Some of the recent advances made by the author and associates in the genetics of British fruit crops are described. Stamen pattern is useful for studying the Pomoideae and Prunoideae, and strawberries. It may sometimes be used as an additional diagnostic character. The role of polyploidy as it affects the distribution of cultivated apples and cherries in Britain is considered in relation to other factors, such as fertility and frost damage.
The genic and environmental relations of flowering time in raspberry, and the genetics of the raspberry plant wild in Britain are stated. There is no recognisable cline of the biometrical characters. The more important biometrical characters used in raspberry breeding are evaluated: seedlings with the best general biometrical assessments usually prove to be the higher yielders.
Variation in apomictic blackberries has been investigated, especially concerning auto-segregation, and the term subsexual reproduction illustrated. The vigour of apomictic progenies, termed pseudo-gamous heterosis, depends on the pollen parent. Correlated responses follow the intense selection of an apomictic species: selection for prickle intensity produces a change in leaf shape reminiscent of other species closely related taxonomically. The pollination milieu of blackberries has also been examined. Graphical analyses are considered as useful visual aids when attempting to assess segregations in sexual-apomictic progenies. The distribution of black berries in Britain may have been influenced by the extent of previous glaciation: the greatest diversity of Rubus species is in south-east England, adjacent to the ice-free Continent.
Attention is drawn to the practical values of these discoveries.