Genetic differences for size and shape in inbred lines of Poecilia reticulata

1984 ◽  
Vol 26 (3) ◽  
pp. 331-333
Author(s):  
Maria Luisa Vanelli ◽  
Gabriella Rocchetta ◽  
Carlo Pancaldi

The model of K. Mather is applied to partition the mean phenotypic expression of the "size" and "shape" traits during the growth in inbred lines and their F1 generations of Poecilia reticulata. In particular, the dynamics of the environmental and interaction components during growth have been analyzed. The results obtained for the "shape" show that the genotype – environment interaction is proportional to the effect of the environment so that the genetic differences evaluated for this trait are amplified in the last age considered. On the other hand, the lack of this kind of relationship, estimated for the size trait, and a greater weight of the environmental component, suggest that it is not possible to identify a particular age at which genetic differences between lines could be more easily detectable for this trait within the range analyzed.Key words: Poecilia, quantitative.

1966 ◽  
Vol 67 (2) ◽  
pp. 235-237 ◽  
Author(s):  
D. A. Bond ◽  
J. L. Fyfe ◽  
Gillian Toynbee-Clarke

The yields of seed from a hybrid, one of its parents and different mixtures of the hybrid and parent were compared in the case of two different hybrids. Open-pollinated controls were included in the trial, which was sown at about the normal rate for beans. With both hybrids a mixture of 11 of hybrid to 1 of parent yielded as well as the hybrid itself and mixtures of 2 of hybrid to 1 of parent yielded in both cases about 7 cwt./acro more than the mean of the open-pollinated controls. With the higher-yielding hybrid, which had less contrast in vegetative vigour between hybrid and parent, mixtures in the proportions 5:1 and 2:1 showed declining yields, but with the other hybrid they yielded as well as the pure hybrid.


1975 ◽  
Vol 191 (1104) ◽  
pp. 387-411 ◽  

The responses of two characters, number of sternopleural chaetae and total yield of offspring (which depends on the mother’s genotype), to change in the temperature at which the flies were raised and type of culture container in which they bred were followed in the two inbred lines, Wellington (Well) and Samarkand (Sam). In respect of chaeta number Well was more sensitive to change of the environment than Sam, which furthermore responded in the opposite direction to Well. In respect of yield of offspring the two lines responded similarly. The genetic control of these responses to environmental change was investigated by using the eight substitution lines which comprise all the possible true breeding combinations of the three major chromosomes (X, II and III) from Well and Sam. Two experiments were carried out, the first a diallel experiment at three temperatures (18, 21.5 and 25 °C), and the second an experiment in which the eight lines were raised in nine environments comprising all combinations of the three temperatures and three types of culture. Chaeta number changes more with temperature than with type of culture, whereas the reverse is true of yield of offspring. In respect of chaeta number the genes chiefly responsible for response to environmental change are borne on a different chromosome (II) than those chiefly responsible for variation in mean chaeta number (III), and there are indications of a similar situation in respect of yield of offspring. It is concluded that different characters are separately adjustable by selection in their responses to enviromental change, that sensitivity of a character to environmental change is adjustable separately from mean expression of the character, and that the detailed patterns of response to a range of environments (e. g. temperatures) are separable from the magnitude of the overall change induced by these environments.


2017 ◽  
Vol 68 (11) ◽  
pp. 1013 ◽  
Author(s):  
Josefina C. Sillero ◽  
María M. Rojas-Molina ◽  
Amero A. Emeran ◽  
Mohamed Kharrat ◽  
Johanna Winkler ◽  
...  

A germplasm collection of 484 accessions of Vicia faba was screened for resistance to rust (Uromyces viciae-fabae) under field conditions. Accessions varied in the levels of rust infection, although no complete resistance was identified. Stability of resistance of the 39 most-resistant accessions was tested in a multi-location experiment in Austria, Egypt, Tunisia, United Kingdom and Spain over three additional field seasons. Genotype × environment interaction accounted for 43% of the sum of squares of the multi-environment evaluation, revealing instability of the phenotypic expression across environments. This might hamper the efficiency of selection suggesting the need for selection in different environments. Three possible mega-environments were discerned in the studied area, Mediterranean (Spain, Tunisia and Egypt), Oceanic (UK) and Continental (Austria). Córdoba (Spain) and Kafr El-Sheik (Egypt) showed as ideal environments for rust resistance screenings within Mediterranean environment. Several accessions (300, 303, 311, 313, 720, 1196 and 1271) were grouped as moderately to highly resistant in the three defined mega-environments. These accessions showed clear differences both in terms of reduced disease severity and high stability, which make them good candidates for international faba bean breeding programmes. Concerning each mega-environment, accessions 300 and 311 were the most resistant and stable ones across the Mediterranean one, followed by accessions 720, 1022, 1272, 1320 and BPL261. On the contrary other accessions (313, 452, 481 and 1196) were the most resistant in Oceanic and Continental environments. However, 452 and 481 were susceptible in the Mediterranean mega-environment. This contrasting performance across the environments was also supported by contradictory performance of the checks BPL261 and Baraca in Oceanic and Continental environments, suggesting differential virulence in rust populations, which deserves further attention.


