Cytochemical methods are used to examine the distribution and localization of acid phosphatase, non-specific esterase, ribonuclease and peroxidase activity in the walls of the spores of the heterosporous Marsileaceae before and during germination. In the quiescent spore, the principal activity is associated with the perine layer of the wall and the intine, with some activity in the outer, gelat...

Sweepoviruses have been identified globally and cause substantial yield losses and cultivar decline in sweet potato. This study aimed to investigate the interaction between sweepovirus and plant host by analyzing the function of the viral protein C4 of Sweet potato leaf curl virus-Jiangsu (SPLCV-JS), a sweepovirus cloned from diseased sweet potato plants in East China. Ectopic expression of the...

Studies of postmeiotic chromosomes have been impeded by the thick exine of immature pollen grains. Chromosome staining of immature and adult pollen grains through conventional acetocarmine procedure is tedious and often leads to unsatisfactory results. An acetocarmine stain, used in conjugation with Carnoy’s solution as fixative for 72 hrs or until the chlorophyll-containing tissues of spike be...

In this research, five species of the genus Polystichum, belonging to Dryopteridaceae, namely, P. lonchitis, P. woronowii, P. setiferum, P. braunii and P. aculeatum, were collected from Gilan and Mazandaran Provinces and studied micro-morphologically. In order to compare the spores, their morphology and their ornamentation was studied. The spores each were picked from sporangia and each sample ...

Here we report on angiosperm-like pollen and Afropollis from the Anisian (Middle Triassic, 247.2-242.0 Ma) of a mid-latitudinal site in Northern Switzerland. Small monosulcate pollen grains with typical reticulate (semitectate) sculpture, columellate structure of the sexine and thin nexine show close similarities to early angiosperm pollen known from the Early Cretaceous. However, they differ i...