Search published articles


Showing 2 results for Exine

Manijeh Pakravan,
Volume 3, Issue 2 (9-2016)
Abstract

The pollen grains of 34 populations, representing 16 species of Consolida (DC.) Gray, have been examined by LM and SEM. The polar axis (P), equatorial diameter (E), P/E ratio and exine patterns were measured. The pollen grains were found out to be 3-zonocolpate, euprolate to subprolate. The shortest polar axis to belong to C. tehranica (Boiss.) Rech.f. and the longest to belong to C. trigonelloides (Boiss.) Munz (28.15-37.3 µm); the shortest equatorial axis to belong to C. stocksiana (Boiss.) Nevski. and the longest to C. orientalis Schrödinger (17.5-25.2 µm). Based on exine ornamentation observed under SEM, two types of pollen grains were recognized. Type I, exine distinctly thickened at poles with broad colpi and stronglymicro-echinate sculpturing, and type II, with exine obtuse at poles, narrow colpi and weekly micro-echinate sculpturing. Pictures of all species and characteristics of pollen grain structure were presented. Our results showed that pollen shape and sculpturing were diagnostic characters for distinguishing the species. Although they did not suffice enough to resolve taxonomic conflicts in the genus, our results confirmed embed of Aconitella in Consolida due to the occurrence of Aconitella species in two pollen groups.

                                                                                                                                                             


Razieh Kasalkheh, Eisa Jorjani, Hossein Sabouri, Meisam Habibi, Ali Sattarian,
Volume 4, Issue 1 (6-2017)
Abstract

Pollen grains of 7 species of the genus Rubus L. were investigated using light microscopy (LM) and scanning electron microscopy (SEM). 14 different pollen characters were described, illustrated and compared in the present st-udy. All pollen grains were monad, tricolporate, radially symmetrical, isopolar, and medium in size. As for pollen sh-ape, 3 forms were recognized in the same specimens: prolate, perprolate and prolate-spheroidal. Endopore was located in the middle of colpi. The sculpture of the grains was confirmed to have striate pattern. The size of perforation and the orientation of the muri were compared and appeared to indicate the differences between the species. R.caesius, R. disc-olor, R. dolichocarpus and R. hirtus appear to have steriate-scabrate sculpture; in contrast, R. hyrcanus Juz., R. persicus Boiss. and R. sanctus Schreber. appear to have meandrical and fingerprint-like sculpture. Perforations are of two types. They are either large or often extending to tectal ridges or minute holes. Characters of pollen grains were proved their usefulness for separating taxa at the specific level. It seems that there is a link between the diversity of pollens and the vegetation habitats.



Page 1 from 1     

Creative Commons Licence
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.



© 2024 CC BY-NC 4.0 | Nova Biologica Reperta

Designed & Developed by : Yektaweb