The robustness of universal optimal binary balanced block (BBB) designs for diallel crosses has been investigated for the loss of any t (~1) observations (crosses) in a single block as per connectedness and A-efficiency criteria. It is observed that all the BBB designs for diallel crosses with the minimum eigenvalue strictly greater than 2 are robust as per connectedness criterion. Further A-ef...

Eight winter rapeseed genotypes GA096, Geronimo, Okapi, Orient, Sunday, Zarfam, SW0756, and Modena were used as parents of a complete diallel mating design. A set of 56 diallel F1 hybrids (with reciprocals) including their parents were evaluated in a 8×8 simple lattice design with two replications during 2007/08. Several agronomic traits like Plant height, number of lateral branches per pod, nu...

Definition of plant breeding, Sources of genetic variability Significance of genetic variability. Selection methods (SM). Factors affecting (SM). Heterosis & examples Hybridization crossing methods –inbreeding/ outcrossing. Convergent breeding, Divergent breeding. Evaluation of inbred lines by: Single crosses; 3-way crosses, Performing top crosses, Diallel analysis. Combining ability. General &...

A comparison among two forms of half-diallel analysis was made. The different half-diallel techniques used were Griffing's model I, method 2 and 4. These methods of diallel analysis were found to be interrelated. However, as Griffing's model I, method 4 partitioned heterosis into different components as well as gave information about combining ability and this method had certainly some advantag...

Advanced button mushroom cultivars that are less sensitive to mechanical bruising are required by the mushroom industry, where automated harvesting still cannot be used for the fresh mushroom market. The genetic variation in bruising sensitivity (BS) of Agaricus bisporus was studied through an incomplete set of diallel crosses to get insight in the heritability of BS and the combining ability o...

Artemisia annua is an important medicinal crop used for the production of the anti-malarial compound artemisinin. In order to assist in the production of affordable high quality artemisinin we have carried out an A. annua breeding programme aimed at improving artemisinin concentration and biomass. Here we report on a combining ability analysis of a diallel cross to identify robust parental line...

N previous papers (JINKS 19544,1956) the analysis of the parents, F,’s, F2’s and I backcross generations of an 8 x 8 diallel between inbred varieties of Nicotiana rustica using the method of diallel analysis described by JINKS and HAYMAN (1953) , and extended by SINKS (1954) , HAYMAN (1954) , DICKINSON and JINKS (1956) and JINKS (1956) have been presented. They showed that nonallelic interactio...

Aflatoxins, produced by the fungus Aspergillus flavus, occur naturally in maize. Contamination of maize grain with aflatoxin is a major food and feed safety problem and greatly reduces the value of the grain. Plant resistance is generally considered a highly desirable approach to reduction or elimination of aflatoxin in maize grain. In this investigation, a diallel cross was produced by crossin...

Pepper species of the genus Capsicum have been cultivated over centuries, producing both pungent and sweet fruit; the pungency is caused by alkaloids called capsaicinoids. Among the five cultivated species, Capsicum chinense is one of the most popular, being native to the Amazon basin. This species is characterized by a wide variety of fruit sizes, shapes and colors, with different capsaicinoid...

Most of the available results on optimal block designs for diallel crosses are based on standard linear model assumptions where the general combining ability effects are taken as fixed. In many practical situations, this assumption may not be tenable since often one studies only a sample of inbred lines from a possibly large (hypothetical) population. Recently Ghosh and Das (2003) proposed a ra...