벼 葯培養에 관한 硏究 Ⅶ. colchicine 處理에 의한 半數體의 染色體倍加

Studies on anther culture of oryza sativa L. Ⅶ. Diploidization of haploid plants by colchicine treatment

To improve the diploidization efficiency of haploid plants derived from rice anther culture, rice plants which were regenerated from the anther culture of Hwacheongbyeo and F₁s of 35 crosses were used for the materials. Haploid plants, obtained from the ratoon culture, were used for investigating optimum colchicine concentration, continuance of colchicine activity, proper plant stage of treatment and adequate treatment duration. In other way, haploid plantlets which were discriminated from spontaneous diploid by the macroscopic appearance of plantlet vigorousity were treated with 0.1% colchicine just after the hardening of regenerated plantlets(3-to 5-leaf stage). The results were summerized as follows ; Frequency of the haploid of plants regenerated from anther culture was 67% and the frequency of spontaneous diploidization from the ratoon culture of haploids was very low(0.6%). Plant survival rate was decreased in higher concentration and longer time by colchicine toxicity whereas the frequency of diploidization was increased. The activity of colchicine solution(0.1%) on diploidization was the highest till 6 hours after colchicine treatment. When haploid plants were treated at 3-to 5-leaf stage for 24 firs. at 30℃ with a solution of 0.1% colchicine, the fequency of diploidization with doubled sector was the most effective as 79%. The probability of ploidy prediction of plantlets, divided by plantlet vigor at 3-to 5-leaf stage, was about 80% and diploidization rate was 86.5% which was higher than ratoon culture. Accordingly, this method largely abridged the effort of conchicine treatment.