Row-Column Designs for Diallel Cross Experiments with Specific Combining Abilities

Abstract

In plant breeding programmes, Mating-Environmental (ME) designs are commonly used under one-way blocking setup to get an estimate for general and specific combining abilities (gca and sca) of inbred lines involved in the crosses. When a large number of crosses are to be compared, which lead to a large experimental area, it may be important to account for or eliminate the effects of fertility trends in the land in two directions. In such situations, designs with crosses arranged in a row-column (RC) set up can be more advantageously used. Though information on both gca and sca effects are important to the breeders, most of the statistical papers dealing with these designs assume sca effects as negligible for reducing the complexity in mathematical derivations. In this paper, a linear fixed effects model under a row-column setup with gca and sca components has been defined and the information matrix for estimating gca effects free from sca effects has been derived. Further, some classes of efficient MERC designs have been obtained for complete diallel cross (CDC) experiments and the designs obtained are found to be variance balanced for estimating the contrasts pertaining to gca effects. Macros have been developed using PROC IML of SAS software for the generation of the MERC designs so constructed.