Search results for "Breeding"
showing 10 items of 475 documents
Winter male plumage coloration correlates with breeding status in a cooperative breeding species
2007
The function of colored ornaments is usually related to the signaling of individual quality in intra- and intersexual interactions. In cooperative breeding species, where only a fraction of the male population access the breeding status and the other fraction has the option to help breeding pairs, colored traits might provide the females with a reliable information on the quality of potential mate. Males of the cooperative breeding azure-winged magpies (Cyanopica cyanus) display conspicuous blue plumage coloration. Here we explored the role played by structural blue coloration of males and the probability of becoming a breeder or a helper. Birds were trapped during 4 consecutive years, and …
Effects of self- and cross-fertilization on parental fecundity and offspring survival in eight populations of Lymnaea stagnalis
2008
A deterministic simulation study of embryo marker-assisted selection for age at first calving in Nellore (Bos indicus) beef cattle
2007
Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:04:58Z No. of bitstreams: 1 S1415-47572007000400008.pdf: 85300 bytes, checksum: 7422029b120457123fb366c1bd71e758 (MD5) Made available in DSpace on 2013-08-22T19:04:58Z (GMT). No. of bitstreams: 1 S1415-47572007000400008.pdf: 85300 bytes, checksum: 7422029b120457123fb366c1bd71e758 (MD5) Previous issue date: 2007-01-01 Made available in DSpace on 2013-09-30T20:08:32Z (GMT). No. of bitstreams: 2 S1415-47572007000400008.pdf: 85300 bytes, checksum: 7422029b120457123fb366c1bd71e758 (MD5) S1415-47572007000400008.pdf.txt: 39461 bytes, checksum: 2796161439379a834535eeaff8aac2ba (MD5) Previous issue date: 2007-01-01 Submitt…
Anther Culture Effectiveness in Producing Doubled Haploids of Cereals/ Putekðòu Kultûras Efektivitâte Graudaugu Dubultoto Haploîdu Izveidoðanâ
2014
Abstract Our goal was to improve the method of obtaining double haploids (DH) by anther culture from Latvian breeding material for several agriculturally important cereals in Latvia: barley, spring and winter wheat. Hybrids from Latvian breeders were initial material. It was found that copper (2.5 mg/l) added to barley anther pre-treatment media and to both barley (C3) and wheat (liquid AMC) induction media, resulted in a higher percentage of green plants-regenerants. In general, the winter wheat hybrids exhibited lower embryogenesis than spring wheat hybrids. Obtaining a large number of DH lines from barley and wheat hybrids with unknown androgenesis response can be organized in two stages…
Opposing health effects of hybridization for conservation
2021
The continuing decline of many natural plant and animal populations emphasizes the importance of conservation strategies. Hybridization as a management tool has proven successful in introducing gene flow to small, inbred populations, but can be also associated with health risks. For example, hybridization can change susceptibility to infection in either direction due to heterosis (hybrid vigor) and outbreeding depression, but such health effects have rarely been considered in the genetic management of populations. Here, we investigated the effects of experimental outcrossing between the critically endangered Saimaa landlocked salmon (Salmo salar m. sebago) and the genetically more diverse A…
Demographic characterization and genetic variability of the Girgentana goat breed by the analysis of genealogical data
2004
The aim of this paper is to present an overview of the actual Sicilian Girgentana population structure by the analysis ofgenealogical data. Statistics show that in 1983 the population consisted of 30,000 Girgentana goats; ten years lateralmost 98% of the entire Girgentana population disappeared. The remaining population consists of 461 individuals (134males and 327 females), with 368 living animals. The effective population size is 380 individuals. The inbreeding rate pergeneration was equal to 0.13%. The average estimated inbreeding level within the living male population was equal to0.8% (0-15%); and the average inbreeding level within the living female population was equal to 0.7% (0-31%…
Inbreeding depression in perennial Lychnis viscaria (Caryophyllaceae): effects of population mating history and nutrient availability.
2005
We studied inbreeding depression in a perennial plant, Lychnis viscaria, in three populations differing in their inbreeding history and population size by measuring several traits at two nutrient levels over the plant's life cycle. The observed levels of inbreeding depression (cumulative inbreeding depression, from -0.057 to 0.629) were high for a plant with a mixed mating system. As expected, the population with a low level of isozyme variation expressed the least inbreeding depression for seed germination. Highest inbreeding depression for germination was found in the largest and genetically most variable population. No clear differences between populations in expression of inbreeding dep…
2014
Captive breeding for conservation purposes presents a serious practical challenge because several conflicting genetic processes (i.e., inbreeding depression, random genetic drift and genetic adaptation to captivity) need to be managed in concert to maximize captive population persistence and reintroduction success probability. Because current genetic management is often only partly successful in achieving these goals, it has been suggested that management insights may be found in sexual selection theory (in particular, female mate choice). We review the theoretical and empirical literature and consider how female mate choice might influence captive breeding in the context of current genetic…
Highly asymmetric fine-scale genetic structure between sexes of African striped mice and indication for condition dependent alternative male dispersa…
2011
Sex-biased dispersal is observed in many taxa, but few studies have compared sex-biased dispersal among and within populations. We addressed the magnitude and habitat dependency of sex-biased dispersal in social African striped mice by separating group-related from population-related genetic variance to understand the contribution of each sex to deme structure. As dispersal over unoccupied habitat is likely to be more costly than dispersal within a population, we predicted that individuals leaving the natal population have a lower body condition, being inferior to heavier territorial individuals. Fine-scale genetic structure was detected in both sexes. Female relatedness decreased continuou…
A population genetics view of animal domestication
2012
The fundamental shift associated with the domestication of plants and animals allowed for a dramatic increase in human population sizes and the emergence of modern society. Despite its importance and the decades of research devoted to studying it, questions regarding the origins and processes of domestication remain. Here, we review recent theoretical advances and present a perspective that underscores the crucial role that population admixture has played in influencing the genomes of domestic animals over the past 10000 years. We then discuss novel approaches to generating and analysing genetic data, emphasising the importance of an explicit hypothesis-testing approach for the inference of…