DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 9-10/1973 str. 56 <-- 56 --> PDF |
Summary Heritability of certain characteristics of European Larch of the Varažđinbreg population Part II The results of an estimate of the narrow sense heritability in a progeny test of European Larch for all studied characteristics obtained through variance analysis and one parent-progeny regresion demonstrated that: — The height increment is under a stronger genetic control than the diameter increment, while the latter is under influence of environment than of heredity. The ratio of additive genetic variance to total variance is greater in the height increment than in the diameter increment. The heritability for the characteristics of the diameter increment (diameters at breast height and diameters at mid-crown) amounts to h2 = 0.04, while for the heights to h2 = 0.16; through one paren-progeny regresion the heritability for the heights is h2 = 0.196 (h2 = 2b). — The amounts of heritability for the characteristics of the growth and increment almost coincide with the amounts of heritability in a broader sense, which were obtained by Matthews J. D. et al. (1960) when working with Larch, while they are somewhat smaller in the Pinus genus. — The amounts of heritability for the characteristics of branches and crown in some cases do not agree with the amounts obtained in works with other species. For the number of branches per 1 m of length an interfamily component of variance ( the stoutest branch amounts to h2 = 0.07, and for the lenght of the stoutest branch to h2 = 0.15. — in younger progenies (below ten years) it is difficult to estimate the heritability for the branch insertion angle in spite of that it was proved that this characteristic is under a fairly strong genetic control. This characteristic in young trees is very variable because of the strong influence of external factors and because of the genetic differences between trees. This finding is confirmed by the works with Scots Pine and by the author´s own investigations. The heritability was not estimated, because the interfamily component of variance ( progeny test of European Larch corroborates that this property is under an intermediary to strong genetic control. — The amounts of heritability for the percentage of surviral are almost as identical with the amount obtained by applying transformed date (h2 = = 0.29—0.39), as with the amount obtained by applying the Robertson-Lerner´s procedure (h2 = 0.29). — The amounts of heritability obtained on the basis of the analysis of variance in the progeny are probably greater than the actual ones. This is explained by the fact that the test was established in a locality, where the site situation and conditions for the growth of progeny were mainly uniform, which is the reason why the relation of the additive genetic variance to the total phenotypic variance is greater and thus also the heritability greater. Therefore, if computed, the genetic gain would be greater. The results obtained through the one parent-progeny regresion also deserve attention because the progeny and parents were grown in diferent conditions and are of different ages. |