Subjects: Biology >> Botany >> Applied botany submitted time 2023-07-13 Cooperative journals: 《广西植物》
Abstract： The genus Impatiens exhibits some varied floral features with a dichogamous reproductive system, in which pollination biology plays a key role in speciation and adaptive evolution. China is one of the centers of Impatiens species, comprising over 300 species including a large number of endemic and sympatric distributions, but there are few data on their pollination biology. Comparative pollination biology of two Chinese endemic and sympatric species, Impatiens corchorifolia and I. polyceras, were investigated, including flowering phenology, floral features, flower visitors, behavior of pollinators, and as well as breeding systems. It was turned out as below. (1) Morphology of spur was varied in two species, which played a key role in different floral syndromes. The spurs in I. corchorifolia and I. polyceras could produced a similar nectar sugar content, (45.48 ± 2.28) % and (46.12 ± 1.48) % respectively. They could shared two pollinators, Apis cerana and Vespa. However, the short spur in I. corchorifolia produced less amount of (4.57 ± 1.43) μL nectar while the long spur in I. polyceras yielded more nectar content of (10.15 ± 3.28) μL. And then, the latter also could be pollinate by the other insects including one species of Macroglossum and two species of Bombus. (2) The behavior of the common pollinators shared in I. corchorifolia and I. polyceras were obviously distinguished by their staggered flower visits and differential sizes of flower channels for visitors with inconsistent positions of pollens carried. (3) Both species were dependent on pollinators to set fruits, which were self-incompatible, as well as cross-incompatible between two sympatric species. The results provide new data for better understanding of floral syndrome and speciation of the large genus of Impatiens.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-12-19 Cooperative journals: 《广西植物》
Abstract： In order to clarify the morphology of floral organs and the development status of male and female gametophytes at different development stages of Bambusa tuldoides in wild, and to summarize their abortion types, the appearance morphology of each part of floral organs and the development process of male and female gametophytes of B. tuldoides were observed by means of anatomy and sectioning, and the reasons for the low seed setting rate were also analyzed. The results were as follow: (1) The spikelets of B. tuldoides were of infinite inflorescences. The florets in the lower part of the spikelets developed first, and there were latent buds developed at the base, which had the characteristics of definite inflorescence. The petioles of spikelets were undeveloped, and the spikelets developed in cluster at each node of the floral branch. (2) Each floret had 1 palea, 1 lemma, 6 stamens, 3 lodicules and 1 pistil. The lodicule was transparent and had well-developed cilia on the edge. The ovary had prismatic protrusions and the upper part of which had villi, and was unilocular and lateral membranous with a anatropous ovule. The stigmas were three-lobed and feathery. (3) The anther of B. tuldoides had four sporangia, and the anther wall was composed of four layers, epidermis, endothecium, middle layer and tapetum. The tapetum was glandular, and degenerated completely after maturity. The meiosis was successive and the microspore tetrads were bilaterally. The mature pollen grains were three-celled（. 4）Several abortion types were found in pistils and stamens, which might be the main reason for the low seed setting rate of B. tuldoides. All the above results indicate that the morphological structure of B. tuldoides floral organs is normal, while the female and male gametophytes developed abnormally, which cause the low seed setting rate.
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