During the period of the diploid to tetraploid conversion, a number of cultivars were produced with more than 48 chromosomes.  Although there is evidence that the 50-chromosome cultivars actually constituted a fertile family, it was not explored.  Instead, they were used with the 48-chromosome tetraploids to produce the artificial species that has evolved into today's tetraploid TBs.

This raises a significant possibility for modern lines:

If they were indeed amphidiploids, they are a "Road Not Taken".  Had they been linebred, their descendants would probably be much like today's TBs [and compatible enough to intercross] but carry traits that have been long lost. In other words, the chromosomes lost during the stabilization process might well have carried traits that are no longer prevalent [or even present at all] in the modern gene pool.  It is therefore possible that some desirable traits could be recovered by backcrossing to these early breakthrough cultivars.

Program Objective:  to determine 

Stage 1:

1. Compile a list of 50-chromosome cultivars [see HIPS list for more].

2. Find photos to identify desirable traits [see HIPS photos].

3. Collect as many such cultivars as possible.

Stage 2:

1. Intercross the 50-chromosome cultivars, to determine whether they are actually functional amphidiploids.

2. Inter-cross the 50-chromosome cultivars with modern TBs, preferably those with recessive traits, to identify desirable historical traits that are dominant.

Stage 3:

1. Linebreed the amphidiploid seedlings to explore their possibility and identify dominant/recessive relationships.

2. Use selected seedlings with modern TBs, linebreeding to retain newly introduced dominant traits that are desirable and eliminate the ones that aren't.