| 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. |
