SOME OBSERVATIONS ON NATURAL CLONES IN FESTUCA OVINA

Abstract

Evidence is presented in support of the hypothesis that ramets of the same natural clone of Festuca ovina in hill grazings may be collected from points up to 10 yd apart. When a reasonable estimate is made of the annual rate of growth of such clones it appears that their age is to be measured in centuries. During the first stage of the work, which is not described in detail, 1050 plants were collected from defined points within a 10‐yd square quadrat and examined morphologically. Several fairly homogeneous groups were recognized and four are described. In the second stage, experiments were conducted with these groups to determine which plants could be regarded as isoclonal. In ‘cloned clone’trials some of the characters were noticeably discontinuous in distribution and using these a more satisfactory clonal classification of the groups was achieved. From cross‐pollination tests it was concluded that morphologically distinct plants were cross‐compatible whereas morphologically similar plants were cross‐incompatible and yielded no more seed from this crossing than they did on selfing. This type of test, therefore, confirmed the reality of the morphological groupings. Characters with a more continuous distribution in the ‘cloned clone’trials behaved differently. There were statistically significant differences between isolates within supposed clones in these characters but some, and it is assumed all, of the difference could be traced to a virus infection of the material. A separate trial, where infection was introduced in a controlled manner from plants derived from the ‘cloned clone’experiments, indicated that this interpretation was not unreasonable. When allowance is made for the differences between the two species it is evident that natural clones of F. ovina closely parallel those of F. rubra in respect of their temporal and spatial distribution in hill grazings. Copyright © 1962, Wiley Blackwell. All rights reserved