Isolation of Diazotrophic Endophyte Bacteria from Sugarcane and Bacterial Characterization using Phenotypic Approach

Wiwik E. Widayati

Pusat Penelitian Perkebunan Gula Indonesia, Jl. Pahlawan 25 Pasuruan

Abstract

Isolation and characterization bacteria are the unity steps in microbiology methods. Those steps are usefull to simplify the bacteria diversity which were isolated in this research for further observations. The aim of this study was to isolate diazotrophic endophyte bacteria from sugarcane and to characterize bacteria obtained by using phenotypic properties. The diazotrophic endophyte bacteria were isolated by using selective isolation, while their diazotrophic properties were determined with nitrogenase activity (ARA). Similarities among bacteria were then figured out as a dendogram by using phenotypic and chemosystematic characters. The results showed that 12 isolates of bacteria endophyte were successfully isolated and 7 isolates of them were identified as diazotrophic bacteria. Congruence of the results was obtained from phenotypic characterization including morphology, biochemical characters and cellular protein profile. The data showed that 4 isolates (10.2.2; 10.2.3; 10.3.2.1 and 10.3.2.2) were strongly indicated from the same genus, because those isolates located at ≥ 96% of index similarity. These isolates were also indicated different from other isolates (10 K1, 10 K2 and NB12). Numerical systematic used in this research was useful for selecting the bacteria isolates that will be used for further steps of the research.

Key words : diazotrophic bacteria, endophyte, sugarcane, phenotyphic dan numerical systematic

Application of Na and Partial Substitution of K-Na in Differrent Varieties of Sugarcane Planted on Inceptisol Soil

Indonesian Sugar Research Institute

ISRO ISMAIL

Senior researcher at Indonesian Sugar Res. Institute,
Jln. Pahlawan 25 Pasuruan, Indonesia.

ABSTRACT

Green house and field experiments have been conducted to evaluate the effects of Na and partial
substitution of K-Na on nutrient status of soil, growth and yield of sugarcane, juice quality, and sugar yield.
Three factors (varieties: PS 82-3605 and PS 78-2274-P4B; KCl dosages: 0, 40, 60, 80, 100% of standard
dosage; and NaCl dosages: 0, 20, 40, 60 % equivalent to standard KCl dosage) have been combined in a
randomized block design (green house experiment) and a split plot design (field experiment) with three
replications. In the green house experiment, a certain level of Na resulted in a positive effect on the sugar
yield. Dealing with NaCl dosage, the result showed that the highest sugar yield (229 g/pot) was reached by
the addition of 125 kg NaCl/ha. This beneficial effect of Na was due to the increase of sugarcane weight and
juice quality. There was an indication that Na was required by sugarcane and could inhibit the accumulation
of K in juice. Substitution of KCl (20-40 % of its dosage) by NaCl showed no negative effect on sugarcane
growth. The treatment of 60% KCl (240 kg/ha) + 40% NaCl (125 kg/ha) gave the highest sugar yield (243 g/
pot), while the yield of the standard K treatment (400 kg KCl/ha) was only 187 g/pot. Results from the field
experiment showed that partial substitution of K-Na did not influence the sugarcane weight, rendement, and
sugar yield. PS 82-3605 was superior than that of PS 78-2274-P4B and there is no difference in substitution
capacity of K-Na for both varieties.

Key Words: Potassium, sodium, sugarcane, substitution, varieties, soil properties

The effect of ratooning and application of nitrogen and potassium fertilizers to total of soluble proteins in the leaves of M 442-51 and PS 60 cane varieties

Suyoto Hadisaputro
(Indonesian Sugar Research Institute Jl.Pahlawan 25 Pasuruan 67126)

ABSTRACT

Ratooning system has been implemented in all cane fields, but the system can reduce productivity and growth performance of cane. One factor that affects the cane growth performance is enzyme activities, and its activities are in general can be indentified as total of soluble proteins. This experiment was done to study the effect of ratooning and application of nitrogen (N) and potassium (K) fertilizers to the total of soluble proteins in the leaves of M 442-51 (cane variety with good ratooning ability) and PS 60 (cane variety with bad ratooning ability). The experiment was conducted at the Indonesian Sugar Research Institute (ISRI) Pasuruan, East Java. The results showed that the totals of soluble proteins in cane leaves were influenced by genetic and environmental factors. There was found that ratooning system reduced the total of soluble proteins, but it depended on the cane variety. The reduce of the total of soluble protein on M 442-51 was higher than that of PS 60. Meanwhile, it was found that by increasing the dosage of both N and K fertilizers, the total soluble proteins in cane leaves can increase, but there were different responses between two cane varieties observed. M 442-21 had a better response to N dosage application than PS 60, and conversely PS 60 had a better response to K dosage application than M 442-51. Moreover, it was also found that improvement of the total of soluble proteins as a result of increasing K fertilizer dosage application on sugarcane with N deficiency was higher than that of sugarcane with enough N. Similarly, improvement of the total of soluble proteins as a result of increasing N fertilizer dosage application on sugarcane with lack of K nutrient was better than that of sugarcane with enough K. Anyway, the rate of improvement of the total of soluble proteins caused by N and K fertilizers was not an addition model but it was a resultant model as the effect of each nutrient studied.
Key words: sugarcane, M 442-51, PS 60, ratooning ability, nitrogen, potassium, total of soluble proteins