Germplasm evaluation in genus Carex of family Cyperaceae

To prepare a database of germplasm diversity in the Indian sedges, cytological studies were initiated on population basis from Punjab plains and adjoining areas. About 2000 taxonomical species have been recorded for major genus Carex but the cytological picture is quite dismal at the world level with chromosome records for only 579 species and 14 out of about 148 Indian species. The chromosome number varies from 2n=12 to 2n=114 on worldwide basis. Polyploids, intraspecific and aneuploid cytotypes are very common. Data suggest the existence of x=6, 7, 8, 9, 10, 11, 13, 17 and 19. Chromosome numbers 2n=60 is most frequent which support x=6 as the primary base numbers for Carex. The genus is dominated by polyploids with 98.96% of the taxa being polyploid ranging from 4x-12x ploid level. The chromosome size of the genus is small which support the breakage of diffuse centric chromosomes to account for existence of high %age of chromosome number variations which are perpetuated through vegetative multiplication prevalent in the family.