Investigation of mitosis, microsporogenesis and pollen germination in the critically endangered plantAmsonia orientalis(Apocynaceae)

Abstract

Amsonia orientalis Decne. (Apocynaceae) is a medically useful and critically endangered plant which has very restricted distribution world-wide. The root tips and flower buds of A. orientalis were used as an experimental material and they were squashed in aceto-orcein. Fresh flowers and a liquid medium were used for pollen germination tests. In spite of the small size of the cells and chromosomes, all phases of mitosis and meiosis were observed. Generally the phases of mitosis were regular but there were a few abnormalities, such as laggard chromosome in metaphase and bridge formation in anaphase. There was a good relationship between the stages of pollen development and floral bud length. As a result of the cytokinesis, tetrahedral types of tetrads were occurred in microsporogenesis. The tetrad nuclei resulting from the simultaneous type of meiosis were found to be of equal size. Pollen germination had started from the first hour and pollen tube lengths and germination percentages regularly increased with increasing time. This is the first study that identifies mitotic and meiotic cycles and pollen germination in A. orientalis. Our findings about the mitosis and reproduction biology of this critically endangered plant will be useful for in vitro and in situ conservation, taxonomic and genetic studies.

Microsporogenesis, microgametogenesis andin vitropollen germination in the endangered speciesFritillaria stribrnyi(Liliaceae)

“…The pollen tubes of F. stribrnyi can grow about 79 μm per hour within 24 h. Aksoy et al (2013) report that the average pollen tube length in Amsonia orientalis is 1678 μm after 12 h in the germination medium. The tube length of germinating pollen is measured as approximately 95.25 ± 38 μm in Hypericum perforatum and 165.92 ± 53 μm in Hypericum rumeliacum 4 h after inoculation (Arda et al 2006).…”

The Effects of Salicylic Acid on Helianthus annuus L. Exposed to Quizalofop-P-Ethyl

“…Pollutants enter the biosphere as liquids, gases, fine particles, solids and radioactive substances, and they do serious damage to plants in the form of toxic gases, ozone, acid rain, insecticides, herbicides and different types of radiation [2]. Herbicides are used in agriculture to control weeds [3], and for liquids and gases, various pollutants either adhere to the plant surface or enter the leaf through the cuticle or stomata, where physiological and structural responses occur [2].…”