scholarly journals Genetically influenced resistance to stress and disease in salmonids in relation to present-day breeding practice - a short review

2018 ◽  
Vol 87 (1) ◽  
pp. 35-45
Author(s):  
Jan Mendel ◽  
Kristýna Jánová ◽  
Miroslava Palíková

While intensive fish production has many advantages, it also has a number of drawbacks as regards disease and stress. To date, there has been no conclusive review of disease resistance at Czech fish farms. The aim of the study was to describe briefly the existing salmonid breeding practice in the Czech Republic and to point out the trends and new possibilities gaining ground around Europe. However, the present situation in the Czech stocks is not rare at all and therefore it is used here as a model example representing numerous breeding practices in Europe. Stress and disease resistance in fish is polygenic and quantitative, making selection for such traits difficult. In recent years, however, fish breeding methods have developed rapidly, with the use of genetic analysis tools, for example, now allowing much greater selection accuracy. Gradual progress in understanding the importance of individual genetic markers offers many new options that can be utilised in breeding practice. New selection methods, such as quantitative trait loci (QTLs) and genomic selection, are increasingly employed in European aquaculture. Next generation sequencing techniques now help in the finding of new and promising QTLs that can be used in assisted selection. This review maps the current progress in improving salmonid resistance to stress and disease in aquaculture and at the same time provides the breeders with a short overview of the latest tools of genetically controlled breeding and of the newest products available at the European market.

Botany ◽  
2015 ◽  
Vol 93 (5) ◽  
pp. 307-316 ◽  
Author(s):  
L.I. Lindström ◽  
L.F. Hernández

In sunflower (Helianthus annuus L.), there has been an intense genetic selection for achenes with agronomic value, such as greater mass, oil content, and disease resistance. However, the information regarding the anatomical events that control their growth and maturation is surprisingly scarce. The aim of the present work was to study sunflower male and female sporogenesis and gametogenesis, as well as cell division and enlargement and tissue differentiation in the ovary and the embryo, linking the timing of these events to two frequently used phenological scales and a thermal time scale. In addition, we propose an ontogenetic scale that integrates the results of the present work to that of previous studies on sunflower reproductive development. The unified scales presented here provide a framework for others to investigate the relationships uncovered in this study in different genetic backgrounds and under different growing conditions.


Heredity ◽  
2013 ◽  
Vol 112 (5) ◽  
pp. 552-561 ◽  
Author(s):  
M Gowda ◽  
Y Zhao ◽  
T Würschum ◽  
C FH Longin ◽  
T Miedaner ◽  
...  

Author(s):  
F. A. Altayeva

The article presents the results of growing tilapia to marketable weight in experimental sites (Chilikskoye pond pond farms LLP, KATU named after S. Seifullin JSC and Kapshagai spawning farm — 1973 LLP). In the process of carrying out research works, the methods generally accepted in fish farming, hydrochemistry, hydrobiology, hydrology, ichthyology, as well as foreign normative and technical guidelines and methodological instructions on the technology of growing commercial tilapia in industrial conditions were used. Monitoring of hydrochemical analyses of water in ponds, swimming pools, and closed water supply installations is given. Fish-breeding and biological indicators of tilapia grown in various experimental conditions are presented. The results of the studies have shown the real possibility of growing tilapia in various conditions of fish farms in Kazakhstan. Based on the results of the work, the following conclusions were made: — satisfactory fish-breeding indicators were obtained with various cultivation technologies (as when growing tilapia in polyculture and monoculture in ponds, in pools, as well as cultivation in the recirculation system); — the cultivation of tilapia in the experimental ponds of the fish farm of the Almaty region of the Republic of Kazakhstan has shown the possibility of obtaining high fish-breeding biological indicators of tilapia and the ability to grow to marketable mass in a short time; — as a result of experimental cultivation in various conditions, it was found that the survival rate was not lower than 97%; — as a result of the analysis of the profitability indices of the developed technologies, it was found that the most profitable was the technology of growing marketable tilapia products in monoculture ponds on water with a natural thermal regime in Chilik Pond Economy LLP.


