Polyploidy From Twin Seedlings

Abstract

1) The chromosome numbers of twin seedlings in various species of cultivated plants have been examined. Though most of the twins have the normal chromosome number, twin seedlings with deviating chromosome numbers were found in the following species: Triticum vulgare, Triticum turgidum, Secale cereale, Avena sativa, Phleum pratense, Poa pratensis, Lolium perenne and Solanum tuberosum.2) If the twin plants differ in chromosome number, one of the twins is generally triploid in relation to the other one. This may be due to simultaneous fertilization of reduced and unreduced embryo sacs.3) Attention is called to the theoretical and practical importance of the twin method. Though the twins are formed in a low frequency, a rieh material may be obtained by cooperation with seed control stations.