Study on Polyploid Induction and Identification of Nervilia fordii / 广州中医药大学学报

ABSTRACT

Objective To investigate the polyploid induction and identification of Nerviliae fordii for harvesting the polyploid plants. Methods The materials and methods for polyploid induction of Nerviliae fordii were screened separately by comparing the induction rates of rhizomes and bulbs under natural conditions and tissue culture environment, and by comparing soaking method with agar method. The effects of colchicine concentration ( 200, 300, 400, 300 mg/L), colchicine action time ( 7, 14, 21, 28 d), DMSO concentration ( 0, 10, 20, 40 mL/L) and KT concentration ( 0, 1.0, 2.0, 4.0 mg/L) on induction rate were observed by orthogonal design method. The polyploid induction in the treated plants was identified by morphology, cytology and chromosome methods. Results After the tissue culture rhizomes were treated with 300 mg/L colchicine, 10 mL/L DMSO, and 2.0 mg/L KT by agar method for 28 days, the polyploid induction rate arrived to 50%, showing better induction effect. The morphology of polyploid plants was characterized by giantism, and the leaf length, leaf width and plant height were respectively 152.17%, 158.67%and 60.90%of those of the diploid plants. The length, width and density of stoma of leaf epidermal cell as well as the number of chloroplast in the treated plants were 138.46%, 153.00%, 59.09% and 109.09% of those of the untreated plants. The results of chromosome identification showed that the amount of the tetraploid ( about 40) was 2 times of the diploid chromosome ( about 20) in the treated plants, proving that the achieved Nerviliae fordii was a tetraploid plant. Conclusion Polyploid plants of Nerviliae Fordii have been successfully obtained, which will supply evidence for improving species, richening seed-breeding resources, and selecting of improved seeds of Nerviliae fordii.