Rick, C. M., F. M. Martin, and A. Gentile
Routine testing of Ve segregating in F2 populations with various markers gave the following consistent indication of linkage with e on chromosome 4. For the first sowings standard procedures were followed of pulling seedlings and inoculating them shortly after emergence. One of the difficulties of this method for genetic purposes is the killing of some segregants before they could be classified for certain tester genes. Since e can be classified satisfactorily in small primary leaves, scoring was nearly complete in the first sowing. Segregations for Ve in the first sowing generally conformed well to the expected 3:1. For the second sowing of the e F2, seedlings were treated after true leaves had emerged, permitting a complete classification. The second sowing was disturbed, however, by excessive verticillium killing, likely affecting many Ve/+ seedlings as well as +/+. Indications of non-random segregation are nevertheless significant for both sewings, rendering it likely that e and Ve are linked.
Tester Sowing + + + t Ve + Ve t Contingency Co.
Chi-square
a\1 1 42 9 118 29 0.01
a\1 1 29 10 119 39 0.01
c 1 27 12 109 45 < 0.01
d\1 1 21 6 115 26 0.04
e 1 28 17 130 14 17.69 32.5
e 2 77 34 96 21 4.34
Wo 1 11 41 47 83 3.19
Xa 1 20 32 48 80 < 0.01