American Journal of Plant Sciences, 2011, 2, 1-14 1 doi:10.4236/ajps.2011.21001 Published Online March 2011 (http://www.SciRP.org/journal/ajps) Numerical Taxonomic Study of Some Tribes of Gramineae from Egypt Ahmed Osman1, Mohammed Zaki2, Sohar Hamed1, Nagwa Hussein1 1South Valley University, Qena, Egypt; 2Cairo University, Giza, Egypt. Email: [email protected] Received October 10th, 2010; revised November 26th, 2010; accepted December 9th, 2010. ABSTRACT A systematic study of eleven tribes of Gramineae surveyed 34 characters including fruit morphology, fruit anatomy and palynology. The results were conducted to some numerical analysis aspects. On the basis of UPGMA (Unpaired Group Method of Average) clustering and PCA (Principal component analysis), the results show congruence between the UPGMA clustering and PCA method, in suggesting two major clads/groups and five subclads. Keywords: Gramineae, Numerical Taxonomy, UPGMA, Cladistic Tree 1. Introduction group have been based on many different types of data e.g. isozymes [7], restriction site data [8,9] and sequence Poaceae (grasses) is one of the most species-rich flower- data from a number of different coding and/or ing plant families and includes many economically im- non-coding regions, viz.5S RNA [10]. Among the mod- portant crops. Parallel evolution of such features as the ern tools for plant taxonomy, reference [11] stated that annual habit, C4 photosynthesis and several highly char- increasing use has taken place of computers for data stor- acteristic reproductive structures has facilitated a series age and analysis during the past twenty years. Data de- of major radiations within Poaceae, culminating in the rived from all tools of taxonomical investigations has to existing global distribution of about 10000 species and be analyzed mathematically and cladistic trees have to be 700 genera [1,2]. A phylogeny of Poaceae was recently drawn. Despite of the criticism of using cladistic analysis established using a combination of multiple data sets in taxonomy, cladistic methods have become a most from both molecules and morphology [3], enabling im- useful technical tool for clarifying intrafamilial relation- proved understanding of relationships between basal and ships. Moreover; the advantages of using more rigorous derived grasses. techniques to elaborate natural classifications or evolu- Poaceae tribes and genera are subject to different stud- tionary diagrams instead of those that have been used ies in order to understand the phylogenetic relationships traditionally in botany have been well presented by [12]. between taxa. Many attempts have been made to address A phylogenetic analysis of Triticeae was performed by phylogenetic relationships of Chloridoideae; synonym means of numerical methods due to [13]. Five methods, Eragrostoideae that comprises approximately 146 genera each based on extreme assumptions of parameters so and 1360 species, whose adoption of efficient C4 photo- interpreted under [14] evolutionary model, were used. synthesis had led to its successful proliferation in the The most parsimonious tree obtained served as a base for tropics and subtropics [1]; mainly based on the basis of subsequent elaboration of the final tree, taking into con- morphological and molecular data [4,5], but general sideration genetic information primarily, and for the agreement is still lacking. The grass tribe Triticeae in- erection of the proposed phylogenetic classification of cludes some of the world’s most important cereals and a Triticeae. A key is provided for identification of the significant number of important forage grasses [6]. Due groupings in the tribe. The proposed classification is to its renownedly complicated evolutionary history and discussed in the light of previous classifications, even its economic importance there has been an increasing though none of them were phylogenetic in the sense of interest in producing molecular phylogenies for the Hennig. Reference [15] have introduced a cladistic ana- Triticeae. Attempts to unravel the relationships in the lysis, primarily based on morphological data from 40 Copyright © 2011 SciRes. AJPS 2 Numerical Taxonomic Study of Some Tribes of Gramineae from Egypt taxa representing the 24 genera of the Triticeae. They program. A principal component analysis (PCA) was used Bremer support as a measure of branch support. The also performed according to [19]. trees based on morphology and on molecular data are largely incongruent. Also; [16] and [17]; in their study 3. Results showed the relationships of graminid/restiid of poales in Figure 1 shows the UPGMA cladistic tree comprising all a cladistic tree. This report aims to apply numerical tax- OTUs in the present study. The tree separated into two onomy; UPGMA and Cluster Analysis; to reveal better major clads at 100 dissimilarity distance. The first major the relationships between genera within a tribe and tribes clad at 53 dissimilarity distance, comprised only two within the family based on the data collected from the species of the total number; Panicum turgidum and previous investigations for caryopses morphology and Arundo donax; while the second major clad at 93 dis- anatomy and pollen grains morphology. similarity comprised the rest 32 species. 