Estimation of Genetic Parameters of some Important Agronomical Traits in Oilseed Rape by Griffing's Diallel Method

oilseed rape is one of the most important oilseed plants for supplying required oil and its products. To extent its cultivation area, the introduction of new cultivars with higher genetic diversity is necessary via breeding programs.

To establish of new genetic diversity and evaluation of genetic parameters, the 11 oilseed rape genotypes were crossed in full diallel method; consequently, different traits of parents and their F1 offspring were evaluated in a randomized complete block design replicated thrice.

Analysis of variance revealed that traits including days to flower initiation, physiological maturing, plant height, number of pods per plant, number of grain per pod, thousand-grain weight, and grain yield were significant. The genetic parameters analysis by Griffing's method I model II showed significant GCA, SCA, and REC effects of different traits which represent the evaluated traits were controlled by additive, non-additive, and cytoplasmic gene action effects. Analysis of combining ability represented that among parents, genotype SRL-97-1 had the highest GCA for physiological maturing, number of pod per plant, thousand-grain weight, and grain yield. Also, cross SRL-97-4×SRL-96-20 and SRL-97-15×SRL-97-3had the highest SCA and REC for grain yield, respectively. Besides, the broad sense heritability was higher in traits such as plant height, number of pod per plant and grain yield (H2=0.99); meanwhile, grain yield had a higher narrow sense heritability (h2=0.39).

Consequently, results showed that there was sufficient genetic diversity among evaluated genotypes in which the achieved diversity from the crossing of these genotypes could be applied in cultivar introduction. It is recommended that, genotypes with higher GCA and SCA are suitable for the foundation of a desirable population for selection of promising pure lines with higher yield attributes.