Multifunctional properties of mycorrhizal helper bacteria: improve mycorrhizal colonization and increase phosphate uptake in Banana

Abstract

Using mycorrhizal fungi with their helper bacteria (MHB) to alleviate phosphate deficiency improve plant growth and rejuvenate the soil is the newer safer and most promising environment-friendly approach to limiting synthetic agrochemicals. Here 65 MHBs were isolated from the mycorrhizosphere of the Banana plant and 12 were screened based on their biofilm formation protease and N-acyl homoserine lactones production. A newly reported MHBEnterobactersp. was identified through the 16S ribotyping method and posed plant growth-promoting properties i.e solubilized phosphate produced indole acetic acid ammonia and hydrogen sulfide. The biocompatibility experiment showed a 4-fold increased mycorrhizal proliferation in MHB added plate compared to the control. Further field experiments suggested the banana plants 10-4-fold increment in plant height (216.54 cm) and stem diameter (10.66 cm). At the same time10-fold significant improvements were noted in leaf carbohydrate (639.9 mg g-1) protein (432.76 mg g-1) chlorophyll (268.66 mg g-1) phenol (1.9 mg g-1) and proline (uMole g-1) content of experimental plant compared to control. The study also showed a 5-fold increase in phosphate content (12.84 mg g-1) than the control (2.4 mg g-1). The isolates increased the mycorrhizal colonization and spore number by 79.33 % and 14.31 g-1in the rhizospheric soil. Total organic carbon and nitrogen (0.68 %) total phosphorus (55 kg ha-1) and potassium (499.66 kg ha-1) content of soil were positively affected by MHB and AMF. Further-more principal component analysis (PCA) and Pearsons correlation analysis of all the obtained results clearly showed the positive insights of inoculated MHB and AMF on the growth of the banana plant and soil restoration.