Inbreeding Depression of Progenies of Castor Bean, From of the Variety FCA-PB, Results of Three Types of Pollinations

Oil of castor bean despite its wide range of use, still present a relevant deficit in the Brazilian market. This deficit could be softened or extinguished with increased productivity, in which the genetic aspect has a great contribution. The most productive genotypes are the hybrid varieties, however for obtaining the hybrids pure lineages are required which have appropriate agronomic characteristics and that express the minimum of inbreeding depression. Thus, the objective of this research was to evaluate the inbreeding depression of castor bean progenies, from the cultivar FCA-PB, resulting from three types of pollination. The experiments were implanted in design in randomized blocks, in the 30 × 3 factorial scheme, being 30 progenies and 3 types of pollination (free, cross and self-pollination), in 2 environments (São Manuel and Araçatuba) and in 2 crops (2004/2005 and 2005/2006), with three replications. Inbreeding depression was estimated under the grain productivity variable. It was observed that cross-pollination presented grain productivity close to 2500 kg ha-1, in which the lowest coefficient of inbreeding was determined, zero (0). Opposed It self-pollination, in which resulted in lower productivity, around 2000 kg ha-1, and the highest inbreeding coefficient being of 0.77. The reflection of the coefficient of inbreeding on productivity presents inversely proportional behavior, ie, the measure that increases the coefficient of inbreeding decreases the grain yield.