Effects of seed pre-soaking with aqueous extract of coconut shell biochar on biochemical profile of chiltepín pepper (Capsicum annuum L. var. glabriusculum) under different light environments

Chiltepín pepper (Capsicum annuum L. var.glabriusculum (Dunal) Heiser & Pickersgill) is a genetic resource with high economic potential; however, it shows high agronomic variability in response to the developmental environment.The aim of the present study was to investigate the effects of pre-soaking wild chiltepín seeds in a coconut shell biochar aqueous extract (BC) on the phytochemical profile (leaf and fruit) and yield of chiltepín peppers under different light environments.The BC treatments studied were 0.00%, 0.05%, 0.25%, and 0.75% (BC0, BC05, BC25, and BC75, respectively) and the light environments studied were low (LLE, 180 ± 26 µmol m - 2 s -1 ), medium (MLE, 437 ± 37 µmol m -2 s -1 ), and high (HLE, 959 ± 49 µmol m -2 s -1 ).In leaf tissue, BC25•LLE increased the total chlorophyll content by 7% and flavonoids by 13%.Vitamin C was higher in BC0•HLE (3.23 mg g -1 DW), while total phenols increased by 5.4% in BC25•HLE.RuBisCO presented the highest activity in BC05•MLE (126% higher than the control), whereas BC75•LLE increased phosphoenolpyruvate carboxylase (PEPC) activity by 92.9%.Fruit quality parameters such as phenols and flavonoids increased by 31.5% and 10.7% in BC25•HLE and BC05•LLE, respectively (p < 0.05).The BC05•MLE increased fruit production and yield by 118 % (p < 0.05) and 106%, respectively.Seeds pre-treated with 0.05% of BC and grown in an environment of 437 ± 37 µmol m - 2 s -1 could be a reliable strategy to improve phytochemical profile and yield of chiltepin pepper.