الفهرس 
The genus panicumOnly 14 pages are availabe for public view
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Abstract
The genus Panicum L is the largest grass genus belonging to the tribe Paniceae. It consists of more than 500 species distributed in both tropical and subtropical warm regions. Species of this genus show great variation in morphology and many other characters, comprising annual and perennial forms used for cereals (mostly annual species) and fodder (perennial species). In the present study 24 accessions belonging to 11 species were investigated cytologically. In addition to cytological studies, meiotic, reproductive, electrophoretic, microdensitometric and autoradiographic studies were also carried out. The chromosome numbers reported in this genus varied from one species to another, and even varied within the same species. The basic chromosome number reported in this study is 9 (8 for P.maximum only). Cytological investigations of these accessions according to the chromosome length and arm ratio found that some accessions are karyologically primitive and others are more derivative in origin. The mean chromosome length found in diploid accessions was higher than in tetraploids and hexaploids, while the mean arm ratio of diploids was found to be lower than for tetraploids and hexaploids. This indicates the primitive origin of most diploid accessions. In general, the relationship between mean chromosome length and mean arm ratio was found to be strong, and nearly separates the accessions according to their karyological origin.