Growth Rate Parameters Research Articles

Respon Pertumbuhan dan Hasil Microgreens Beberapa Varietas Tanaman Caisim (Brassica juncea L.) pada Berbagai Jarak Tanam

The diminishing amount of land available for agriculture and the growing demand for nutritious food have made it necessary to find alternative sources of fresh vegetables. Urban farming, especially the cultivation of microgreens, can help meet this demand. Microgreens offer several advantages, such as time and cost savings, and they require minimal space while growing quickly. However, the optimal spacing for different types of microgreens is not extensively documented, as research on microgreens is still limited in Indonesia. The Brassicaceae family is one of the most commonly cultivated families for microgreens. This study was carried out at Room A, Faculty of Agriculture, Singaperbangsa Karawang University, Campus 2. The experimental method used was a factorial randomized block design (RBD Factorials) with two treatments for varieties and three for spacing, repeated five times, resulting in 30 experimental units. Factor I, Varieties, consisted of v1 (Tosakan) and v2 (Shinta). Factor II, Spacing, consisted of j1 (1 cm x 1 cm), j2 (1 cm x 2 cm), and j3 (2 cm x 2 cm). The data were analyzed using an analysis of variance (Uji F) at a 5% level. If the results of the analysis of variance were significantly different, the study continued with a multiple range test (DMRT) at a 5% level to determine the best-performing treatment. There was an interaction between the treatments for microgreen varieties and spacing on parameters such as plant density, dry weight of the plant, and fresh weight. There was a significant effect of the variety on the parameter of chlorophyll content, and a significant effect of spacing on the parameters of plant growth rate and the age of leaf appearance. Additional types of plants are needed to determine significant differences related to spacing and their interactions.

Behavioral and biochemical effects of environmental concentrations of caffeine in zebrafish after long-term exposure

Caffeine (CAF) is widely detected in aquatic environments, serving as an indicator of anthropogenic contamination. Its high consumption, and persistence raise environmental concerns. This study was to evaluate the chronic effects in terms of growth rate, weight, behavior, and biochemical parameters of environmental concentrations of CAF on adult zebrafish. Adult zebrafish were exposed, for 30 d, to 0, 0.5, 1.5, and 300 µg L−1 CAF, with behavior (feeding latency, exploration, aggression, sociability, sound response) and biochemical endpoints (acetylcholinesterase (AChE), lactate dehydrogenase (LDH), and cortisol levels) assessed at the end of the exposure. CAF 0.5 µg L−1 increased feeding latency time, while 300 µg L−1 reduced growth and weight. Exposure to CAF affect fish behavior in terms of vertical exploration, aggressiveness, shoaling, and sound responses although were concentration specific. All concentrations tested increased social behavior, with fish swimming closer to the shoal. At a biochemical level, CAF exposed showed reduced AChE activity, while LDH activity, and cortisol levels increased at 300 µg L−1. Low concentrations of CAF caused neurotoxicity in zebrafish which may compromise their feeding behavior, and social interactions in the wild. These changes suggest potential ecological impacts of chronic exposure to CAF, such as impaired feeding and stress responses.

The effect of laboratory diet and feeding on growth parameters in juvenile zebrafish

Despite being one of the most used laboratory species in biomedical, behavioral and physiological research, the nutritional requirements of zebrafish (Danio rerio) are poorly understood, and no standardized laboratory diet exists. Diet and feeding regimen can substantially impact the welfare of the fish and, in turn, experimental reproducibility. Consequently, the establishment of a standardized diet and feeding protocol for laboratory zebrafish is imperative to enhance animal welfare, guarantee research reproducibility and advance the economic and environmental sustainability of laboratory dietary practices. Here the aim of this systematic review is to provide an overview of the parameters that need to be standardized in future nutritional studies to facilitate future meta-analyses for confirmation of an optimal juvenile diet for growth. A comprehensive search was conducted in PubMed and Scopus to identify relevant studies published up to August 2023, and the studies were selected on the basis of the predefined inclusion/exclusion criteria. The databases yielded a total of 1,065 articles, of which 14 were included in this review. We conducted data extraction and risk-of-bias analysis in the included studies. Statistical comparisons for specific growth rate, weight gain (%) and length gain (%) parameters were performed to determine the optimal feed for enhanced juvenile growth. We identified significant heterogeneity and caveats to our findings owing to a lack of standardization of experimental conditions in nutritional studies. Our findings highlight an urgent need for research on zebrafish nutrition. Therefore, the standardized parameters we have reported here represent a critical starting point for studies.

