On the Chromosomes of Lilium tigrinum, KER-GAWL

Abstract

1. Not in accordance with the previous investigators' statements that the haploid chromosome number of Lillian tigrinum, KERGAWL is 12, the present writers observed at the heterotypic metaphase of the pollen mother-cells various numbers of the trivalents as shown in the following frequency table. Those chromosomes which failed to form trivalents remain as bivalents and univalents in equal numbers.
Number of Trivalents 12 11 10 9 8 7 6
Frequency 4 12 14 24 9 4 2
2. In the root-tip cells, the writers constantly observed 36 chromosomes, 6 of which being markedly larger. In regard to the mode of spindle attachment, those 6 chromosames may be divided into 2 groups, 3 median and 3 submedian type. All 30 shorter chromosomes are of either terminal or subterminal types.
3. Lilium tigrinum, which has been hitherto known as a highly sterile plant, is found to be a triploid species.
4. The cause of sterility in Lilium tigrinum is ascribed to the irregular meiosis in the formation of non-viable pollen grains with abnormal chromosome or gene complements. From a preliminary examination, the same situation is also supposed of the embryosac of the plant.