Investigation of the nutritional and functional roles of a combinational use of xylanase and β-glucanase on intestinal health and growth of nursery pigs

Background Xylanase andβ-glucanase combination(XG)hydrolyzes soluble non-starch polysaccharides that are anti-nutritional compounds.This study aimed to evaluate the effects of increasing levels of XG on intestinal health and growth performance of nursery pigs.Methods Forty pigs(6.5±0.4 kg)were assigned to 5 dietary treatments and fed for 35 d in 3 phases(11,9,and 15 d,respectively).Basal diets mainly included corn,soybean meal,and corn distiller's dried grains with solubles,contained phytase(750 FTU/kg),and were supplemented with 5 levels of XG at(1)0,(2)280 TXU/kg xylanase and 125 TGU/kgβ-glucanase,(3)560 and 250,(4)840 and 375,or(5)1,120 and 500,respectively.Growth performance was measured.On d 35,all pigs were euthanized and jejunal mucosa,jejunal digesta,jejunal tissues,and ileal digesta were collected to determine the effects of increasing XG levels and XG intake on intestinal health.Results Increasing XG intake tended to quadratically decrease(P=0.059)viscosity of jejunal digesta(min:1.74 m Pa·s at 751/335(TXU/TGU)/kg).Increasing levels of XG quadratically decreased(P<0.05)Prevotellaceae(min:0.6%at 630/281(TXU/TGU)/kg)in the jejunal mucosa.Increasing XG intake quadratically increased(P<0.05)Lactobacillaceae(max:40.3%at 608/271(TXU/TGU)/kg)in the jejunal mucosa.Increasing XG intake quadratically decreased(P<0.05)Helicobacteraceae(min:1.6%at 560/250(TXU/TGU)/kg)in the jejunal mucosa.Increasing levels of XG tended to linearly decrease(P=0.073)jejunal Ig G and tended to quadratically increase(P=0.085)jejunal villus height to crypt depth ratio(max:2.62 at 560/250(TXU/TGU)/kg).Increasing XG intake tended to linearly increase the apparent ileal digestibility of dry matter(P=0.087)and ether extract(P=0.065).Increasing XG intake linearly increased(P<0.05)average daily gain.Conclusions A combinational use of xylanase andβ-glucanase would hydrolyze the non-starch polysaccharides fractions,positively modulating the jejunal mucosa-associated microbiota.Increased intake of these enzyme combination possibly reduced digesta viscosity and humoral immune response in the jejunum resulting in improved intestinal structure,and ileal digestibility of nutrients,and finally improving growth of nursery pigs.The beneficial effects were maximized at a combination of 550 to 800 TXU/kg xylanase and 250 to 360 TGU/kgβ-glucanase.

Comparative effects of soy protein concentrate,enzyme‑treated soybean meal,and fermented soybean meal replacing animal protein supplements in feeds on growth performance and intestinal health of nursery pigs

