相互転座法

The authors have been engaged in the linkage analysis of rice plants, Oryza sativa L., by the conventional genetic method and reciprocal translocation method. Through the coordination of these two approach, ten linkage groups have been assigned to the relevant chromosomes (Table 1). In the previous paper, linkage groups corresponding to the chromosomes 1, 2, 3 and 4 were described. In this paper, the correspondence of the chromosomes 5, 6, 8, 9, 10 and 11 to the linkage groups was presented. Twenty nine kinds o f reciprocal translocation homozygote (Table 2) and twenty one marker genes (Table 3) were used in this study. The following seven genes, described newly by the authors, were contained among these genes (Tables 4-10). dl: A gene for drooping leaf. Midrib of leaf blade and sheath are poorly developed, so cross sections of the basal part of seedling show round shape (Fig. 1). ch: A gene for chlorina. sp: A gene for short panicle. Primary rachis in the lower part of panicles degenerated (Fig. 3). tri: A gene for triangular hull. Tip of lemma recurved over palea (Fig. 2). d_w : A gene for "Waisei-shirasasa" type dwarf (Fig. 4). Twisted leaf and easy threshing. gh_2: A gene for gold hull. Hull and internode take yellowish orange colour by this gene, while only hull is coloured by gh. d_11: A gene for "Shinkane-aikoku" type dwarf. Small and round grain, lax panicle (Fig. 5). The reciprocal translocation homozygotes were crossed with the linkage testers, and F_2 segregations for marker genes and for fertility were examined. The results were shown in Table 11. The recombination values between marker genes and interchanged points were estimated by the maximum likelihood method and the data were shown in Tables 13, 16, 21, 23 and 25. Results of linkage analysis by the conventional genetic method were shown in Tables 12, 14, 15, 17-20, 22 and 24. In these cases, recombination values between marker genes were also estimated by the maximum likelihood method. The conclusions obtained are as follows: 1) The eleventh linkage group, to which bc, dl and ch belong, is corresponded to chromosome 5, and the order of arrangement of these genes and the interchanged points is RT4-5-bc-(RT4-5)-RT2-5-RT3-5-(RT2-5)-dl-RT5-9-ch (Fig. 6). 2) The first linkage group, to which wx, dp_1 , C, ws and Cl belong, is corresponded to chromosome 6, and the order of arrangement is wx-dp_1-RT6-11-C-ws-Cl-RT6-8-RT6-7-(RT6-8) (Fig. 8). 3) The tenth linkage group, which consist of tri, bl_1, d_w and gh_2, is corresponded to chromosome 8, and arrangements of tri-RT7-8a-RT3-8b-bl_1-(RT3-8b)-RT1-8-RT8-10a-d_w-RT7-8b-gh_2 and tri-RT8-10b-bl_1-RT6-8-RT8-10a-d_w-RT3-8a-gh_2-(RT3-8a) are considered (Fig. 9). 4) The eighth linkage group, of which members are la and sp, is corresponded to chromosome 9, and these genes and the interchanged points are arranged in an order of RT9-10-la-RT7-9-RT5-9-sp-(RT5-9) (Fig. 7). 5) The fourth linkage group, of which members are d_6, g and Rc, is corresponded to chromosome 10, and they are arranged in a order of RT6-10-d_6-g-RT8-10a-Rc-RT_1-10-RT8-10b (Fig. 10). 6) The second linkage group, which contains d2, PI, I_g, Ph, Pr and d_11, is corresponded to chromosome 11, and they are arranged in a order of d_2-RT3-11b-Pl-RT10-11_a-lg-RT6-11-Ph (RT6-11)-(RT3-11a)-Pr-RT3-11a-d_II-RT1-11 (Fig. 11).