Genetic variability and heritability are two important factors for plant improvement programs where the magnificence and type of this variability determine the selection criteria to be used by the breeder. This study aimed to estimate the genetic components associated with variance and covariance based on partial diallel crosses and factorial mating designs, as well as, to identify the association between yield components and other quantitative traits to extend an orientation for selection. Six cowpea varieties were used in this study. All possible crosses were done according to partial diallel mating design in addition to the F1 hybrid which were arranged in a factorial mating design. The parents, F1 and their F2 generations were evaluated in a field trial experiments at El-Baramon station, Dakahlia Governerate, in a randomized complete blocks design with four replicaties. The results revealed that both two mating designs were suitable to study the genetic parameters. The means of F1 hybrids exceeded the mid parents (MP) and the better parent (BP). Significant values of heterosis were obtained for all studied traits. The highest values were 43.84% for pod length versus MP and 15.68% for number of pods per plant versus BP. The magnitude of both additive and non-additive genetic variances were high that means the possibility to development inbred lines of cowpea through selection. The higher values of broad-sense and narrow-sense heritability indicating good genetic variability for effective selection. The following traits; pod length, pod weight, weight of 100-seeds, and number of seeds per pod could be considered in breeding for grain yield, as they contribute significantly to its improvement.

F LORAL traits for the parents used in hybrid rice seed production are very effective in hybrid rice seed production especially in the three line system used in this study.The longer anther, stigma and filament are, the wider anther and stigma besides high exertion ratio and angle of spikelets opening are important factors that increase the outcrossing rate which increases seed set and production. This study was conducted out at the farm of Sakha Agric. Res. Station during 2014 and 2015 seasons to contribute in choosing best CMS, maintainer and restorer lines to use in hybrid rice seed production depending on its floral traits. Also, it can be used in a breeding program for improving the floral traits of other lines that can serve as good parents in hybrid rice breeding and seed production.In brief, we found that among the studied CMS lines,Pusa13A was the best line in stigma length, angle of spikelets opening, filament length,exertion ratio (%), number of filled grains panicle-1 , seed set (%),panicle weight and plant yield characters, while Pusa13B line was the optimum owing to its high characters like, anther length, good filament length, high exertion ratio (%),number of filled grains panicle-1 and plant yield.For restorer lines, PR1 was the best in anther length, stigma length, stigma width, filament length,number of spikelets plant-1 , number of filled grains panicle-1 and panicle weight.