Macrosporogenesis and development in Bambusa tuldoides Munro and Dendrocalamus asper (Schult & Schult) Backer ex K. Heynek

Though the viability, morphology, and development of bamboo pollen have received considerable study, the female gametophyte has received comparatively less attention. In the present work, it was performed a detailed study of macrosporogenesis in three stages of flower development in Dendrocalamus asper and Bambusa tuldoides looking at to elucidate the absence of caryopses formation. The gynoecium in three stages of floral development was analyzed using scanning electron microscopy and light microscopy techniques. Megasporogenesis in B. tuldoides begins at stage one of floral development with the formation of two megaspores, and megagametogenesis begins in the pre-anthesis with the formation of three abortive and one viable megaspores and ends in anthesis with the formation of a polygonum type embryonic sac. Megasporogenesis in D. asper starts at stage two of floral development with the formation of the megaspore mother cell and megagametogenesis occurs between stages two and pre-anthesis, during anthesis, the caryopsis developed, and the torpedo-stage embryo collapsed. The studies of the developmental stages of B. tuldoides and D. asper elucidated the absence of caryopsis formation, the first being related to the failure in the development of the pollen grain and in the second, the early inbreeding depression seems to be the reason for the non-formation of pollen grains caryopsis production. In addition, the absence of seeds negatively affects genetic variability, which is so important for genetic improvement programs and conservation of plant genetic resources.

Automated summary

This study examined the development of three stages of flowers in Dendrocalamus asper and Bambusa tuldoides. The gynoecium in these stages was analyzed using scanning electron microscopy and light microscopy techniques. The results revealed that B. tuldoides formed two megaspores in the first stage, while D. asper formed the megaspore mother cell in the second stage. The absence of caryopsis formation was found to be related to the failure in the development of pollen grains and early inbreeding depression. This absence of seeds negatively affects genetic variability, which is crucial for genetic improvement programs and conservation of plant genetic resources.