Background Soy protein supplements,with high crude protein and less antinutritional factors,are produced from soybean meal by different processes.This study evaluated the comparative effects of various soy protein supplements replacing animal protein supplements in feeds on the intestinal immune status,intestinal oxidative stress,mucosaassociated microbiota,and growth performance of nursery pigs.Methods Sixty nursery pigs(6.6±0.5 kg BW)were allotted to five treatments in a randomized complete block design with initial BW and sex as blocks.Pigs were fed for 39 d in 3 phases(P1,P2,and P3).Treatments were:Control(CON),basal diet with fish meal 4%,2%,and 1%,poultry meal 10%,8%,and 4%,and blood plasma 4%,2%,and 1%for P1,P2,and P3,respectively;basal diet with soy protein concentrate(SPC),enzyme-treated soybean meal(ESB),fermented soybean meal with Lactobacillus(FSBL),and fermented soybean meal with Bacillus(FSBB),replacing 1/3,2/3,and 3/3 of animal protein supplements for P1,P2,and P3,respectively.Data were analyzed using the MIXED procedure in SAS 9.4.Results The SPC did not affect the BW,ADG,and G:F,whereas it tended to reduce(P=0.094)the ADFI and tended to increase(P=0.091)crypt cell proliferation.The ESM did not affect BW,ADG,ADFI,and G:F,whereas tended to decrease(P=0.098)protein carbonyl in jejunal mucosa.The FSBL decreased(P<0.05)BW and ADG,increased(P<0.05)TNF-α,and Klebsiella and tended to increase MDA(P=0.065)and IgG(P=0.089)in jejunal mucosa.The FSBB tended to increase(P=0.073)TNF-α,increased(P<0.05)Clostridium and decreased(P<0.05)Achromobacter and alpha diversity of microbiota in jejunal mucosa.Conclusions Soy protein concentrate,enzyme-treated soybean meal,and fermented soybean meal with Bacillus could reduce the use of animal protein supplements up to 33%until 7 kg body weight,up to 67%from 7 to 11 kg body weight,and entirely from 11 kg body weight without affecting the intestinal health and the growth performance of nursery pigs.Fermented soybean meal with Lactobacillus,however,increased the immune reaction and oxidative stress in the intestine consequently reducing the growth performance.

Weed Management Practices in Nursery Propagation

Weeds are inimical to the nursery growers as they negatively interfere with the growth and aesthetic value of nursery crops. Propagated crops are more vulnerable to weed competition. Nursery growers are adopting hand weeding, mulching, and different herbicides to get rid of the weeds in propagation. However, the most effective and efficient methods for weed control in propagation are still obscure. In this study, we comprehensively review the most used propagation techniques and weed management practices along with their pros and cons. Hand weeding is the most common method of weed control, but it is labor intensive and costly. Nowadays, herbicides are widely used for weeds management. But there are a limited number of registered and labelled herbicides for greenhouse use. Most of the herbicides contain dinitroanilines (DNAs) which inhibit root growth. Along with the leaching problem, several detrimental effects of herbicides have been revealed in propagation. Considering drawbacks of the use of herbicides, mulching in propagation is gaining popularity. But mulch type and depth may affect rooting of cuttings and weed control efficacy. Therefore, it is crucial to conduct additional research aimed at discovering efficient mulching materials and preemergence herbicides for weed control during propagation, while preserving root initiation, plant development, and growth.

Study on Cotton Nursery Substrate Using Cotton Seed Hulls Residue after Producing Edible Mushroom

In order to discuss the localization application technology of cotton seedling using substrate, the author used cotton seed hulls after the production of edible fungi residue, river sand and peat in different proportion formula using in field and laboratory cotton seedling test. The results showed that： dry mass per plant and leaf area per plant of formula 3 were higher than Jiangxi cotton seedling nurs- ery substrate.the higher proportion were 48.4% and 73.5%; the rate of forming plantlets, survival rate of transplant and the unginned cotton yield had no obvious difference with the other matrix seedling and transplanting; nursery substrate was returned using as fertilizer, reduced environment pollution, achieved comprehensive utilization and cyclic utilization. Cotton seed hulls after the production of edible fungi residue was a cotton seedling substrate material of saving work,reducing cost and protecting environment and would have a good application prospect.

Study on Planning and Design of Sightseeing Nursery—A Case Study of Nanchong Huangcheng Garden Ecological Sightseeing Park

By taking Huangcheng Garden Ecological Sightseeing Park for example,the study was conducted from the aspects of its general situation,planning target and guiding ideology,planning layout and landscape planning,project planning,and road traffic engineering planning;proposed seven principles for planning and design of sightseeing nursery,so as to provide reference for planning and design of garden nursery of the similar type.

