激光、r—射线、中子对向日葵不同品种辐射效应的初步研究

本试验利用激光,r—射线,中子三种辐射类型,照射向日葵种子,从出苗日期,出苗率以及植物学性状的改变,了解这三种物理因素,对向日葵的辐射效应及诱发有益突变的适宜辐射剂量。三种辐射类型照射向日葵播前种子,均表现随剂量的增高,出苗延迟,出苗率降低。辐射对于生长的抑制作用,常随生育期的推移而逐渐消失。不同的品种对辐射的敏感性是有明显差异的,农家品种比墨葵抗辐射。当辐射剂量较高时(如r—射线四万伦,中子5×10~11～1×10~12)常出现顶端生长点破坏,多头,叶片的卷曲撕裂状,这均属于辐射引起的生理及结构的损伤,并不遗传。从各种辐射类型对不同品种,及同一辐射类型不同剂量的辐射效应看,植株生长基本正常的剂量,往往会出现一些性状优良的单株: 钕玻璃激光5次,氮分子激光5分、10分、 r—射线2万伦, 中子5×10~10～1×10~11,可作为向日葵的适宜诱变剂量,从中选出的A_2—38—6突变系,其特点为,早熟,产量超过对照29.7％。

A Preliminary Study on the Effects of the Radiations of Laser,r-Ray,and Neutron on Sunflower

Three kinds of radiations, laser, r-ray and neutron, were used in treating sunflower seeds. In order to know the effects of different radiations on sunflower and to find out the proper radiation dosage which may bring out desirable mutation, the date and.the rate of emergence of sunflower and also the botanical variations were studied. Results from our research showed that the date of emergence would be delayed and the rate of emergence decreased as the radiation dosage increased.At the same time inhibitory action to the crops by the radiation would gradually disappear as the crops grew up.It was noticed that different varieties of suuflower showed different sensitivities to the radiation, common varieties showed stronger action against radiation than Maxican varictes.It was also noticed that when exposed under strong radiation,(r-ray 40000R, neutron 5×10~11—1×10~12)the growing points of the crops would tend to branch out more flowers, the leaves were likely to be rolled up or cut into strips. These are caused by radiations.They are not hereditory. Through an extensive research on the effects of different kinds of radiations on the crops, the researchers noticed the existence of a proper radiation dosage under which the crops are likely to produce a number of desirable seedlings, the proper radiation dosages of different kind sol cadiations for sunflower are as follows: Neodymium laser,five times Nitrogen laser,five or ten minutes r-Ray,20,000 R Neutron,5×10~(10)—1×10~(11) A nem variety of sunflower selected through radiation method is a shart-stalked early-maturing variety, which can increase yield by 29.7％ as against the check varieties.