1961 ◽  
Vol 2 (1) ◽  
pp. 158-160 ◽  
Author(s):  
E. C. R. Reeve

Two apparently very similar quantitative characters, the numbers of hairs on the sternopleural region and on the abdominal sternites of Drosophila melanogaster, show unexpected differences in their genetic behaviour. In particular, the amount of left-right asymmetry of the sternopleurals (i.e. the mean absolute difference in numbers of hairs on the two sides of the fly) tends to decline when inbred lines are intercrossed, and can be both increased and decreased by straightforward selection; the corresponding index for the sternite hairs—the uncorrelated variance between two sternites, or the mean absolute difference between the numbers of hairs on each—appears, on the other hand, to be susceptible neither to selection nor to change when inbred lines are crossed (Mather, 1953; Reeve & Robertson, 1954; Reeve, 1959).


2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
Lúcio Borges de Araújo ◽  
Mario Varela Nualles ◽  
Mirian Fernandes Carvalho Araújo ◽  
Carlos Tadeu dos Santos Dias

This work applies the three mode principal components analysis to analyze simultaneously the multiple attributes; to fit of models with additive main effects and multiplicative interaction effects (AMMI models) and the regressions models on sites (SREG models); to evaluate, respectively, the multivariate response of the genotype × environment interaction and the mean response of 36 genotypes of corn tested in 4 locations in Brazil. The results were presented by joint plots to identify the best genotypes for their adaptability and performance in the set of attributes.


1981 ◽  
Vol 23 (1) ◽  
pp. 141-149 ◽  
Author(s):  
M. Luisa Vanelli ◽  
Carlo Pancaldi ◽  
Rita Alicchio ◽  
Domenico Palenzona

Genetic variability and growth pattern of metric traits were studied in inbred lines of Lebistes reticulatus (Peters) obtained by crossing full sibs in three generations. Sub-sublines with different growth rates of body length and body weight were identified; on the whole inbred population a genetical analysis was performed for both traits at different ages on raw data and on data adjusted for growth rate regression. Both analyses reveal the presence of a great amount of genotype—environment interaction and of a certain amount of genetic variation for body traits. The differences concerning the genetic components of variation observed in the two analyses within each population indicate an influence of the different growth rates of sub-sublines on the detection of genetic variability.


1970 ◽  
Vol 50 (1) ◽  
pp. 77-80 ◽  
Author(s):  
P. J. KALTSIKES

Estimates of genotype by environment interaction variances were obtained from the western Canada Co-operative fall rye tests grown in 1963–1967. All first-order interactions and the second-order interactions were significantly greater than zero at the 0.05 level of probability. Although the estimate of cultivar by year interaction variance was relatively small, it accounted for 40% of the variance of a cultivar mean when only three years of testing were considered. However, testing in 20 locations for three years with four replicates could detect yield differences of approximately 10% of the mean of the highest yielding cultivar. If further reduction of the yield difference detectable is desired, more locations should be included in the test.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jun Luo ◽  
Yong-Bao Pan ◽  
Liping Xu ◽  
Hua Zhang ◽  
Zhaonian Yuan ◽  
...  

The discrepancies across test sites and years, along with the interaction between cultivar and environment, make it difficult to accurately evaluate the differences of the sugarcane cultivars. Using a genotype main effect plus genotype-environment interaction (GGE) Biplot software, the yield performance data of seven sugarcane cultivars in the 8th Chinese National Sugarcane Regional Tests were analyzed to identify cultivars recommended for commercial release. Fn38 produced a high and stable sugar yield. Gn02-70 had the lowest cane yield with high stability. Yz06-407 was a high cane yield cultivar with poor stability in sugar yield. Yz05-51 and Lc03-1137 had an unstable cane yield but relatively high sugar yield. Fn39 produced stable high sugar yield with low and unstable cane production. Significantly different sugar and cane yields were observed across seasons due to strong cultivar-environment interactions. Three areas, Guangxi Chongzuo, Guangxi Baise, and Guangxi Hechi, showed better representativeness of cane yield and sugar content than the other four areas. On the other hand, the areas Guangxi Chongzuo, Yunnan Lincang, and Yunnan Baoshan showed strong discrimination ability, while the areas Guangxi Hechi and Guangxi Liuzhou showed poor discrimination ability. This study provides a reference for cultivar evaluation and essential test locations identification for sugarcane breeding in China.


Sign in / Sign up

Export Citation Format

Share Document