The effect of using Echinacea extract as an immune system stimulant and antioxidant on blood indicators, growth efficiency, and carcass characteristics in broiler chickens to produce a healthy product

This study aimed to discover how echinacea powder extract (EPE), an antioxidant, affects the growth rate, body composition, and blood parameters in broilers as an alternative to antibiotics. In a completely randomized design study, four experimental groups received 280 broiler chicks, 5 days old (Cobb 500). Each group was distributed into seven replicates, each containing ten unsexed chicks. Four groups were randomly selected from the chicks; the first group (the control group) was given drinking water only. Conversely, the birds in treatments 2, 3, and 4 were supplemented with EPA in their drinking water. They received 1.0, 2.0, and 3.0 cm3 EPA/liter water every 3 days weekly until the end of the trial (30 days). Our findings found significant differences in avian mass between experimental treatments during growth phases. The control group weighed 887 g, while the 3.0 cm3 EPE group weighed 850 g. The Duncan test showed a difference in FI and FCR among those favoring the EPE groups. Our results showed no significant changes in carcass features, except for spleen, gizzard, and abdominal fat, with the 3.0 cm3 EPE group having weight-higher organs and lower abdominal fat. Also, the control had higher TP, albumin, and globulin levels, while the EPE diet increased ALT and AST and decreased TC, TG, LDL, and VLDL levels. Furthermore, EPE-containing diets resulted in higher IgG concentrations, lower MDA levels, and higher SOD activity compared to the control group. According to the ANOVA analysis, the water consumption rate did not significantly differ across the trial groups. It included adding EPE with 3.0 cm3 enhanced growth performance, carcass traits, and antioxidant activity to obtain health outcomes for end users.

Catalog-level blinding on the bispectrum for DESI-like galaxy surveys

We evaluate the performance of the catalog-level blind analysis technique (blinding) presented in Brieden et al. (2020) in the context of a fixed template power spectrum and bispectrum analysis. This blinding scheme, which is tailored for galaxy redshift surveys similar to the Dark Energy Spectroscopic Instrument (DESI), has two components: the so-called “AP blinding” (concerning the dilation parameters α ∥, α ⊥) and “RSD blinding” (redshift space distortions, affecting the growth rate parameter f). Through extensive testing, including checks for the RSD part in cubic boxes, the impact of AP blinding on mocks with realistic survey sky coverage, and the implementation of a full AP+RSD blinding pipeline, our analysis demonstrates the effectiveness of the technique in preserving the integrity of cosmological parameter estimation when the analysis includes the bispectrum statistic. We emphasize the critical role of sophisticated — and difficult to accidentally unblind — blinding methods in precision cosmology.

Difference in the toxic effects of micro and nano ZnO particles on L. minor - an integrative approach.

