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1.
The proximate composition of three varieties ofPiper guineense (Odusa — Ibibio/Efik) viz. Uyat Odusa (cultivated and peppery), Eting-keni Ikot (wild forest variety) and Eting-keni mben inyang (wild, riverine variety), were determined using available standard methods. Also determined were mineral, antinutrient and ascorbate levels. The cultivated pepperic variety had the highest content of crude protein and moisture (18.9% and 97% respectively) while the wild, riverine variety had the highest content of ether extract, carbohydrate and calories (7.79%, 63.38% and 398 cals respectively). The cultivated variety had appreciable amounts of phosphorus (1.12 mg/100 g), potassium (1.2 mg/100 g), sodium (0.24 mg/100 g), zinc (0.18 mg/100 g), and copper (0.18 mg/100 g) while the forest variety contained more of calcium (12.38 mg/100 g), magnesium (1.21 mg/100 g) and iron (0.85 mg/100 g). The wild riverine variety appeared to have the least mineral content but had the highest ascorbate level of 173.4 mg/100 g. Of four antinutrients assayed, the cultivated pepperic one had the least quantities while the forest variety was highest in hydrocyanic acid (85.8 mg/100 g) and glucosinolates (0.20 mg/100 g). The wild riverine variety had the highest level of total oxalate (165.0 mg/100 g). These quantities are however far below documented toxic levels.  相似文献   

2.
Thermally modified wood is being increasingly offered in Europe as an alternative to preservative-treated timber. The aim of this study is to determine the change of various physical properties (oven-dry density, air-dry density, weight loss, swelling and anti-swelling efficiency (ASE)), compression strength parallel to grain, colour difference (ΔE), glossiness and surface roughness of sapele (Entandrophragma cylindricum), limba (Terminalia superba) and iroko (Chlorophora excelsa) woods after heat treatment under different temperatures and durations. For this study wood specimens were subjected to heat treatment under atmospheric pressure and air at two different temperatures (160 °C and 180 °C) and two different times (2 h and 4 h). Multiple physical properties (oven-dry density, air-dry density, and swelling), compression strength parallel to the grain and surface roughness of the heat-treated wood and control samples were tested. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements using the stylus method were made in the direction perpendicular to the fiber. Four main roughness parameters which are mean arithmetic deviation of profile (Ra), mean peak-tovalley height (Rz), root mean square roughness (Rq), and maximum roughness (Ry) obtained from the surface of wood were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Significant difference was found (P = 0.05) between physical and technological properties, and surface roughness parameters (Ra, Rz, Ry, Rq) at two temperatures and two durations of heat treatment. Based on the findings of this study, the results showed that oven-dry density, air-dry density, swelling, compression strength parallel to grain and surface roughness values decreased with increasing treatment temperature and treatment time. Thus, sapele, iroko, and limba wood can be utilized with proper heat treatment techniques for outdoor and indoor applications.  相似文献   

3.
Three Lolium perenne L. genotypes collected from different natural habitats were tested for the effects of their fungal endophyte Neotyphodium spp. on plant growth and seed yield. Half the clones of the originally infected plants were subjected to fungicide treatment to eradicate the endophytes. In an experiment, the clones were planted separately into pots and were either watered adequately or subjected to drought stress. In the genotype collected from a dry site, the endophyte infection reduced plant growth at an adequate water supply, but increased regrowth under drought. In the genotype from a periodically either flooded or dry site, endophyte infection significantly promoted the development of reproductive tillers and seed production (effects which are associated with adaptation to drought). In contrast, the genotype that originated from a wet site showed higher sensitivity to drought stress when endophyte infection was present. The results suggest that environmental conditions in the original habitat of the plants may influence the symbiotic interaction between plant and fungus, probably through natural selection. However, endophyte‐induced increases in root dry weight and root/shoot ratio were recorded for all three genotypes. These features could be beneficial for plant persistence, especially on sites where water is the growth‐limiting factor.  相似文献   

4.
棕榈藤是菲律宾最重要的非木材林产品之一,在菲律宾的经济社会发展中占有一定的地位。文章介绍菲律宾的棕榈藤资源状况及资源保护与管理的法规;基于菲律宾的林业统计数据,综合分析棕榈藤材的生产及其产品开发与贸易的发展现状,对于我国发展棕榈藤业具有很好的借鉴意义。  相似文献   

