2. Linkage data involving an and Ts3 or Ts6 - Striking differences between complementary crossover classes were reported by Emerson 1941 News Letter (p. 13-15). Those records may not have been wholly accurate for the following reason. Some of the Ts plants failed to develop ears since the tassels were not removed at the time of emergence. Classification of an from the tassel when combined with Ts is difficult. Therefore, similar progenies were repeated this summer and the classification of an based on the ear.
|+ Ts3/an +||+ Ts3||++||an Ts3||an +|
|1941, tassels removed||174||109||5||288|
|1940, tassels not removed||183||80||8||238|
|+ Ts6/an +||+ Ts6||++||an Ts6||an +|
|1941, tassels removed||75||36||17||67|
|1940, tassels not removed||213||159||50||151|
The results of both plantings are essentially alike. One may conclude that the unequal nature of the complementary crossover classes is not primarily due to inaccuracies of classification but rather to some other cause.
Using the totals of both seasons, the following ratios occur:
|370||Ts3||:||715 +||D/PE||=||.9 for 1:2 ratio|
|546||+||:||539 an||D/PE||=||.4 for 1:1 ratio|
|355||Ts6||:||413 +||D/PE||=||3.1 for 1:1 ratio|
|483||+||:||285 an||D/PE||=||3.3 for 2:1 ratio|
In the Ts3 data, Ts3 is deficient while an is normal; whereas, in the Ts6 data, Ts6 is only slightly deficient and an greatly so. If these effects are due to an interaction between an and either Ts3 or Ts6 as Emerson 1941 News Letter (p. 15) suggests, the interaction is presumably different for the two tassel-seed genes.
M. J. Murray