The toxicity of nano-sized ZnO particles (nZnO) was evaluated and compared to that of their micro-sized counterparts (mZnO) using an integrative approach to investigate the mechanism of toxicity, utilizing duckweed (Lemna minor) as plant model. Following 7days of exposure to nZnO or mZnO (2.5, 5, 25, and 50mg L-1) growth rate, photosynthesis, oxidative stress, and genotoxicity parameters have been determined in duckweed. Phytotoxicity of both ZnO forms at relatively low concentrations was due to the release of free Zn ions into the nutrient media. However, the accumulation of Zn in plants treated with nZnO was significantly higher than in those treated with mZnO. Both mZnO and nZnO significantly reduced growth rate and impaired the functionality of the photosynthetic apparatus as evidenced by structural changes of chloroplasts, a decline in the efficiency of photosystem II, and chlorophyll a content. Additionally, exposure to mZnO and nZnO resulted in the accumulation of reactive oxygen species (ROS), increased lipid peroxidation, the formation of carbonylated proteins, DNA damage, and alterations in antioxidant defense mechanisms. Overall, nZnO caused significantly stronger toxic effects than mZnO. The mechanism of nZnO toxicity to L. minor, as determined by multivariate statistical analysis, involved the disruption of primary photosynthetic reactions due to a redox imbalance in the cell caused by the enhanced absorption of Zn into plant tissues.

Effects of Zinc Oxide Nanoparticles (ZnO NPs) on Growth, Immune Responses and Histopathological Alterations in Asian Seabass (Lates calcarifer, Bloch 1790) under Low-Salinity Conditions.

In the present study, Asian seabass (Lates calcarifer, Bloch) fingerings were used as an animal model to investigate the toxicological effects of zinc oxide nanoparticles (ZnO NPs) under 5 ppt estuarine conditions. The fish were exposed to 0, 1, 5 or 50 ppm ZnO NPs for 8 weeks. It was found that ZnO NP concentrations of 5-50 ppm negatively affected several growth rate parameters, such as the weight and total length of the fish. Additionally, 5 and 50 ppm ZnO NPs led to 32.55% and 100% mortality, respectively, after 8 weeks after exposure (WAE). Furthermore, compared with the control, exposure to 1-50 ppm ZnO NPs strongly affected hematological indices, such as total blood cells, red blood cells, leukocytes and hematocrit, and suppressed lysozyme activity, superoxide anion production and bactericidal activity. High Zn concentrations accumulated in the head kidney, gills and liver, whereas low levels were detected in the gut, skin and muscle. Expression analysis of immune-related genes via quantitative real-time RT-PCR revealed that 5 and 50 ppm ZnO NPs significantly upregulated the cc and cd4 genes at 1 WAE. In contrast, 50 ppm ZnNPs downregulated the expression levels of the cd8, cc, hsp70, hsp90, tcrα, lyz and igmh genes at 1 WAE (p < 0.05). Finally, at 8 WAE, histopathological analysis revealed that 5 and 50 ppm ZnO NPs severely induced alterations in the head kidney, gills and liver.

A study on the effect of fluorescently stained micro(nano)plastics on the full life history of Skeletonema costatum

As a new type of environmental pollutant, micro(nano)plastics have become a research hotspot in recent years, and their effects on the full life history of marine microalgae have not been studied. To investigate the effects of micro(nano)plastics on the growth, photosynthesis, physiological morphology and interaction of microalgae during the full life cycle, we selected fluorescently stained polystyrene (PS) plastic microbeads as the target pollutant. By sampling and testing the growth rate, photosynthesis and physiological morphology parameters of algal species, the influence of different concentrations of PS (10, 50 and 100 mg/L) and different particle sizes (0.1, 0.5 and 1 μm) on the full life history of Skeletonema costatum (S. costatum) was investigated. The results showed that after adding PS (particle sizes of 0.5 and 1 μm), the response of S. costatum showed a dual character, while adding the same kind of microplastics (MPs) with a particle size of 0.1 μm inhibited S. costatum throughout the full life cycle. Compared with previous studies, short-term experimental data may overestimate the true ecological risks of MPs. In addition, 0.1 μm fluorescent-stained MPs obviously accumulated around the microalgae, indicating that MPs mainly adhered to the surface of algal cells and may enter the food chain by direct or indirect ways, which can cause negative effects on the aquatic ecosystem. This study supports a more accurate assessment of the true risk of MPs to marine aquatic ecosystems.