5.
Three Tomicus pine shoot beetles, T. yunnanensis (Kirkendall and Faccoli) (Coleoptera: Scolytidae), T. minor (Hartig), and T. brevipilosus (Wood and Bright), have been causing serious damage to Yunnan pine ( Pinus yunnanensis (Franchet) (Pinales: Pinaceae)) stands in Yunnan, southwestern China. However, their ability to coexist in the crowns of the same trees during the shoot-feeding phase has not been elucidated. In our study, we investigated and compared the shoot-feeding ecology of the three species of pine shoot beetle in P. yunnanensis in Anning County, Yunnan Province. Shoot-feeding by T. yunnanensis, T. minor, and T. brevipilosus initiated in April, May, and June, and ended in February, April, and May, respectively. Individual T. yunnanensis and T. minor adults fed in shoots for about seven months, and T. brevipilosus for nine months, before initiating reproduction. All three Tomicus species fed in the current-year shoots close to the apical bud. No specific overwintering behavior was observed prior to reproduction. The entrance hole of T. yunnanensis was furthest away from the apical bud, and T. minor was the closest to the apical bud. Differences in the spatial distribution of these shoot-feeding sites might reduce competition among the three beetle species. The long-lasting and overlapping shoot-feeding by the three Tomicus species may reduce the resistance of P. yunnanensis and facilitate the reproduction of these beetles in the trunks of living trees, and thus help explain the severe damage by Tomicus in P. yunnanensis.  相似文献   

6.
Toxicities of the eight quinones were evaluated through leaf dip bioassays conducted against Tetranychus urticae, Myzus persicae, Myzocallis walshii, and Illinoia liriodendri. Based on LC50 values, plumbagin (LC50 = 0.001%) was the most active compound against T. urticae and ubiquinone Q0 (LC50 = 0.005%), plumbagin (LC50 = 0.010%), and dibromothymoquinone (LC50 = 0.012%) were the most active compounds against M. persicae. The most active compounds against M. walshii were juglone (LC50 = 0.011%) and ubiquinone Q0 (LC50 = 0.019%), whereas dibromothymoquinone (LC50 = 0.030%), plumbagin (LC50 = 0.033%) and ubiquinone Q0 (LC50 = 0.058%) were the most toxic to I. liriodendri. Ecotrol (positive control) was the least toxic compound (LC50 = 0.39%) against T. urticae and M. persicae (LC50 = 0.447%). Although the majority of the compounds tested were toxic to all four test species in residual bioassays, there was little overlap among the test species in terms of susceptibility to the compounds and interspecific differences were observed. Regarding structure-activity relationships for quinones, the addition of a hydroxyl group resulted in a significant increase in the toxicity of the 1,4-naphthoquinones, and those possessing a methyl group exhibited the highest levels of activity in T. urticae. The bromine atom at the 2- and 5-positions of the benzoquinone ring is crucial to the toxicity of the compounds against I. liriodendri. Toxicity was greatly affected not only by the number of hydroxyl groups, but also by their positions in the ring in the case of M. walshii. Juglone and plumbagin as residual toxins in the laboratory also reduced the population of two-spotted spider mites compared to EcoTrol™ (positive control) and the negative control in the greenhouse experiment. Some quinones tested may have potential as commercial insecticides and miticides, or alternatively, could serve as lead compounds for the development of more potent crop protection agents.  相似文献   

7.
成良计 《杂交水稻》2005,20(1):60-64
稻米是菲律宾人的主要食物. 多年来,菲人口快速增长,消费需求压力很大.虽然大面积推广现代水稻品种,促进了粮食大幅度增长,但是稻米生产整体水平低,不能满足人口快速增长的消费需求,每年要进口稻米60万t以上.实现菲律宾稻米自给的最佳途径是加快杂交水稻发展,工作的重点是尽快解决投入不足、种子短缺、推广乏力等问题.  相似文献   

8.
Calonectria pauciramosa is a pathogen of numerous plant hosts worldwide. Recent studies have indicated that it included cryptic species, some of which are identified in this study. Isolates from various geographical origins were collected and compared based on morphology, DNA sequence data of the β-tubulin, histone H3 and translation elongation factor-1α regions and mating compatibility. Comparisons of the DNA sequence data and mating compatibility revealed three new species. These included Ca. colombiana sp. nov. from Colombia, Ca. polizzii sp. nov. from Italy and Ca. zuluensis sp. nov. from South Africa, all of which had distinguishing morphological features. Based on DNA sequence data, Ca. brasiliensis is also elevated to species level.Taxonomic novelties: Calonectria brasiliensis (Bat. & Cif.) L. Lombard, M.J. Wingf. & Crous, comb. nov., Calonectria colombiana L. Lombard, Crous & M.J. Wingf., sp. nov., Calonectria polizzii L. Lombard, Crous & M.J. Wingf., sp. nov., Calonectria zuluensis L. Lombard, Crous & M.J. Wingf., sp. nov.  相似文献   