Author(s):  
Nina Sergeevna Badryzlova

A description of biotechnical methods of harvesting pike perch in natural reservoirs, methods of catching pike perch spawners, keeping in adaptation cages and transporting pike perch from fishing sites to the farm is given. Pike perch breeders were caught from the reservoirs with fixed and floating nets during the period: in the Kapshagai reservoir from 10 to 20 April; in the Syrdarya river — from April 20 to May 5. The adaptation was carried out in cages located in the coastal zone. Transportation to the fish farm was carried out in live fish tanks with a volume of 1 and 3 m³ with water aeration. The reproduction of pike perch was carried out in two fish farms of the Republic of Kazakhstan. The data on spawning of pike perch in two ways are given: in cages on nests; as well as the receipt of reproduction products by the factory method from “flowing” producers. In the first case, females and males were placed in cages in a ratio of 1:1 and 1:2; a spawning nest was installed in each cage and spawning was monitored. In the second case, from the “flowing” pike perch breeders ready for spawning, reproductive products (eggs and sperm) were obtained, fertilization and degluing were carried out with a suspension of white clay. The monitoring of hydrochemical indicators was constantly carried out, the dates of the beginning and end of spawning of pike perch were determined. The article presents the fish-breeding and biological characteristics of pike perch producers participating in spawning. The mass of spawned pike perch females in LLP “Halyk Balyk” ranged from 2 kg to 2.5 kg, males — 1.5–2.5 kg; females weighing 2.1–2.6 kg were used in the Republican State Enterprise “Kamyshly-Bashsky Fish Hatchery”; males — from 1.2 kg to 2.4 kg. Based on the results of the research, biotechnical standards were developed for the preparation of pike perch producers in water bodies, for transportation to fish farms, standards for spawning of pike perch in various ways.


Author(s):  
П.Е. Гарлов

С целью повышения эффективности искусственного воспроизводства популяций ценных видов рыб разработаны новые методы управления их размножением, выживаемостью и ростом, которые представлены в виде изобретений. Для управления размножением производителей разработаны методы стимуляции и задержки полового созревания производителей осетровых и костистых рыб. Для стимуляции полового созревания были разработаны препараты изолированной передней и изолированной задней долей гипофиза. Их внедрение в осетроводстве позволило повысить степень их рыбоводного использования в среднем на 15% и достичь экономии гипофиза до 40%. Для задержки полового созревания производителей разработан метод их промышленного резервирования в среде критической солёности 4–8‰, причём как в морской воде, так и в растворах поваренной соли. Производственными испытаниями доказана возможность сохранения рыбоводного качества производителей и получения доброкачественного потомства в этой среде при верхних нерестовых температурах в течение производственно необходимых сроков. С целью заводского воспроизводства природных популяций промысловых рыб разработан метод управления их размножением триадой адекватных экологических факторов ‒ «критической» солёностью, температурой и освещённостью при видоспецифических пороговых воздействиях. На этой основе разработан полносистемный метод воспроизводства популяций ценных видов промысловых рыб (севрюги и Балтийского лосося), охватывающий все этапы заводской биотехники. Новый метод осуществляется путём массовой морской заготовки производителей, получения потомства в морских садках и, после заводского речного выращивания молоди до готовности к миграции, конечного доращивания в морских садках крупной жизнестойкой молоди. Для промышленного внедрения всей предложенной биотехники и круглогодичной аквакультуры разработаны системы водоснабжения рыбоводных заводов и рыбоводных хозяйств на основе внесезонного подземного гидрокондиционирования среды выращивания и на природно-промышленных принципах инженерной экологии. In order to increase the efficiency of artificial reproduction of populations of valuable fish species new methods for managing their reproduction, survival and growth have been developed, which are presented in the form of inventions. To control the reproduction of producers methods have been developed to stimulate and delay puberty of sturgeon and bony fish producers. To stimulate puberty preparations for the isolated anterior and isolated posterior lobes of the pituitary gland have been developed. Their introduction in sturgeon breeding made it possible to increase the degree of their fish farming use by an average of 15% and to achieve a pituitary gland economy of up to 40%. To delay the puberty of producers, a method for their industrial reservation in an environment of critical salinity of 4–8‰ has been developed both in sea water and in solutions of sodium chloride. Production tests have proven the possibility of preserving the fish-breeding quality of producers and obtaining benign offspring in this environment at the upper spawning temperatures during the production required periods of time. With the aim of factory reproduction of natural populations of commercial fish a method has been developed to control their reproduction by a triad of adequate ecological factors – “critical” salinity, temperature and illumination under species-specific threshold effects. On this basis a full-system method of reproducing populations of valuable species of commercial fish (stellate sturgeon and Baltic salmon) has been developed covering all stages of factory biotechnology. The new method is carried out by mass marine harvesting of producers obtaining offspring in sea pens and after the factory river rearing of hatchling until ready for migration the final rearing of large viable juveniles in sea pens. For the industrial introduction of all the proposed biotechnics and year-round aquaculture, water supply systems for fish breeding plants and fish farms were developed on the basis of off-season underground hydroconditioning of the growing environment and on the natural and industrial principles of engineering ecology.


