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  • Author or Editor: W. L. George Jr. x
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Abstract

Flowers of 3 parthenocarpic tomato (Lycopersicon esculentum Mill.) genotypes, ‘Severianin’ (pat-2), PSET-1 (pat-2) and RP 75/79, and one nonparthenocarpic genotype, ‘Tiny Tim’ (pat-2+), were given various pollination treatments in a greenhouse study: a) natural pollination, b) pollination with a hand vibrator, c) emasculation followed by pollination with mentor (heat-killed) pollen, d) emasculation only, e) removal of stigmas, and f) removal of the distil half of the anthers and styles. RP 75/59 had greater total fruit set than did the pat-2 genotypes. Treatments preventing pollination inhibited seed formation of all genotypes and inhibited fruit set of ‘Tiny Tim’. Mentor pollen did not increase parthenocarpic fruit set for any genotype. Vibration of the flowers completely inhibited parthenocarpic fruit set for all genotypes except PSET-1, which had 15.7% parthenocarpic fruit. No difference in fruit size or days to ripening for seeded vs. seedless fruit were evident for the pat-2 genotypes. Seeded fruit of RP 75/59 were larger than seedless fruit (34.2 g vs. 20.3 g), and also took longer to ripen (2.9 days).

Open Access

Abstract

Two inbreds of tomato (Lycopersicon esculentum Mill.) with exserted stigmas, one without and the other with positional sterility (ps), were crossed without emasculation, at 3 stages of maturity under 3 environmental conditions. Seed production was maximal when flowers at anthesis were pollinated during cloudy weather with relative humidities (RH) of about 70% and temperatures about 24°C. Seed production was poor when flowers were pollinated 3 days before anthesis during hot (32°C), clear, dry weather (RH - 48%). The ps inbred had less than 1% selfing at all stages of flower development and environments. Selfing contamination for the ps + inbred was less than 4% per line except in some cases when flowers were crossed before anthesis. Selfing of 35% occurred when flowers were crossed 3 days before anthesis during favorable pollinating weather.

Open Access

Abstract

Newly opened flowers of 4 parthenocarpic tomato (Lycopersicon esculentum Mill.) genotypes, PSET-1 (pat-2), ‘Severianin (pat-2), RP 75/59, and Stock 2524 (pat), and 3 nonparthenocarpic genotypes, ‘Walter’, ‘Flora-Dade’, and ‘Homestead 24’, were excised and placed on nutrient media. The ovaries of the parthenocarpic genotypes increased in diameter and weight to a much greater extent than the ovaries of the nonparthenocarpic genotypes during a 6-day period at 25°C. In other comparisons, the parthenocarpic genotypes had larger ovaries than the nonparthenocarpic genotypes after 2, 4, 6, 12, 18, and 24 days. The ovaries of buds excised 1 and 3 days before anthesis and at anthesis from PSET-1 and ‘Severianin’ were larger after 6 days than those excised from ‘Walter’ and ‘Flora-Dade’.

Open Access