9.
介绍了菲律宾杂交水稻的发展现状及发展中存在的诸多障碍,提出了相关发展对策.  相似文献   

10.
11.
This study investigated the effects of advancing stage of maturity and additive treatment on the fermentation characteristics of three common grassland species. Perennial ryegrass (PRG; Lolium perenne L., var. Gandalf), timothy (Phleum pratense L., var. Erecta) and red clover (Trifolium pratense L., var. Merviot) were harvested at three dates in the primary growth (11 May, 8 June and 6 July; Harvests 1–3) and ensiled with the following additive treatments: (1) control (i.e. no treatment), (2) formic acid‐based additive, (3) homofermentative lactic acid bacterial (LAB) inoculant and (4) heterofermentative LAB inoculant. Additive application to the PRG (irrespective of harvest date), the late‐harvest timothy (Harvest 3) and the red clover (Harvests 2 and 3) herbages had little impact on silage fermentation characteristics, where a lactic acid dominant fermentation already prevailed. However, the application of the formic acid‐based additive to the Harvest 1 and 2 timothy and Harvest 1 red clover herbages, where the silage fermentation characteristics were poorer, resulted in an increase in the proportion of lactic acid in total fermentation products and a decrease in pH. In contrast, the heterofermentative LAB inoculant had a negative impact on silage fermentation characteristics where a poor preservation prevailed in the corresponding control silage.  相似文献   

12.
The aim of the present study was to obtain quantitative information on egg hatching with respect to temperature and light to clarify the effect of cultivation methods on three Japanese Sympetrum species. Eggs of three Sympetrum species were collected on October 2005 at Akita prefecture located at north of Japan, and the eggs had been laid on soil surface of paddy field till April 2006. The eggs (3 trays with 50 eggs each) were held under four constant temperatures (8, 13, 18 and 23°C) with a photoperiod (L:D 14:10; relative light intensity 3,000 Lux) and 23°C in darkness. No S. infuscatum eggs, but 67 and 60% S. frequens and S. darwinianum hatched in constant darkness. This result suggests that S.frequens and S.darwinianum do not require light for hatching, but S.infuscatum requires light for hatching. Eggs of S. darwinianum and S. infuscatum did not hatch at 8°C. In S. frequens, some eggs hatched but the hatching rate was significantly lower at 8°C than at higher temperatures (P < 0.05). At higher temperatures, the hatching rate did not differ significantly for three Sympetrum species. At 13°C, S. infuscatum hatched fastest, 0.18 for S. infuscatum, 0.11 for S. darwinianum and 0.08 for S. frequens. The mean head width of second stadium larva of S. frequens, S. darwinianum and S. infuscatum were 0.4 ± 0.01, 0.4 ± 0.01 and 0.6 ± 0.01 mm (SD), respectively. These results suggest that S. infuscatum may have a competitive advantage over S. frequens and S. darwinianum under conditions that favor S. infuscatum through hatching speed.  相似文献   

13.
Potato production using true potato seed (TPS) was evaluated with a cooperative group of farmers. The cooperative grew TPS or seed tubers (1 to 3 g) produced from TPS in beds in screenhouses to avoidPseudomonas solanacearum (BW). From 250 to 400 tubers/m2 were obtained. Tubers > 3 g were replanted by farmers at high elevation for further multiplication. Yields always exceeded the control (clonally produced cultivar). Seed tubers from TPS of 3 to 5 g produced up to 32 t/ha resulting in a multiplication rate of 145:1. Farmers are in various stages of adopting this technology. An early maturing progeny with resistance to BW is needed to permit a more rapid spread of this technology.  相似文献   

