Identification of Interchanged Chromosomes in Isogenic Reciprocal Translocation Lines Originated from Rice Variety Taichung 65

Of 29 isogenic reciprocal translocation lines of Taichung 65 introduced from Dr. Oka of National Institute of Genetics in Japan (RT 61～RT 89), 23 lines were used in this study. The remains were excluded from the study, because they were unsuitable for cytological observation. Interchanged chromosomes were mainly analyzed by observing chromosome configurations at meiosis in F_1 of crosses between these lines and reciprocal translocation testers, intercrosses of these lines and crosses of these lines with trisomics. In this study, the numerical numbers of chromosomes were accorded with Nishimura\u27s (1961). From the results shown in Tables 4, 5, 6 and 7, interchanged chromosomes in all lines were identified (Table 9). As seen in the table, some lines had the same interchanged points. The interchanged point of RT 61 was presumed to be different from RT 65, because the seed fertility and the chromosome configurations at diakinesis in the translocation heterozygote of RT 61 were different from those of RT 65 (Table 8).国立遺伝学研究所岡彦一博士から分譲された,水稲品種台中65号に由来し,均一な遺伝的背景をもつ29の相互転座系統(RT61～RT89)の転座染色体の同定を行なつた.1.RT61～RT89の中には,相互転座ヘテロの減数第1分裂移動期で明確な4連染色体を観察できないものが6系統存在した.これは細胞学的手法による転座染色体の同定には不適であると考え,以下除外した,2.主として,既に転座染色体の明白な西村(1961),岩田(1970)の相互転座系統との交配,RT61～RT89の系統間の交配,さらには三染色体植物との交配を行ない,F1個体の減数第1分裂の染色体行動の観察を行なつた(Tables4,5,6)。3.供試した23系統すべてについて,転座染色体を同定できた.その結果をTable9に示した,なお,染色体番号は酉村(1961)によつた