The Genetics of LYCOPERSICUM ESCULENTUM Mill 1. the Trisomic Inheritance of "Dwarf".

The occurrence of triploidy in the tomato has recently been reported (LESLEY 1925). In 1923 one of two triploid plants of Dwarf Aristocrat, a dwarf variety with scarlet fruit, was crossed with Globe, a diploid with standard habit and crimson fruit. The dwarf habit is a simple recessive to standard, and the yellow skin of scarlet fruit is a simple dominant to the colorless skin of crimson. An F1 of three plants was grown, all of which were different in appearance from the F, diploid Dwarf Aristocrat X Globe and also from one another. Two of them were found to have 26 chromosomes or 2 more than the diploid (somatic) number; as was to be expected from their origin, these plants were double trisomics. The third plant developed two cotyledons and one pair of first leaves but no bud. I ts chromosome number was not determined. The more vigorous of the 26-chromosome plants, no. 23. 123.1, was a standard with scarlet fruit. It was less hairy than the diploid F’, the leaves were decidedly thicker and more leathery in texture and their surface more rugose. The margin of the leaflets had fewer deep indentations and was more undulate. The lateral leaflets were narrower than in the diploid, but the terminal one was broader than the laterals and often somewhat twisted. The sepals were shorter and the petals somewhat deeper yellow, narrower at the base and blunter. The stamens were more slender, paler yellow and often incompletely syngynesious. The pollan was less in amount and contained more empty grains. The stigma, unlike that of the diploid, was usually below the apex of the staminal cone. One flower was entirely without a gynoecium. Under field conditions the plant was unfruitful unless artificially pollinated. The fruit was somewhat less regular in shape than that of the diploid F1, and the seeds were relatively few. This plant gave rise to an F P consisting of 41 plants, of which 3 were found to be simple trisomic, while the remainder were probably diploid. The diploids consisted of 22 standards and 16 dwarfs, a departure from