Inharitance of the number of productive tillers in hibrid obtained by top-cross in rice(Oryza Sativa L.)

Subject of investignation are ten rice varieties (Oryza Sativa L.) and their F1 and F2 generation hibrids obtained by top-cross, where two varieties (Monticelli and Loto) are used as a father, and eight varieties as a mother (M-101, Drago, Osogovka, Oanda, Mesen Blatec, Rosa Marcheti, Koral and Kripto). The property-number of productive tillers was analysed and the average values, variability, mode of inheritance, heritability and combining ability were investigated. Significant variability (29,42%), in the F1 generation hibrid combination Rosa Marcheti x Monticelli, to a very strong variability (71,32%) in the F2 generation, hibrid combination Panda x monticelli were obtained in the investigations. Heritability ranges from (15,38%) in the hibrid combination Koral x loto to (69,95%) in the combination M-101 x loto. A dominant mode of inheritance has been determined in most of the combinations and three combinations had heterosis