CD Tesis

Kemampuan Rizobakteri Sebagai Agens Biokontrol Terhadap Xanthomonas Sp. Pada Bibit Eucalyptus Pellita Dan Identifikasinya Berdasarkan Gen 16s Rrna

---

Eucalyptus sp. is one of the plant developed as a wood fiber-producing industrial plantation forest in Indonesia. Xanthomonas sp. attack which causes Bacterial Leaf Blight (BLB) to be one of the obstacles to obtaining uniform seeds with good quality. Infected plants grow with many stems and are stunted compared to plants that are not infected. Thus, it is necessary to have an environmentally friendly control effort so that the problem of bacterial leaf blight on eucalyptus is resolved, but also does not cause problems to the environment. One of the environmentally friendly controls is to utilize rhizobacteria. Various studies have proven that Rhizobacteria can act as Plant Growth Promoting Rhizobacteria (PGPR) to increase growth and control disease in plants.
This study aims to obtain rhizobacteria which have the ability as biocontrol against Xanthomonas sp. and determine the identity of rhizobacteria that have the ability as the best biocontrol against Xanthomonas sp. The research was conducted in vitro and in vivo through three stages, namely the first stage was antagonistic testing and in-vitro characterization, the second stage was identification of selected rhizobacteria based on 16S rRNA gene, and the third stage was testing the antagonistic ability of rhizobacteria against Xanthomonas sp. in vivo. The research design on the antagonism test and in vivo test was carried out using a completely randomized design. Data analysis was performed using variance (ANOVA) and Duncan Multiple Range Test (DMRT) at 5% level.
There were 123 isolates of rhizobacteria obtained in this study. One positive isolate in the hypersensitivity test. A total of 122 isolates that did not cause hypersensitivity reactions to tobacco leaves were then tested for their antagonistic activity against Xanthomonas sp. The test results obtained as many as 14 isolates showed antagonistic activity against Xanthomonas sp. The results of the analysis of variance showed that the rhizobacterial treatment had a significantly different effect on the resulting inhibition zones. This shows that these rhizobacteria have the ability to produce compounds that can inhibit the growth of Xanthomonas sp. The results of characterization tests of 14 isolates showed that all isolates produced siderophores and IAA, thirteen isolates produced proteases, three isolates produced HCN, and eight isolates were able to dissolve phosphates. RE081 showed the best properties in the antagonism test, producing HCN, IAA, and its ability to dissolve phosphates.
Molecular analysis based on the 16S rRNA gene, by matching the sequence of nitrogenous bases to the sequenced via the NCBI site, showed that RE081 had 100% homology to Pseudomonas aeruginosa. Based on the phylogenetic tree, the species Pseudomonas. aeruginosa RE081 is closely related to Pseudomonas aeruginosa MAJPIA03 which was isolated from the rhizosphere soil of the castor plant in India. Furthermore, Pseudomonas aeruginosa RE081 was used as an in vivo test candidate, with different concentration treatments (105, 106, 107, 108 CFU/mL). The highest concentration (108 CFU/mL) showed
xiv
activity in reducing disease severity by 2.13%. The percentage reduction in disease severity in vivo is small, indicating that the size of the inhibition zone in the in vitro antagonism test does not guarantee that the bacterium is effective for in vivo testing.
Thus, rhizobacteria Pseudomonas aeruginosa RE081 is a candidate that can be used as a biocontrol agent as evidenced by in-vitro testing, and it is necessary to carry out further in-vivo testing by adding other variables to obtain more optimum results.
Keywords: 16S rRNA gene, characteristic, identification, rhizobacteria, Pseudomonas aeruginosa

---

Ketersediaan

Informasi Detail

Judul Seri

-

No. Panggil

2010241823

Penerbit

Pekanbaru : Universitas Riau – Pascasarjana – Tesis Ilmu Pertanian., 2023

Deskripsi Fisik

-

Bahasa

Indonesia

ISBN/ISSN

-

Klasifikasi

2010241823

Tipe Isi

-

Tipe Media

-

Tipe Pembawa

-

Edisi

-

Subjek

ILMU PERTANIAN

Info Detail Spesifik

-

Pernyataan Tanggungjawab

FATAH

Versi lain/terkait

Lampiran Berkas

Komentar

---

Anda harus masuk sebelum memberikan komentar