scholarly journals Evidence for Outcrossing via the Buller Phenomenon in a Substrate Simultaneously Inoculated with Spores and Mycelium of Agaricus bisporus

2006 ◽  
Vol 72 (4) ◽  
pp. 2366-2372 ◽  
Author(s):  
Philippe Callac ◽  
Cathy Spataro ◽  
Aurélie Caille ◽  
Micheline Imbernon
Keyword(s):  
Population Dynamics ◽  
Life Cycle ◽  
Agaricus Bisporus ◽  
Lower Proportion ◽  
Field Conditions ◽  
Wild Populations ◽  
Breeding Programs ◽  
Parent Culture ◽  
Commercial Breeding ◽  
Traditional Cultivars

ABSTRACT In Agaricus bisporus, traditional cultivars and most of the wild populations belong to A. bisporus var. bisporus, which has a predominantly pseudohomothallic life cycle in which most meiospores are heterokaryons (n + n). A lower proportion of homokaryotic (n) meiospores, which typify the heterothallic life cycle, also are produced. In wild populations, pseudohomothallism was thought previously to play a major role, but recent analyses have found that significant outcrossing also may occur. We inoculated a standard substrate for A. bisporus cultivation simultaneously with homokaryotic mycelium from one parent and spores from a second parent. Culture trays produced numerous sporocarps that could theoretically have resulted from five different reproductive modes (pseudohomothallism, selfing or outcrossing via heterothallism, and selfing or outcrossing via the Buller phenomenon [i.e., between a homokaryon and a heterokaryon]). Most or all of the sporocarps resulted from outcrossing between the inoculated homokaryon and the inoculated heterokaryotic spores (or mycelia that grew from them). These data broaden our understanding of population dynamics under field conditions and provide an outcrossing method that could be used in commercial breeding programs.

Variance component estimates and genetic trends in a broiler breeder dam line using animal model methods

1995 ◽  
Vol 1995 ◽  
pp. 51-51
Author(s):  
A.J. Morri ◽  
G.E. Pollott
Keyword(s):  
Breeding Value ◽  
Data Set ◽  
Breeding Programs ◽  
Broiler Breeder ◽  
Value Prediction ◽  
Recent Developments ◽  
Commercial Breeding ◽  
Variance Component Estimates ◽  
Poultry Data ◽  
Genetic Trends

Recent developments in computing technology have seen the widespread implementation of animal models for parameter estimation and breeding value prediction in both experimental and commercial breeding programs. These techniques have several benefits over traditional least squares and index methods, including the ability to monitor genetic trends in die absence of an unselected control population. This paper reports heritabilities and genetic trends estimated from a large poultry data set for three broiler traits.

scholarly journals Long-term trends in wild-capture and population dynamics point to an uncertain future for captive elephants

2019 ◽  
Vol 286 (1899) ◽  
pp. 20182810 ◽  
Author(s):  
John Jackson ◽  
Dylan Z. Childs ◽  
Khyne U. Mar ◽  
Win Htut ◽  
Virpi Lummaa
Keyword(s):  
Population Dynamics ◽  
Wild Populations ◽  
Birth Rates ◽  
As Species ◽  
In Captivity ◽  
Elephant Population ◽  
Long Term Trends ◽  
Uncertain Future ◽  
Primary Focus

Maintaining sustainable populations in captivity without supplementation through wild-capture is a major challenge in conservation that zoos and aquaria are working towards. However, the capture of wild animals continues for many purposes where conservation is not the primary focus. Wild-capture hinders long-term conservation goals by reducing remaining wild populations, but the direct and long-term indirect consequences of wild-capture for captive population viability are rarely addressed using longitudinal data. We explored the implications of changes in wild-capture on population dynamics in captivity over 54 years using a multi-generational studbook of working Asian elephants ( Elephas maximus ) from Myanmar, the largest remaining captive elephant population. Here we show that population growth and birth rates declined between 1960 and 2014 with declines in wild-capture. Importantly, wild-caught females had reduced birth rates and a higher mortality risk. However, despite the disadvantages of wild-capture, the population may not be sustainable without it, with immediate declines owing to an unstable age-structure that may last for 50 years. Our results highlight the need to assess the long-term demographic consequences of wild-capture to ensure the sustainability of captive and wild populations as species are increasingly managed and conserved in altered or novel environments.

