Effect of Foliar Spraying with Methyl Jasmonate on Growth and Production of some Cardiac Glycosides of Digitalis purpurea L. Under Water Stress

Abstract

The experiment was conducted in one of the greenhouses affiliated to Baquba Nursery Research Station Center / Diyala Agriculture Directorate during autumn season of the year 2021-2022, to study the effect of methyl Jasmonate on the growth and production of some cardiac glycosides of Digitalis purpurea under water stress. A factorial experiment (2 × 3 × 3) was conducted according to the RCBD, with three replicates, and the results of the experiment were as follows: The results of the experiment indicated that there was a significant effect of the treatments for the irrigation periods, as the irrigation treatment every three days showed a significantly excelled in the percentage of nitrogen (2.04%), the percentage of phosphorus (0.51%) and the percentage of potassium (2.31%) The percentage of carbohydrates in the leaves was (8.02%). As for the irrigation treatment every seven days, the best results were recorded in the proline content in the leaves (0.31 mg gm-1), digitoxin content (441.81 μg g -1), and digoxin content (649.83 μg g-1) and Gitaloxin content (900.22 μg g-1) and Digitalin content (815.64 μg g-1). The results showed that there was a significantly excelled when spraying Methyl Jasmonate at a concentration of 100 mg L-1 in the percentage of nitrogen (1.88%), the percentage of phosphorus (0.43%), the percentage of potassium (2.22%) and the percentage of carbohydrates in the leaves (6.81%). Leaves proline content (0.30 μg g-1), digitoxin content (421.52 μg g-1), digoxin content (592.37 μg g-1), Gitaloxin content (885.05 μg g-1), and digitalin content (665.49 μg g-1). The results of the binary interactions between the study factors indicated a significant effect in improving most of the biochemical treatments and the production of cardiac glycosides of the digitalis plant, and the interaction treatments Ir3 × Mj100 excelled in recording the best results.