Results and Discussions Objectives 1. To share lesson learned and best practices among alumni on bio-
58 Figure 1. Two Isolate of endophytic bacteria with different antibiosis
activity against Pyricularia grisea on PDA and TSA medium, isolate Ci10 A and isolate Si27 B.
Research has been conducted on the plant growth-promoting abilities of various microorganisms. Endophytes also promote plant growth by a
number of similar mechanisms. These include nitrogen fixation activity, phosphate solubilization activity, indole acetic acid production and the
production of a siderophore. Endophytic organisms can also supply essential vitamins to plants Pirttila et al. 2004. Moreover, a number of
other beneficial effects on plant growth have been attributed to endophytes and include osmotic adjustment, stomatal regulation, modification of root
morphology, enhanced uptake of minerals and alteration of nitrogen accumulation and metabolism Compant et al. 2005. It is believed that
certain endophyte bacteria triggera phenomenon known as induced systemic resistance ISR, which is phenotypically similar to systemic-
acquired resistance SAR Ryan et al. 2008.
Figure 2. Effect of selected endophytic bacteria on plant height of rice var. Batutegi at 21, 28 and 35 days after planting.
59 The results from this study demonstrated that root endophytic bacteria from
rice plants were able to promote growth of host plant and inhibit miselium of R. solani under in vitro condition. Although the mechanism by which the
endophyte promote growth was not investigated in this study, it suggested that endophyte could be attributed to the production of hormones and
phytohormone, such as gibberellins and auxin IAA Chen et al. 1997. Unique endophytes could be used directly to treat seeds or transplants
limiting substantially the side-effects of abiotic and biotic factors on the biological agent by almost immediately protecting them within plant tissue.
4.
References
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–3. doi:10.1016 j.biocontrol.2008.03.009
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Agric. Boreali-Occidentalis Sinica 6:22-25. 3. S. Compant, B. Duffy, J. Nowak, C. Cl, E.A. Barka. 2005. Use of plant
growth-promoting bacteria for biocontrol of plant diseases: principles, mechanisms of action, and future prospects. Appl Environ Microbiol
71: 4951 –4959.
4. S.L. Doty. 2008. Tansley review: enhancing phytoremediation through the use of transgenics and endophytes. New Phytol 179:318
–333. 5. M.I. Frommel, J. Nowak, G. Lazarovits. 1991. Growth enhancement
and developmental modifications of in vitro grown potato Solanum tuberosum
sp. tuberosum as affected by a nonfluorescent Pseudomonas sp. Plant Physiol 96:928
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ethylene concentrations by plant growth promoting bacteria. J Theor Biol 190:63
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bacteria in agricultural crops. Can J Microbiol 43:895 –914.
8. C.B. Jacobson, J.J. Pasternak, B.R. Glick. 1994. Partial purification and characterization of 1-amino-cyclopropane-1-carboxylate deaminase
from the plant growth promoting rhizobacterium Pseudomonas putida GR 12
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endophytic bacteria from micropropagated echinacea plants using 16S rRNA sequencing. Plant Cell Tissue Organ Cult 85:353
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60 10. D.J.
O’Sullivan, F.O. Gara. 1992. Traits of fluorescent Pseudomonas sp. involved in suppression of plant root pathogens. Microbial Rev 56:662
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61
Effect of oxygen concentration on storage of sapodilla fruit Achras zapota l.
Bambang Susilo
1,
, Rini Yulianingsih
1
, Dyah Ayu Agustiningrum
1
1
Faculty of Agricultural Technology, University of Brawijaya, Malang, Indonesia Corresponding author: bmsusilogmail.com
Abstract
Sapodilla fruit Achras sapota L. is one of tropical fruit commodities from Indonesia. It is one of important fruit in agricultural
sector that has a high economy. Sapodilla fruit is a klimateric fruit that is damaged easily. The process of respiration is increase rapidly in the ripening
phase. By decreasing the rate of respiration, the ripening process will be inhibited. Modified Atmosphere Storage MAS is one method of
controlling the concentration of the gas in the storage room so that the respiration of the fruit can be controlled as well. The aim of this research is
to study the effect of the oxygen O
2
concentration used in the storage chamber on respiration rate and shelf life of sapodilla fruit.The fruit is stored
in the room at various concentrations of oxygen and then measured the rate of their respiration. The treatment used in this study using O
2
concentrations in 5 variations. Sapodilla fruit storage was done at normal conditions 21
O
2
, and 4 other treatments performed at lower O2 concentration: 12.4 –
12.5 O
2
, 9.2 – 9.3 O
2
, 5.9 – 6.1 O
2
, and 3.5 – 3.7 O
2
. Storage was done at room temperature ± 27°C. The parameters observed during
storage include O
2
uptake rate, the CO
2
production rate, texture, color, weight loss, water content, Total Dissolved Solids TDS, and the physical
condition of the fruit. The experiment was conducted in three replications and observations were made once a day.The results showed that the
O
2
concentration in the modified atmosphere storage affects the sapodilla fruit respiration rate and shelf life. O
2
uptake rate is getting lower as well as lower O
2
concentration in air storage. In the observations on each parameter can be seen that the shelf life of sapodilla fruit in normal conditions is 4
days. The longest shelf life of sapodilla fruit is 8 days which ripening was occurred in the storage treatment with O2 concentration of 5.9 to
6.1. While the lowest concentration of O
2
3.5 to 3.7, sapodilla fruit is not ripening until 9 days.
Keywords
oxygen concentration, modified atmosphere storage, sapodilla fruit
62