14.
We investigated the post-passage movement patterns of three freshwater fish species, Carassius auratus, Hemibarbus longirostris, and Silurus asotus, frequently captured in a fishway trap as they were released into the lentic dam reservoir. Acoustic telemetry was used to monitor fish movement. Acoustic tags were attached to 10 individuals (C. auratus, [n = 6], Ca1–6; H. longirostris, [n = 2], Hl1 and Hl2; and S. asotus, [n = 2], Sa1 and Sa2). The individual (Sa1) was particularly monitored to changes of vertical distribution between day and night a depth transmitter. The lentic species, C. auratus and S. asotus, were grouped into those that moved into upper streams (Ca1, Ca2, Ca3, and Sa1) and those that stayed in the reservoir (Ca4, Ca5, Ca6, and Sa2); all individuals utilized almost the entire area of the reservoir. However, H. longirostris, which favor lotic environments, showed different responses; one (Hl1) immediately moved into one of upper the streams, whereas the other (Hl2) utilized the entire dam reservoir area. No significant correlations were observed between size of the C. auratus individuals (total length and total weight) and monitored parameters (total movement distance, movement distance per day, and number of receivers encountered). Moreover, S. asotus used the water at a mean depth of 2.89 ± 1.52 m, and its vertical distribution changed more actively during the night than that during the day. Therefore, the efficacy of the Jangheung Dam fishway could be improved through release of the confluence of the inflow streams at the dam reservoir, which would provide both lentic and lotic environments without extended migration for fish.  相似文献   

15.
16.
A series of 14 on-farm trials indicated that improved seed-storage facilities, in the form of additional diffuse light and ventilation, may considerably reduce losses of seed-tubers and result in a better quality product: less weight loss in store, more sprouts per tuber and shorter, more robust, sprouts. This improvement resulted generally in improved emergence, stem number per hill, yield of marketable tubers and economic return. The improved onfarm stores compared favourably with the refrigerated storage available locally.  相似文献   

17.
菲律宾杂交水稻发展现状与对策   总被引:2,自引:0,他引:2  
菲律宾从1995年开始与中国合作进行杂交水稻研究与开发,经过6a努力,杂交水稻技术已基本成熟。介绍了菲律宾杂交水稻育种、制种和推广的现状,杂交水稻发展中存在的一些问题及其相应的发展对策。  相似文献   

18.
Grasses on the Pakistani coast are moderately to highly salt tolerant and have potential for utilization as a cash crop. This study was designed to determine whether seed germination of three halophytic grasses (Phragmites karka, Dichanthium annulatum and Eragrostis ciliaris) could be improved by exogenous application of ascorbic acid (AsA) under saline conditions. Seeds of P. karka were germinated in varying concentrations of NaCl and AsA under different temperature regimes, and seeds of Dichanthium annulatum and Eragrostis ciliaris were germinated at optimal temperatures only. In P. karka, concentrations of AsA (5 and 10 mM) alleviated the salinity effects better at cooler and moderate thermo‐periods, whereas higher concentrations (20 mM of AsA) failed to improve germination under all temperature regimes. AsA was ineffective at a warmer thermo‐period (25/35°C). The rate of germination also increased at all thermo‐periods with the application of AsA except at 25/35°C under saline conditions. Application of AsA improved the germination of E. ciliaris seeds under saline conditions but was inhibitory for D. annulatum in comparison with the untreated control. The rate of germination followed the similar pattern as that of seed germination. Results indicate that AsA has the ability to partially alleviate the effect of salinity on seed germination of some grass species under optimal temperature regime.  相似文献   

19.
Xu  Jia  Wang  & Niu 《Grass and Forage Science》1999,54(4):371-375
Seeds of sainfoin ( Onobrychis viciifolia Scop.), alfalfa ( Medicago sativa L.) and Astragalus adsurgens Pall. were put into and recovered from earth orbit from China in 1994. The isoenzymes in leaves and flowers and amino acids in leaves of the first post-flight generation of plants were analysed. Germination of their seeds under NaCl and polyethylene glycol (PEG) stress were tested. The results showed that space flight caused some changes in the pattern of peroxidase and esterase in sainfoin and A. adsurgens , and variation in amylase patterns in leaves of alfalfa. The total amino acid content increased in sainfoin and alfalfa leaves. Under salt and water stress, the proportion of progeny seeds of alfalfa and A. adsurgens , respectively, germinating after 7 and 18 days' imbibition was not markedly different between treatment and control. However, the progeny seeds of sainfoin which had been in orbit exhibited higher tolerance to NaCl and PEG stress during germination.  相似文献   

20.
It is well known that rice seed contains large amount of seedborne bacterial pathogens. However, little is known about antagonistic bacteria of the rice seed.  相似文献   

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