Interpreting Chinese Nursery Rhymes from Mental Space Theory

Although nursery rhymes and other texts for children often involve implausible or even fantastic combinations of elements,children seem to have no trouble following them.The paper tries to account for the phenomenon in perspective of mental space theory,suggesting that children are adept at the sort of mental process called as conceptual integration.

Impact of Rice Nursery Nutrient Management, Seeding Density and Seedling Age on Yield and Yield Attributes

To help farmers in the mid hills of Nepal improve their crop management and rice yields, we conducted a study testing different nursery management options and their effect on grain yield and yield components under rainfed conditions. The experiment was conducted in a farmer’s field during the cropping season 2009 and 2010 at Sundarbazar, Lamjung, Nepal, using a 3-factor factorial RCB design with 3 replications. The three management factors tested were 1) fertilizer management in the nursery, 2) seeding density, and 3) seedling age at transplanting, using the rainfed lowland rice variety Radha-4. There were eight treatment combinations, consisting of two levels of fertilization (0 and 20:20:0:13 kg NPKS ha-1 at 15 DAS), two levels of seeding density (607 and 303 g·m-2) and two seedling ages (20 and 40 days old). Two years’ results showed that top-dressed fertilizer in the nursery had no consistent effect on grain yield. However, lower seeding density (303 g·m-2) resulted in taller plants, more productive tillers m-2, less sterility and higher grain yield. In addition, older seedlings (40 days) produced taller plants, more productive tillers, more filled grains, and a higher grain and straw yield. The interaction analysis between both factors indicated that 40 days old seedling with a low seeding density produced the highest grain yield, both in the drought season 2009 and the high-yielding season 2010. The economic analysis confirmed that the treatment with low seeding density and 40 days old seedlings produced by far the highest net returns and B:C ratio in both seasons, independent of the fertilizer treatment. The combination of these two management components is therefore economically viable and profitable, and can be recommended to farmers. However, the results need to be confirmed for other varieties used by farmers in the region.

Effects of phosphorus and potassium addition on growth and nodulation of Dalbergia sissoo in the nursery

A study was conducted to test the influence of different inorganic fertilizers （phosphorous and potassium） on the nodulation and growth of Dalbergia sissoo grown in the nursery. Before seeds sowing, different combinations of P, K fertilizers were incorporated with the nutrient-deficient natural forest soils, and then amended with cowdung （soil： cowdung = 3：1）. Nodulation status （nodule number, shape, fresh weight, dry weight and color） in the roots and the plant growth parameters （length of shoot and root, collar diameter, fresh and dry weight of shoot and root） were recorded 60 days after seeds sowing. Nodulation status and growth of the plants varied significantly （P〈0.05） in the soils amended with fertilizers in comparison to the control. The highest nodule number （62）, fresh （0.50 g） and dry （0.07 g） weights were recorded with the dose of PK at the rate of 160 kg/hm2. Nodule shape and color also varied widely in different treatments. In case of plant growth parameters, shoot and root length, collar diameter, fresh and dry weight of the plants took on a significant difference （P〈0.05） among various combination of fertilizers. From the study, it is revealed that PK at the rate of 160 kg/hm^2 fertilizer with soil and cowdung mixture （soil： eowdung = 3：1） is recommended for optimum growth and nodule formation of D. sissoo in degraded soils at a nursery level.

The Sediment and Hydrographic Characteristics of Three Horseshoe Crab Nursery Beaches in Hong Kong

