The thesis describes the genetic bases of 2n-pollen formation. A comparison was made of the frequencies of 2n-pollen production in a different environment using the progeny of diallel crosses between five well-known diploid clones and three clones of <em>Solanum phureja.</em> It was evident that this character has a complex type of inheritance; through repeated cycles of selection for 2n-pollen a four-fold increase could be achieved at population level. Through proper selection of diploid male parents it was established that 2n-pollen genotypes can be effective for transferring useful characters, like bacterial wilt resistance, in 4x-2x crosses. The progenies derived from 4x-2x, 4x-4x and 4x-selfings were compared to find the optimal breeding approach for the production of TPS varieties. There were clear indications that it was possible to breed TPS varieties directly by 4x-2x crosses. This means that the advantages of breeding at diploid level and the effective transfer of desirable Units by 2n-gametes can be used in the TPS breeding.
|Qualification||Doctor of Philosophy|
|Award date||12 Feb 1996|
|Place of Publication||S.l.|
|Publication status||Published - 1996|
- solanum tuberosum
- seed testing