Genetic analysis of plant mixtures.

Plant mixtures are difficult to analyze genetically because of possible interactions between neighboring plants (i.e., between plants in the same biological group). However, a genetic modeling scheme has been devised which, theoretically, can accommodate such interactions. This study was an attempt to put the theoretical modeling procedure to an experimental test. To this end an experimental procedure was devised that generated biological groups from a well defined base population. A cultural system was used which permitted growing plant mixtures in controlled environmental facilities. This allowed the experiment to be conducted over a wide range of temperature and nutrient conditions. Application of the theoretical gene model to the experimental data permitted identification of those classes of gene effects that were responsible for genetic variation exhibited by the mixtures. Adequacy of the genetic modeling description was corroborated by precise prediction of an independent genetic response. The genetic analyses also identified statistically significant temperature-and nutrient-dependent forms of heterosis. It was concluded that the study demonstrated the suitability of the theoretical group gene model for describing complexities inherent in plant mixtures.