Horseshoe crab juveniles have been recorded from sand and sandy-mud nursery beaches at Pak Nai (western New Territories), San Tau and Shui Hau (Lantau Island), Hong Kong. In order to provide a better understanding of these beaches and to identify those plausible factors which have made them preferred by spawning horseshoe crabs, environmental parameters, including temperature, salinity, pH and dissolved oxygen content of the water, and particle size distribution and organic matter content of the sediments at the three sites, were determined and compared. The hydrographic and sediment data obtained for the three study sites have revealed some common environmental features. The three nursery beaches are relatively remote, and far (in Hong Kong terms) from urbanized and densely populated areas. The beaches are generally well sheltered from strong wave action and inundated regularly by estuarine waters. Horseshoe crab adults tend to select these beaches for spawning as their protected features ensures the laid eggs are less likely to be washed out of the sand, and hatched juveniles can feed on the meiofauna and grow. Sediments of the three beaches largely comprise medium-sized sand particles and are moderately sorted, suggesting medium porosity and good water permeability. Such a sand type, with the generally high oxygen levels in incursing waters, may help create a well-oxygenated micro-environment for the normal development of horseshoe crab eggs, larvae and juveniles. Lantau Island beaches at San Tau and Shui Hau are relatively free from organic pollution, as reflected in generally high dissolved oxygen level, and low BOD 5 and ammonia nitrogen values. Pak Nai is, however, more polluted.

The Quality of Sour Cherry Maidens Fertilized with Various Biopreparations in an Organic Nursery

The study was conducted in an organic nursery of sour cherry cultivars ＂Debreceni Botermo＂ and ＂Sabina＂ in the years 2010 and 2011. Cherry trees grafted on Mahaleb （Prunus mahaleb L.） seedlings were grown at a spacing of 25 crn × 1.0 m. In the nursery, an assessment was carried out of the effect of various biopreparations on such growth characteristics as the thickness and height of the maidens, the formation of lateral shoots and the total increase in their length. The control trees were not treated at all, but fertilized with an NPK fertilizer only （second control）. To stimulate growth, use was made of granular manure, mycorrhizal fungi in the form of the preparation Micosat, humic preparations or so-called vermicomposts （Humus UP, Humus Active）, extracts of marine algae （BF Quality） and of terrestrial plants （BF Arnin）, a product derived from yeast （Vinassa） and Tytanit. The specific biological effects of the preparations used in the sour cherry nursery for each morphological feature are presented in this paper in graphical form. A beneficial effect on the increase in the number of lateral shoots and the increase in their length was produced by the use of such products as： Micosat, Humus UP, Humus Active ＋ Aktywit PM and Vinassa. The most effective in this respect was BF Amin.

Responses of Bruguiera sexangula propagules to beneficial microbes in the nursery

Bruguiera sexangula （Lout） Poir., a threatened mangrove tree, was inoculated with beneficial microbes in a nursery to assess any improvements in growth and bio- mass. From soil samples from the rhizosphere of B. sexangula in a mangrove forest in Panangadu of Kerala India, nitrogen-fixing bacteria Azotobacter chroococcum and Azospirillum brasilense were isolated. The phosphatesolubilising bacterium Bacillus megaterium and potassiummobilizing bacteria Frateruria aurantia were also isolated and cultured on suitable media. Later, ripe propagules of B. sexangula were collected from matured trees and raised in sterilized soil bags （13 × 25 cm） containing sterilized soil and sand （2：1 ratio）. The cultured beneficial microbes were propagated and used to inoculate the ripe propagules of B. sexangula and maintained in the nursery for 6 months. After 6 months, growth and biomass of the inoculated propagules were greater than for the uninoculated control propagules. Shoot length, number of leaves, stem girth and root length were also significantly greater than in the controls. This study showed that the mangrove-specific beneficial microbes influenced the growth of B. sexangula

Dietary substitution of soybean oil with coconut oil in the absence of dietary antibiotics supports growth performance and immune function in nursery and grower pigs

