Rick, C. M.
The stock of this mutant traces to a single fruit purchased in the public market at Tacna, Peru. The fruit was large, flat, and highly fasciated--typical of the most widely cultivated tomato of that region--and gave no clue to this inherited disorder. In two separate sowings from the seed of this fruit, the following segregations were observeds 27+ : 4 wv; 33+ : 7 wv. The mutant seedlings emerged later and remained decidedly weaker and slower than normal segregants for a long period after emergence. Cotyledons are whitish yellow with stronger pigmentation toward the base, later developing more chlorophyll. True leaves are always chlorotic in immature stages and retain a peculiar white speckling even at maturity. Once the delicate seedlings stage is passed, plants of wv grow vigorously and are highly fruitful under green house conditions. Since this mutant showed a completely different pheno type from any others that I know, it was retained for further inheritance studies,
All F1 hybrids obtained from four different crosses had normal phenotype. Segregation data obtained for 7 F2 families indicate monogenic segregation, and for the total (1841), a significant (X^2 = 7.314) deficiency of recessives (410 wv). The heterogeneity Chi-square (34.113, 6 df) is also significant. Segregation does not depart from 3:1 in five of the families; the remaining two families contribute most of the deviation--a strong deficiency of recessives. This pattern is very typical of weak recessives and suggests that germination troubles account for the observed deficiencies.
The following summary of linkage tests clearly indicates that wv is on chromosome 2.
Contingency
Tester + + + t wv + wv t Chi-square Co.
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a\1 106 42 27 10 0.0002
a\1 190 62 74 22 0.035
ah 43 16 23 5 0.451
ah 75 33 37 13 0.158
c 113 35 30 7 0.155
d\1 101 47 30 7 1.777
d\1 selected prog. 55 5 8.022
d\1 204 81 92 7 17.771 28.0
d\1 136 71 25 4 4.033 34.0
d\1 41 18 23 5 0.974
d\1 81 27 37 13 0.039
e 196 56 70 26 0.662
l selected prog. 40 20 1.800
La 20 39 10 18 0.006
r selected prog. 46 12 0.368
rv 310 26 67 4 0.134
sf 293 43 57 14 1.845
y selected prog. 47 11 0.890
yv 42 17 23 5 0.691
yv 91 17 40 10 0.188