Turing–Hopf bifurcation in a diffusive predator–prey model with schooling behavior and Smith growth

This paper explores the dynamics of a diffusive predator–prey model, considering schooling behavior and Smith growth in prey. Initially, we have formulated the pertinent characteristic equations. Subsequently, We proceed to examine the existence of the Turing bifurcation and Hopf bifurcation, phenomena that describe the emergence of spatial and temporal patterns due to diffusion and oscillations, respectively, and focusing on the parameters of the intrinsic growth rate γ and the diffusion coefficient d2 of the prey. Finally, we conduct numerical simulations to validate our theoretical findings and further illustrate the dynamics of the predator–prey system, considering schooling behavior and Smith growth in prey.

Growth and biomass of Wolffia arrhiza with different sources of organic fertilizer

Wolffia arrhiza has a growth rate and biomass as well as a good nutritional content for the growth of cultivated fish, especially herbivorous fish. Due to the high protein content (up to 45% of the dry weight), Wolffia is an excellent plant for the production of various biologically active substances, especially proteins. These plants can double every 1-6 days, similar to algae or mushrooms, and the number of leaves doubles every 2-3 days. This study aims to determine the effect of different fertilizer sources on doubling time, relative growth rate, population density and biomass of Wolffia arrhiza and water quality. The method used in this research is experimental. The research design used a completely randomized design (CRD) consisting of 4 treatments and 3 replications. The treatments were as follows: treatment A: chicken manure, B: cow manure, C: buffalo manure and D: goat manure with each dose of 200 grams. Parameters observed included doubling time, relative growth rate, population density, biomass and water quality parameters. The results showed that treatment B (cow manure) gave the highest value for doubling time, 1.59 days, relative growth rate 0.392 g/day, population density 209.75 ind/cm2, biomass 94.97. Keyword: Biomass; Fertilizer; Growth; Wolffia

Mechanisms and Applications of Pseudomonas monteilii SX001: A Promising Agent for Improving Cucumber Tolerance to Salt Stress

To investigate the effects of Pseudomonas monteilii SX001 on various parameters of cucumber plants under salt stress, the salt-sensitive cucumber variety “Jinyou No. 4” was used as the test material, and coconut bran was used to simulate salt stress by applying NaCl solution. The results indicated that salt stress significantly reduced the morphological structure, relative growth rate, root morphology, and photosynthetic parameters of the cucumber plants. Leaf starch, soluble sugar, and sucrose contents significantly increased, whereas their levels in roots decreased. Cell membrane damage leads to the accumulation of reactive oxygen species and malondialdehyde, with notable increases in the activities of major antioxidant enzymes such as SOD, CAT, and POD. Nitrogen metabolism was disrupted, as evidenced by a significant decrease in nitrate nitrogen content and an increase in ammonium nitrogen content, as well as a significant reduction in the activity of NR enzymes involved in nitrogen metabolism. The enzyme activity in the cucumber rhizosphere soil decreased. However, Pseudomonas monteilii SX001 significantly enhanced the growth of cucumber seedlings under salt stress, improved photosynthetic efficiency, and facilitated sugar transformation and transport via glucose metabolism. Additionally, Pseudomonas monteilii SX001 reduced the reactive oxygen content and increased antioxidant enzyme activity. It also increased the activity of substrate enzymes and decreased the diversity of rhizosphere soil microorganisms but also increased the abundance of Asticcacaulis, Acinetobacter, Brevundimonas, Pseudomonas, and Enterobacter. These findings demonstrate that Pseudomonas monteilii SX001 is a promising bioinoculant for alleviating salt stress in cucumber production and improving soil health.