2008 ◽  
Vol 40 (2) ◽  
pp. 454-472 ◽  
Author(s):  
Ivan Gentil ◽  
Bruno Rémillard

While the convergence properties of many sampling selection methods can be proven, there is one particular sampling selection method introduced in Baker (1987), closely related to ‘systematic sampling’ in statistics, that has been exclusively treated on an empirical basis. The main motivation of the paper is to start to study formally its convergence properties, since in practice it is by far the fastest selection method available. We will show that convergence results for the systematic sampling selection method are related to properties of peculiar Markov chains.


Author(s):  
Evgeny Alekseevich Melchenkov ◽  
Aleksey Vladimirovich Myshkin ◽  
Vera Veniaminovna Kalmykova ◽  
Aleksandr Pavlovich Vorob’yov ◽  
Arthur Alekseevich Archibasov

With the development of commercial sturgeon breeding, creating hybrid forms of sturgeon fish in order to obtain a larger volume of gourmet marketable products is of increasing interest to fish farmers. The choice of objects for creating hybrid forms for commercial cultivation depends on the conditions and biotechnologies of intensive fish culture. One of the widely used technologies that can several times reduce the time for growing objects and receive viable juveniles and marketable products year-round is the technology using recirculating aquaculture system (RAS). With this cultivation technique, the advantage is given to species with high adaptive capabilities and growth intensity. The most popular objects for hybridization and creation of hybrid forms are beluga, sterlet, Siberian and Russian sturgeon, etc. Beluga is the largest representative of the sturgeon family. It reaches commodity weight (3–5 kg) against the background of natural temperatures within 2–3 years. The Sterlet is a pure freshwater form. It is an excellent object for cross-breeding with other sturgeon species, in particular with beluga to obtain a bester hybrid. The Siberian sturgeon grows most intensively at a temperature of 15–25 °C, however, the growth persists at lower temperatures (1–10 °C). The Russian sturgeon in artificial conditions reaches a marketable weight of 1.5–3.0 kg in the second-third years of cultivation. In order to facilitate the orientation of fish farms, fish farmers engaged in the production of commercial products, the article discusses the creation of hybrid forms of sturgeon fish in domestic and foreign aquaculture, provides their brief fish-breeding and biological characteristics when grown in fish farms of various types. Knowledge of the fish-breeding and biological characteristics of sturgeon fish species hybrids when grown in specific conditions will make it possible to successfully introduce them into the practice of commercial cultivation.


Sign in / Sign up

Export Citation Format

Share Document