In each area (a) and (d) were largely and (c) always confined to dense native vegetation along streams, whilst (b) was more frequent along streams than on slopes. More animals were found away from streams in young pine plantations than in other forest types.

scholarly journals Characterization and fungicides sensitivity of Phytophthora cinnamomi isolates causing avocado root rot in Zitácuaro, Michoacán

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Alejandra Mondragón-Flores ◽  
Patricia Manosalva ◽  
Salvador Ochoa-Ascencio ◽  
Marlene Díaz-Celaya ◽  
Gerardo Rodríguez-Alvarado ◽  
...  
Keyword(s):  
Growth Rate ◽  
Mating Type ◽  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Potassium Phosphite ◽  
Pathogenicity Tests

<em>Phytophthora cinnamomi</em> is the pathogen most frequently associated with avocado root rot. In Zitácuaro, Michoacán, production has increased by 19.8%; however, there are no studies of root rot in this area. The objective of the study was to characterize the isolates obtained from avocado roots and assess the sensitivity to fungicides. Samples from 5 avocado orchards were collected, sampling 5 trees per orchard (a total of 25 samples). The samples isolated were characterized morphological and molecularly. Mating type was analyzed using reference isolates of<em> P. cinnamomi</em> A1 (isolate from camelia) and A2 (isolate from avocado). To confirm the pathogenicity, tests were performed on avocado fruits with the isolates. The sensitivity of 15 isolates to potassium phosphite and to metalaxyl-M at different concentrations was evaluated<em> in vitro</em>. In a subgroup of six isolates, it was evaluated whether there was a relationship between growth rate and potassium phosphite sensitivity. Fifteen isolates were obtained with coenocytic coraloid mycelium, chlamydospores, sporangia without papilla, ovoid to ellipsoid, with internal proliferation, heterothallic with mating type A2, with amphigynous antheridia and plerotic oospores, characteristics consistent with <em>P. cinnamomi</em>. The inoculated isolates were pathogenic on avocado fruits. The isolates were more sensitive to potassium phosphite than to metalaxyl-M, with mean EC50 values of 24.62 and 0.215 ?g mL-1 of i.a., respectively. No relationship was observed between growth rate and potassium phosphite sensitivity. It is necessary to obtain a greater number of<em> P. cinnamomi</em> isolates for virulence studies.

Pathogenicity of Pythium spp. And Phytopththora drechsleri to Eucalyptus spp

1974 ◽  
Vol 22 (4) ◽  
pp. 661 ◽  
Author(s):  
GC Marks ◽  
FY Kassaby
Keyword(s):  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Pythium Ultimum ◽  
Pythium Species ◽  
Marked Contrast ◽  
Small Juvenile ◽  
Eucalypt Forest ◽  
Stage Of Development ◽  
Eastern Australia ◽  
Phytophthora Drechsleri

A number of Pythium spp, and Phytophthora drechsleri have been associated with Phytophthora cinnamomi in the die-back disease of eucalypts in forests of southern and eastern Australia. Although P. cinnamomi is generally considered to be the most important pathogen causing root rot and die-back, there is some uncertainty whether it is the only pathogen. The pathogenicity of Pythium ultimum, P. irregulare, P. debaryanum, P. vexans, P. mamillatum, three unidentified Pythium species from eucalypt forest soil and Phytophthora drechsleri was compared with that of Phytophthora cinnamomi on juvenile and intermediate-aged seedlings of Eucalyptus sieberi and juvenile seedlings of other eucalypt species. Of the Pythiums, only P. ultimum, P. irregulare and P. debaryanum could kill small juvenile seedlings at the two-leaf stage of development. Neither any of the Pythiums nor Phytophthora drechsleri could kill E. sieberi at the intermediate growth stage. In marked contrast, Phytophthora cinnamomi showed considerable pathogenicity, killing seedlings and saplings with rapidity. The unidentified Pythium spp, from native forests were completely innocuous.

