Plant Population Management and Breeding

Utilization of Parametric and Nonparametric Yield - Stability Measurements and their Relationship in Yellow Maize

“…Selection under various environments is very difficult due to G x E interaction (Badu et al 2003 andMortazavian andAzizi-Nia 2014). The emergence of GEI due to unpredictable macro and micro-environmental influences as temperature, humidity and rainfall (Abo-Hegazy et al 2013) The stability of yield depends on the ability of a given variety to react to environmental changes (Frey 1983). There are many methods to estimate the GEI and to select stable genotypes including, parametric, nonparametric measures and graphical estimation.…”

Competition among wild rice, landrace, improved cultivar and F1 hybrid rice

“…Growing environment is also equally important in the expression of characters in genotypes. Since genotypes are generally evaluated under several environmental conditions, the differential competing abilities of genotypes under different environments inflate the genotype  environment interaction (Frey, 1983). Sakai (1955) concluded from a study of paired mixtures of six rice varieties that variation in plant characters due to competition effects must be considered in the estimation of heritabilities.…”

Comparison of mass selection and S1-testing recurrent selection methods in sorghum

“…The objective of recurrent selection is to gradually increase the frequency of favorable alleles that influence quantitative trait(s) in the population, while maintaining genetic variability, so that further inprovement of the trait(s) can be made. Summaries of a large number of experiments have indicated that recurrent selection has been effective in inproving quantitative traits in many species (Sprague and Eberhart, 1977;Frey, 1983Frey, , 1984Hallauer, 1986;Miranda, 1988, Hallauer et al, 1988).…”

“…Many different recurrent selection methods have been designed and most methods have been modified for use with various crop species. Ease of intermating and producing progenies, the desired type of a commercial cultivar, and the type of gene action and heritability of the trait often influence the type of recurrent selection used (Nath, 1982;Frey, 1983;Hallauer, 1987;Hallauer and Miranda, 1988).…”