It sure looks like PMMV to me. Pepper Mild Mottle Virus (aka PMMoV. See link below of additional pics and the Hot Pepper forum here for more discussions. Recommendation is to pull and dispose of the plant away from the garden as it can be spread by contact from plant to plant or hand to plant. It is a seed borne virus so the use of only disinfected or treated seeds is recommended. Dave Here is a link that might be useful: PMMCV pics

Not positive it works There is a GA (Georgia) treatment that is 1 part clorox and 9 parts water. Soak seeds for about 10 min, rinse for 5 min then plant. I would suggest growing these seeds in pots with plastic between the pots and the soil. This to prevent the disease from becoming soil borne ( would need a soil replacement at that point Finding true TSP will be tough in some states because of a phosphate reduction rule

Yeah. I'll probably be saying 'too many peppers' soon! But they'll dry nicely in the Old Smokey. The herbicide carryover article from OSU is good. My plants are growing in a sandy-clay loam amended with a little composted chicken manure, bloodmeal, and BTN cotton burr compost. Also soft rock phosphate and langbeinite for their minerals. Now I know the cotton burr sounds suspicious for herbicide contamination. But I want to trust the seller, I read what he says about it on dirtdoctor..cotton burr compost

1. Commercial peppers ( grocery produce) are hybrids with extensive disease resistance. If they are ripe ( Yellow, Orange or red) the seeds will be viable. Green peppers may or may not be mature enough. 2. Bell peppers are prone to multiple diseases, which may account for for your observations. Many garden center peppers are older varieties that have no resistance to several pepper diseases. Garden centers also tend crowd vegetable plants, beddings plants etc. in close proximity which encourages the transfer of disease. I introduced Tomato Spotted wilt virus into my garden from infected plants. Needless to say, I grow from seed now. 3.Second generation hybrids (F2) are usually grown from inbred lines and show less variation non certified Open pollinated varieties. separation will increase with subsequent generations. 4. If you can identify the disease prevalent your area, you can choose a variety with varying resistance to that disease. Bacterial Leaf Spot BLS is probably the most prevalent and has 11 known races. Pepper Mottle virus (PMV) and Pepper mild mottle virus (PMMV) is a problem in many areas. Those of us in the south have to fight Tomato Spotted Wilt Virus (TMWV) You also find varieties with resistance (N) nematodes, (Pc) Phytophthora , (PVY potato virus, (Sip) (Stip), (TEV) Tobacco Etch Virus. (TMV) ,ToMV. Antebellum X10R has the broadest disease package that I am aware of.