Enhancing in vitro solid culture of Boletus edulis and Boletus reticulatus through elicitation with indoleacetic acid and oxalic acid

The rapid urbanization trend has resulted in the neglect of rural areas worldwide, leading to economic and social challenges. However, rural regions possess abundant resources that, if properly harnessed, can significantly improve the well-being of their communities. One such resource is the chestnut tree, which has been utilized for centuries due to its timber and edible fruits. Spain’s substantial chestnut production provides a valuable opportunity to explore complementary economic activities, such as mushroom harvesting. Despite this potential, the slow growth of Boletus edulis complex in vitro culture poses a significant obstacle. In this study, an innovative approach using organic acids as potential growth elicitors was developed, aiming to enhance the chestnut mycorrhization process with Boletus edulis complex and contribute to the economic development of rural areas. To address the slow mycelial in vitro growth challenge, a novel cultivation protocol utilizing organic acids as growth elicitors was designed. Specifically, the effects of indoleacetic acid and oxalic acid at three different concentrations on the mycelium growth of Boletus edulis and Boletus reticulatus was investigated. The mycelium growth was evaluated using image analysis techniques, providing quantitative data for analysis and comparison. This methodology focused on identifying effective concentrations of organic acids that promote optimal mycelium growth and could be implemented in a sustainable cultivation process at industrial level. Preliminary results revealed that the supplementation of oxalic acid at higher concentrations stimulated greater mycelium growth in both Boletus species, indicating its potential as a growth elicitor. These findings suggest that organic acids play a crucial role in promoting the development of mycelium, thus offering a promising avenue for improving the cultivation of commercially valuable boletus mushrooms. Further optimization of the cultivation protocol based on these results holds the key to unlocking the economic potential of mushroom production in rural areas.