Diploid Solanum species, diploid species-haploid S. tuberosum hybrid and tetraploid S. tuberosums were used for 4x-2x cross breeding method. 15 diploid bulk seed families and 26 diploid clones were planted to find clones with high yield and to find cl...
Diploid Solanum species, diploid species-haploid S. tuberosum hybrid and tetraploid S. tuberosums were used for 4x-2x cross breeding method. 15 diploid bulk seed families and 26 diploid clones were planted to find clones with high yield and to find clones producing unreduced male gametes to cross to tetraploids. Two to 21 clones from 11 bulk seed families were saved among 15 bulk seed families to use as breeding materials. Two clones out of sixteen studied had more than 4% of unreduced diploid pollen and 14 clones had less than 1% of unreduced pollen. Four diploid clones were selected, because of high yield, in order to cross with FDR clones to transfer the FDR producing gene into them. 30 to 250 seeds were obtained in eleven 4x-2x cross combinations.