COMPARISON OF INTRA-POOL AND INTER-POOL CROSSES IN FABA BEANS (VICIA-FABA L) .1. HYBRID PERFORMANCE AND HETEROSIS IN MEDITERRANEAN AND GERMAN ENVIRONMENTS

Two recently detected, promising CMS systems in faba bran have opened up new possibilities in hybrid breeding. This study was conducted to d etermine hybrid performance and heterosis of 33 intra-pool and 66 inte r-pool crosses from a factorial of six European small-seeded (Minor), six European large-seeded (Major), and eight Mediterranean faba bean l ines. The parent lines and F-1 crosses a ere evaluated at two German a nd seven Mediterranean environments for anthesis, maturity. yield, yie ld components and plant height. Yield in the Mediterranean environment s was 60% of that in the German environments. European Minor lines and their intra-pool crosses were unadapted to Mediterranean environments and yielded only 31% compared with the Mediterranean lines and their crosses. whereas European Major genotypes yielded 58%. In German envir onments the European crosses yielded 107% of the Mediterranean crosses . Heterotic yield increase over the parental mean was largest for Euro pean Minor x Mediterranean inter-pool crosses, amounting to 95% in the Mediterranean and 73% in German environments. Our results confirmed t he expectation of an increased heterosis in inter-pool over intra-pool hybrids and poor adaptation of European genotypes in Mediterranean en vironments. In the latter, Mediterranean intra-pool hybrids were the m ost promising, whereas in Germany inter-pool hybrids of the European M inor x Mediterranean type were most promising.