Induction and characterization of autotetraploid Mas Jambe Banana using oryzalin treatment

Triploid banana breeding could be achieved by crossing tetraploid to improved diploid banana genotypes. The availability of tetraploid bananas is naturally very limited. One of methods to produce tetraploid bananas is inducing tetraploid plants using chemicals that inhibit spindle fiber formation during mitosis such as oryzalin or colchicines. The present study selects and characterizes autotetraploid Mas Jambe Banana (Musa, AAAA) induced by in vitro oryzalin treatment that will be used as 2n gamete donors in crosses with improved diploids to generate secondary triploids. In vitro–cultured shoots of Mas Jambe Banana parthenocarpic diploid banana (Musa AA) were treated with oryzalin at a concentration of 60μM for 7 days in a liquid MS basal medium with addition of 2 mg/l BA. Ploidy identification of induced Mas Jambe Banana was conducted using a flow cytometer. Forty-two plants were evaluated, of which 24 were autotetraploids. Compared with the original diploids, the Mas Jambe Banana autotetraploids showed significant increases in pseudo-stem height and diameter, fruit size, and bunch weight. The autotetraploid plants exhibited useful agronomic traits and can therefore be used as 2n gamete donors for generating secondary triploids. Keyword: Mas Jambe Banana, pseudo-stem, triploid banana, oryzalin