Role of Some Genetic Parameters on Breeding Work for Resistance to Pre-Harvest Sprouting in Winter Wheat.

For wheat (Triticum aestivum), periods of prolonged rainfall and high humidity after the grain has ripened and before it can be harvested can contribute to, so called pre-harvest sprouting (PHS), which can be considered as a premature germination. PHS can be defined a complex quantitative character having two important components: sprouting score and falling number. The two these components are controlled by gene effects which are predominant of additive nature. Our research have been conducted on parental, F₁, F₂) backcross generations means, from 4 cyclic crosses with common parents differing in their reaction to PHS and falling number. Broad sense heritability coefficients for PHS score showed high values in the case of majority hybrids that indicate the important role of genotype in phenotypic expression of reaction to sprouting. Concerning to falling number, broad sense heritability coefficients had smaller values. For wheat as a self pollinated crop, is preferable to be used narrow sense heritability which reflects additive genetic contribution to phenotypic expression of sprouting or falling number, because only additive gene effects can be fixed to progeny. When PHS score, or falling number have high values for narrow sense heritability (higher 50), is recommended the beginning of selection in F₂ and in these cases can be successful applied pedigree selection. Concluding, high heritabilities associated with other genetic parameters can be important tools at hand of breeders. They indicated that wheat selection for PHS tolerance or falling number would be effective in populations involving crosses of sensitive and tolerant parents. [ABSTRACT FROM AUTHOR]