Premium
Diallel Crosses of Maize in Experiments Repeated over Locations and Years 1
Author(s) -
Matzinger D. F.,
Sprague G. F.,
Cockerham C. Clark
Publication year - 1959
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1959.00021962005100060012x
Subject(s) - diallel cross , agricultural experiment station , south carolina , library science , geography , political science , agriculture , agronomy , biology , archaeology , computer science , public administration , hybrid
KNOWLEDGE of variances of general and specific combining ability and of their interactions with different environments is useful in formulating corn breeding procedures. Variances accounted for by general and spec& combining ability were compared in different materials by Sprague and Tatum (19). In highly selected material the variance of specific combining ability was larger than the variance of general combining ability, while in unselected material the variance of general combining ability was the larger. General Combining ability was assumed to be primarily a measure of additive gene action and specific combining ability of deviations from additivity. Rojas and Sprague (18) obtained estimates of the variances of general and specific combining ability for yield and of their interactions with years and locations in experiments conducted at several locations for a 3-year period. Components of variance involving specific effects were consistently largei than corresponding ones involving general effects. The fact that iribreds entering into the single crosses were selected would tend to reduce the level of variance of general combining ability to that of specific combining ability and probably also reduce the variance of their interactions with years and locations. Variances of interactions of both general and specific effects with years were larger than with locations, as might be expected. Since Rojas and Sprague used selected material, it seemed advisable then to use all possible crosses among lines that had undergone no previous selection and that traced to a common random mating population. The purpose of this study was to compare variances of general and specific combining ability and of their interactions with years and locations in unselected material.