الفهرس | Only 14 pages are availabe for public view |
Abstract The morphological characters of the whole plant, lamina epidermal characters (LM & SEM), lamina vein architecture as well as molecular data (ISSR) of 19 wild and cultivated taxa of the Polygonaceae were investigated. These taxa represent nine genera viz. Antigonon, Coccoloba, Emex, Muehlenbeckia, Persicaria, Polygonum, Rumex, Ruprechtia and Triplaris were collected from different phytogeographical Egyptian regions and botanical gardens. Plumbago auriculata Lam was designed as an outgroup for phylogenetic analysis. The cumulative tables and colored plates are designed to illustrate the similarities and dissimilarities to provide a full identification of the studied taxa of Polygonaceae. Ten primers were selected amplify ISSR based on polymerase chain reaction. The ten primers were successfully generated reproducible polymorphic products. The primers are ISSR 1, ISSR 2, ISSR 4, ISSR 5, ISSR 6, ISSR 7, ISSR 8, ISSR 9, ISSR 15 and ISSR 18. The fingerprints generated by these primers revealed characteristic profiles for each taxon. The data obtained from the morphological and molecular attributes (289) of the investigated taxa were subjected to the numerical analysis to produce the dendrogram and comparing it with the current systems of taxonomic classification. The results illustrated that the taxa investigated were split into four subgroups(SG 1, SG 2, SG 3 & SG 4), five groups (Ga, Gb, Gc, Gd & Ge) two clusters (C1 & C2) and two main series (SI & SII). The clustering of Antigonon, Coccoloba and Muehlenbeckia in the present study support their traditional placement in tribe Coccolobeae (Bentham & Hooker, 1880; Dammer, 1893; Gross, 1913; Haraldson, 1978 and Brandbyge, 1993). On the other hand, Meissner (1856), Perdrigeat (1900) and Roberty & Vautier (1964) and APG (2009 & 2016) distribute them into more than tribes and subfamilies. The segregation of Muehlenbeckia platyclada (previously known as Homalocladium platycladum) as a distinct identity in the present study support previous authors who included Homalocladium platycladum in Muehlenbeckia (Meisner 1865; Bailey, 1929; Brandbyge, 1993; Sanchez et al., 2009 and Schuster, 2011). The placement of Ruprechtia species with Triplaris confirms that they were previously placed in the same tribe Triplarideae or subtribe Triplareae (Meissner, 1856; Bentham & Hooker, 1880; Dammer, 1893; Gross, 1913; Roberty & Vautier, 1964; Haraldson, 1978 and Brandbyge, 1993) and in the same subfamily Eriogonoideae (APG, 2009 & 2016). Emex, Rumex and Polygonum are clustered together in accord with Roberty & Vautier (1964), Haraldson (1978), Brandbyge (1993) and APG (2009 & 2016) where they were included in the same subfamily Polygonoideae while the most current taxonomic systems distribute them in different subfamilies, tribes and subtribes. Persicaria segregated as a distinct genus away from Polygonum in agreement with the morphological and anatomical studies carried out by Gross (1913), Clapham et al. (1962), Roberty & Vautier (1964), Coode & Cullen (1965), Graham & Wood (1965), Haraldson (1978), Brandbyge (1993) and Kim & Donoghue (2008 a). The morphological and molecular character states (193) were subjected to the phylogenetic analysis using WinClada-NONA 1.6 software to produce the cladogram and comparing it with the current systems of taxonomic classification. The results indicate that Polygonaceae has five major lineages viz. Muehlenbeckia lineage (M. platyclada, Emex spinosa and Rumex pictus), Ruprechtia lineage (R. salicifolia, Triplaris cumingiana, R. apetala and R. laxiflora), Coccoloba lineage (C. peltata, C. uvifera, Antigonon leptopus and Muehlenbeckia complexa), Rumex lineage (R. vesicarius, Polygonum patulum and Rumex dentatus subsp. dentatus) and Polygonum lineage (P.equisetiforme, Persicaria senegalensis, P. lapathifolia, P. decipiens and P. lanigera). It is concluded that there is a support for monophyly of some lineages viz. Emex spinosa belongs to tribe Rumiceae which is strongly supported as monophyletic by Sanchez (2011), Triplaris cumingiana, Antigonon leptopus, Coccoloba and Persicaria and a sister-group relationship between some others (Emex spinosa & Rumex pictus), (Ruprechtia salicifolia & Triplaris cumingiana), (Ruprechtia apetala & R. laxiflora), (Coccoloba peltata & Coccoloba uvifera), (Antigonon leptopus & Muehlenbeckia complexa), (Rumex dentatus sub dentatus & Polygonum patulum) and (Persicaria lanigera & P. decipiens). On the other hand it is revealed that the genera Rumex, Muehlenbeckia, Ruprechtia and Polygonum is not monophyletic group. |