ISOZYME VARIATION IN SPANISH NATURAL-POPULATIONS OF ELYTRIGIA-PUNGENS(PERS) TUTIN AND E-REPENS (L) NEVSKI

Genetic variability in 20 natural populations of the species Elytrigia repens (L.) Nevski and Elytrigia pungens (Pers.) Tutin collected at d ifferent geographical places in Spain has been analysed using eight is ozyme systems. Analysis of the isoenzymatic patterns indicates inter- and intrapopulational variability in all of the isozyme systems except LAP. The data of intrapopulational variability level, calculated in e ach population, did not show significant differences in either species . The factorial analysis of correspondence showed a specific distribut ion of the populations into two groups, based on a series of discrimin atory isoenzymatic bands that belonged to different systems and whose relative importance is discussed. The dendrogram obtained with the UPG MA method established a specific distribution for the populational sub groups within each species grouping, and showed a lower level of inter populational variability in E. repens than in E. pungens. Our results suggest a significant relationship between isozyme variability and sev eral geographical variables (latitude, longitude and altitude).