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11.
12.
David Gela Martin Kocour Martin Flajšhans Otomar Linhart Marek Rodina 《Reviews in Fish Biology and Fisheries》2010,20(3):301-306
A triennial performance test of five groups of tench, Tinca tinca (L.): Vodnany induced triploid V3n, Vodnany meiotic gynogenic Vgyn, diploid Vodnany V2n, Hungarian H2n and German G2n) in pond
monoculture was carried out with diploid golden tench as control (C) to compute corrected weight of the groups tested. Survival
rate ranged from 11.6% (V2n) to 30.6% (Vgyn) in yearlings, from 71.2% (V2n) to 91.5% (H2n) in 2 year-olds, from 60.0% (Vgyn)
to 75.7% (V2n) in 3 year-olds while that of the control group was 8.5, 38.3 and 40.2% in the respective seasons. After three
growing seasons the corrected weight of the fish in the groups H2n (254.6bg), V3n (257.0cg) and G2n (371.4cg) was higher (P < 0.05, Tukey HSD test) than that from the C (183.3ag) and V2n(205.6abg) groups. Among the chromosomally manipulated groups, ANCOVA test found the least slaughtering value for Vgyn (84.3%); among
the purebreds the highest value was found for H2n (87.32%), significantly differing from V2n and G2n strains. A high gonadosomatic
index in females (2.94 vs. 0.44% in males) resulted in inferior slaughtering values. 相似文献
13.
Martin Flajšhans David Gela Martin Kocour Hana Buchtová Marek Rodina Martin Pšenička Vojtěch Kašpar Veronika Piačková Eliška Sudová Otomar Linhart 《Reviews in Fish Biology and Fisheries》2010,20(3):317-329
Performance and physiological traits and health of spontaneous and induced triploid tench are reviewed. Triploidy is best
induced with cold shock; with triploids exhibiting 13.5–51.5% better weight gain, 2.69–3.94% higher slaughtering value, 20–60%
lower gonadosomatic index, 0.9–4.5% higher dry matter in flesh and up to 107% more flesh fat than diploids, if farmed untill
post sexual maturity. Triploids exhibit more abdominal fat and less polyunsaturated fatty acids of the n-3 and n-6 groups
in the flesh. Triploid females are sterile, while triploid males may produce aneuploid spermatozoa with varying DNA content
(1–1.9n) which may initiate development of embryos. Triploids have milder seasonal dynamics in their erythrocyte profile than
the diploids. Thinner diffusion distance in gills of triploids than in diploids is interpreted as adaptation to lower aerobic
capacity. Triploids show neither stronger tendencies to anatomic malformations, nor have bigger affinity to parasitic diseases
than the diploids. Production of triploid tench could be an economically interesting method of farming to higher marketable
weight, bringing a relatively high product quality. 相似文献
14.
The aim of the present study was to elaborate cryopreservation methods for ex situ conservation of tench. Success of cryopreservation was tested during two series of experiments. The first set of experiments studied the effects of two types of cryoprotectants (DMSO and a combination of DMSO with propanediol at ratio 1:1) at concentrations of 8 and 10% and three different equilibration times in two different immobilization solutions (IS) (Kurokura 180 and Kurokura) before freezing (0.0, 2.0 and 4.0h after T(0)). The K4 cooling programme was used to freeze 1ml of cryoextended sperm using 1.8ml cryotubes. Main monitored parameter was hatching rate after using of cryopreserved sperm. The second set of experiments studied the volume effect of 0.5, 1 and 5ml straws and compared these with 1.8ml cryotubes as well as the effect of the cooling programme (K4 and L1). Following the results of the first study, a combination of DMSO and propanediol (ratio 1:1) at concentration of 10% was added to extended sperm in Kurokura 180 IS. Main monitored parameter was hatching rate after using cryopreserved sperm, supplementary parameters were sperm velocity and motility percentage assessed at 10s post-activation. Sperm was collected directly into IS and stored at 4 degrees C for 2.5h. Thereafter were sperm samples pooled, equlibred in IS (first set of experiments) or directly mixed with cryoprotectants (DMSO or a mixture of DMSO with propanediol at ratio 1:1) and transferred to 1.8ml cryotubes or straws (0.5, 1 and 5ml). Then the cryotubes/straws were directly transferred to pre-programmed PLANER Kryo 10 series III and cooled using two different cooling programmes including a slow cooling programme (a) named K4 (from +4 to -9 degrees C at a rate of 4 degrees Cmin(-1) and then from -9 to -80 degrees C at a rate of 11 degrees Cmin(-1)) and a rapid cooling programme (b) named L1 (directly from +4 to -80 degrees C at a rate of 20 degrees Cmin(-1)). Both slow (K4) and rapid (L1) cooled samples were held 6min at -80 degrees C. Finally, samples were transferred into liquid N(2). The frozen spermatozoa were thawed in a water bath (40 degrees C) according to the frozen volume and checked for fertilization and hatching rates. Percentage of sperm motility and sperm velocity were measured using video recorded frames. ANOVA showed a significant influence of frozen and fresh sperm in all treatments. The hatching rates of 33.8% were obtained when sperm was equilibrated for 0h before freezing in IS of Kurokura 180 and frozen with a 10% of mixture 1:1 of DMSO and propanediol into straws of 5ml and cooled using program L1. The velocity of frozen-thawed spermatozoa ranged from 31 to 46microms(-1) and in post-thawed sperm was not significantly different according to frozen sperm volume, but a higher velocity was obtained when sperm was fast frozen using programme L1. A large volume of frozen sperm could reveal the best procedure for freezing, but also for simulating methods of artificial propagation for future practical use of frozen tench sperm at a large scale. 相似文献
15.
