Title: Linkage Studies in Rice (Oryza sativa L..) : On Some Mutants Derived from Chronic Gamma Irradiation
Abstract: Thirteen of the mutant genes induced by gamma irradiation and neous mutant genes of rice were newly described and determined as follows :two of the spontatheir linkage groups Group I; spotted leaf 4 (spl,).Group II; narrow leaf 1 (nal,), yellowish leaf margin (ylm) and round kernels 1 (rk,).Group I or III; semi-rolled leaf 2 (rZJ.Group IV; spotted leaf 5 (spl,).Group VI; neck leaf 2 (nla).Group VIII; zebra leaf 2 (zz) and tillering dwarf (d,, spontaneous).Group X; dwarf (dK_J, brittle culm 3 (bc,) and gold hull 3 (gha).Group XI; fine culm and tillering (fc), spotted leaf 3 (spl,) and virescent 1 (vi, spontaneous). RESULTS AND DISCUSSIONF, plants of all cross combinations between mutant stocks and linkage testers had normal phenotype.The F, segregation modes of all mutant characters tested, except for those of M 88 described later, fitted well the expected ratio of 3 : 1 as shown in Table 3.The linkage relations between the mutant characters and the marker genes are as follows. Linkage group IM 114: It is characterized by a kind of physiological disease showing relatively large brown spots in leaves.A gene of the character is designated as