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Monoecious cucumber (Cucumis sativus L.) parents with high, medium, and low percentage of nodes with distillate flowers had a stronger effect on the percentage of gynoecious plants in F1 and F2 progenies than did degree of gynoecious expression in incompletely gynoecious parents. Highest percentages of gynoecious plants were obtained by using both gynoecious and monoecious parents with the highest level of distillate flowering tendency. According to our data, monoecious parents with a low percentage of distillate flowering nodes should be avoided when gynoeciousness is transferred to monoecious cultivars. Self-pollination of gynoecious F2 plants, requiring induction of staminate flowers by chemical treatment, was more effective in obtaining a high percentage of gynoecious plants in F3 progenies than selfing predominately gynoecious plants, or sibmating predominately gynoecious plants.

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Fruit of the cultivated tomato (Lycopersicon esculentum Mill.) store predominantly glucose and fructose whereas fruit of the wild species L. hirsutum Humb. & Bonpl. characteristically accumulate sucrose. Reducing sugar and sucrose concentrations were measured in mature fruit of parental, F1, F2, and backcross (BC1) populations derived from an initial cross of L. esculentum `Floradade' × L. hirsutum PI 390514. Generational means analysis demonstrated that additive effects were equal to dominance effects for percentage of reducing sugar. It was determined that a single major gene, dominant for a high percentage of reducing sugar, regulates the percentage of reducing sugar in tomatoes. We propose that this gene be designated sucr. Only additive effects were demonstrated to be important for glucose: fructose ratios. Using L. hirsutum as a donor parent for increasing total soluble solids concentration in the cultivated tomato is discussed.

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