Search results for " Breeding"
showing 10 items of 185 documents
Food for flight: pre-migratory dynamics of the Lesser Kestrel Falco naumanni.
2014
Capsule The post-reproductive stage of Lesser Kestrel is crucial for migratory fuelling and survival. Aims To describe the summer pre-migratory ecology of the Lesser Kestrel in Sicily and review existing data in Southern Europe. Methods We identified the main summer roosts and then made roost counts every ten days from 2010 to 2012. We used case-sensitive modelling procedures to detect biases in counts (generalized linear mixed models), assess the annual population trends from 2005 to 2012 (TRends and Indices for Monitoring); and to model habitat preferences (generalized linear model). We sampled pellets to describe the birds’ diet during the peak month prior to migration. Results We discov…
Anther culture in Citrus clementina: a way to regenerate tri-haploids
2005
Abstract. Regenerants from anther culture of Citrus clementina Hort. ex Tan. cvv. Nules, SRA 63, and Monreal were obtained in different experiments from 1994 to 2002. Genetic analysis of 37 such regenerants was carried out using 4 microsatellite markers that were heterozygous in the parental genotypes. The results showed that in all cases but one the regenerants carried only one or the other allele of the parental genotype, and were therefore homozygous and produced through a process of gametophytic embryogenesis. Ploidy analysis by flow cytometry of 94 regenerants showed that as many as 82% of them were tri-haploids, rather than haploids or doubled-haploids as expected, with other ploidy …
Maternal antibody transmission and breeding densities in the Black-headed Gull Larus ridibundus
2004
1. The offspring of avian species, especially those of colonial breeders, are exposed to a number of pathogens immediately after birth. The chick's immune system is, at that early stage still immature and inefficient. As a consequence, diseases can have a strong impact on chick survival.2. The ability of mothers to transmit passive immunity in terms of antibodies of their own acquired immunity to their chicks is probably an essential pathway to enhance the chick survival. Since the production of antibodies is costly, females are expected to adjust the transmission of passive immunity to the local disease environment.3. We found that in Black-headed Gulls (Larus ridibundus L.) yolk antibody …
Olive embryo in vitro germination potential: Role of explant configuration and embryo structure among cultivars
2014
The in vitro germination of excised embryos can break dormancy rapidly and shorten the time required to produce seedlings, speeding up olive breeding programmes as well as rootstock production. In this study, the in vitro germination potential of four Sicilian olive cultivars was evaluated during two years of experiments, using explants with three different morphological configurations that represent three different degrees of embryo exposure: (1) intact stoneless seeds containing the embryo, the endosperm and the seed coat (Emb+En+SC), (2) seeds without the seed coat (Emb+En) and (3) naked, isolated embryos (seed coat and endosperm both removed: Emb). Differences were found in the germinat…
New insights on the role of ecology and life-history in social evolution
2017
Biological altruism, defined as a behaviour that benefits others at an apparent cost to the focal individual, is found abundantly across different levels of biological organization. While kin selection has been useful for explaining both cooperation and conflict in specialized cooperative societies, more theoretical work has to be done to develop models for realistic ecological and life-history contexts. This thesis aims to fill this gap by providing several new insights on the role of ecology and life-history in various social systems. Firstly, I propose a model that incorporates realistic ecological mechanisms of population regulation and study how different population regulation mechanisms affe…
Chemical Composition of the Essential Oil of the New Cultivars of Lavandula angustifolia Mill. Bred in Ukraine
2021
Lavender, otherwise known as Lavandula angustifolia Mill., is widely used in landscaping, and its oil is a valuable raw material used in many industries. Therefore, new varieties of this plant are bred. The essential oil composition obtained from fresh flowers of thirteen new Ukrainian cultivars of L. angustifolia were analysed by GC-MS, and eighty-two components were identified. Linalool and linalyl acetate were principal constituents of all of the samples, and ranged from 11.4% to 46.7% and 7.4% to 44.2%, respectively. None of the studied samples fulfilled the requirements of Ph. Eur. and ISO 3515:2002. The main reason was a high content of α-terpineol (0.5–4.5%) and/or terpinene-4-ol (1.…
The rare isotope beams production at the Texas A&M university Cyclotron Institute
2013
The Cyclotron Institute at Texas A&M is currently configuring a scheme for the production of radioactive-ion beams that incorporates a light-ion guide and a heavy-ion guide coupled with an electron-cyclotron-resonance ion source constructed for charge-breeding. This scheme is part of an upgrade to the facility and is intended to produce radioactive beams suitable for injection into the K500 superconducting cyclotron. The current status of the project and details on the ion sources used in the project is presented. peerReviewed
Data from: Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits
2015
Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing population genetic structure at different spatial scales is thus a crucial step towards understanding mechanisms underlying intraspecific differentiation and diversification. Here, we studied the population genetic structure of a highly mobile species – the great tit Parus major – at different spatial scales. We analysed 884 individuals from 30 sites across Europe including 10 close-by sites (< 50 km)…
Ģinšu un sugu krustošanas mēģinājumi krustziežu dzimtā (Cruciferae)
2020
Raksts satur informāciju par latviešu botāniķa Aleksandra Zāmeļa (1897 - 1943) doktora disertāciju "Ģinšu un sugu krustošanas mēģinājumi krustziežu dzimtā (Cruciferae)" (1942), kas glabājas Latvijas Universitātes Muzeja Botānikas un mikoloģijas kolekciju krājumā.
Second report on chicken genes and chromosomes 2005.
2005
International audience