CD Tesis

Kemampuan Bakteri Rizosfer Dan Endofit Dalam Mengendalikan Cylindrocladium Sp., Dan Memacu Pertumbuhan Bibit Eucalyptus Pellita

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Eucalyptus pellita is one of the annual commodity species that is widely
developed and utilized as a raw material for pulp and paper by Industrial Timber
Plantation (HTI) companies in Indonesia, especially in dryland areas. The
success of an HTI plantation starts with the availability of strong and healthy
seedlings in the nursery. However, there are problems with plant pathogen
attacks. One of the pathogens that often attack eucalyptus seedlings is the fungus
Cylindrocladium sp., the cause of leaf blight disease.
This disease can cause a decrease in quality and even death of eucalyptus
seedlings in the nursery. Control measures that are often carried out include the
use of resistant clones, thinning, eradication, chemical pesticides, and biological
control. Biological control that has been carried out is the use of Trichoderma
sp., and Gliocladium sp., but this control has not shown maximum results in
controlling Cylindrocladium sp. Therefore, there is a need for other biological
agents that are capable of controlling Cylindrocladium sp., such as the use of
rhizosphere and endophytic bacteria.
This study aims to obtain rhizosphere and endophytic bacteria that are
capable of controlling Cylindrocladium sp., and stimulating the growth of E.
pellita seedlings. This research was conducted from April to December 2022 in
the Laboratory and Green House Plant Protection Department, PT. Arara Abadi,
Tualang District, Siak Regency, Riau.
The study was conducted in two stages: in vitro antagonism testing and in
vivo testing of selected rhizosphere and endophytic bacterial isolates in
controlling Cylindrocladium sp., on E. pellita seedlings. The second stage of
testing was carried out using a randomized block design consisting of 9
treatments and 5 block, namely T0-: without treatment, T0+: Cylindrocladium sp.,
inoculum, T1: R15 isolate + Cylindrocladium sp., T2: R19 isolate +
Cylindrocladium sp., T3: R24 isolate + Cylindrocladium sp., T4: R28 isolate +
Cylindrocladium sp., T5: E320 isolate + Cylindrocladium sp., and T6: E323
isolate + Cylindrocladium sp. The observed variables were the percentage of
disease incidence and severity, seedling height, stem diameter, dry weight of
seedlings, dry weight of roots, and peroxidase enzyme content. The data obtained
were analyzed qualitatively by describing the results obtained and quantitatively
by statistical analysis using standard deviation, followed by Duncan Mean Range
Test (DMRT) at the 5% level.
The research results showed that out of 94 rhizosphere bacterial isolates
and 4 endophytic bacterial isolates, 5 rhizosphere bacterial isolates and 2
endophytic bacterial isolates were able to produce inhibition zones greater than
30% against Cylindrocladium sp. The characterization of the selected bacterial
isolates revealed that 6 isolates produced protease enzymes, 4 isolates produced
cellulase enzymes, 1 isolate produced chitinase enzymes, and 1 isolate produced
HCN. All of the selected bacterial isolates were also able to produce growth
xiv
hormones such as IAA and phosphate solubilizer, as well as 5 isolates producing
siderophores. The in vivo research results showed that treatments T1, T2, T3, T4,
T5, T6, and T7 were able to suppress the severity of leaf blight disease caused by
Cylindrocladium sp., by 6.80% to 26.53%, increase seedling height, stem
diameter, dry weight of seedlings, and roots. Treatments T1, T2, T5, T6, and T7
were able to increase peroxidase enzyme content as one form of defense
mechanism through induced systemic resistance (ISR). The T4 treatment is a
better treatment than the other treatments in terms of the observed variable of
disease severity, but it has not been able to produce better biomass than T0-
(control without bacteria and pathogen).
Keywords: eucalyptus, leaf blight, induce systemic resistance, PGPR

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Ketersediaan

Informasi Detail

Judul Seri

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No. Panggil

2010241704

Penerbit

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

Deskripsi Fisik

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Bahasa

Indonesia

ISBN/ISSN

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Klasifikasi

2010241704

Tipe Isi

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Tipe Media

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Tipe Pembawa

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Edisi

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Subjek

ILMU PERTANIAN

Info Detail Spesifik

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Pernyataan Tanggungjawab

FATAH

Versi lain/terkait

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