The characteristics of the seeds of 7 annual and perennial species of Trifolium, Lotoidea section, in Iran were investigated by means of Scanning Electron Microscopy (SEM) and a stereomicroscope. Contrary to Zohary's belief who maintained that the micromorphology of the Trifolium's seed played no role in taxonomy, the results revealed that such characteristics can play a determining role in differentiating such species and distinguishing them from one another. The results of the micromorphologic study of the seed confirmed the morphological results of the species of the Lotoidea section to a great extent, but was involved in the separation and differentiation of the two species of T. repens and T. nigrescens. In general, the characteristics of the species' seeds proved quite effective in determining their phenetic relationship. Among the characteristics studied in the present research, mention can be made of seed shape, hilum shape, seed sculpture and seed length and width (L/W ratio). The results demonstrated that the characteristics of seed length and hilum shape showed the greatest diversity in the species. The longest seed length was that of the species T. radicosum and the shortest that of T. repens. The spindle shape of the hilum was an exclusive characteristic of T. radicosum which distinguished it more than any other characteristic from all the other species of this section. The difference in hilum shape in the two species of T. repens and T. nigrescens was an important distinctive characteristic.

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ABSTRACT. Chromosome numbers in 140 accessions of 37 annual and perennial species of Trifolium L. in Iran were counted and studied here. The chromosome number of 2n=16 was documented in Trifolium radicasum in Iran. New cytotypes were found in Trifolium ambigum, T. fragiferum, T. montanum, T. nigrescens, T. stellatum and T. tumens. This study deposited more data in chromosome numbers of Trifolium to determine the genus has high diversity of ploid level. Their karotypic formula showed that the most of the chromosomes were median-, submedian-or terminal-centromeric. The smallest chromosomes were found in Sections Versicaria and Mistyllus, while the largest chromosomes were found in Sections Trifolium and Tricocephalum. Thus, Trifolium seemed to be heterogeneous with respect to morphological characters of chromosomes.

There are many discussions about taxonomic position of Linum glaucum in different Flora. In this study, the morphological traits associated with the nuclear genome size were used for identification of infraspecific variations in the nine populations of L. glaucum. Twenty three qualitative and quantitative morphological characteristics were investigated. The Analysis of variance tests showed significant difference for some morphological features. The Canonical Correspondence Analysis of habitat ecological factors showed that each of the habitats had prominent characteristics, and also Pearson's coefficient of correlation confirmed the significant correlations between the morphological features in relation to ecological factors. In the morphological Unweighted Paired Group using Average method tree, populations were separated from each other, so that population No. 4 was separated from others. In the flow cytometery investigations, variation of about 1.19 times was presented between the maximum and minimum averages of the genome sizes in the populations. Minimum amount of genome size was found in populations No. 4. Significant correlations occurred between the nuclear genome size with habitat elevation as well as some of the quantitative morphological features. The mentioned variations caused to difference between the populations and lead to creation of ecotype and ecophene in the studied populations.