Effects of proton irradiation on growth and development of Abelmoschus manihot and related RAPD analysis of genomic vaiation

In this studythe seeds of Abelmoschus manihot were irradiated with different dose of proton irradiation, then the seeds were planted, observed and analysed by RAPD Randomly Amplified Polymorphic DNA molecular marker assay method to explore the irradiation effects on their growth and development. The results showed that the vegetative growth and reproductive growth of A. manihot which were irradiated by the dose of 200 c 1 c = 4.6 108 protons/cm2), 500 c and 1 000 c was obviously different from that of control group. The plants were significantly higher and their stem diameters were greater than those of control group. The length andwidth of fruits reduced and the seed number of every fruit increased when the seed kernels fell. But thechange with the dose of 100 c was not obvious. The RAPD analysis showed that the molecular weight ofirradiation groups focused on the band between 200 bp to 2 000 bp. The genomic DNA of every irradiatio group changed to a certain degree, with electrophoretic bands increasing or missing, and staining depth changing. The Nei 's genetic distances of electrophoresis bands between experimental groups(of 100 c, 200 c, 500 c and 1 000 c) and control (based short) were 0.1126, 0.2444, 0.2081 and 0.2000, respectively. The results proved that proton irradiation could cause genomic change of A. manihot and the mutant A. manihot exhibited higher plant, thicker stem, increased seeds, longer and narrower fruit, and lighter seed kernel. The mutagenic effect was more apparent with the irradiation dose of 200-1 000 c.