Abstract
Continued from the previous report(Mizushima and kondo, 1959) results of test crosses between F3 (Surjamkhi (CBSp)×Norin No. 1 (CBSpa)) and Japanese tester varieties were reported. 24 colorless offsprings, which were originated form the colorless F2 segregants unexpectedly obtained between colored parents and considered presumably to lack either C or Sp grene locus, were crossed to 3 tester varieties of known genotype in respect to apiculus color (CBrSp, CBSp+ and CBp Sp+) and the mode of segregation in 16 of their F2 strains was investigated (Table 1). C and Sp are the fundamental genes responsible for the production of anthocyanin, the former producing chromogen and the latter turning it into anthocyanin. Theoretical segregation ratios were calculated on the assumption that the position of C-locus of the parental varicties was different either by criptic translocation or by included inversion (recombination value 56%) and that of Sp-locus by included inversion (recom. va., 93%) based on the results already reported (Tables 2, 3 and 4). Comparison of the actual segregntion ratios with the theoretical ones was made (Tables 5 and 6). From the results of the test of goodness of fit of single segregation ratio (Table 5) as well as of their summed one (Table 6), it was confirmed that the parental F3 plants of the 3 F2 strains (F2-4, -5 and -7) contained exclusively the C-locus of Norin N0.1 origin (Cj) that of strain (F2-6) only the C-locus of Surjamkhi origin (Ci) and those of the 3 strains (F2-1.-2 and -19) both Cj and Ci, e., duplicated C-loci. From these facts it has been concluded that, as far as the C-locus is concerned. there is structural difference of chromosomew between the Japanese and Indian vareties used. However, the mnechanism which caused the different structural differentiation cannot be determined exactly, because the theoretical segregation ratios calculated on both bases of criptic translocation and included inversion are nearly equal and the actual ratios observed fitted them almost equally.