scholarly journals The Possibility of the Indirect Selection for Ovulation Rate Based on Testis Size in Golden Hamsters

1992 ◽  
Vol 63 (5) ◽  
pp. 495-502
Author(s):  
Tsutomu FURUKAWA ◽  
Takashi AWATA ◽  
Yasuo SHIOYA ◽  
Hirotaka TANAKA
Keyword(s):  
Indirect Selection ◽  
Ovulation Rate ◽  
Testis Size ◽  
Golden Hamsters ◽  
Selection For

scholarly journals Early generation selection strategy for yield and yield components in white oat

2005 ◽  
Vol 62 (4) ◽  
pp. 357-365 ◽  
Author(s):  
Giovani Benin ◽  
Fernando Irajá Félix de Carvalho ◽  
Antônio Costa de Oliveira ◽  
Claudir Lorencetti ◽  
Igor Pires Valério ◽  
...  
Keyword(s):  
Grain Yield ◽  
Indirect Selection ◽  
Grain Weight ◽  
Yield Potential ◽  
High Yield ◽  
Direct Selection ◽  
Selection Strategy ◽  
Breeding Method ◽  
Growing Seasons ◽  
Selection For

Several studies have searched for higher efficiency on plant selection in generations bearing high frequency of heterozygotes. This work aims to compare the response of direct selection for grain yield, indirect selection through average grain weight and combined selection for higher yield potential and average grain weight of oat plants (Avena sativa L.), using the honeycomb breeding method. These strategies were applied in the growing seasons of 2001 and 2002 in F3 and F4 populations, respectively, in the crosses UPF 18 CTC 5, OR 2 <FONT FACE=Symbol>´</FONT> UPF 7 and OR 2 <FONT FACE=Symbol>´</FONT> UPF 18. The ten best genetic combinations obtained for each cross and selection strategy were evaluated in greenhouse yield trials. Selection of plants with higher yield and average grain weight might be performed on early generations with high levels of heterozygosis. The direct selection for grain yield and indirect selection for average grain weight enabled to increase the average of characters under selection. However, genotypes obtained through direct selection presented lower average grain weight and those obtained through the indirect selection presented lower yield potential. Selection strategies must be run simultaneously to combine in only one genotype high yield potential and large grain weight, enabling maximum genetic gain for both characters.

Selection on ram 18-month weight to improve lamb growth rate

1983 ◽  
Vol 36 (2) ◽  
pp. 159-164
Author(s):  
D. Croston ◽  
J. L. Read ◽  
D. W. Jones ◽  
D. E. Steane ◽  
C. Smith
Keyword(s):  
Growth Rate ◽  
Live Weight ◽  
Indirect Selection ◽  
Direct Selection ◽  
Selection For ◽  
The Relationship ◽  
Lamb Growth

ABSTRACTThirteen pairs of Suffolk rams were selected on high and low 18-month adjusted live weight from six farms over 2 years, to establish the relationship between 18-month weight and early lamb growth. Progeny were first produced in recorded crossbred flocks (618 lambs) and then in an experimental flock of crossbred ewes (1083 lambs). Different results were obtained from the recorded and experimental flocks. The regressions of lamb 12- to 13-week weight on ram 18-month weight (within farm deviation) were 0·053 ± 0·022 kg and –0·004 ± 0·020 kg, respectively. These regressions for indirect selection correspond to ‘effective’ heritabilities for direct selection for lamb growth of 0·18 ± 0·07 and 0·02 ± 0·06 respectively. Improvement of early Iamb growth is discussed and it is concluded that selection for 18-month weight is unlikely to be a useful method.

scholarly journals Correlations and path analysis of morphological and yield traits of cactus pear accessions

2013 ◽  
Vol 13 (3) ◽  
pp. 203-207 ◽  
Author(s):  
Diogo Gonçalves Neder ◽  
Fabiane Rabelo da Costa ◽  
Ricardo Loiola Edvan ◽  
Lenildo Teixeira Souto Filho
Keyword(s):  
Path Analysis ◽  
Dry Matter ◽  
Selection Process ◽  
Morphological Characteristics ◽  
Indirect Selection ◽  
Strongly Correlated ◽  
Fresh Matter ◽  
Cactus Pear ◽  
Green Matter ◽  
Selection For

The objectives of this study were to evaluate the relationships between morphological characteristics and fresh matter yield of cactus pear and identify their direct and indirect effects. Nineteen accessions were evaluated for the following traits: number (NCl), thickness (ThCl), length (LCl) and width (WCl) of cladodes, plant height (PH) and plant width (PW), and green matter yield (GMY), dry matter yield (DMY) and dry matter percentage (DM). The correlations were estimated, and path analysis was performed by the method proposed by Wright. GMY was strongly correlated with DMY, allowing indirect selection for this trait. NCl and ThCl had a direct effect on GMY and can be used for indirect selection or as secondary traits in the selection process. Given the lack of significant correlations between MS and DMY, it is possible to select a palm variety with high DMY and DM.

scholarly journals Correlated Response on Growth Traits and Their Variabilities to Selection for Ovulation Rate in Rabbits Using Genetic Trends and a Cryopreserved Control Population

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2591
Author(s):  
Rosa Peiró ◽  
Celia Quirino ◽  
Agustín Blasco ◽  
María Antonia Santacreu
Keyword(s):  
Growth Traits ◽  
Ovulation Rate ◽  
Control Population ◽  
Individual Growth ◽  
Correlated Response ◽  
Phenotypic Variance ◽  
Correlated Responses ◽  
Growth Variability ◽  
Selection For ◽  
Genetic Trends

The aim of this work was to estimate correlated responses in growth traits and their variabilities in an experiment of selection for ovulation rate during 10 generations in rabbits. Individual weight at 28 days old (IW28, kg) and at 63 days old (IW63, kg) was analyzed, as well as individual growth rate (IGR = IW63 − IW28, kg). The variability of each growth trait was calculated as the absolute value of the difference between the individual value and the mean value of their litter. Data were analyzed using Bayesian methodology. The estimated heritabilities of IW28, IW63 and IGR were low, whereas negligible heritabilities were obtained for growth variability traits. The common litter effect was high for all growth traits, around 30% of the phenotypic variance, whereas low maternal effect for all growth traits was obtained. Low genetic correlations between ovulation rate and growth traits were found, and also between ovulation rate and the variability of growth traits. Therefore, genetic trends methods did not show correlated responses in growth traits. A similar result was also obtained using a cryopreserved control population.

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