Flower and seed production in a series of flowerings from sporadic events before to after mass flowering of the dwarf bamboo Sasa veitchii var. hirsuta

The aim of this study was to determine seed production patterns in a series of flowerings from sporadic events before to after mass flowering and to clarify the relationship between the occurrence of second flowering and seed production in the first flowering of mass-flowering events for S. veitchii var. hirsuta. The results revealed that ratios of numbers of seeds to florets per inflorescence in the first and second flowerings of a mass-flowering event were as large as those in the first flowering of a sporadic-flowering event before mass flowering, and were larger than those in the second flowering of a sporadic-flowering event before mass flowering and in both flowerings of a sporadic-flowering event after mass flowering. However, estimated number of produced seeds per square meter in mass flowering was higher than that in sporadic flowering before it. This suggests that seed production is promoted in mass flowering, and that sporadic flowering beforehand can potentially contribute to successful regeneration. At a site where seeds were produced in the first flowering of a mass-flowering event, flower production and the seed germination ratio were smaller in the second flowering. Conversely, at a site where few seeds were produced in the first flowering of a mass-flowering event, there was no significant difference in flower production between the first and second flowerings, and the seed germination ratio in the second flowering was more than 40 %. This suggests that the second flowering of a mass-flowering event is related to seed production in the first flowering.