Background:We hypothesized that supplementation of nursery and grower pig diets with coconut oil in the absence of antibiotics would yield maintenance of glucose homeostasis,growth performance,and immune function similar to what is achieved with nursery and grower pig diets containing antibiotics.Pigs received the same base treatment diets from d24(weaning)to d71 of age and had blood and fecal samples collected on d24,d31,d45 and d71 for measurement of whole blood glucose,serum insulin,cortisol and cytokines,and fecal microbiome.Pigs had weekly weights and daily feed consumption measured throughout the study.Animals were euthanized at d71 and subcutaneous fat and ileal contents were collected for assessment for fatty acids and microbiome,respectively.Diet treatments consisted of 2%soybean oil plus antibiotics(ABX;n=22),2%soybean oil without antibiotics(NABX;n=22),and 2%coconut oil without antibiotics(COC;n=22).Statistical analysis examined the effect of diet within each timepoint using a repeated measures ANOVA.Results:Pigs fed COC diet had decreased serum insulin levels,maintained feed intake,feed conversion and weight gain,and,based on serum cytokines and fecal microbiome,were immunologically similar to ABX-fed pigs.However,NABX-fed pigs performed similarly to the ABX-fed pigs in all parameters except for serum cytokines.Additionally,there was no difference in the incidence of diarrhea between any of the diet treatments.Conclusions:This study demonstrates that dietary antibiotics are not necessary to maintain growth performance in nursery and grower pigs.However,dietary antibiotics appear to modulate circulating cytokine levels.Dietary coconut oil is neither harmful nor helpful to growth performance or immune function in nursery and grower pigs but does modulate serum insulin levels.Therefore,while coconut oil fed at 2%by weight is a suitable substitute for dietary antibiotics,this study suggests that no substitute for dietary antibiotics is needed at all.

Treatments Comparison of Mineral and Bio Fertilizers in the Apple and Sour Cherry Organic Nursery

Maiden trees of apple cultivars ＇Topaz＇ and ＇Ariwa＇ grafted on M26 rootstock and of sour cherry cultivars ＇Debreceni Botermo and ＇Sabina＇ on mahaleb cherry （Prunus mahaleb L.） were fertilized with bioproducts such as： Fertigo-granulated manure, Micosat-microbial inoculum consisting of mycorrhizal fungi; Humus UP-an extract from vermicompost; Humus Active ＋ Aktywit PM-an extract from vermicomposts with PM （Positive Microorganism）; BioFeed Amin--a plant extract reinforced with amino acids; BioFeed Quality-a seaweed extract reinforced with humic and fulvic acids; Tytanit-titanium; Vinassa-molasses residue from yeast production; Florovit Eko-composed of many environmentally-friendly products. Control maidens were fertilized with mineral fertilizers containing mainly NPK. The maiden trees fertilized with the preparations Tytanit and Humus UP grew less vigorously and produced smaller increases in the length of lateral shoots than those fertilized with mineral fertilizers. On the other hand, bio preparations such as BF Amin, BF Quality, Micosat and Vinassa promoted tree branching and intensified the growth of lateral shoots, stimulating tree growth to a greater extent than the mineral fertilizers.

THE DISCUSSION ON THE MEASURES OF INCREASING NURSERY STOCK QUALITY IN FRIGID REGION OF CHINA

Through several years seedling-growing experiments in nursery in Daxing‘anMountains forest region,the author posed that the seedling cultivated for the region mustpossess the characteristics of being suited to thin and meager soil and having strongresistance to adverse conditions.For this purpose,the cultivation regime ought to bedirectization,standardization and programmatization;seedling growth ought to be promotedby regulating ecological conditions;and the mursery stock quality ought to be tested usingvigor index.

Addition of tert-butylhydroquinone(TBHQ)to maize oil reduces lipid oxidation but does not prevent reductions in serum vitamin E in nursery pigs