2. Materials and Methods The second major clad separated into two branches, the first branch includes five subclads: 1) A subclad at 86 2.1. Plant Material dissimilarity distance with five species; Lamarckia aurea, Oryzopsis miliacae, Polypogon monspeliensis, Eragrostis The study dealt with 34 species belonging to 25 genera cilinensis and Stipagrostis ciliata. 2) A subclad at 84 dis- of 11 tribes of Gramineae; Andropogoneae, Aristideae, similarity distance with Aegilops kotshyi. 3) A subclad at Arundineae, Aveneae, Brachypodieae, Bromeae, Er- 80 dissimilarity distance comprises six species; Aegilops agrostideae, Paniceae, Poeae, Stipeae and Triticeae. The ventricosa, Hordeum murinum ssp. leporinum, Lolium study based on herbarial specimens dried and kept in the perenne, Bromus scoparius, Brachypodium distachyum QNA Herbarium (in South Valley University, Qena, and Avena fatua. 4) A subclad at 74 dissimilarity dis- Botany Department) and some species received on loan tance includes nine species; Stipa capensis, Dactylis from CAI Herbarium for the palynological study (Table glomerata, Stipa lagascae, Bromus rubens, Echinocoloa 1). In the following analysis, species and genera consti- colona, Coelachryum bervifolium, Schismus arabicus, tuted the OTUs (Operational Taxonomic Units). In order Stipa parviflora and Aristida funiculata and 5) A subclad to broadly sample variation, the OUTs consist of a num- at 54 dissimilarity distance with nine species, Poa annua, ber of collections from different localities in Egypt, illus- Polypogon maritimus, Eragrostis minor, Phalaris minor, trated in Table 2. Avena barbata, Aristida mutabilis, Cenchrus ciliaris, 2.2. Characters Observations Leptochloa fusca and Aristida adscensionis. The second branch of the second major clad comprises two species; Table 3 shows the characters and character states scored Dactylochtenium aegyptium and Sorghum variegatum; at for fruit anatomy, fruit morphology and pollen morphol- 66 dissimilarity distance. ogy, averaged for each OUT. A total of 37 characters Factor analysis using Principal Component Analysis were measured, comprising 22 qualitative and 15 quanti- (PCA) showed that the most intrinsic characters en- tative characters. For recording the total characters; a hanced separation of the total OTUs are fruit shape, color main using of different microscopic techniques; light, type and fruit surface sculpture of the morphological scanning electron and stereomicroscope were used for characters, of the fruit anatomical characters; section investigating different samples and recording data col- outline shape, hull cells type, aleurone cells shape and lected. Table 4 shows the data matrix used for analysis orientation, scutellum shape and thickness and en- of taxa studied. For some of the OTUs, some characters’ dosperm thickness are intrinsic characters for separation. observations were lacked and these omissions were Meanwhile, all the pollen characters are good data for coded as missing data (−0.999). separating of taxa; pollen class, shape, size, surface 2.3. Data Analysis sculpture, annulus thickness, pore diameter, pollen wall thickness, sexine and nexine thickness. The characters of Two types of analysis were performed with STATIS- separation are of high factor loadings ≥ (± 0.7) Table 5. TICA version 5.0 computer software. Firstly, the total These represented by a percentage of the total variation data coded were analyzed by the Unpired Group Method as 24.01% from the three factors extracted as; factor 1 is of Average (UPGMA) clustering. Construction of the responsible for 16.54% of the variation, factor 2 is re- tree illustrating the relationships between the studied sponsible for 4.34% of the variation and factor 3 is re- species was performed using Arthimetic Average (UP- sponsible for the minimum value of the total variation; is GMA) proposed by [18]. Secondly, factor analysis and 3.13%. The plot of 34 OTUs on the first two factors ex- factor loadings were applied to determine the major and tracted in the PCA method is shown in (Figure 2). Plot specific characters that aid in separation using the same of factor 1/2 shows two groups. 1) Group of 6. Arundo Copyright © 2011 SciRes. AJPS Numerical Taxonomic Study of Some Tribes of Gramineae from