MULTIVARIATE STATISTICAL-ANALYSIS OF THE EFFECTS OF RYE TELOMERIC HETEROCHROMATIN ON THE AGRONOMIC TRAITS OF HEXAPLOID TRITICALE

Two pairs of sister lines of hexaploid triticale (X Triticosecale Witt mack) differing by the presence (++) or absence (-) of telomeric heter ochromatin on chromosome arms 7 RL (cv. Drira) and 6 RS (cv. Rosner) w ere used in order to study the effects of telomeric heterochromatin lo ss on twelve agronomic traits, The following multivariate statistical techniques were used : multivariate analysis of variance, partial corr elation, multiple regression analysis and canonical correlation, The l oss of telomeric heterochromatin was accompanied by significant change s in the means of the twelve traits as a whole as evidenced by the res ults of the multivariate analysis of variance and in the regression of yield on the other traits. Many more partial correlation coefficients were changed in the Drira lines than in the Rosner lines; most coeffi cients became larger in the Rosner line lacking heterochromatin while the opposite was true in the corresponding Drira line, The traits most affected differed from cultivar to cultivar, There were also changes in the regression of seed yield on the other traits with number of spi kes contributing significantly only in the lines lacking telomeric het erochromatin with a concomitant loss of the significant contributions in these lines of spike length, number of spikelets per spike and the derived variable spike density. It is concluded that the loss of telom eric heterochromatin has significant effects on the expression and the relationships between agronomic traits and groups of traits in hexapl oid triticale and that for some traits these effects can be cultivar a nd chromosome specific.