Inheritance Of Growth Rate Research Articles

Evidence for Inheritance of Age of Maturity in Chinook Salmon (Oncorhynchus tshawytscha)

We report results of age-specific mating experiments carried out with chinook salmon (Oncorhynchus tshawytscha) at Elk River Hatchery, Oregon. Our analysis of returns from these experiments includes assessment of the marine growth of progeny, and we also account for the negative bias on mean age of returning mature progeny that is a consequence of troll fishery harvest of immature salmon. Results suggest that (a) heritability of age of maturity is relatively high in this species (calculated h2 were 0.49–0.57 and 0.39–0.41 for males and females, respectively), (b) inheritance of age of maturity of females appears to be independent of age of male parent, and (c) for a given parental age, "faster-growing" progeny generally mature at younger ages, but (d) progeny from older parents are not generally smaller at age than progeny from younger parents. Inheritance of age of maturity therefore cannot be a simple reflection of inheritance of growth rate. We tentatively propose the existence of heritable minimum threshold lengths that differentially trigger maturation according to age and sex of parents. We also consider the significance of these experiments for artificial propagation of this species.

Growth rate inheritance and associations with other traits in backcross populations of Avena sativa x A. sterilis

Improved grain yields in lines of oats from matings of Avena sativa x A. sterilis were found to be due to increased plant growth rate. Growth rates of oats were quantitatively inherited, with the minimum number of effective factor pairs segregating in the interspecific matings ranging from 3 to 9. Heritability values for this trait averaged 0.4. Growth rate was highly and positively correlated with bundle weight, straw yield, grain yield, and unit straw weight, but it was uncorrelated with heading date and harvest index. Correlations with plant height were low. Thus, it should be possible for oat breeders to combine the high growth rates from A. sterilis with any combination of agronomic traits.

Selection for growth-rate during asexual and sexual propagation in Phytophthora cactorum

SUMMARYSelection for high and low growth-rate was carried out during eight generations of asexual propagation by zoospores and seven generations of sexual reproduction by oospores. The fungus has previously been shown to be diploid during its vegetative phase. In the zoospore lines there was no significant variation and no response to selection, except for the occasional appearance of fast-growing sectors. A high line was established from such a sector; in its sexual progeny the inheritance of growth-rate was non-Mendelian. Propagation through self-fertilized oospores released very considerable genetic variation, and both high and low lines responded to selection. At first the variation within families, and the response to selection, increased with succeeding generations, despite the intense inbreeding. In later generations the high line became less variable, and the progeny oospore cultures resembled the fast-growing sectors. It is concluded that growth-rate is controlled by a polygenic system and by cytoplasmic determinants, a mutant form of which is responsible for the fast-sectoring phenotype.

Growth Rate Inheritance in Japanese Quail: 5. Protein and Energy Requirements of Lines Selected Under Different Nutritional Environments

WHILE selection under different environments has been reported in mice (Falconer and Latyszewski, 1952), tribolium (Hardin and Bell, 1967) swine (Fowler and Ensminger, 1960), and quail (Marks and Lepore, 1968), information on the nutritional requirements of these populations is unavailable. Comparisons of the protein and energy requirements of populations undergoing selection under different environments are critical for the evaluation of environmental stressors’ contributions to ultimate selection progress. Weber and Reid (1967) found the protein requirement of a population of nonselected quail (to five weeks of age) to be 24 percent when fed a soybean meal diet supplemented with methionine.The present study was conducted to determine whether quail selected under different nutritional environments were being separated through a mechanism involving the differential utilization of dietary protein.MATERIALS AND METHODSThree stocks were involved in this study. The P line was established by selection for high four-week body weight on a…

Growth Rate Inheritance in Japanese Quail: 4. Body Composition Following Four Generations of Selection Under Different Nutritional Environments

WHILE selection can dramatically alter body weight, relatively little information is available regarding concurrent changes in tissue composition. Fowler (1958) and Timon et al. (1970) found that selection for increased body weight in mice increased the rate of fat deposition. With the advent of selection under different environments, examination of possible changes in body composition becomes increasingly important. This is particularly true when different planes of nutrition are used as the environmental variables. Falconer and Latyszewski (1952) reported that mice selected on a restricted diet had less fat than mice selected on a full diet.The present study was designed to measure differences in body composition of quail lines undergoing selection on a conventional 28 percent protein diet (P population) and on a 20 percent protein diet containing 0.2 percent thiouracil (T population). The early responses to selection for these lines have been reported by Marks and Lepore (1968) Herein…

Growth Rate Inheritance in Japanese Quail: 3. Thyroid Activity of Lines Selected Under Different Nutritional Environments

ALTERATIONS in thyroid activity accompanying growth rate selection have been difficult to detect. In comparing mice selected for large and small body size, Edwards (1962) could find no significant strain differences in either thyroidal radioiodine uptake or thyroid secretion rate. In a comprehensive study with chickens selected for high and low body weight at 8 weeks of age, Washburn and Siegel (1963) measured the influence of dietary thiouracil upon body weight, feather development, blood pressure, hematocrit, and oxygen consumption. A significant line by goitrogen interaction was reported only in respect to hematocrit level. Using similarly selected lines of chickens, Farrington and Mellen (1966) found no significant differences in thyroxine secretion rate when birds were compared at the same age (4 weeks). If, however, birds were compared at different ages but at less discrepant body weights, a significant difference in thyroxine secretion rate was observed (4-week high line, 1.41 μg./100 g. .

