POLLEN CONTAMINATION OF BROMEGRASS (Bromus inermis Leyss.) IN THE GREENHOUSE

Abstract

Contamination of bromegrass (Bromus inermis Leyss.) by wind-blown pollen was measured in the greenhouse using a homozygous recessive virescent mutant as the female parent. Pollen distribution was enhanced by manual shaking of male parents and by use of a fan. In previous tests, the mutant produced less than 0.005% normal green seedlings upon selfing. In this trial, green seedlings averaged 81.1, 40.8, 13.1, 6.9 and 1.1% among the progenies of the mutant when it was grown at 0, 1.5, 3.0, 4.5 and 7.5 m, respectively, from normal green parents. We conclude that satisfactory spatial isolation of several groups of bromegrass clones for breeding can be readily obtained in a greenhouse.