Allelism test of high-pigment phenotypes by the 'Yellow film method.'

Mochizuki. T. and S. Kamimura

Four kinds of high-chlorophyll phenotypes have been described: hp (Reynard, 1956),dg (Sanders et al., 1975) and hp\1, hp\2 (Palmieri et al., 1978). Sayama (1979) studied the allelism of these four phenotypes using isogenic hp stocks of 'Rutgers,' the dark green (dg) mutant of 'Manapal' and high-pigment mutants of 'San Marzano.' He concluded that all the four high chlorophyll phenotypes were allelic because all the F1 hybrids showed anthocyan pigmentation in the radicle which is typical of these high chlorophyll mutants. Jarrett (1982) studied the allelism of hp and dg using the same materials and F2 populations of them and concluded that hp and dg were not allelic because of the segregation for the characteristic fruit phenotype in F2 populations between hp and dg.

To clarify the allelism of these four phenotypes, we studied the segregation of the high-pigment phenotype in F2 populations among these mutants by the 'yellow film method' previously describ4ed (TGC 35:12-13). 'Morioka 15,' the dark green mutant of 'Manapal' and high-pigment mutants of 'San Marzanol' were used as the hp, dg, hp\1, and hp\2, parents respectively. No segregation was observed in F2 plants and all combinations showed the high-pigment phenotype as identified by the yellow film method. Seedlings did not elongate and never lost the anthocyan pigmentation in the hypocotyl under the yellow film. These results suggest that these four high-pigment phenotypes are allelic and result from mutation at the same locus.

Table 1.  Result of allelism test by 'Yellow film method'

Lines               hp     hp+
Morioka 15 (hp)     49      0
Manapal (dg)        27      0
San Marzano (hp\1)  36      0
San Marzano (hp\2)  43      0

(F2 populations)

hp     X  dg        36      0
hp     X  hp\1      31      0
hp     X  hp\2      34      0
hp\1  x  dg         52      0
dg     X  hp\2      22      0
hp\1  x  hp\2       40      0

Florida   MH-1 (+)   0     34
F1 (hp  X    +)      0     55
F2 (hp  X    +)    181    468
F1 (+   X    hp\2)   0     25
F2 (+   X    hp\2)  49    151