Pollen Micromorphological Study of Ten Genera of Brassicaceae in West Iraq Desert

Abstract

Abstract This research included a micromorphological study of pollen grains of 11 taxa belonging to 10 plant genera of the Cruciferae family (Brassicaceae) distributed in Western Desert District of Iraq. The pollen grains of all species were monads, homopolar, regular, in addition to being tricolpate. They differed in shape, ranging from prolate, subprolate and Subprolate-subspheroidal. The polar dimension also differed greatly among species, which ranged between 25.2 μm. as an average in Morettia philaeana to 37.3 μm. as an average in Zilla spinosa. Thus, the equatorial dimension ranged between 21.4-30.1 μm. in the two species Leptaleum filifolium and Rapistrum rugosum respectively. As for the remaining species, they are graded between them. The difference in the length of the colpus resulted in important taxonomic characteristics in isolating species, if its length ranged between isolating 13.8 -30.3 μm. The Apocolpium also contributed through the variance that ranged between 3.9-8.6 μm., as well as the mesocolpium, which also varied between species, the shortest was 7.2 μm. in Morettia philaeana and the longest 18.3 μm. in Myagrum perfoliatum as indicated in the measurement tables. The two species, Eruca vesicaria and Strigosella africana are distinguished by their thin pollen walls (1.3 μm.), while Morettia philaeana had a thick wall (2.7 μm.), and then the reamining species came between them. This study identified two types of Ornamentation, namely, Microreticulate in 7 species and Macroreticulale in 4 species.