Is Organic Rice bean (Vigna umbellata) Farmers Economically better Off? AnEmpirical Analysis

2022 ◽  
Vol 58 (1) ◽  
pp. 17-20
Author(s):  
Singyala Chiphang ◽  
Ram Singh ◽  
S. M. Feroze
Keyword(s):  
Growth Rate ◽  
Allocative Efficiency ◽  
Sampling Technique ◽  
Potential Yield ◽  
Rice Bean ◽  
Organic Rice ◽  
Vigna Umbellata ◽  
North Eastern ◽  
The World ◽  
Multistage Sampling

The study was conducted in North Eastern Hill (NEH) region of India during 2018-2020.Multistage sampling technique was adopted. Sikkim was selected purposively as the controlstate and Nagaland was selected based on the highest area and production under pulses. 60respondents each from organic adopter and non-adopter were selected making a total samplesize of 120. The growth rate in area, production and productivity at the world, India andNEH states were found to be positive. However, higher growth rate were observed forthe NEH region. Significance difference was observed only on cost of fertilizers. The totalcost of rice bean cultivation was lower in organic adopter by 1.71 per cent. The averageyield was significantly higher for the organic adopter. The gross income and net incomewere also higher for the organic adopter. Organic farming was found to be more profitableand it can enhance the farmer’s income. Allocative efficiency indicates that all the resourcesused in the region need to be increase so as to achieve the maximum potential yield andhenceforth increase the returns.

Growth Rate of Pulses in Eastern Uttar Pradesh a Zone-wise Analysis

2021 ◽  
Vol 66 (3) ◽  
Author(s):  
Ekta Pandey
Keyword(s):  
Growth Rate ◽  
Time Series ◽  
Time Series Data ◽  
Uttar Pradesh ◽  
Series Data ◽  
The North ◽  
North Eastern ◽  
Eastern Uttar Pradesh ◽  
Negative Growth ◽  
Made In

Attempts are made in this paper to investigate the trend of pulses in Eastern Uttar Pradesh, as well as their instability and non-linear model. This time series data on pulses pertains to the period 1980-1981 to 2014-15 and includes information on the area, production, and productivity of pulses. Pulses have had negative growth in terms of area, production, and productivity in all three zones of Eastern Uttar Pradesh, namely, the North Eastern plain zone, the Eastern plain zone, and the Vindhyan zone. Since 1980-81, there has been a rise in the area and output of pulses in the Vindhyan zone, as seen by the percentage change. The Eastern plain zone has the most stable pulse crop in terms of instability

Comparative performance of Ghungroo and Large Black pig at organized institutional farm conditions

2015 ◽  
Author(s):  
Manas Kumar Patra ◽  
Yhuntilo Kent ◽  
Lily Ngullie ◽  
R. K. Das ◽  
Bidyut C. Deka
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Birth Weight ◽  
Comparative Performance ◽  
Lower Birth Weight ◽  
Hill Region ◽  
North Eastern ◽  
Reproduction Performance ◽  
Research Complex

Present study was conducted to compare the production and reproduction performance of Ghungroo and Large Black breeds maintained at ICAR Research Complex for North Eastern Hill Region, Nagaland Centre, Jharnapani, Nagaland. The birth weight (1.09 vs. 0.96 kg), pre-weaning growth rate (174.90 vs. 141.40 g/day) and matured body weight at 7 months (64.74 kg vs. 53.13 kg) were significantly higher (p. 9.96 kg) and weaning (47.35 vs. 52.50 kg) were recorded in Ghungroo and Large Black, respectively. The pre-weaning mortality was higher in Ghungroo (2.64) due to lower birth weight and larger litter compared to the Large Black (1.47, py breed not by parities. Thus, from this study it is concluded that the Ghungroo breed matured early, produce more litter and performs similar to the popular Large Black breed under organized farm condition.

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