16.
Linhart YB Keefover-Ring K Mooney KA Breland B Thompson JD 《The American naturalist》2005,166(4):517-529
We investigated the effects of chemical variation in thyme (Thymus vulgaris L.) on its interactions with competitors, herbivores, and herbivore predators. Four different thyme monoterpene phenotypes (chemotypes) were grown in a 4x2x2 factorial of chemotype, caging (sham half-cages vs. full cages), and competition (control vs. the grass Bromus madritensis L.). Cages reduced numbers of arthropod predators. Thyme-feeding aphids Aphis serpylli Koch passed through full cage walls to increase more than fourfold. As a result, freed from their predators, aphids had a large negative effect on thyme size and flowering. Similarly, competition from Bromus had a negative effect on thyme size and flowering. Individual effects of aphids and competition were nonadditive, however, and their combined effect was significantly less than that predicted by a multiplicative null model. Differential thyme sizes among chemotypes were not mediated by herbivores or competitors, but differential flowering was due to the effects of chemotype on aphids. We thus document differential selection by aphids among thyme chemotypes and the influence of Bromus on the strength of these negative effects of aphids. 相似文献
17.
EXPERIMENTAL STUDIES IN PONDEROSA PINE. I. RELATIONSHIP BETWEEN VARIATION IN PROTEINS AND MORPHOLOGY
Ponderosa pine from California (Pinus ponderosa var. ponderosa) were crossed to one another and also to individuals from the Rocky Mountains (P. p. var. scopulorum). All crosses involved a single mother and a single pollen donor. Patterns of inheritance of electrophoretically-detectable loci followed Mendelian expectations with one exception. Shikimate dehydrogenase showed unpredictable banding patterns in intervarietal crosses. Variability at these biochemical loci was compared to variability at 14 morphometric characters. The relationship between these two levels of variation is complex and permits only one generalization: variability at one level is not a good predictor of variability at the other level. 相似文献
18.
19.
In a study of the effect of short-term storage on the hatching rate of common carp Cyprinus carpio and tench Tinca tinca ova in vitro in various extenders at 21° C under aerobic conditions, the best extender for 30 min storage for common carp appeared to be Dettlaff 1. This gave the same hatching rate as controls without extender (55% v. 56%). For 60 min storage of ova, the best extenders were Dettlaff 2 (24% hatching rate) and Dettlaff 3 (30%), but hatching was significantly lower than in the control (58%). In carp ovarian artificial fluid (CAF) extender, the hatching rate of common carp ova was also high after 10 min, but decreased to 12% after 30 min. In tench, the hatching rate of ova increased after 10 min storage in Dettlaff 5 extender (44%) compared to the control (41%) without extender. However, it was significantly lower after storage in Dettlaff 1, 2, 3, 4, 5 and CAF extenders for 20, 30 and 60 min, compared to controls. Malformations (10–50%) were observed in the tench second control groups without extender after 10, 20 and 30 min storage of ova. 相似文献
20.
Disturbance and climatic influences on age structure of ponderosa pine at the pine/grassland ecotone, Colorado Front Range 总被引:1,自引:0,他引:1
Abstract. In the Colorado Front Range, disturbances and climatic variation influence stand structure of ponderosa pine (Pinus ponderosa) along the lower timberline ecotone. Over the past 100 years there has been a shift to a greater density and extent of ponderosa pine at the forest-grassland boundaries. Ponderosa pine regeneration at lower timberline appears to be influenced by fires in the 1860s and decreased grazing pressure in the 1970s–1980s. Climatic variation may also have influenced age structure, even though analyses of age structure at a 10-year class scale prevented the detection of climatic influences occurring at a finer scale. These changes in disturbance regimes, possibly together with moister springs/early summers, created favourable conditions for the increase in density and extent of ponderosa pine at lower timberline ecotone. 相似文献