A COMPARISON OF PSEUDOMONAS SOLANACEARUM-RESISTANT TOMATO CULTIVARS AS HYBRID PARENTS

Seven tomato Lycopersicon esculentum lines, 'Venus', 'Saturn','Rodade', 'Rotam 4','Hawaii 7998', 'UC-82B', and 'Stevens', and their 21 crosses were evaluated for; their ability to resist infection by seven virulent strains of Pseudomonas solanacearum E.F. Sm. representing race 1 biovars 1 and 3. The Gardner and Eberhart model III analysis was used to evaluate the response of lines in crosses to P. solanacearum infection. General combining ability mean squares were significant for all strains and in 5 of 7 instances specific combining ability mean squares were significant, In four instances the parent vs. cross contrast was significant. 'Hawaii 7998' was resistant to all seven strains of P. solanacearum, whereas 'Rotam 4' and 'Rodade' were resistant to biovar 3 and two races of biovar 1. 'Venus' and 'Saturn' were resistant to two other biovar 1 strains. 'Hawaii 7998' transmitted greater resistance than the other resistant parents, but its small fruit size and indeterminate growth habit make it a poor choice for a hybrid parent.