Search

Hidayah AN, Yahya S, Sopandie D. 2020. The tolerance of oil palm (Elaeis guineensis) seedlings to Al stress is enhanced by citric acid and natural peat water. Biodiversitas 21: 4850-4858. Management technology on soil containing high levels of Aluminum (Al) toxicity is still needed to be developed so that the growth and development of plants will be optimum. The aims of the research were to investigate the response of oil palm seedlings (Elaeis guineensis Jacq.) toward aluminum stress, and to evaluate the effects of several exogenous compounds to improve the tolerance of oil palm. The research was conducted from September 2018 to March 2019 at PT Gunung Sejahtera Ibu Pertiwi, Central Kalimantan. This research consisted of two nutrient culture experiments, namely: Al toxicity on oil palms seedlings and the role of various exogenous compounds to improve plant tolerances. The results revealed that the solution at concentrations of 400 μM, 800 μM, and 1600 μM of Al significantly inhibited root growth, increased MDA levels, decreased the photosynthesis rate, activity of CAT and APX. Therefore, a solution at concentration of 400 μM of Al can be used as the selection level of Al tolerant oil palm varieties on nutrient culture. Ethephon at concentrations of 25 ppm, 50 ppm, and 100 ppm inhibited root and shoot growth, increased MDA levels but reduced the photosynthesis rate, chlorophyll content, APX, and CAT activity. Addition of 25 ppm and 50 ppm of citric acid, 200 ppm and 300 ppm of peat water significantly increased root length, root dry weight, photosynthesis rate, chlorophyll content, carotenoids, CAT, and APX activities as MDA levels decreased. Addition of citric acid and peat water enabled seedlings of oil palm to improve their tolerance to Al stress on nutrient culture.

The growth of Indonesian tea industry requires a serious attention. Land conversion due to weather changes is considered as one of the reasons why the tea industry decreased. This is proved by the declining of Indonesian position as tea exporting country to rank 7. The potential of Indonesian tea plantations is considered to be high due to both quality and quantity. This research is aimed to explore the relationship between production and weather conditions (rainfall, temperature, and humidity) that cause land conversion. Another aim is assessing the dynamic change of the institutional role within tea plantation in West Java. The first research was initiated by literature review and sampling of primary field, meanwhile the second research was conducted by interview and questionnaire in Bandung Regency and Cianjur Regency. The results showed that humidity factor determines the tea production in West Java. The institutional role as a weakened agent in all sector is a second finding.

Effective and efficient fertilization is affected by fertilizer dose, and therefore information on the appropriate dose of a single fertilizer for oil palm will be beneficial to increase the efficiency and effectiveness of fertilization in oil palm plantations. The objectives of this research were to study the response patterns and to determine optimum rate of single fertilizer package related to the growth of one year old oil palm trees. The experiment was conducted from March 2013 to February 2014 at IPB-Cargill Teaching and Research Farm of Oil Palm, Jonggol Bogor. The experiment was arranged in randomized block design with one factor and replicated three times. The treatments were four single fertilizer package as followed: control, 300 g urea + 375 g SP-36 + 350 g KCl + 25 g boric acid + 25 g CuSO4.5H2O, 600 g urea + 750 g SP-36 + 700 g KCl + 25 g boric acid + 25 g CuSO4.5H2O, 900 g urea + 1125 g SP-36 + 1050 g KCl + 25 g boric acid + 25 g CuSO4.5H2O per plant. The result showed that application of single fertilizer package significantly increased the growth of young oil palm linearly as shown by plant height, stem girth, leaf area of frond number 9, chlorophyll and P content of the leaves and quadratically on leaf number at the last observation. The optimum rate of single fertilizer for one year old oil palm trees had not been attained at this research because the plant growth response to fertilization was still linear.Keywords: inorganic, leaf frond number 9, optimum rate, growth response, stem girth

The effects of mycorrhizal endosymbiotic bacteria Bacillus subtilis B10 and composite of arbuscular mycorrhizal fungal spores in green house experiment were examined in order to evaluate their effectiveness and compatibility with oil palm seedlings in the presence of a fungal pathogen Ganoderma boninense , the most serious pathogen in oil palm ( Elaeis guineensis Jacq) in Indonesia. A three factors experiment were conducted, with mycorrhizal inoculation (M0 and M1), bacterial B. subtilis B10 inoculation (B0 and B1), and G. boninense inoculation (G0 and G1) as the first, second, and third factors, respectively. The results showed that disease severity index, plant height, root dry-weight, and phosphorus uptake were affected by co-inoculation of mycorrhizal endosymbiotic bacteria B. subtilis B10 and composite of arbuscular mycorrhizal fungi. Co-inoculation of mycorrhizal endosymbiotic bacteria B. subtilis B10 and arbuscular mycorrhizal fungi did not only reduce the percentage of basal stem rot incidence, but also significantly increased plant height and phosphorus uptake by oil palm seedlings. Our results suggest that in oil palm seedlings mycorrhizal endosymbiotic bacteria B. subtilis B10 worked synergistically with arbuscular mycorrhizal fungi in increasing plant adaptation toward biotic stress of pathogen G. boninese and could be promising biocontrol agents.

