The Status of Arbuscular Mycorrhiza Fungi in the Soil and Roots of Upland Rice Plant of Manokwari

Abstract Arbuscular Mycorrhiza (AM) fungi are ubiquitous in the soil and play an important role in phosphorus nutrition by enhancing its availability to plants especially in P deficient soil. The aim of this research was to determine the number, type of spores, and the percentage of roots infected by AM fungi in the roots and soil of upland rice plants. This study was conducted in the upland rice areas of Juar village Warmare in Manokwari Region of Papua Barat on March to July 2023. Soil and root samples were taken at a depth of 0 – 20 cm across the upland rice areas with total of 44 composite samples. Isolation and extraction of spores used the Wet Sieving and Decanting methods, the percentage of root infection were used the trypan blue and gridline method and some soil properties were also analysed. The results showed that soil pH ranges from 4.5 - 5.0 (acidic) and the C-organic content ranges from 1.5 - 2.1% (low). The number of AM fungi spores ranges from 1 – 5 spores/50 grams of soil, which classified as very low, this might be influenced by the soil conditions due to the continuously cultivated by the same crop and the low of soil pH in the upland rice areas. There are 3 morphotypes of AM Fungi spores, namely Glomus sp1 , Acaulospora sp1 and Gigaspora sp1 . The highest percentage of roots infected by AM fungi in the roots of upland rice plant was 75% and the lowest was 34.12%. The high percentage of root infected was not followed by the highest of AM spores in the soil. Soil chemical properties greatly influenced the ability of AM fungi to associate with host plants, however no significant correlation among AM fungi and soil properties in this study. In soil conditions that are marginal and lack of nutrients, especially soil that has a low phosphorus content, AM fungi will be more optimal for infecting plant roots. This shows that the ability of AM fungi colonization on the roots of upland rice plants is moderate to very high, so that it can help the uptake of nutrients well, especially phosphate.