Growth of organized flow coherent motions within a single-stream shear layer: 4D-PTV measurements

This study investigates the evolution of a single-stream shear layer (SSSL) originating from a wall boundary layer past a backward-facing step. Utilizing a time-resolved 3D-Particle Tracking Velocimetry (4D-PTV) technique, we track the trajectories of fluorescent particles to gain insight into the flow characteristics of the SSSL. A compact water tunnel facility (Reτ=1240\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ extrm{Re}_\ au =1\\,240$$\\end{document}) is fabricated to obtain an SSSL with a perpendicular slow entrainment stream past the separation edge. A hybrid interpolation approach that combines ensemble binning and Gaussian weighting is implemented to derive minimally filtered mean and instantaneous lower- and higher-order flow field parameters. Spanwise-dominant coherent motion accompanied by finer flow scales is observed to grow due to flow entrainment through “nibbling” actions of small-scale vortices, “engulfing” by large-scale vortices, and vortex pairing events. Furthermore, the non-zero-speed stream edge grows relatively faster than the zero-speed stream edge, showing a strong asymmetry in mixing composition across a mixing layer. The SSSL reaches self-similarity at a streamwise distance of ≈55θ0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\approx 55\\,\ heta _{0}$$\\end{document}, where θ0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta _0$$\\end{document} is the initial momentum thickness from the separation edge, i.e., considerably shorter than reported in previous studies. A literature comparison of growth rate parameters raises intriguing questions regarding a potential inclusive growth scaling unifying the free shear layers. A turbulent kinetic energy (TKE) budget analysis reveals a negative production region immediately downstream of the separation edge attributed to a large positive streamwise gradient of streamwise velocity. In the self-similar region, the phase-averaged flow mapping demonstrates a larger concentration of turbulence production rate around the outer edges of spanwise vortices, specifically at the intersection of braids and vortices. Furthermore, a spatial separation exists in the regions of peak production and dissipation rates within the vortex core region favoring dissipation. The braids exhibit a larger concentration of turbulence diffusion rates, indicating their function as a conduit for exchanging turbulence between neighboring coherent motions.

VARIASI PADAT TEBAR TERHADAP PERTUMBUHAN UDANG VANNAMEI (Litopenaeus vannamei) DENGAN PEMELIHARAAN PADA KOLAM TERPAL HIGH DENSITY POLYETHYLENE (HDPE)

Vaname shrimp (Litopenaeus vannamei) is a type of shrimp that has high economic value and has great potential as an export commodity. The aim of the research was to analyze growth parameters, specific growth rate (SGR) and feed efficiency of vannamei shrimp in HDPE (High Density Polyethylene) tarpaulin ponds with different stocking densities. The research was carried out for 5 months with three treatments (stocking density of 100 shrimp/m3, dense stocking of 150 shrimp/m3 and dense stocking of 200 shrimp/m3) with 3 replications each. The results of the research on the specific growth rate (SGR) parameter had a significant effect (P&gt;0.05), while the feed efficiency level (EP) parameter had no significant effect) on different densities in high Density Polyethylene (HDPE) tarpaulin ponds. The best specific growth rate (SGR) variable was in the 100 head/m2 stocking density treatment with a value of 9.72 ± 0.13b%, while the best feed efficiency variable in the 100 head/m2 treatment was 73.98 ± 5.09a%. Based on this, the treatment of 100 shrimp/m3 is the optimal dense stocking treatment.

On the Disappearance of the Pleiotropic Effect of the N Gene of the Scale Cover in Carp (&lt;i&gt;Сyprinus carpio&lt;/i&gt; L.)

Previously, numerous studies have shown a broad pleiotropic effect of the dominant allele of the scaly cover gene N. Carriers of this allele are inferior to recessive nn homozygotes in terms of growth rate and viability, and also differ in a number of physiological and meristic traits. In the present work, a case of the absence of pleiotropy was found: when scaleless females (ssNn) and males with scattered scale cover (ssnn) were crossed, naked and scattered offspring did not differ in growth rate, viability, and hematological parameters. The pleiotropic effect of the N gene was preserved only in terms of meristic characters. The absence of a negative effect of the N gene on productivity traits opens up the possibility of using naked carps in aquaculture.

