11. The order of br f an. - There were published in the Linkage Summary 1935 (p. 35), three-point tests involving 960 individuals which indicated that the order is as given above. Bryan, in the 1938 News Letter (p. 5), reported four-point tests with 293 individuals involving br, f, Kn, and bm2 which indicated that f is to the left of br. An attempt was made last summer to check this situation. A total of 1352 individuals were noted, but only 34 per cent of them were recorded as f. Moreover both orders of the genes indicated double crossovers as more numerous than singles in one region and equal to singles in the other region. It is obvious that many f plants were recorded as normal. This is not unlikely in cultures such as these in which f was poorly expressed. It seems likely that plants recorded as f were certainly of that nature. The following data, therefore, include only the f plants.
|F1 genotype||0||1||2||1, 2||Total|
|+ + +||347||22||77||7||453|
|br f an||4.8%||17.0%||1.6%|