A research of interphase nuclei and chromosome number of Isoetes sinensis Palmer was made in the article. The chromosome number of Isoetes sinensis Palmer was 2n=4x=44. The interphase nuclei were categorized to be sim...A research of interphase nuclei and chromosome number of Isoetes sinensis Palmer was made in the article. The chromosome number of Isoetes sinensis Palmer was 2n=4x=44. The interphase nuclei were categorized to be simple chromocenter type. The metaphase chromosomes were about 5 μm in length.In addition,the mitotic process was observed. These results could supply the cytological evidence for the exploration of the biosystematics and endangerment mechanism of this species.展开更多
Isoetes sinensis Palmer (Isoetaceae) is an aquatic or amphibious plant that is critically endangered in China. Previous studies have revealed the crassulacean acid metabolism (CAM)-like photosynthetic pathway occurs c...Isoetes sinensis Palmer (Isoetaceae) is an aquatic or amphibious plant that is critically endangered in China. Previous studies have revealed the crassulacean acid metabolism (CAM)-like photosynthetic pathway occurs commonly in submerged leaves in genusIsoetes. Water chemistry parameters and the titratable acidity content of the plant extract were measured from samples obtained in the early morning (7∶00) and late afternoon (15∶00) from twoI. sinensis populations in China. One population occurs in the eulittoral zone of a freshwater tidal river at low elevation (134 m) and another occurs in a densely vegetated, high elevation (1 100 m) alpine shallow pool. Significant differences in pH and titratable acidity of the plant extract were detected between the morning and afternoon samples. These changes are associated with diurnal changes in water chemistry. Our results provide the first evidence for the existence of the CAM pathway in the East Asian endemicIsoetes sinensis Palmer. The magnitude of fluctuations in the titratable acidity of the plant extract may be correlated with the severe carbon limitation imposed on the plants by its aquatic habitat.展开更多
文摘A research of interphase nuclei and chromosome number of Isoetes sinensis Palmer was made in the article. The chromosome number of Isoetes sinensis Palmer was 2n=4x=44. The interphase nuclei were categorized to be simple chromocenter type. The metaphase chromosomes were about 5 μm in length.In addition,the mitotic process was observed. These results could supply the cytological evidence for the exploration of the biosystematics and endangerment mechanism of this species.
基金the State Key Basic Research and Development Plan(G2000046805)
文摘Isoetes sinensis Palmer (Isoetaceae) is an aquatic or amphibious plant that is critically endangered in China. Previous studies have revealed the crassulacean acid metabolism (CAM)-like photosynthetic pathway occurs commonly in submerged leaves in genusIsoetes. Water chemistry parameters and the titratable acidity content of the plant extract were measured from samples obtained in the early morning (7∶00) and late afternoon (15∶00) from twoI. sinensis populations in China. One population occurs in the eulittoral zone of a freshwater tidal river at low elevation (134 m) and another occurs in a densely vegetated, high elevation (1 100 m) alpine shallow pool. Significant differences in pH and titratable acidity of the plant extract were detected between the morning and afternoon samples. These changes are associated with diurnal changes in water chemistry. Our results provide the first evidence for the existence of the CAM pathway in the East Asian endemicIsoetes sinensis Palmer. The magnitude of fluctuations in the titratable acidity of the plant extract may be correlated with the severe carbon limitation imposed on the plants by its aquatic habitat.
