SELECTION FOR YIELD, TUBER SPECIFIC-GRAVITY AND HIGH 2N POLLEN PRODUCTION IN POTATO HYBRIDS BETWEEN SOLANUM-TUBEROSUM L AND THE WILD-SPECIES SOLANUM-CHACOENSE BITT

Hybrid clones between dihaploid Solanum tuberosum x wild potato specie s were developed to allow the introgression of desirable genes from wi ld germplasm into cultivated species, to increase the allelic diversit y and to obtain maximum heterozygosity. A total of 167 hybrids were as sessed in two experiments carried out in Lavras, State of Minas Gerais , to select hybrids with high tuber yield and greater than 5% 2n polle n production. There were highly significant differences among the clon es, demonstrating wide genetic variability for all the assessed traits . The broad sense heritabilities at the level of clone means were rela tively high for the traits assessed, indicating that gain with selecti on may be obtained. Selection was very efficient for tuber yield but t he other traits showed relatively low gains, probably due to the low c orrelations found between tuber production and the other agronomic tra its assessed. However, with the exception of specific gravity, signifi cant gains would be obtained if selection was carried out directly on the individual traits.