Search results for "Var"
showing 10 items of 14701 documents
High variation in last male sperm precedence and genital morphology in the emerald damselfly, Lestes sponsa
2020
Abstract In organisms in which individuals mate multiply, knowledge of the proportion of offspring sired by the last male to mate (P2) under field conditions is important for a thorough understanding of how sexual selection works in nature. In many insect groups, pronounced intraspecific variation in P2 is commonplace. Interestingly, however, in stark contrast to these observations, compilation of P2 data in dragonflies and damselflies (Odonata) indicates that a high P2, seldom below 0.95, is a feature of this taxon. Here we used double digest restriction-site associated DNA sequencing to generate a panel of single nucleotide polymorphisms (SNPs) with which we could determine paternity and …
Effect of Harvest Date on Mango (Mangifera Indica L. Cultivar Osteen) Fruit’s Qualitative Development, Shelf Life and Consumer Acceptance
2021
The qualitative characteristics of mango fruits change throughout their development process and are also influenced by their duration. Harvesting at different times after the fruit set affects external and internal quality and the post-harvest behavior and management possibilities of the fruits. The objective of this study was to assess the evolution of the most important physicochemical and organoleptic parameters of cv. Osteen fruits concern the length of their stay on the plant and also to their post-harvest management. For this reason, fruits were harvested progressively in ten pickings. The study showed that mango fruits that are kept on the tree reach the best quality traits, correspo…
Seed germination under osmotic stress across different wild populations of mountain rye (Secale strictum (C.Presl) C.Presl))
2020
The selection of resilient cultivars could help stem the losses in forage production due to a changing climate. Secale strictum is a wild grass with interesting potential as a forage crop. We studied the germination requirements of six wild S. strictum populations, representative of the whole species distribution range in Italy and occurring under different osmotic conditions (0 MPa, −0.8 MPa, −1.0 MPa, −1.2 MPa, −1.4 MPa and −1.6 MPa). Our aim was to find beneficial seed and germination traits for the possible use of this species as a crop. Different accessions of domesticated Secale cereale and ×Triticosecale were used as comparison. Some populations of S. strictum were drought tolerant a…
Ecdysone and ecdysterone in physogastric termite queens and eggs of Macrotermes bellicosus and Macrotermes subhyalinus
1978
Abstract Physogastric queens and freshly laid eggs of two species of termites ( Macrotermes bellicosus and Macrotermes subhyalinus ) are found to contain high levels of ecdysteroids (molting hormones) as indicated by radioimmunoassay and Musca bioassay. Ecdysteroids are accumulated in the ovaries of the queen and then stored in the eggs since newly laid eggs contain ecdysteroid concentrations similar to those found in the ovaries. Gas chromatography-mass spectrometry demonstrates that ecdysone (α-ecdysone) as well as ecdysterone (β-ecdysone) are present in queen ovaries and in eggs and that ecdysone is quantitatively the more important ecdysteroid in both ovary and eggs.
Data-Based Forest Management with Uncertainties and Multiple Objectives
2016
In this paper, we present an approach of employing multiobjective optimization to support decision making in forest management planning. The planning is based on data representing so-called stands, each consisting of homogeneous parts of the forest, and simulations of how the trees grow in the stands under different treatment options. Forest planning concerns future decisions to be made that include uncertainty. We employ as objective functions both the expected values of incomes and biodiversity as well as the value at risk for both of these objectives. In addition, we minimize the risk level for both the income value and the biodiversity value. There is a tradeoff between the expected val…
Poplar Biochar as an Alternative Substrate for Curly Endive Cultivated in a Soilless System
2020
Imminent necessity for eco-friendly and low-cost substitutes to peat is a defiance in the soilless plant cultivation systems. Wood biochar could entirely or partly substitute peat as a plant growing constituent to produce vegetables. Nevertheless, knowledge concerning potential plant performance of leafy green vegetables grown on wood biochar is restricted. The present study assessed the main physicochemical traits of various growing media constituted by decreasing the content of peat and by increasing the percentages of poplar wood biochar. Yield, nutritional and functional properties of curly endive plants cultivated in a protected environment were also tested. Biochar was pyrolyzed from …
Bayesian spatio-temporal discard model in a demersal trawl fishery
2014
Spatial management of discards has recently been proposed as a useful tool for the protection of juveniles, by reducing discard rates and can be used as a buffer against management errors and recruitment failure. In this study Bayesian hierarchical spatial models have been used to analyze about 440 trawl fishing operations of two different metiers, sampled between 2009 and 2012, in order to improve our understanding of factors that influence the quantity of discards and to identify their spatio-temporal distribution in the study area. Our analysis showed that the relative importance of each variable was different for each metier, with a few similarities. In particular, the random vessel eff…
Measuring phenotypes in fluctuating environments
2020
Despite considerable theoretical interest in how the evolution of phenotypic plasticity should be shaped by environmental variability and stochasticity, how individuals actually respond to these aspects of the environment within their own lifetimes remains unclear. We propose that this understanding has been hampered by experimental approaches that expose organisms to fluctuating environments (typically treatments where fluctuations in the environment are cyclical vs. erratic) for a pre‐determined duration while ensuring that the mean environment over that the entire exposure period is invariable. This approach implicitly assumes that responses to the mean and variance/predictability in the…
Fruit quality evaluation of affirmed and local loquat (Eriobotrya japonicaLindl) cultivars using instrumental and sensory analyses
2016
Introduction. Fruit quality can be evaluated by combining instrumental and sensory analyses. These methodologies have been affirmed and tested on different fruit tree species, but loquat is still little known from this point of view. Materials and methods. In this trial, conducted in Palermo and Catania (Sicily, Italy), both instrumental and sensory analyses were carried out on fruit of 8 loquat affirmed cultivars (‘Golden Nugget’, ‘Peluche’) and local cultivars (‘Marceno’, ‘Sanfilippara’, ‘Nespolone di Trabia’, ‘Virticchiara’, ‘Bianco Dolce’ and ‘BRT20’) with the aim of assessing their quality traits. Results and discussion. The sensory results agreed quite well with the physicochemical da…
Selection for reproduction under short photoperiods changes diapause-associated traits and induces widespread genomic divergence.
2019
The work has been supported by the Academyof Finland to A.H. (project 267244) and Natural Environment Research Council (NERC) funding (NE/J020818/1 to M.G.R.; NE/L501852/1 to R.A.W.W.). The incidence of reproductive diapause is a critical aspect of life history in overwintering insects from temperate regions. Much has been learned about the timing, physiology and genetics of diapause in a range of insects, but how the multiple changes involved in this and other photoperiodically regulated traits are inter-related is not well understood. We performed quasinatural selection on reproduction under short photoperiods in a northern fly species, Drosophila montana, to trace the effects of photoper…