The Studies Of Chromosome And Phenotype Analysis Between Tobacco And Basilicum

In this paper .based our studies ,it is to breed novel tobacco germplam with medical value by distang hybridization between tobacco and perrila xoinmum bailicm.L..To enrich the tobacco germplasm .we developed an optional strategy for tobacco distant hybridization and the new hybrid lines of tobacco with medical value .which were approved by a series of analysis such as offspring variants and their genetic ,chloroplast content.The optimal technology for distant hybridization included using the grafted tobacco plants as female.repeated pollination by pollen from medical plants and establishing an environmental condition with lower temperature and higher moisture for crossing .Combined using of these technique could effectively overcome hybridization incompatibility.The date of esterase isoenzyme indicated that these hybid have intergrated some loci derived from the genomes and have a new characteristic of gene expression .Chromosome analysis revealed that the euploid and aneuploid exit the same cellin these genetically hybrid bred by distant hybridization between tobacco and medical plants.(1) In meiosis ,the chromosome shape and the chromosome number have a big extending.(2) In mitosis ,. the chromosome shape and karyotype pattern of F2 hybrid have more chromatids ,more chromatid breaks ,at the same time ,there are less and less chromosome associations.The hybrid generated a lot of different variants, which exhibited a higher similarity with tobacco plants in the main agronomic traits while they also showed the characteristics of medical plants in the traits such as leaf color and shape .The date of chloroplast content analysis and photosynthesis analysis displayed that different hybrid lines have different improvement in chloroplast content .accompanied with photosynthesis.