Genetic Analysis of the Life Cycle of Agaricus Bisporus

Mycologia ◽  
1972 ◽  
Vol 64 (5) ◽  
pp. 1088-1117 ◽  
Author(s):  
Carlene A. Raper ◽  
John R. Raper ◽  
Robert E. Miller
Keyword(s):  
Life Cycle ◽  
Genetic Analysis ◽  
Agaricus Bisporus

Seasonal Abundance and Population Dynamics of a Bamboo Aphid, Takecallis arundinaria (Homoptera: Aphididae)

1990 ◽  
Vol 25 (4) ◽  
pp. 526-534 ◽  
Author(s):  
Mark A. Coffelt ◽  
Peter B. Schultz
Keyword(s):  
Population Dynamics ◽  
Life Cycle ◽  
Plant Species ◽  
Woody Plant ◽  
Early Spring ◽  
Climatic Conditions ◽  
Seasonal Abundance ◽  
Alternate Host ◽  
Woody Plant Species ◽  
Aphid Populations

The anholocyclic life cycle of the aphid Takecallis arundinaria (Essig) on golden stem bamboo, Phyllostachys aurea (Carrie're) was investigated in 1987 – 1988. Aphid populations peaked from March – May, declined from June – October, and peaked again in December. Aphid population dynamics were strongly influenced by climatic conditions. When aphid populations were at constant or rising levels, significantly more nymphs were found in the southern and eastern quadrants, than in the northern and western quadrants. This directionality may have allowed T. arundinaria populations to be exposed to increased sunlight and decreased winds during the winter and early spring periods. Alate viviparae had a mean fecundity of 147 nymphs and a longevity of 46.5 days. Predators were few and no parasites were found. An alternate host study revealed no aphids on yellow sticky traps placed on nine woody plant species.

Life cycle of Calanus finmarchicus in the lower St. Lawrence Estuary: the imprint of circulation and late timing of the spring phytoplankton bloom

2001 ◽  
Vol 58 (4) ◽  
pp. 647-658 ◽  
Author(s):  
Stéphane Plourde ◽  
Pierre Joly ◽  
Jeffrey A Runge ◽  
Bruno Zakardjian ◽  
Julian J Dodson
Keyword(s):  
Population Dynamics ◽  
Life Cycle ◽  
Production Rate ◽  
Egg Production ◽  
Phytoplankton Bloom ◽  
Food Limitation ◽  
Calanus Finmarchicus ◽  
Lawrence Estuary ◽  
Egg Production Rate ◽  
St Lawrence Estuary

The life cycle of Calanus finmarchicus in the lower St. Lawrence estuary is described based on observations of female egg production rate, population stage abundance, and chlorophyll a biomass collected over 7 years (1991–1997) at a centrally located monitoring station. The mean seasonal pattern shows maximum abundance of females in May, but peak population egg production rate and naupliar (N3–N6) abundance occur in early July just after onset of the late spring – early summer phytoplankton bloom. The population stage structure is characterized by low summer abundance of early copepodite stages C1–C3 and high stage C5 abundance in autumn. Between 1994 and 1997, there was important interannual variation in both timing (up to 1 month) and amplitude (five- to eight-fold) of population reproduction. Patterns of seasonal increase of C5 abundance in autumn suggest interannual variations of both timing and magnitude of deep upstream advection of this overwintering stage. Thus, the main features of C. finmarchicus population dynamics in the central lower St. Lawrence Estuary are (i) late reproduction resulting from food limitation prior to the onset of the summer phytoplankton bloom, (ii) probable export of early developmental stages during summer, and (iii) advection into the central lower St. Lawrence Estuary of overwintering stage C5 in autumn from downstream regions. These results support the hypothesis that circulation, mainly driven by discharge from the St. Lawrence River and its tributaries, is a key factor governing population dynamics of C. finmarchicus in this region.

Evaluation of genetic diversity among some commercial cultivars and Iranian wild strains of Agaricus bisporus by microsatellite markers

Botany ◽  
2016 ◽  
Vol 94 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Nader Rokni ◽  
Ebrahim Mohammadi Goltapeh ◽  
Alireza Shafeinia ◽  
Naser Safaie
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
Agaricus Bisporus ◽  
Breeding Programs ◽  
Banding Patterns ◽  
Commercial Cultivars ◽  
Wild Strains ◽  
Cultivated Mushroom ◽  
High Level ◽  
Promising Source

Agaricus bisporus (Lange) Imbach is the most widely cultivated mushroom in Iran. Lack of diversity in mushroom crops, especially where disease is concerned, creates a crucial risk for the currently grown cultivars. The aim of this study was to assess the genetic diversity among Iranian wild strains and some commercial cultivars by using microsatellite markers. Eighteen codominant microsatellite markers of A. bisporus (AbSSR) were used to distinguish 17 wild and commercial strains. All of the microsatellite markers used in this research gave clear banding patterns, and only one strain remained undistinguished. Among 106 generated alleles, the wild subgroup presented 53 alleles never found both in brown and white commercial cultivars, and 42 alleles never found in commercial brown strains. The dendrogram obtained by UPGMA clustering analysis separated A. bisporus strains into six groups. Based on our results, the high level of genetic diversity among Iranian wild strains, compared with the commercial strains, provides a new and promising source of diversity for A. bisporus breeding programs. To our knowledge this is the first relevant study of biodiversity in native Iranian populations of A. bisporus.

Importance of life cycle events in the population dynamics of Gonyaulax tamarensis

1983 ◽  
Vol 76 (2) ◽  
pp. 179-189 ◽  
Author(s):  
D. M. Anderson ◽  
S. W. Chisholm ◽  
C. J. Watras
Keyword(s):  
Population Dynamics ◽  
Life Cycle
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