Prevalence of Linear Configuration among Chain Trivalents at Metaphase I in Pollen Mother Cells of Petunia axillaris (LAM.) B. S. P.

Abstract

During a Wageningen workshop (1987) on multivalent orientation much current diversity in the interpretation of microscopic observations was taken note of. Particularly with reference to linear chain multivalents descriptive terms were commended. The phrase ‘linear configuration’ is preferred to linear orientation. Linear chains of three may have two syntelic centromeres, one at either end, and a mid-member described variously as amphitelic, late, ineffective or even actually inactivated. Thus the present report describes chain trivalent behaviour at metaphase I in pollen mother cells of Petunia axillaris (Lam.) B. S. P. and subordinates interpretation. The stable configurations are tentatively termed alternate orientation, adjacent orientation and linear configuration with or without centromere amphitely.