Genetical studies on aenothera / Bradley moore Davis.

  • Davis, Bradley Moore.
Date:
1913
Catalogue details

Licence: In copyright

Credit: Genetical studies on aenothera / Bradley moore Davis. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    GENETICAL STUDIES ON OENOTHERA. IV II DR. BRADLEY MOORE DAVIS UNIVERSITY OF PENNSYLVANIA 3. Hybrids of grandiflora B X biennis D in the F2 Generation In my last paper (Davis, ’12a, pp. 392-406) there was described an especially interesting Fj generation, culture 11.35, of the cross grandiflora B X biennis D. The biennis male parent of this cross (Davis, ’12a, pp. 385- 389, Figs. 1-3) was of a race with the stem coloration characteristic of Lamarckiana, i. e., the papilhe or glands at the base of long hairs were colored red on green por- tions of the stem. The grandiflora female parent bears the same type of papillae, but they follow the color of the stem and therefore lack the red over green portions of the stem. The biennis parent then presented a character, the red coloration of the papillae, that might be expected to be present or absent in the Fj, and to present an alter- native inheritance in the F2 generation. It will be remembered that in the Fj generation of this cross, grandiflora B X biennis D, consisting of 180 plants, two sharply contrasted classes appeared (Davis, ’12a, p. 395). Class I was represented by 12 plants which had the stem coloration of the biennis parent (red papillae on green portions of the stem). Class II was represented by 168 plants with the stem coloration of the grandiflora parent (stems above clear green). Other peculiarities of these classes are described in the paper cited above, but we are concerned at this time chiefly with the behavior of this color character. The mixed conditions in this Fj generation naturally suggested the probability that the male biennis parent was heterozygous with respect to the red coloration of the papillate glands and that it formed