Background: Maize oil is abundantly used in foods and feeds and is highly susceptible to oxidation. Consequently,commercially available antioxidants should be evaluated for effectiveness against lipid oxidation in swine diets. Our study was conducted to evaluate growth performance of nursery pigs fed oxidized maize oil and to determine effects of using antioxidants on oxidative status in a 2 × 2 factorial design. Two hundred eight weaned pigs were blocked by initial BW into 13 blocks, resulting in 4 pigs per pen and 13 pens per treatment. Dietary treatments included 6% unoxidized or oxidized maize oil, and 0 or 60 mg/kg of tert-butylhydroquinone(TBHQ), which was added after lipid oxidation. Data for growth performance were collected from 5 time periods of a two-phase feeding program(Phase 1 = d 0 to 12 and Phase 2 = d 13 to 34). Serum and liver samples were collected from one pig per pen, which had initial BW closest to average BW to determine oxidative status on d 34.Results: Oxidized maize oil was heated for 12 h at 185 °C with 12 L/min of air, yielding a peroxide value(PV) of 5.98 m Eq O2/kg and TBARS of 0.11 mg MDA eq/g. Addition of TBHQ to diets containing oxidized maize oil decreased PV by 37% and increased the oil stability index by 69%. Final BW, ADG, ADFI, and G:F of pigs were not different among the four dietary treatments. However, pigs fed oxidized maize oil tended(P < 0.08) to increase hepatosomatic index by 5% compared with those fed unoxidized oil, and this was not affected by adding TBHQ.The serum vitamin E concentration of pigs fed oxidized maize oil was less(P < 0.03) than pigs fed unoxidized oil,but this reduction was not reversed by adding TBHQ. Finally, the serum and liver selenium concentration were not different among the treatments.Conclusions: The addition of TBHQ did not affect growth performance and vitamin E status in pigs fed moderately oxidized maize oil, but TBHQ reduced lipid oxidation, enhanced the oil stability, and appeared to reduce oxidative stress.

EFFECTS OF SOIL MOISTURE CONTENT ON DRY NURSERY SEEDLING QUALITY OF LATE DOUBLE CROPPING RICE IN SOUTH CHINA

In the present paper, an experiment was conducted to study the effects of soil moisture content on dry nursery seedling quality in Guangzhou in 1995. Through comparing the difference of dry nursery seedlings and wet nursery seedlings, we found a close relationship between soil moisture content and seedling growth. The seedling emergence of dry nursery seedling was more even, tidy and faster, and the survival rate was higher than that of wet nursery seedling. Dry nursery seedlings had small plant stature, slow leaf stretching speed and low individual seedling dry weight, but had high dry/fresh weight ratio. This was abeneficial factor for seedlings to recover from transplanting shock more quickly. As com-pared with the wet nursery seedlings, dry nursery seedlings had poor rooting ability,but had more vigorous white roots and fewer rust roots. It was the possibly important reasonfor dry nursery seedlings to form strong“explosive force”.

Role of milk carbohydrates in intestinal health of nursery pigs: a review

Intestinal health is essential for the resistance to enteric diseases and for nutrient digestion and absorption to support growth.The intestine of nursery pigs are immature and vulnerable to external challenges,which cause negative impacts on the structure and function of the intestine.Among nutritional interventions,the benefits of milk are significant for the intestinal health of pigs.Milk coproducts have traditionally been used in starter feeds to improve the growth of nursery pigs,but their use is somewhat limited due to the high costs and potential risks of excessive lactose on the intestine.Thus,understanding a proper feeding level of milk carbohydrates is an important start of the feeding strategy.For nursery pigs,lactose is considered a highly digestible energy source compared with plant-based starch,whereas milk oligosaccharides are considered bioactive compounds modulating intestinal immunity and microbiota.Therefore,milk carbohydrates,mainly composed of lactose and oligosaccharides,have essential roles in the intestinal development and functions of nursery pigs.The proper feeding levels of lactose in starter feeds could be variable by weaning age,body weight,or genetic lines.Effects of lactose and milk oligosaccharides have been broadly studied in human health and animal production.Therefore,this review focuses on the mechanisms of lactose and milk oligosaccharides affecting intestinal maturation and functions through modulation of enterocyte proliferation,intestinal immunity,and intestinal microbiota of nursery pigs.

