Effects of High Temperature on metaphase Pairing in Lilium longiflorum

Abstract

Plants of the Creole and Giganteum vars. of L. longiflorum with young flower buds were removed from a cool greenhouse (10[degree]-16[degree] C) and exposed for 30 min. to a temp. of 45[degree]-46[degree] C. They were then returned to a greenhouse with a temp. of 13[degree]-19[degree] C. Meiotic irregularities of 3 classes were found (a) translocations, (b) asynapsis, and (c) elimination of the entire nucleus or addition or subtraction of chromosomes from the normally expected numbers. The degree of asynapsis varied from cell to cell, some with all 24 chromosomes unpaired, others with variable numbers of bivalehts. Large cells with numerous fragments were also observed, but only in the Creole var. The 3d type of irregularity included enucleate cells, others with but 1-2-3 etc. to 15 bivalents. This occurred only with the Giganteum var. All these irregularities with the exception of the 3d type were also observed in untreated plants but at a much lower frequency.