Vol. 40 No. 2 (2012): Jurnal Agronomi Indonesia

The average productivity of upland rice is still relatively low. Therefore, it is necessary to improve agronomic characters related to grain yields, maturity, and their adaptation in dry land. The aims of this research were to evaluate agronomic traits, genetic parameters such as genetic and phenotype variance, heritability and G x E interaction of rice mutant lines derived from gamma irradiation treatment on upland rice. This research was conducted in Situbondo and Madiun, during rain season. The analysis of variance (ANOVA) showed that DT15/11/KU and 1058/Cty mutant lines have higher yield compared with Situgintung (check variety). The grain yield per hectare from DT15/11/KU and 1058/Cty mutant lines were 7.76 ton ha-1and 7.18 ton ha-1respectively, with 12% of water content. Broad-sense heritability, genetic and phenotypic and environmental variances for agronomical traits such as filled grain per panicle, weight of 1,000 grain, yield per plot and yield per hectare were observed. The results showed that broad-sense heritability for weight of 1,000 grain was 94%, whereas other characters was less than 40%. Phenotypic variance was dominated by genetic variance for weight of 1,000 grain. Further selection for filled grain per panicle, yield per plot and yield per hectare needs to be conducted. G x E interaction and genotype were highly significant, whereas location variance was highly significant for filled grain and weight of 1,000 grains.

Keywords: agronomic characters, broad-sense heritability, G x E interaction, genetic variance, upland rice

One of the causes of the low productivity of rice grown on peat soils was the high levels of of toxic phenolic compounds in the soil. Development of tolerant rice varieties is one of strategies to grow rice on peat soils. The aims of this research were to select rice varieties tolerant to peat soils and to study the correlation between the plant phenolic acid content with plant tolerance to peat soil. This research was conducted at the Seed Farm Centre Lubuk Minturun, Padang from February to July 2009. The research consisted of two experiments i.e. in peat soil and in mineral soil. The experiments used a completely randomized design using 21 varieties of rice as treatments which were replicated four times. The results showed that there were nine rice varieties categorized as tolerant to peat soil. These tolerant varieties showed higher stress tolerance index (STI), demonstrated by a high level of phenolic acids (coumaric, syringic, and ferulic) in the plant tissues. The STI value had positive correlation with the content of plant phenolic acids, thus the level of plant phenolic acids can be used as an indicator to determine tolerant rice varieties in peat soils.

Keywords: peat soil, phenolic acids, tolerant rice, STI

Selection method is one of the most important factors in determining the success of pepper breeding programs. Selection method will be effective if it is supported by a complete knowledge of genetic character inheritance. The aim of this research was to investigate the inheritance patterns to quantitative characters using large pepper (P1 (IPB C5)), curly pepper (P2 (IPB C105)), F1, F1R, BCP, BCP2 and F2. The result showed that dichotomous height, days to harvest and weight per fruit characters were not maternally inherited. The additive-dominant genetic model was the most suitable for dichotomous height character. The additive-dominant with influence of interaction additive-dominant and interaction dominant-dominant genetic model was suitable for days to harvest character. The additive-dominant with influence of interaction additive-additive and interaction dominant-dominant genetic model was suitable for the weight of fruit character. Broad-sense and narrow-sense heritabilities range medium for dichotomous height and weight per fruit characters. Heritability of the days to harvest character was high in a broad-sense but was low in the narrow-sense.

Keywords: genetic model, heritability, inheritance

The development of biological products based on beneficial microorganisms could extend the range of options for maintaining the health and yield of crops. Rhizobacteria have been used for ‘promoting plant growth. The objectives of this research were to determine the best method of preplant seed treatment through seed conditioning with rhizobacteria which would be effective to improve yields and increase seed quality of hot pepper. This research was conducted in Agronomy Laboratory Haluoleo University and in the field of Wawotobi Seed Farm Centre of Southeast Sulawesi Province. Seed conditioning with rhizobacteria was effective in improving plant growth, yield and seed quality of hot pepper. However, the most effective treatment was the integration of sawdust seed matriconditioning with rhizobacteria Bacillus polymixaBG25. The seed treatment increased fruit total per plant to 51, compared with 26 in the control seeds. The treatment was also effective in increasing seed viability and vigor (germination percentage and vigor index) to 81% and 46% compared with 41% and 26% in the control seeds. Based on this experiment, rhizobacteria B. polymixaBG25 integrated with sawdust seed matriconditioning could be recommended as biofertilizer in improving yield and seed quality of hot pepper.

