| Double recessive plants between chlorina and
striata of T. monococcum T. FUJII National Institute of Genetics, Misima, Japan All F1 plants from a cross between chlorina and striata were of normal green color and showed at meiosis the chromosome conjugation 1IV+5II while in both parents seven normal bivalents were formed. Normal, chlorina, striata and double recessive plants segregated in the F2 generation. The segregation ratio was also observed in F3 generation, but the linkage relationship was not clear because the germination rate of chlorina was low, and that of striata was still worse. In F3 striata (or chlorina-striata) plants were segregated only from the F2 plants with a tetravalent (Table 1). Moreover, F1 plants from the crosses between striata and the mutants basi-virids I or II, slender and early also showed the conjugation 1IV + 5II. From these facts, the striata gene must be located on one of the chromosomes involved in the reciprocal translocation. |