who/what is the fastest?

Ak-48(can be done as soon as 48 days)

and Top44

Both these are fast.

I would guess that autoflowering Lowrider varieties would be the fastest, from seed to finish. Not sure how much these yield though

Does anyone know of any popular strains used to reduce flowering time.
A real answer from an actual breeder would be nice.
NOT AUTO FLOWER

Are you planning on breeding yourself? I believe speed may be significant to most breeders when trying to deal with a sativa cross, which is why they use Afghani in the mix.

I found a strain called Critical+ from DINAFEM seeds (Spain) that can finish in 45 days. It's a cross between Big Bud and Skunk..

Why are you in such a rush? Most indica dominant strains come in a 7-8 weeks anyway. You can also speed things up slightly by taking your light cycle to something less than 12 hours. I've noticed plants that normally go as long as 56 days are finishing about 50 using 11:45. The only reason I did this is because my lights are on separate timers and this compensates for any differences between the timers making sure to stay under 12 hours.

Peace, Farmer Rich

For a sativa high and short flowering, has to be apollo 11.