Morphoanatomy and Chlorophyll of Lettuce Plants Induced by Rhizobacteria

Abstract

Lettuce is a consumed crop in the world, and increased yield is a desirable trait, and can be realized with the use of biopromotors, already described in many cultures. The objective of this work was to test the ability of two rhizobacterial isolates P. fluorescens (BRM-3211) and B. pyrrocinia (BRM-3213) to promote anatomical and growth changes in lettuce plants in the seedling stage. The increments promoted by B. pyrrocinia were smaller when using P. fluorescens. The BRM-32111 isolate, promoted increases in leaf area of 133%, 31% and 307% of fresh shoot and root mass, also increased 51% and 143% of aerial and root dry mass. The plants inoculated with BRM-32111 increased in 100% and 68% of the aerial part and radicular compared to the control treatment, and induced alterations in the anatomical characteristics in the root in 74% in the radicular diameter, 20% of the thickness of the cortex, 67% of the exoderme and 171% of the endoderm. In the leaf anatomy, BRM 32111 increased by 18% in the parenchyma expansion, 56% in the number of parenchyma cell layers, 122% adaxial endoderm, 23% epidermis, 174% beam expansion, 37% when compared to control. In this way the use of BRM-32111 influences the growth and morphology of lettuce seedlings.