抄録
An autotetraploid was raised as a result of colchicine treatment in Petunia hybrida Hort. to enhance the ornamental value. Treated plants were showing gigantism in comparison to their diploids and also improvement in flower parts through colchiploidy breeding. Moreover, the tetraploid flowers stayed longer resulting in an improvement in keeping quality and extension of blooming period to some extent. Detailed cytological observations made during the present study have shown the occurrence of multiple association of chromosomes which often lead to meiotic irregularities in the induced tetraploids. Yet, abnormalities appeared due to the effect of colchicine, the consequences of these being increased pollen sterility which lowered plant fertility. The gigas characters of C1 also tended to lessen in C2 generation but more in comparison to their diploid plants.