Early multi-parameter detection study of lithium-ion batteries based on the ratio of blue to infrared light and gas concentration

As the use of lithium-ion batteries in energy storage and transportation grows, the number of fires and explosions caused by battery thermal runaway increases, emphasizing the vital need for enhanced early detection technology. Existing research does not clarify the effect of airflow environment and detection location on battery smoke flow and detection effectiveness. The purpose of this study is to illuminate the environmental effects on battery smoke diffusion, allowing for the selection of more appropriate detection parameters while also improving detection sensitivity and robustness. Here, the investigation focuses on the smoke characteristics of 18650 LiFePO4 (LFP) batteries, using the ratio of blue to infrared light and concentrations of CO and H2. Additionally, a detrending algorithm was developed to interpret smoke signals, and the smoke characteristics of batteries in different states of diffusion after thermal runaway occurred at different states of charge (SOC) were further investigated. It is shown that the smoke signal values processed by the detrending algorithm are more suitable for smoke detection in thermal runaway batteries. Using smoke and fugitive gas growth rate parameters, the results show that airflow interference is important in promoting smoke diffusion. Notably, the ambient state and the SOC of the battery have a greater influence on the maximum concentration of CO compared to H2. The linear equations and the addition of the environmental influence parameter DR imply that H2 is a better choice as the primary gas parameter for identifying battery runaway. The airflow disruption reduced the smoke response time by around 40 % while having minimal influence on gas diffusion. This study establishes a theoretical foundation for optimizing battery operating environments and gives practical guidelines for the use of multi-parameter monitoring and early detection of lithium-ion batteries. Furthermore, this study improves the safe management and protection of lithium batteries in their application.

Invariant analysis of the two-cell tumor growth model in the brain

In this study, we explore the invariance properties of a tumor growth model involving two distinct cell populations. These populations are characterized by different diffusion coefficients but share a common killing rate. This particular model serves as a representation of tumor growth within the brain. By employing the Lie group method, we unveil a two-dimensional symmetry algebra for cases where both diffusion coefficients are allowed to vary arbitrarily. Interestingly, this method reveals a nine-dimensional symmetry algebra when the diffusion coefficients are held constant. In both scenarios involving varying and constant diffusion coefficients, we conduct similarity reductions to deduce group invariant solutions, thus elucidating the model’s behavior. Notably, our findings demonstrate that the tumor’s growth remains exponential irrespective of the presence or absence of a killing rate. This remarkable phenomenon holds for various configurations of diffusion coefficients. To validate our observations, we employ Mathematica simulations, which corroborate the model’s exponential growth behavior and emphasize the role of killing rates, diffusion coefficients, and growth rate parameters in driving this exponential trend. Also, the conserved flows and conserved quantities of the model are demonstrated.

Using lactoferrin and N-acetylcysteine to augment the growth rate and hemato-biochemical parameters of Egyptian Baladi goats kids

Using lactoferrin and N-acetylcysteine to augment the growth rate and hemato-biochemical parameters of Egyptian Baladi goats kids

Photosynthetic response of Chlamydomonas reinhardtii and Chlamydomonas sp. 1710 to zinc toxicity.

