Effects of Seed Biopriming with Rhizospheric Bacterium Pseudomonas putida (Trevisan) on Growth Trend of Milkweed Seedling (Calotropis procera Ait)

The present study was conducted to improve root, shoots growth, and seedling quality index of milkweed (Calotropis procera) using biopriming bacteria Pseudomonas putida (Trevisan) strain 169. An experiment was performed with two levels of inoculum including control and rhizospheric bacteria and three growth periods of one, two, and three months, using a factorial experiment in a completely randomized design with five replications. Biopriming results showed that seedlings obtained from bacterial priming in one-month, two-month, and three-month periods compared to the control, increased 707.5, 1823.1 and 47.6% in root volume; 654.6, 1798.6 and 40.3% in root area; 270.6, 38.5, and 6.6% in fresh weight of stem and 58.5, 19.3 and 2.5% in seedling height, respectively. The highest value of the quality index was observed in seedlings inoculated with the bacterium in the third month. The results of Pearson correlation showed that the parameters of aerial parts such as height, collar diameter, and stem weight were significantly correlated with each other, except root length and root dry weight. Results revealed that the priming of rhizosphere bacteria used in this study had a positive effect on improving the growth parameters of milkweed seedlings. Therefore, it is suggested that more research be done on the coexistence of rhizosphere bacteria in different plants and the interaction of their effects so that this technique can be used more for plant production and desertification.