菊花X光線誘變育種之研究（一）X光線對菊花種子之發芽及生長之影響

The X-Ray Treatments to Induce Somatic Mutation in Chrysanthemvm Plants-The Effects of X-Ray Treatments on Germination and Growth of Chrysanthemvm Seeds

本實驗使用日本小菊種子，分乾燥和浸水2區，各照射2.5、5、10、20、40、80、160KR等不同線量之X光線，觀察其發芽率和發芽後之生長情形。處理後之種子播種後，低線量區都能在1~2星期內發芽，高線量區則有一部份種子在35天後尚在發芽。發芽率在高線量之160KR區，乾燥種子尚有63.3%。而浸水區則降到33.3%。發芽後能發生本葉而繼續生長的生存限界線量，在乾燥種子為20KR，浸水種子為10KR。本文並討論乾燥種子和浸水種子感受性差異之原因。

Experiments have been conducted study the effects of X-ray irradiation on occurence of mutation in chrysanthemum seedlings. Dry and soaked seeds (variety Japanese small flower) were irradiated at doses of 2.5~160KR. The irradiated seeds germinated within one to two weeks at the lower dosages, while few seeds germinated even after 35 days at higher dosages. At the highest dosage of 160KR, germination percentage was 63.3% in dry seeds, and 33.3% in soaked seeds. However, the percentage was slightly higher when the treated seeds were sown in pots. The critical dosage was comparatively low that is, 20KR in dry seeds and 10KR in soaked seeds.