Effect of genotypes and foliar spray of methyl jasmonate and salicylic acid on andrographolide yield in Andrographis paniculata (Burm. f.) Wall. ex Nees. under semi-arid climate

Abstract

Abstract Background Andrographis paniculata (Burm. f.) Wall. ex Nees. is an important medicinal plant grown in tropical and sub-tropical regions where semi-arid condition restricts economically viable cultivation. Foliar exogenous application of methyl jasmonate (MeJ) and salicylic acid (SA) was tested for their effectiveness in preventing yield loss in five different morphotypes of A. paniculata subjected to deficit soil moisture stress imposed during 90–140 days after transplanting. Results Soil moisture content below 6% reduced chlorophyll and carotenoid content and upregulated antioxidant enzymes activity. The dry herbage yield was adversely affected by deficit soil moisture stress causing a 14% decline. The andrographolide concentration ranged between 1.40% and 1.54%. Though andrographolide concentration increased by 6%, andrographolide yield declined by 8.21% due to soil moisture stress. Moderately high doses of MeJ and SA reduced chlorophyll and carotenoid content and upregulated antioxidant enzymes activity, however, failed to prevent the loss in dry herbage yield or total andrographolide yield in any morphotype. Conclusions Foliar application of MeJ and SA do not warrant any protection against stress induced yield loss in field grown A. paniculata. However, morphotype AP 13 (round canopy, open-type branch, long narrow leaf) and AP 35 (columnar canopy, closed-type branch, long broad leaf) for having comparatively high herbage yield remained at a better position for total andrographolide yield under deficit soil moisture stress in the semi-arid climate.