Yeah, they exist, but I think it's not exactly right. So first, you need to choose Breeder on the left side in the menu. There you can filter by g/plant, and then the different breeders will show up along with the diaries made by the growers. But like I said, it's inaccurate; if someone claims 1000g, then the breeder shows up way up high.
But you can also just take the default setting there and see the breeders by ranking. When you click on one, you'll see the different strains and what they have tolerated as maximum grams.
Just give it a try!