محمد مدرسی

Milk thistle (Silybum marianum L.) is an annual or biannual herbaceous species belong to Asteraceae family which is highly effective in treatment of cardiovascular diseases, liver diseases, gallbladder diseases, diabetes and hyper lipidemia. These compounds are made and stored in its fruits (seeds) and will appear as a yellow substance Environmental stresses such as heat stress, drought and salinity cause changes in quantitative and qualitative performance of medicinal plants as well as their medicinal properties. One of the possible ways to maintain the grain yield and even increase in the active components of medicinal plants under stress condition is applying the plant regulators.The most popular plant regulators are jasmonic acid and salicylic acid. Therefore, the present study aims to assess the impact of these two hormones on the quantitative properties of natural herb milk thistle under natural heat stress of Bushehr province. The experiment carried out as a factorial in a completely randomized block design with three replications. Factors included hormone salicylic acid in five levels (0, 10, 25, 50 and 100 milligrams per liter) and Jasmonic acid at three levels (0, 1 and 2 milligrams per liter). Evaluated traits encompassed plant height, flower diameter, number of lateral branches, number of seeds per flower, grain weight, seed yield, oil content and the efficiency of total extract. The results suggested that the effect of environmental conditions on all studied treatments is remarkable. The interaction between environmental conditions in jasmonic acid and salicylic acid as well as the triple interaction between environmental conditions in both hormones for number of seeds per flower, grain weight, seed yield, oil content and the efficiency of total extract.