Excessive use of chemical fertilizer could potentially decrease soil productivity by decreasing soil microbiome diversity. In this study, we evaluated the effects of fermented seaweed fertilizer in the soil microbial community of paddy plants (Oryza sativa L.). The paddy seedlings were divided into five groups, control (C0), chemical fertilizer (CF), seaweed fertilizer (SF), chemical and seaweed fertilizer combination 50:50 (CFSF1), and chemical and fertilizer combination 75:25 (CFSF2). The CFSF1 combination showed to be the most effective in inducing plant height (83.99 ± 3.70 cm) and number of tillers (24.20 ± 4.08). After 8 weeks after transplantation, the isolated DNA from each soil treatment were subjected to 16S rRNA (v3–v4 region) next-generation sequencing. The beneficial Acidobacteriota was most abundant in CFSF1. At genus level, the nitrifying bacteria MND1 was seen to be abundant in CFSF1 and also present in other SF treatments. The genus Chujaibacter is highly abundant in CF, which potentially plays a role in denitrification resulting in soil degradation. In addition, the CFSF1-treated soils show significantly higher diversity of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). The current results could potentially contribute to the utilization of SF as a bioremediator and promoting green agriculture practice by reducing the amount of CF usage.

The red macroalga Gelidium latifolium is widely distributed in the coastal areas of Indonesia. However, current knowledge on its potential biological activities is still limited. In this study, we investigated the potential bioactive compounds in Gelidium latifolium ethanol extract (GLE), and its cytotoxic effects against the murine B16-F10 melanoma cell line. GLE shows high total phenolic content (107.06 ± 17.42 mg GAE/g) and total flavonoid content (151.77 ± 3.45 mg QE/g), which potentially contribute to its potential antioxidant activity (DPPH = 650.42 ± 2.01 µg/mL; ABTS = 557.01 ± 1.94 µg/mL). ESI-HR-TOF-MS analysis revealed large absorption in the [M-H]^- of 327.2339 m/z, corresponding to the monoisotopic molecular mass of brassicolene. The presence of this compound potentially contributes to GLE’s cytotoxic activity (IC₅₀ = 84.29 ± 1.93 µg/mL). Furthermore, GLE significantly increased the number of apoptotic cells (66.83 ± 3.06%) compared to controls (18.83 ± 3.76%). Apoptosis was also confirmed by changes in the expression levels of apoptosis-related genes (i.e., p53, Bax, Bak, and Bcl2). Downregulated expression of Bcl2 indicates an intrinsic apoptotic pathway. Current results suggest that components of Gelidium latifolium should be further investigated as possible sources of novel antitumor drugs.

Seaweed has often been reported on for it potential bioresources for fertilizers to improve crop productivity and reduce the use of chemical fertilizers (CF). However, little is known about the nutritional status of the crop grown with the implementation of seaweed fertilizers (SF). In this study, the amino acid content of rice produced by SF implementation was evaluated. Furthermore, the rhizosphere bacterial community was also investigated. The paddy seedlings were divided into five groups, control (C0), chemical fertilizer (CF), seaweed fertilizer (SF), chemical and seaweed fertilizer combination 25:75 (CFSF1), and chemical and fertilizer combination 50:50 (CFSF2). The CFSF2 group shown significantly better growth characteristics compared to other groups. Based on the concentration of macronutrients (N, P, K) in paddy leaf, CFSF2 also shown the best results. This also correlates with the abundant amino acid composition in CFSF2 in almost all tested amino acids, namely, serine, phenylalanine, isoleucine, valine, glycine, tyrosine, proline, threonine, histidine, and arginine. Interestingly, beneficial bacteria Rhizobiales were significantly higher in CFSF2-treated soil (58%) compared to CF (29%). Another important group, Vicinamibacterales, was also significantly higher in CFSF2 (58%) compared to CF (7%). Hence, these potentially contributed to the high rice amino acid content and yield in the CFSF2-treated paddy. However, further field-scale studies are needed to confirm the bioindustrial application of seaweed in agricultural systems.

