© 1993 Heron Publishing—Victoria, Canada
Floral biology and breeding behavior in the bamboo Dendrocalamus strictus Nees.
Rajani S. Nadgauda, C. K. John and A. F. Mascarenhas
Division of Plant Tissue Culture, National Chemical Laboratory, Pune 411008, India / Received September 28, 1992
Summary
Floral biology and breeding behavior were studied in the bamboo Dendrocalamus strictus Nees. The inflorescence in this species is a large branching panicle. Fertile florets are intermixed with smaller sterile
ones. There are six stamens. The ovary is stipitate and turbinate. The style is long and the stigma is bifid and plumose.
Dendrocalamus strictus is typically dichogamous and protogynous. The gynoecium matures 3–4 days before the androecium, effectively preventing self
pollination. Flower bloom, which took place over a period of 2 to 3 h, was dependent on air temperature and only occurred
between 0600 and 1300 h. Dendrocalamus strictus is anemophilous. Flowers in the male phase were visited by insects. These insects completely neglected the flowers at the
female phase. The insects fed on the pollen and were not pollen vectors. When wind was excluded by enclosing the inflorescences
in bags there was no seed set, indicating that cross pollination by wind is necessary for fertilization and that parthenocarpy
and apomixis are not occurring in this species. Pollen fertility was about 98% as indicated by staining fresh pollen at the
time of anther dehiscence and pollen release with Alexander’s stain (Alexander 1969). When placed on a modified Brewbaker-Kwak
medium containing 1% glucose, the pollen grains germinated well, and the pollen tubes grew to 15–20 times the diameter of
mature pollen grains.
Although profound protogyny has its disadvantages in times of sporadic flowering, it can be useful in breeding programs because
it eliminates the need for emasculation.
Keywords:
bamboos, breeding behavior, Dendrocalamus strictus, floral biology.