Growth Rate Inheritance in Japanese Quail: 2. Early Responses to Selection under Different Nutritional Environments

IN 1962, Siegel summarized 176 published heritability estimates of body weight obtained for chickens 6 to 12 weeks of age. The median heritability of these estimates, which were obtained by various methods of computation, was 0.41 and the interquartile range was 0.29 to 0.54. Siegel (1962) reported a realized heritability of 0.30 for 8-week body weight, while Maloney et al. (1963) obtained an estimate of 0.34 for body weight at 12 weeks of age. Recently, Maloney et al. (1967) observed a realized heritability of 0.42 in a population selected for high 12-week body weight. Although the magnitude of these reported heritability estimates indicate that responses to selection for body weight are expected to be large, it has generally been observed that response in early generations of selection is greater than that observed in later generations.The utilization of environmental restrictions as selection aids has not been fully investigated. Falconer and .

Growth Rate Inheritance in Japanese Quail: 1. The Establishment of Environmental Conditions which Restrict Juvenile Growth Rate

THE exposition and complete utilization of all sources of genetic variation is a major goal of geneticists. One approach for achieving this goal includes the development of lines selected for growth performance in a variety of adverse environments followed by the testing of these lines and/or line-crosses in an optimum environment.Prior to initiating the selection studies, however, it is necessary to determine which environmental conditions produce a repeatable restriction in growth rate. A preliminary report (Marks and Lepore, 1966) indicated the ineffectiveness of crowding, limiting waterei or feeder space, and temperature stress in consistently restricting 4-week body weight in Japanese quail. Coupling these results with the inherent managerial ease of conducting dietary stress experiments prompted us to investigate using adverse nutritional environments for growth rate depression. A literature search provided many possible dietary treatments which could be used, but for theoretical reasons, thiouracil supplementation and protein deficiency were chosen .

Inheritance of growth rate in Neurospora crassa: reverse selection in an improved strain.

Inheritance of growth rate in Neurospora crassa: reverse selection in an improved strain.

The Genetic Control of Growth and Adult Body Weight in the Domestic Fowl ,

THE greatest single genetic contribution to increased efficiency of production of poultry meat has been the improvement in rate of growth and body weight. Although body size and growth rate inheritance have been extensively studied, very little specific information on the genetic control of growth and adult body size is available.A comprehensive review of the subject has been completed by Lerner (1937), while more recent reviews may be found in the books of Hutt (1949) and Jull (1952). In general, the genetic control is said to be quantitative, and the changes that are possible through breeding programs have been estimated. Heritability estimates of body weight at various ages range from 32 to 75% (Jull, 1952). In addition, some genes have been identified which produce marked and deleterious effects on the size of the organism or parts thereof. Examples of such genes which may be mentioned are Creeper (Cutler, 1925) .

THE INHERITANCE OF GROWTH RATE AND EFFICIENCY OF GAIN

Journal Article THE INHERITANCE OF GROWTH RATE AND EFFICIENCY OF GAIN: In Milking Shorthorn Steers Get access M. L. KOHLI, M. L. KOHLI Search for other works by this author on: Oxford Academic PubMed Google Scholar A. C. COOK, A. C. COOK Search for other works by this author on: Oxford Academic PubMed Google Scholar W. M. DAWSON W. M. DAWSON Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Heredity, Volume 43, Issue 5, September 1952, Pages 249–252, https://doi.org/10.1093/oxfordjournals.jhered.a106321 Published: 01 September 1952

The Inheritance of Growth Rate in Neurospora crassa with Special Reference to Hybrid Vigour and Cytoplasmic Inheritance

Eight crosses have been made between different strains of Neurospora crassa and the growth rates of the segregants and parents determined. Growth rates smaller than, and intermediate between, those of either parent have been found among the segregants, but in only one case has an apparent example of hybrid vigour, i.e. of a greater growth rate, been established. This example of an apparently greater growth rate has been shown on analysis to be due to the segregant type having a respone to temperature different from that of its parents. In consequence it is to be emphasized that in questions of the inheritance of physiological characters deductions based on measurements made under only one set of environmental conditions are unsatisfactory and may readily lead to wrong conclusions. The inheritance of certain morphological characteristics and of two factors affecting the rate of spread of the fungus are recorded. Evidence is adduced to show that cytoplasmic inheritance is demonstrable in this fungus and that it affects both morphological and physiological characteristics. Experiments carried out by the author on Coprinus sphaerosporus are reviewed and are shown to indicate the presence of hybrid vigour in that fungus. A suggestion arising from this discussion indicates a possible interpretation of certain unexpected results in experiments carried out by Ashby and Luckwill. The author has much pleasure in thanking Professor V. H. Blackman for his constant advice during these experiments and also Professor F. G. Gregory for numerous suggestions.