Isolation and Screening of Phosphate and Potassium Solubilizing Endophytic Bacteria in Maize (Zea mays L.)

Hilya Azizah,Saptini M Rahajeng,Yoga D Jatmiko

doi:10.21776/ub.jels.2020.010.03.04

Abstract

Maize ( Zea mays L.) is a functional food source in Indonesia after rice and wheat. Increasing maize productivity can be done by developing a proper environment and nutritional availability during cultivation. The use of endophytic bacteria as biofertilizers is one prospective approach in reducing the synthetic fertilizers in the soil, and improving the absorption of macronutrients, such as nitrogen, phosphate, and potassium, as well. This study aimed to obtain phosphate solubilizing bacteria (PSB) and potassium solubilizing bacteria (KSB). The samples of maize leaves, stems, and roots were isolated using a serial dilution method and selected on a Pikovskaya and Aleksandrov medium. A total of 10 PSB isolates were obtained from PKV selective agar media. The highest density was obtained in the root (8.3x10 5 CFU.mL -1 ), stems (5.7x10 5 CFU.mL -1 ), and leaves (4.6x10 5 CFU.mL -1 ), respectively. Meanwhile, the diversity index of the PSB ranges from 0.7 to 0.78, indicates that the diversity index is high. Four isolates from PSB (AP1.3, AP3.1, AP1.2, and AP1.4) were selected as KSB because of the clear zone formed in Aleksandrov's medium. The highest production of phosphate and potassium was obtained by AP1.3 with value 12.11 µg.mL -1 and 8.38 µg.mL -1 at 72h and 15d, respectively. Therefore, these isolates potential to be used as an organic fertilizer (biofertilizers). Keywords: Biofertilizer, endophytic bacteria, phosphate, potassium.

Highlights

Maize is the third staple food source after rice and wheat
Decreasing soil fertility due to depletion of soil organic matter and environmental damage requires a sustainable, agricultural system, namely organic farming. It is expected, that it can maintain soil fertility, both physically, biologically, and chemically as in natural ecosystems by applying organic fertilizers, one of which is by utilizing the endophytic bacteria as agents of providing soil organic matter
The samples of roots, stems, and leaves of maize plants aged 45-60 DAP were taken from the maize plant conservation area of Indonesian Center of Agricultural Training (ICAT) Ketindan Lawang, Malang, Indonesia with the coordinates of the location (S 07049'53.2'') (E 112041'24.5'') and an altitude of 548 masl

Summary

INTRODUCTION

Maize is the third staple food source after rice and wheat. According to the Trade Analysis and Development Agency (Badan Pengkajian dan Pengembangan Perdagangan - BPPP), Ministry of Trade, Republic of Indonesia the export value of maize in Indonesia in the 2010-2015 periods increased by 4.42%. Decreasing soil fertility due to depletion of soil organic matter and environmental damage requires a sustainable, agricultural system, namely organic farming. One of the important macronutrients is phosphorus and potassium which are required by plants to grow and develop. These efforts become efficient for plants because P is fixed by Al and Fe elements in acidic soils, while in alkaline soils, P will be fixed with Ca so that it was difficult for plants to utilize [3,4]. This study was to obtain phosphate solubilizing endophytic bacteria and potassium solubilizing bacteria from roots, stems, and leaves in maize (Zea mays L.)

MATERIAL AND METHOD Sample Collection

RESULT

Findings

CONCLUSION