Identification endophytic fungi of Nutgrass (Cyperus rotundus L.) as solubilizing phosphate and indole-3-acetic acid producers

Nur Kusmiyati,Septian Tri Wicaksono,Durrotul Maknuna

doi:10.24252/bio.v9i1.21216

Abstract

Low phosphate content in the soil can cause insufficient plant needs. Besides, the endophytic fungi of nutgrass have the potential as a phosphate solvent and can produce IAA (Indole-3-Acetic Acid). This study aimed to determine the levels of solubilizing phosphate and production of IAA (Indole-3-Acetic Acid) by the endophytic fungi of nutgrass and to identify the isolates based on rDNA-ITS sequences. The methods used were the isolation of endophytic fungi, analysis of solubilizing levels of phosphate and IAA production, and molecular analysis with rDNA-ITS sequences. Results of isolation and purification, found five isolates coded URT1, URT2, URT3, URT4, and URT5. The endophytic fungi of nutgrass were able to solubilizing phosphate levels around 54.03 - 87.83 ppm, with the highest levels produced by URT4 isolate. IAA levels around 5.58 - 45.50 ppm, with the highest levels produced by URT1 isolate. Based on molecular analysis with rDNA-ITS sequences, it showed that URT4 had 97.42% similarity to Aspergillus tereus species, while UTR1 had 100% similarity to Fusarium oxyporum species. To conclude, the endophytic fungi of nutgrass from A. tereus and F. oxyporum species have high levels of solubilizing phosphate and IAA production so that they are potential candidates for biofertilizer.

Highlights

Most tropical countries usually have a very large swamp area divided into low and tidal swamps
The common problem with acid sulfate soils is the low availability of phosphate nutrients
The endophytic fungi obtained from the isolation and purification of nutgrass (C. rotundus L.) produced five isolates coded URT1, URT2, URT3, URT4, and URT5

Summary

Introduction

Most tropical countries usually have a very large swamp area divided into low and tidal swamps. The common problem with acid sulfate soils is the low availability of phosphate nutrients. Phosphate constitutes one of the macromolecular nutrients needed in the soil to meet plant needs. It is very important, especially for root growth stimulation, starch metabolism, assimilation process, elevation of homogeneous microspores, viable pollen and ovules, acceleration of flowering, and ripening of seeds or fruits (Ponnu et al, 2011; Kasno & Sutriadi, 2012; Ghanem et al, 2014). The phosphate requirement is inversely proportional in the soil, the availability of dissolved phosphate is usually very low it is not sufficient to meet plant needs. The use of long-term chemical phosphate fertilizers above normal dosage has negative impacts on the environment, such as a decrease in soil quality, soil fertility, and crop yield (Jiao et al, 2012; Kaur & Reddy, 2015; Ning et al, 2017)

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