Study On Polyploids By ⁶⁰Co-γ Ray Radiation And Colchicine Induction In Melilotoides Ruthenicus(L.) Sojak Cv. Zhilixing

Polyploids of different organs and tissues of Melilotoides ruthenicus(L.) Sojak cv. Zhilixing were induced by 60Co-γray radiation and Colchicine, in order to choose the optimal qualification on chromosome doubling.(1) Seeds of Melilotoides ruthenicus(L.) Sojak cv.Zhilixing were radiated by five dosages(600Gy,800Gy,1000Gy,1200Gy,1400Gy) of 60Co-γray. The results showed: The seeds germination rate was lower than CK in initial germination, but it was more than 95% in 48h germination. With the increasing of dosages, the time of metaphase in mitosis was postponed continuously. At the same time, the chromosome by 1200Gy had obvious variation.(2) The effects of polyploidy induction of Melilotoides ruthenicus(L.) Sojak cv. Zhilixing were studied on concentrations of Colchicines and DMSO, and parts, duration and temperature of treatments by orthogonal design. The results showed: The optimal quailfication of chromosome doubling was treating the seeds with 2~3mm root and temper- ature of 10℃for 5h by 1% DMSO and 0.1% Colchicine. The significant factor was the concentration of DMSO for chromosome doubling.(3) In orthogonal design, callus and differentiation were explored by treating different vitro organs with Colchicine.First, Three hormones including 2,4-D,6-BA and NAA with different concentration were added to MS medium, in order to study the effects of the hormones on callus and differentiation. The results showed: The optimal medium for callus induction of Melilotoides ruthenica(L.)Sojak cv. Zhilixing was MS + 2,4-D 0.5mg/L + 6-BA 1.0mg/L + NAA 1.0mg/L and 6-BA had obvious effect on callus induction. At the same time, the optimal medium for differentiation was MS + 6-BA 1.0mg/L and 2,4-D had obvious effect on differentiation.Second, undifferentiated callus was put into MS medium with different concentration of IAA, 6-BAand KT, in order to choose the optimal medium for differentiation. The results showed: the optimal medium for differentiation was MS+ 6-BA 1.0mg/L + KT 1.5 mg/L and 6-BA had obvious effect on differentiation. At last, the effects of differentiation of Melilotoides ruthenicus(L.) Sojak cv.Zhilixing were studied on concentrations of colchicine and DMSO and parts and duration of treatments by treating different vitro organs with Colchicine. The results showed: the optimal medium was treating radicle on three days with 0.2%Colchicine and 1%DMSO and parts of treatment had obvious effect.