One more question from Part 4

The trait "thousand kernel weight" from WTO can be mapped with the trait "Grain weight" with several variables but not with all of them. That mappings are presented in rows 46-47 in Part 4 from the alignment file (https://docs.google.com/spreadsheets/d/1A0EhYcMaMRM8u_isB6NFLUE6Moq4Y8ZpfHChVujPmRI/edit#gid=1495541997). How to distiguish them and to find the right variable? Regards