The first reliable chromosome counts in species of the genus Plantago L. was made by McCullagh (1934). Later more detailed cytological investigations were carried out on more than half of the species in this genus. Some of these investigations were made in connection with taxonomic studies in order to elucidate the relationships in particular groups of related species (Bocher et al. 1955, Rahn 1957, Cartier 1971, 1973, Sopova and Rizova 1975, Zemskova 1977. Other studies were concerned with investigating the cytology of Plantago species in certain floras or phytogeographic regions (Gregor 1939, Runemark 1967, Briggs 1973, Favarger and Vasudevan 1972, Fernandes and Franca 1973.The cytology of the genus Plantago in Egypt has not been a subject of a study. The chro mosome number of only three species was reported by Badr (1980). The numbers of some other species which grow in Egypt are also known from chromosome counts in plants from near floras particularly that of Europe. The present study is therefore conducted to investigate the cyto logical features in species of the genus Plantago from Egypt. This investigation deals not only with chromosome numbers but also with detailed karyotype features such as chromosome length and centromere position. The impact of karyotype features in the taxonomic relationships of the studied species is also elucidated.
Materials and methodsMaterials of 12 samples belonging to 10 different species of Plantago were collected from their natural habitats. The studied species and the localities from which they were collected are given in Table 1. The distribution of localities in the country is illustrated in the map (Fig. 1).Cytological preparations were carried out on root tips obtained from seeds germinated on moist filter paper in petri dishes. Root tips were pretreated with 0.05% colchicine solution for 4 hours and fixed in 3:1 (V/V) ethanol: glacial acetic acid. Squash preparations were made using the Feulgen squash technique and were made permanent by mounting in canada balsam. Cells with good spreading of chromosomes were photographed and prints were enlarged to a magnification of 3000 times. Comparisons of chromosomes of the species studied were made by constructing a karyotype for each species by arranging the chromosomes in homologous pairs in order of their length and arm ratio as measured from the photographic prints. The variation in the chromosome length and arm ratio within the karyotype has been expressed by calculating the standard error (SE) of these parameters.
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