Zinc (Zn) is an essential trace element but can lead to water contamination and ecological deterioration when present in excessive amounts. Therefore, investigating the photosynthetic response of microalgae to Zn stress is of great significance. In this study, we assessed the photosynthetic responses of neutrophilic Chlamydomonas reinhardtii and acidophilic Chlamydomonas sp. 1710 to Zn exposure for 96 h. The specific growth rate (μ), chlorophyll-a (Chl-a) content, and chlorophyll fluorescence parameters were determined. The results demonstrated that Chlamydomonas sp. 1710 was much more tolerant to Zn than C. reinhardtii, with the half-maximal inhibitory concentration (IC50) values of 225.4 mg/L and 23.4 mg/L, respectively. The μ and Chl-a content of C. reinhardtii decreased in the presence of 15 mg/L Zn, whereas those of Chlamydomonas sp. 1710 were unaffected by as high as 100 mg/L Zn. Chlorophyll fluorescence parameters indicated that the regulation of energy dissipation, including non-photochemical quenching, played a crucial role in Zn stress resistance for both Chlamydomonas strains. However, in the case of C. reinhardtii, non-photochemical quenching was inhibited by 5 mg/L Zn in the first 48 h, whereas for Chlamydomonas sp. 1710, it remained unaffected under 100 mg/L Zn. Chlamydomonas sp. 1710 also exhibited a 20 times stronger capacity for regulating the electron transfer rate than C. reinhardtii under Zn stress. The light energy utilization efficiency (α) of Chlamydomonas sp. 1710 had the most highly non-linear correlation with μ, indicating the energy utilization and regulation process of Chlamydomonas sp. 1710 was well protected under Zn stress. Collectively, our findings demonstrate that the photosystem of Chlamydomonas sp. 1710 is much more resilient and tolerant than that of C. reinhardtii under Zn stress.

Growth and Gastrointestinal Conditions of Green Lobster (Panulirus Homarus) With Different Natural Feeding, Which are Raised in a Longline Submerged Cage System on the East Coast of Pangandaran Regency

The purpose of this study was to test what type of natural feed provides growth and physiological conditions of the green lobster gut. One important factor to support the development of aquaculture is appropriate feed to support growth. Efforts can be made in optimizing the growth of sand lobsters through feeding that contains calcium and in natural feed consistently. This study consisted of 4 treatments of natural feed types rich in Calcium and Posfor, namely anchovies, rebon shrimp, gold snails and barnacles. The purpose of this study was to observe different types of natural feed that can increase lobster survival (SR), weight growth rate, intestinal histological features and hepatopancreas in green lobsters and water quality at the study site. The highest survival rate in this study was found in the treatment of rebon shrimp and gold snails of 96%. While the highest growth rate parameter is the treatment of anchovy feed of 113.9 ± 30.7020. Furthermore, the highest intestinal histological condition is the treatment of anchovy feed, namely the area of villi of 1857,667 (?m2) and the number of villi in the intestine in green lobster 1857,667

THE EFFECTIVENESS OF COLCHICINE AND ORYZALIN ON POLYPLOIDY INDUCTION IN TEAK (Tectona grandis Linn. f.) IN VITRO

Indonesian government has launched a community plantation forests program that would be beneficial for remedying shortage in domestic demand for teak wood every year. This program needs to be supported by the availability of quality seeds resources and quality seedlings utilizing polyploid teak (Tectona grandis). Our study aimed to examine the effectiveness of colchicine and oryzalin to modify diploid into polyploid T. grandis based on growth response, morphological, anatomical and cytological alteration, as well as the acclimatization ability of polyploid plantlets. The materials used were aseptic lateral shoots consisting of nodal segments which were immersed in antimitotic agents at the concentration of 0, 15 and 30 μM for 5 days, then cultured on regeneration medium until the 8 weeks and followed by acclimatization. The results showed that colchicine at the concentration of 30 μM was the most effective to induce polyploidy of plantlets in the parameter of high growth rate, the length of internodes, the number of leaf plantlets and increase the leaf surface area and the significant chlorophyll index content compared to the control. Anatomical analysis of polyploid was characterized by increasing the leaf thickness, stomata size, decreased stomatal density and increased chloroplast content in guard cells. Based on cytological examination on polyploidy plantlet, there was an increased in the number of chromosomes in the cell nucleus. The acclimatization of polyploid successfully induced rooting and a 100% survival rate of grown plantlets. Polyploid seedlings were able to grow and well adapted to the new environment of acclimatization