Plant-Growth-Promoting Rhizobacteria Improve Germination and Bioactive Compounds in Cucumber Seedlings

Abstract

Plant-growth-promoting rhizobacteria (PGPR) increase the germination percentage and the vigor of seeds, thus determining aspects for the efficient production of seedlings and the prompt establishment of crops in the field. In this study, the effect of the biopriming of rhizobacteria was evaluated: Bacillus cereus (KBEndo4P6), Acinetobacter radioresistens (KBEndo3P1), Pseudomonas paralactis (KBEndo6P7), and Sinorhizobium meliloti (KBEkto9P6) on some parameters such as the percentage of germination and vigor and the germination index, among others, as well as the synthesis of phytocompounds in the seeds of Cucumis sativus L. biopriming seeds significantly improved germination, the germination index, the vigor, the plumule and the radicle length, in addition to an increase in phytochemical compounds. The rhizobacteria KBEndo3P1 increased the germination percentage by 20%, the germination index by 50%, and the seed vigor by 60%, as well as the length of the radicle by 11%, and the plumule by 48% compared to the control, and the total phenols and antioxidants increased by 9% and 29%, respectively. Biopriming with plant-growth-promoting rhizobacteria increases germination, which allows for the possibility of more outstanding production of seedlings and a greater length of the radicle, thus increasing the efficiency in the processes of water and nutrient absorption and improving its establishment in the field. In addition, the production of phytocompounds enhances their response against any type of stress, making them a viable alternative in sustainable agriculture to increase cucumber yield.