Keywords: hot pepper, matriconditioning, rhizobacteria, sawdust, seed treatment

We investigated the effect of sector (position in canopy) on translocation and distribution of 13C-photosynthates in  mangosteen trees and related the findings to previous analyses of fruit quality. Our experiment was conducted on three 25-year-old mangosteen trees. Tree canopies were divided into 9 sectors based on height (bottom, middle, top) and width (inner, center, outer). One branch from each sector was labeled with 13CO2 in December 2003. Immediately after labeling, 13C concentration in leaves from middle sectors was higher than that in leaves from other positions. 13C concentration in all leaves decreased rapidly for 24 h after 13C feeding, followed by a gradual decrease. In contrast, 13C concentration increased over time in the pericarp and aril of fruits. Translocation of 13C-photosynthates into fruit was high in Sectors 4 and 5, and in top positions (Sectors 7 to 9). At 96 h after 13C feeding, the highest distribution ratio of 13C-photosynthates was observed in stems, followed in descending order by pericarp, leaf, and aril. 13C distribution ratio in the aril was generally highest in fruits from inner and center positions. The relationship between partitioning of photosynthates and quality of mangosteen fruit, which differs among sectors, has been discussed.

Keywords: fruiting positions, Garcinia mangostanaL., photosynthate partitioning, 13C, tree branches

Black pod disease (BPD) of cacao caused by Phytophthora palmivora(Butl.) is one of the major diseases on cacao plantation worldwide. Endophytic fungi (EF), fungi that live asymptomatically inside healthy plants, were examined to study their potentials as biocontrol agent of the disease. Six of EF selected from 37 species (from 2843 isolates), isolated from healthy pods of cacao from Marena in Central Sulawesi were tested for their abilities to control BPD. Pods on living trees in the field were sprayed with each EF propagules. The inoculated pods were harvested two weeks later and subsequently inoculated with P. palmivora. Scoring of disease development was performed and quantified as area under disease progress curve (AUDPC). Latent period, infection rate and effectiveness were also recorded. In vitro growth inhibition of pathogen and induced plant defense mechanisms due to EF were also investigated. Xylariaceaeand Calocybe gambosatreatment generated the highest effectiveness control level, i.e. 38.8% and 33.8% respectively, followed by Resinicium friabileand Aschersoniatreatment, i.e. 17.4% dan 12.7% respectively.  Pestalotiopsisand Fusariumwere not effective to control BPD. There was a strong connection between disease severity of BPD with the latent period of pathogen. Growth inhibition of pathogen and induced resistance of plant were partially responsible for disease suppression by Xylariaceae, C. gambosa, R. friabileand Aschersonia.

Keywords: Calocybe gambosa, induced resistance, peroxidases, salicylic acid, Xylariaceae

Temulawak (Curcuma  xanthorrhizaRoxb.) belongs to the family Zingiberaceae, has been empirically used as herbal medicines. The research was aimed to evaluate three promising lines of Temulawak based on their high bioactive contents (xanthorrhizol and curcuminoid) and its in vitro bioactivity (antioxidant and toxicity), and to obtain information on agrobiophysic environmental condition which produced high bioactive compounds. The xanthorrhizol and curcuminoid contents were measured by HPLC. In vitro antioxidant and toxicity were determined by DPPH (1,1-diphenyl-2-picryl-hydrazyl) method and BSLT (Brine Shrimp Lethality Test). The result showed that promising line A produced the highest yield of bioactive and bioactivity, i.e. 0.157 and 0.056 g plant-1of xanthorrizol and curcuminoid respectively. The IC50 of antioxidant activity was 65.09 mg L-1and LC50of toxicity was 69.05 mg L-1. In this study, Cipenjo had the best temulawak performance than two other locations. According to the agrobiophysic parameters, Cipenjo environmental condition was suitable for temulawak cultivation with temperature 28-34 ºC, rainfall ± 223.97 mm year-1 and sandy clay soil.

Keywords: antioxidant, curcuminoid, promising lines, temulawak, xanthorrhizol

using complete randomized block design with three replications. The means from each plot were compared by using t-student’s test. Application of inorganic fertilizer resulted in a higher shoot production (at 6 week after planting) and a better quality leaves compared to other treatment. This research revealed that high quality waterleaf can be indicated by some criterias, i.e., higher content of primary metabolites (sugar and protein), secondary metabolites (phenolic, flavonoid, and chlorophyll), and antioxidant capacity (low IC50 value). Therefore, application of inorganic fertilizer in wet season is recommended to produce high yields and high quality water leaf.

Keywords: sugar, protein, phenolic, flavonoid, DPPH