Parameters in the estimation of the most suitable F2 population size in conventional maize (Zea mays L.) breeding programs

Abstract

The objective of the present study was to observe differences among four sizes of the F2 populations (100, 200, 300 and 500 plants) on the basis of test-crosses for grain yield according to the average values of the populations, genetic and phenotypic variances, genotypic and phenotypic coefficients of variations and broad-sense heritability. The values of genetic variance did not significantly differ over population sizes according to all possible comparisons, including the comparison of values obtained for the phenotypic variance. Furthermore, the values of broadsense heritability (67.8%-69%) did not significantly vary over different F2 population sizes. Genetic variability of the observed progenies, as a principal prerequisite of successful selection, was at the satisfactory level in all population sizes.

U radu su ispitivane razlike između četiri veličine F2 populacije od 100, 200, 300 i 500 biljaka na bazi test-ukrštanja, za prinos zrna, prema prosečnim vrednostima populacija, genetičkim i fenotipskim varijansama koeficijentima genetičke i fenotipske varijacije i vrednostima heritabilnosti u širem smislu. Vrednosti genetičke varijanse, nisu se značajno razlikovale između različitih veličina populacije u svim mogućim upoređenjima, što važi i za upoređenja dobijenih vrednosti fenotipske varijanse. Takođe, vrednosti heritabilnosti u širem smislu (67.8% do 69%) nisu značajno varirale sa promenom veličine F2 populacije. Genetička varijabilnost ispitivanih potomstava, kao glavni preduslov uspešne selekcije, je bila na zadovoljavajućem nivou u svim veličinama populacije.