Nikmatullah A, Nairfana I, Dewi SM, Sarjan M. 2023. Morphological diversity of Indian jujube (Ziziphus mauritiana) in Sumbawa Island, West Nusa Tenggara, Indonesia. Biodiversitas 24: 4597-4608. Ziziphus mauritiana Lam. (Indian jujube or Bidara) is an evergreen shrub or small tree tolerant to drought, salinity, and high-temperature stress with various ethnobotanical and ecological values. However, minimal information is available on its diversity in Indonesia. The current study aims to assess the morphological diversity of Z. mauritiana accessions collected from 18 locations in Sumbawa Island, Indonesia. The plant's qualitative and quantitative morphological attributes were collected, including size, L/W ratio and color of leaf and fruit, length, and occurrence of spine and stem surface. The results revealed significant differences in some observed characters among the accessions. Petiole length varied from 0.6 to 1.4 cm, leaf length ranged from 2.9 to 5.0 cm, leaf width ranged from 2.6 to 4.2 cm, and leaf L/W ratio was 1.07 to 1.46. All samples of Z. mauritiana in Sumbawa Island had a spine that occurred evenly in every node, ranging from 0.1 to 1.0 cm. Most accessions had single spinal per node except two accessions, which had double horn-shaped spines in each node. The quantitative characters for fruits also varied, either orbicular or oblong. The fruit length ranged from 1.2 to 1.9 cm, the fruit width varied between 1.1 to 1.8 cm, and the fruit L/W ratio was between 1.0 and 1.2. There were also morphological differences in leaf color, fruit color, shape, and taste (sweet, sour, or bitter). The finding suggests some degree of morphological diversity of Z. mauritiana in Sumbawa, as shown by quantitative and qualitative attributes of the leaf, thorn, and fruit.

Carrot is an important sub-tropical vegetable, and in the tropics it is commonly cultivated in high elevated mountainous areas to provide suitable environment (particularly temperature) for the optimum growth and productivity. Availability of suitable cultivation areas in Indonesia is limited while demand for the crop is increased. This research evaluated growth and yield of carrot in warmer temperature of lower land elevations, and examined capability of biofertilizer to increase growth responses and yield of the crop under sub-optimal temperature conditions. The first and second experiments were conducted in medium latitudes of 650 m above sea level (asl) and 550 m asl, while the third experiment was conducted in low land of 170 m asl. The experiments compared growth and yield of carrot plants with biofertilizer and without biofertilizer applications. The growth and yield of carrot were enhancing by biofertilizer application when planted in ca. 650 and 550 m asl. The biofertilizer-treated plants were taller, had a higher number of leaves, higher yield, carrot diameter and sweater than non-treated plants. In low land, however, biofertilizer bio-EXTRIM had no effect on plant growth and yield but the carrots in biofertilizer treated plants were sweeter than non-treated plants.

A study was conducted to investigate the effect of different rates of NPK fertilization on growth and yield of carrot plants in medium latitude. The experiment was undertaken in Setiling Village, Central Lombok (at ca. 650 m amsl) and arranged according to a RCBD two factors: variety (v) and dosages of NPK fertilization (n). The first factor were four carrot varieties: Gundaling (v1), Kirana (v2), New Nantes (v3) and New Kuroda (v4), while the second factor were four dosages of NPK fertilization: 50 kg/ha (r1), 100 kg/ha (r2), 200 kg/ha (r3) and 400 kg/ha (r4). The results showed that there was no interaction between carrot varieties and rate of NPK fertilization on influencing growth and yield of carrot in medium latitude. However, growth and yield of carrot in medium latitude were significantly influenced by variety and rate of NPK fertilization, as shown by differences in the ratio of above and below ground biomass, tap-root weight, tap-root diameter and the ratio between cortex and stele. Accordingly the suitable variety for cultivation in the medium latitude was Gundaling variety (v1), with a higher growth and yield were obtained by NPK fertilization at rate of 200 kg/ha (n3).