Abnormalities in Stamen and Ovary Development Responsible for Low Seed Set of Dendrocalamus hamiltonii Nees et Arn. ex Munro

Abstract

Bamboo propagation and seed collection are severely limited by a protracted and unpredictable flowering cycle. Dendrocalamus hamiltonii Nees et Arn. ex Munro was renowned for its delectable, bitter-free bamboo shoots, making it an exceptional choice for culinary purposes, which has significant economic value in China. To date, no fruit has been collected, and there are currently no comprehensive studies available on the floral morphology and embryology of D. hamiltonii. The morphological and anatomical characteristics of floral organs were described, and the developmental process of male and female gametophytes was elucidated, through anatomical observation. It was found that the floret of D. hamiltonii was composed of one lemma, palea, pistil, and six stamens, but lacked lodicules. The single ovule, possessing a parietal placenta, was anatropous and featured a double integument. The floral organs showed normal in external morphology, whereas male and female gametophyte development was abnormal, such as pollen grain shrinkage, hollow anther chambers, and underdeveloped ovules, which might be the important factors of its low seed setting rate. This study provided important information on the developmental stages of D. hamiltonii flowers and offered a theoretical basis for understanding the low seed setting rate of bamboo.