Effects Of ⁶⁰Co_γ-Rays Radiation On Biological Characters Of Platanus Acerifolia Willd. Seed And Seedlings

There are three categories of Plant anus acerifol ia in our country,Platanus occidentalis,Platanus orientalis Linn.and Platanus acerifolia Willd.With big crown and shadow,rapid growth speed,strong capability of resistance,heterosis and unparalleled growth characteristics,Platanus acerifolia Willd.has become common trees of street trees and landscape garden trees.However,as Platanus acerifolia Willd.in different cities grow to full productive age,a lot of pollen and fruit hair was produced every spring,which brought great harm to industrial production and people life.To solve the problem,many research scholars at home and abroad provided various solutions and hope to breed new species of Platanus acerifolia without fruit through different breeding technologies.Compared with other breeding technologies,the radiation mutation breeding is easier and more economic,and can provide a large number of mutants in a short period of time.So the research project used 60Coγ to study the effect of 60Coγ on seed germination and seedling development of Platanus acerifolia Willd.The research project used different doses of 60Coγ,to treat seeds of Platanus acerifolia Willd.,and measured the seed germination rate and seedling survival rate,as well as the plant height,root length,seedling fresh weight and leaf phenotype.Main results are as follows:(1)In the phase of germination rate statistics,using 50 to 110 Gy irradiation,the effect of different radiation on seed germination were similar,which was about 50%compared with control.(2)In the phase of seedling survival rate statistics,the seedling survival rate of different treated groups decreased with the increase of irradiation dose.The seedlings of irradiation-treated group using 100 and 110 Gy appeared obvious growth disadvantage and it is difficult to recover to normal growth.(3)In the leaf growth phase,true leaf growth of different irradiation-treated groups were disorder than control group.Within the scope of 50 to 110 Gy irradiation,leaf mutation rate showed normal distribution with the increasing of irradiation,and the peak of leaf mutation rate was in 90 Gy.The conclusions of the research were as follows:We think that same radiation dose may produce different results of seed germination rate and seedling survival rate due to different seed moisture content,preservation time and conditions.In addition,environment conditions such as soil,water,temperature may also influence seed germination rate and seedling survival rate.Therefore,in the experiment of seed germination,proper environment conditions are favorable to obtain good experimental data of different repetition.In addition,according to seedling growth and development after different irradiation doses of 60Coγ,we think that 50 to 90 Gy may be suitable to perform seed irradiation experiment of Platanus acerifolia Willd.,which make sure to obtain a certain number of mutations,as well as not affect seedling growth and development.The research was valuable for 60Coγ radiation breeding,and established foundation to produce new variety of Platanus acerifolia Willd.without flowers and fruits.