Study On The Biological Effect Of Heavy Ion Irradiation On Cucumber

The improvement of cucumber varieties has always been an important research content in the breeding work,but its narrow genetic background has hindered the research progress of the breeding work to a certain extent.Heavy ion mutagenesis technology has made remarkable achievements in broadening genetic background of germplasm,obtaining beneficial mutants and cultivating new varieties.Applying it to cucumber breeding research can effectively solve the problems in breeding.In addition,the low light and low temperature stress in northern winter and spring protected agriculture seriously affected the growth and development of cucumber and became an important factor restricting the production of cucumber.Therefore,it is also an important research direction to study the influence of external environment on the photosynthetic characteristics of plants.In this study,the inbred cucumber seed 18C-1 was used as the experimental material.Using¹²C⁶⁺as mutagenic source and 60 Gy,80 Gy,100 Gy and 120 Gy as radiation dose,the biological effects of radiation on cucumber were analyzed from seed vigor,seedling rate,macro biological characteristics,physiological level and gene level.In addition,cucumber seedlings growing under low light and low temperature stress（without radiation）were placed in the light environment of white light 10 000 lx,red light 8 000 lx and blue light 5000 lx,respectively,to analyze the influence of external factors（radiation;light）on the photosynthetic characteristics of seedlings.The results are as follows:（1）Among them,60 Gy was the best dose and positive mutant was screened out,which enriched the germplasm resources of Cucumber.（2）The effect of radiation on Photosynthetic Characteristics of cucumber was significant,among which 80 Gy increased the photosynthetic stress resistance of seedlings compared with other doses,and preliminarily clarified the response of photosynthetic characteristics of seedlings to different doses of¹²C⁶⁺radiation.（3）Light had a significant effect on the photosynthetic characteristics of cucumber,among which the induction advantage of red light 8 000 lx was higher than that of blue light 5 000 lx,and preliminarily clarified the response of photosynthetic characteristics of seedlings to different combinations of light quality and intensityBased on the above experimental results,combined with the current problems of cucumber germplasm resources narrow and the constraints of cucumber production in facility agriculture,the expected experimental objectives were achieved,and the following innovative work was achieved:（1）The method of combining field statistic data with biological experiment was improved,and the optimum dose of¹²C⁶⁺irradiation was determined.（2）New cucumber germplasm resources were screened out.（3）The effects of external factors(Different doses of ¹²C⁶⁺radiation;different light quality,light intensity combination)on Photosynthetic Characteristics of cucumber seedlings were determined.