Impacts of weaning weights and mycotoxin challenges on jejunal mucosa-associated microbiota,intestinal and systemic health,and growth performance of nursery pigs

Background:This study aimed at investigating the effects of mycotoxin challenge on the growth and physiology of nursery pigs with different weaning weights.Results:At weaning,10 pigs were euthanized to collect jejunal mucosa and 90 pigs were assigned following a randomized complete block design in a 2×2 factorial arrangement of treatments with 3 pigs per pen.Factors were:weaning weight(light:body weight,BW<7.5 kg or heavy:BW>9.0 kg);and dietary mycotoxins(supplementation of 0.2 mg/kg aflatoxins,2.0 mg/kg deoxynivalenol).All diets had titanium dioxide as an external marker at 0.5%.Growth performance and fecal score were recorded until pigs achieved 20 kg BW(light pigs average BW=21.1 kg and heavy pigs average BW=20.5 kg).Pigs were sampled for blood,ileal digesta,jejunal tissue and mucosa at 20 kg BW.Data were analyzed using the mixed procedure of SAS.At weaning,light pigs had decreased(P<0.05)jejunal interleukin-8,increased(P<0.05)tumor necrosis factor-α,and increased(P<0.05)α-diversity indexes of jejunal mucosa-associated microbiota.At 20 kg of BW,light pigs had decreased(P<0.05)average daily gain(ADG),average daily feed intake(ADFI),and gain to feed ratio(G/F).Mycotoxins decreased(P<0.05)BW,ADG,ADFI,and G/F.Light pigs tended to have increased fecal score on d 0(P=0.080),d 10(P=0.069),and increased(P<0.05)fecal score at 20 kg.Mycotoxins decreased the apparent ileal digestibility of nitrogen(P<0.05).Light pigs had increased(P<0.05)intestinal malondialdehydes and interleukin 8.Mycotoxins tended to increase(P=0.060)intestinal tumor necrosis factor-α.Conclusions:Nursery pigs with light weaning weight were more susceptible to jejunal inflammation and had impaired intestinal health due to weaning stress,whereas mycotoxins diminished the health and growth of nursery pigs regardless of weaning weight.

EFFECTS OF SEEDING DENSITY AND BASIC MANURE ON THE GROWTH OF DRY NURSERY SEEDLINGS IN LATE DOUBLE CROPPING RICE IN SOUTH CHINA

During the period of dry nursery seedling raising of late double cropping indica rice in South China, both chemical fertilizer and farmyard manure did not show obvious effect on the growth of shoot and root in young seedlings at 4-leaf stage （18-day-old seedling）, but had significant effects on root growth in old seedlings with 6-7 leaves （27-day-old seedling） at suitable seeding densities (65-125g m-2). There were satistically significant differences （at 0.01 or 0.05 levels）between treatments in root number and rooting ability of root-pruned seedlings.

Temporal and spatial variation of fish community and their nursery in a tropical seagrass meadow

Fish species composition and spatio-temporal variability of the community were studied in a tropical seagrass meadow located in a lagoon in the eastern part of North Sulawesi. The diversity of fish community in the seagrass meadows was relatively high, with the Shannon-Wiener index ranging from 1.57 to 3.69. The family Apogonidae was the most dominant in abundance(8.27 ind./(100 m2)) and biomass(28.49 g/(100 m2)). At the species level,Apogon lateralis and Sphaeramia orbicularis were the most dominant species in abundance and biomass,respectively. For spatial distribution on species, the end, middle and mouth of the lagoon clustered together as a whole, which may be due to the substrate types found in those zones. The fish species, fish abundance and fish biomass were greater in the dry and wet seasons than in the transition season, which is explained by the strong monsoon, which provides a more suitable environment and food for the fish. The maximum length of 93.10% of the captured species was less than their length at maturity, indicating that seagrass meadows are nursery habitats for many fishes. Therefore, protection of the seagrass meadows is essential for fisheries and sustainable resource utilization.