Cytogenetical study in Some Genotypes of Lolium perenne

Genetic resources are the raw materials for plant breeding programs. Grasses are among monocotyledons with more than 50 tribes، 650 genus and 1000 species. Lolium is an important genus of grasses. Cytogenetic studies were performed on 4 genotype of Lolium perenne. Genotypes were studied to determine and compare their karyotype characteristics. In laboratory، seed germination، pretreatment، fixation، hydrolysis and staining stages were done. The basic chromosome number was x=7 for all of the genotypes and their ploidy levels were diploed (2n=2x=4). Chromosome characters such as: total length of chromosomes، long and short arms lengths and arm ratio were determined. The parameters such as A1، A2، DRL and %TF were measured for karyotype asymmetry and genotype evolutionary situations. One pair satellite was observed on the karyotype of Friden and Yarand genotypes. A haploid set of chromosomes from each genotype was used for analyzing the data. Among studied genotypes، the highest and lowest total form percentage (%TF) belonged respectively to the Semirom genotype (42/88) and Yarand genotype (36/10). All of the genotypes were classified based on karyotype symmetric parameters A1 and A2. The results of this diagram were consistent with the results of cluster analysis. This study was performed in the cytogenetic laboratory of faculty of agriculture Zanjan University in winter 1388.