Ecological Diversity of Lycopersicon esculentum (Tomato) Root Associated Plant Growth Promoting Rhizobacteria (PGPRs)

Abstract

Tomato member of family Solanaceae is one amongst the foremost important vegetable crop worldwide. It has its significance due to its nutritive, therapeutic and antioxidant properties. An ecofriendly approach to improve the crop yield is the use of PGPRs which improves the growth of plant through nitrogen fixation, phosphorus solubilization and phyto-hormone production. The present study is to evaluate the biodiversity of such PGPRs and their potential role as biofertilizer for tomato crop. A total eight bacteria were isolated and purified from soil and rhizosphere of tomato plant collected from temperate and tropical rainfed regions of Pakistan including Rawalakot and Attock respectively. Soil texture of Rawalakot and Attock varied from sandy loam to loamy. Plant growth promoting traits like N2 Fixation, P-solubilization and IAA production were determined for all the eight isolates. Maximum P-solubilization was shown by isolates from Attock, AS4 (129.72 µg mL-1) and Rawalakot, RS3 (132.73 µg mL-1) and maximum IAA production was observed in Rawalakot isolates, RS2 (22.237 µg mL-1) followed by Attock isolates, AS3 (49.63 µg mL-1) and AS2 (62.86 µg mL-1). PGPRs were selected with multifunctional properties and were used in plant inoculation experiment to study enhanced growth of tomato plants. Bacterial isolates showed remarkable increase in all growth parameters as compare to uninoculated control. These PGPRs can be best developed for improved development of tomato plants with less dependence on chemical fertilizers.