Hanafiah DS, Trikoesoemaningtyas, Yahya S, Wirnas D. 2010. Mutasi induksi irradiasi sinar gamma pada varietas kedelai Argomulyo (Glycine max). Nusantara Bioscience 2: 121-125. Induksi tanaman dengan irradiasi sinar gamma merupakan salah satu cara untuk meningkatkan keragaman genetik tanaman. Penelitian ini menggunakan irradiasi sinar gamma pada tingkat atau dosis rendah (mutasi mikro). Tujuan penelitian ini untuk mengetahui respon pemberian tingkat irradiasi mikro sinar gamma pada benih kedelai. Benih kedelai [Glycine max (L) Merr] yang diuji adalah kedelai varietas Argomulyo yang diirradiasi sinar gamma dengan dosis 0 Gray, 50 Gray, 100 Gray, 150 Gray dan 200 Gray. Keragaman yang diperoleh dari setiap peubah amatan yang diperoleh pada generasi M1 dan M2 menunjukkan bahwa perlakuan irradiasi dapat mempengaruhi pertumbuhan dan perkembangan tanaman secara kualitatif dan kuantitatif, yang akhirnya akan mempengaruhi produksi tanaman. Variasi fenotipe pada tanaman kedelai generasi M2 tertinggi rata-rata terjadi pada perlakuan 200 Gray. Hasil penelitian menunjukkan bahwa irradiasi sinar gamma pada dosis 200 Gray efektif menyebabkan terjadinya keragaman genetik tanaman. Kata kunci : mutasi induksi, mutasi mikro, irradiasi sinar gamma, kedelai varietas Argomulyo.

Basal stem rot caused by Ganoderma boninense is the most serious disease of oil palm ( Elaeis guineensis ) in Indonesia and it has caused major loss in palm oil production. Mycorrhizosphere bacteria offer possible advantages as biocontrol agents as they live and proliferate together with arbuscular mycorrhizal fungi, which have an ability to increase plant resistance against pathogens. A study was conducted to isolate mycorrhizosphere bacteria from spores of arbuscular mycorrhizal fungi and test their antagonistic effects against G. boninense in vitro . All bacterial isolates were identified based on 16S rDNA analysis and it revealed that eleven out of twenty mycorrhizosphere bacteria isolated were related to Bacillus with similarity ranging from 97 to 100%, whereas other isolates were identified as Pseudomonas, Streptomyces, Kocuria, Enterobacter, Brevundimonas , and Alcaligenes with similarities ranging from 96 to 100%. Fourteen out of twenty mycorrhizosphere bacteria showed a varying degree of inhibition towards the growth of G. boninense in vitro . Of these, isolate B10 (closely related to Bacillus subtilis ZJ06) showed the highest inhibitory effect followed by B17 (closely related to Bacillus subtilis N43). Therefore, these bacteria have a potential to be used as biocontrol agents to control basal stem rot disease caused by G. boninense in oil palm.

Present research was aimed to study physiological changes of soybean which were inoculated with vesicular arbuscular mycorrhizal fungi (VAM). Glomus etunicatum was exposed to moderate and severe drought condition. Symbiotic association with VAM improved adaptability as it was shown by the increasing leaf proline content. The MLG 3474 and Sindoro are the more tolerant genotypes while the responses of plant to VAM on improving the adaptability to drought were larger on Lokon.

Present research was aimed to study physiological changes of soybean which were inoculated with vesicular arbuscular mycorrhizal fungi (VAM). Glomus etunicatum was exposed to moderate and severe drought condition. Symbiotic association with VAM improved adaptability as it was shown by the increasing leaf proline content. The MLG 3474 and Sindoro are the more tolerant genotypes while the responses of plant to VAM on improving the adaptability to drought were larger on Lokon.

Molecular genetic analysis of hard bunch phenomenon in oil palm was done in order to elucidate the role of genetic factor underlying hard bunch in oil palm plantation. The aim of this study was to identify the AFLP primer combination that co-segregates with hard bunch phenotype related gene in oil palm. Molecular analysis was done by bulk segregant analysis approach. DNA was isolated from leaves of the normal and hard bunch palm. DNA from ten individual palms from each category were pooled and used as a template. A total of 56 AFLP primer combinations were selected for selection of polymorphic primer, and as a result it was found that 22 AFLP primer combinations (39.28%) were polymorphic. A total of 48 individual of palm DNA containing 24 individual for each group were further genotyped by those 22 polymorphic markers. Of these, one AFLP primer combination (E-ACC/M-CTG) was obtained as a co-segregated marker that distinguished the hard bunch DNA from the normal one. Based on the analysis of the target sequence aligned to the oil palm DNA sequences available in database, we found that our sequence has similarity with Ty-1 copia retrotransposon. This sequence distribute in all 16 linkage group of oil palm genome.Keywords: abnormal fruits, AFLP, oil palm, Ty-1 copia retrotransposon

Identification of differentially expressed genes can be done by cDNA-AFLP analysis. Hard bunch phenomena are not widely studied. The aim of this research was to identify and characterize regions specific to the gene coding sequences involved in the hard bunch phenomena in oil palm fruits. RNA was isolated from three types of ripe oil palm fruits including normal, black and hard bunch fruits. cDNAs were amplified using 16 AFLP primer pairs combinations. The result of a BLAST comparison showed that some of the resulting transcripts have sequence similarity with the existing database sequences, such as a WRKY transcription factor, peroxidase, actin depolymerising factor and glutamine synthetase allegedly associated with hard bunch phenomenon induced by drought stress. However, some transcripts could not be classified since they did not exhibit significant similarity to any existing database sequences. This is might be the transcripts were less conserve region and or 5’ or 3’ UTR region.

This research used gamma ray irradiation on low doses (micro mutation). The aim of this research was to know the respons of doses level bymicro mutation on gamma ray irridation to the growing and development of Argomulyo variety of Glycine max (L) Merr (M1), the seeds isirradiated by gamma ray by micro mutation was 0 Gy, 50 Gy, 100 Gy, 150 Gy, and 200 Gy. Variation that obtained of each characters atgeneration M1 and M2 influences plants growth and development either through qualitative and quantitative that finally will influence plantsproduction. The average highest genetic variation at M 2 generation of soybean was on 200 Gy doses. Results of the research indicated thatgamma ray irradiation on 200 Gy doses was effective caused of plant variation genetic.