ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Estimation of heritability using variety trials data from incomplete blocks (1995)
    Springer
    Theoretical and applied genetics 90 (1995), S. 142-145 
    Details
    ISSN: 1432-2242
    Keywords: Heritability ; Incomplete block design ; Standard error ; Bias ; Genotype by environment interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An assessment of the heritability of a trait is useful in formulating a breeding strategy for crop improvement. We have considered the estimation of broad-sense heritability from a single-location trial and from multi-locational trials conducted in incomplete blocks. Using residual maximum likelihood estimates of variance components, we estimated the heritability and obtained expressions for the estimate of its bias and its standard error. The estimation procedure is illustrated for 25 barley genotypes evaluated at four locations in West Asia and North Africa during 1992.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221008
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Estimation of heritability from varietal trials data (1993)
    Springer
    Theoretical and applied genetics 86 (1993), S. 437-441 
    Details
    ISSN: 1432-2242
    Keywords: Heritability ; Standard error ; Genotype x environment interaction ; Confidence interval ; Invalid estimates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We present the estimation of heritabilities of an observed trait in situations where evaluation of several pure breeding lines is performed in a trial at a single location and in trials from several locations. For the single location situation, we evaluate exact confidence intervals, the probability of invalid estimates, and the percentage points of the distribution of heritability. Simulations were performed to numerically verify the results. Additionally, approximations to the bias and standard error of the estimate were obtained and are presented along with their simulated values and coefficients of skewness and kurtosis. For trials in several locations, explicit expressions for exact values of confidence limits are not available. Further, one would require knowledge of one more parameter, represented by the ratio of genotype x environment (G x E) interaction variance to error variance, in addition to the number of genotypes, replication and true heritability value. Approximations were made for bias and the standard error of estimates of heritability. The evaluation of the distribution of heritability and its moments was recognized as a problem of the linear function of an independent chi-square. The methods have been illustrated by data from experiments on grain and straw yield of 64 barley genotypes evaluated at three locations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00838558
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Precision of the genotypic correlation estimated from variety trials conducted in incomplete block designs (1997)
    Springer
    Theoretical and applied genetics 95 (1997), S. 1044-1048 
    Details
    ISSN: 1432-2242
    Keywords: Key words Genotypic and phenotypic correlations ; Standard error ; Lattice design ; Variety trials ; Incomplete block design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Precise assessment of an association among traits of a crop plant is helpful in developing crop-improvement strategies. Two types of association, genotypic correlation and phenotypic correlation, may be used. An estimate of correlation is required along with a measure of precision in terms of standard error. Methods for the evaluation of the standard errors of genotypic and phenotypic correlations are not available in the literature, and when trials are conducted in incomplete blocks an algebraic evaluation of such correlation is cumbersome. Three methods – simulation, jackknife and bootstrap – have been used to evaluate bias and standard errors of genotypic, phenotypic and environmental correlations. We have evaluated their performance with data on grain yield, days-to-heading, and plant height, in barley genotypes in triple lattices. Simulation and jackknife techniques were found to be closer, compared to bootstrap, and can be recommended for assessing the precision of correlation estimates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220050660
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...