GENETIC-ANALYSIS ON THE HYBRID ORIGIN OF POPULUS-TOMENTOSA CARR

Results supported the hypothesis that P. tomentosa CARR. was the natur al hybrid of P. alba and P. davidiana. Evidence supporting hybrid orig in came from studies in which comparisons of floral bracts of parents and progenies were made as follows: 1) from control-cross progenies of P. alba x P. davidiana, 2) from segregation studies of backcrossed pr ogenies of both P. alba x P. tomentosa and P. davidiana x P. tomentosa , 3) from open-pollinated populations of female and male P. tomentosa plants possessing different bract types. Additional support for hybrid origin came from quantitative analysis of flower organ measurements.