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1.
A pot experiment was conducted to evaluate the efficiency of farm yard manure (FYM) and lime (calcium carbonate) on reducing the uptake of Cd by rice in two Cd contaminated soils of Chittagong. The effects of farm yard manure, lime and farm yard manure mixed with lime (FYM + Lime) on rice (Oryza sativa L.) growth, Cd uptake by rice and 0.1 N HC1 extractable Cd in soil were investigated. Results showed that addition of lime and farm yard manure mixed with lime significantly decreased 0.1 N HCl extractable Cd in the city sewage soil. Application of farm yard manure significantly decreased Cd concentration in rice in the city sewage soil. Lime and farm yard manure mixed with lime significantly reduced Cd concentration in rice m both the contaminated soils. Lime was more efficient than farm yard manure in reducing the uptake of Cd by rice.  相似文献   

2.
The use of allelopathic plants is an alternative technique for controlling weeds in sustainable crop production. This experiment evaluated the allelopathic potential of Murraya paniculata (L.) against four weeds viz., Bidens pilosa L., Amarathus spinosus L., Echinochloa crusgalli (L.) Beauv. and Chloris barbata Sw.. In laboratory test, aqueous extracts from M. paniculata leaves at concentrations of 12.5, 25, 50 and 100 g/L were tested on germination and seedling growth of the weeds. The extracts showed inhibitory effect, varying with weed species and extract concentration. Increase in concentrations increased the degree of inhibition. Concentration at 50 g/L and 100 g/L, completely inhibited seed germination of C. barbara and A. spinosus. Pot experiments were done in a glasshouse, with dry leaf powder as mulch on the soil surface at levels of 2, 4 and 8 t/ha. Dry leaf powder reduced the emergence and growth of all tested weeds, varying with dose and species. Chloris barbara is the most sensitive to M paniculata leaf mulch while E. crus-galli is the most resistant. These results suggest that M. paniculata had the potential lbr weed control and might be the source of a natural herbicide.  相似文献   

3.
This study attempts to examine the effects of salinity on leaf, stem, and nut of Pistacia vera (Ohady and Kaleh Ghochi cultivars) in order to characterize their anatomical structures with electron and light microscopy. A comparative study of the anatomy indicates a difference between the density of simple and glandular trichomes in leaf surface, deposit of wax, the thickness of leaf, the length of epidermal cells, palisade parenchyma cells, crystals in mesophyll, and the manner of compatibility to salinity. The results obtained in this research demonstrate that compatibility of Ohady cultivar is higher than Kaleh Ghochi and the degree of mechanical wounding depends on their development stages. In addition to results of previous studies which considered crop load as the main cause of fruit deformity. The present study indicates that, in spite of some reduction in total production of a tree, salinity decreases fruit deformity and to a high extent prevents the production of deformed fruit. Indeed, a remarkable reduction in production of deformed fruit will be yielded by selecting pistachio varieties which are resistant to salinity. Moreover, salinity increases the resistance of nuts to mechanical wounding. The results of this study suggest that in EC = 7.6, 12.6 deformity of nut is not related to crop load.  相似文献   

4.
Heading date was an important trait that decided the adaptation of wheat to environments. It was modiifed by genes involved in vernalization response, photoperiod response and development rate. In this study, four loci Xgwm261, Xgwm219, Xbarc23 and Ppd-D1 which were previously reported related to heading time were analyzed based on three groups of wheat including landraces (L), varieties bred before 1983 (B82) and after 1983 (A83) collected from Chinese wheat growing areas. Generally, heading date of landrace was longer than that of varieties. Signiifcant differences in the heading time existed within the groups, which implied that diversiifcation selection was much helpful for adaptation in each wheat zone. Photoperiod insensitive allele Ppd-D1a was the ifrst choice for both landrace and modern varieties, which promoted the heading date about four days earlier than that of sensitive allele Ppd-D1b. The three SSR loci had different characters in the three groups. Predominant allele combination for each zone was predicted for wheat group L and A83, which made great contribution to advantageous traits. Xgwm219 was found to be signiifcantly associated with heading date in Yellow and Huai River Winter Wheat Zone (Zone II) and spike length in Middle and lower Yangtze Valley Winter Wheat Zone (Zone III), which implied functional diversiifcation for adaption. Variation for earliness genes provided here will be helpful for whet breeding in future climatic change.  相似文献   

5.
A reliable system was developed for regeneration from mature embryos derived from callus of four maize inbred lines (Liao 7980, Dan 9818, Dan 340, and Dan 5026). The protocol was mainly based on a series of experiments involving the composition of culture medium. We found that 9 pM 2,4-dichlorophenoxyacetic acid in MS medium was optimum for the induction of callus. The induction frequency of primary calli was over 85% for four inbred lines tested. The addition of L- proline (12 mM) in subculture medium significantly promoted the formation of embryogenic callus but it did not significantly enhance growth rate of callus. Efficient shoot regeneration was obtained on regeneration medium containing 2.22 μM 6- benzylaminopurine in combinations with 4.64 μM Kinetin. Regenerated shoots were rooted on half-strength MS medium containing 2.85 μM indole-3-butyric acid. This plant regeneration system provides a foundation for genetic transformation of maize.  相似文献   

6.
Stress-associated protein (SAP) has functions in maintaining plant cell elongation, embryo development and response to abiotic stresses. TaSAP1-A1, one of the Triticum aestivum SAP1 (TaSAP1) members located on wheat chromosome 7A was isolated for polymorphism analysis. HaplII of TaSAP1-A1 was found significantly associated with thousand-grain weight (TGW) in multiple environments. In this study, HaplII also made a positive contribution to TGW in Population 2. The distribution of TaSAP1-A1 HapIII was tracked among varieties released in different years and geographical environments of China. The frequency of HapIII showed an increasing trend during the breeding process in two different populations. The ItapIII was gradually selected and applied from 6.36% in landraces to 13.50% in modem varieties. These results exhibited that TaSAP1-A1 HapIII was positively selected during wheat breeding, which is beneficial for grain-yield improvement. The preferred HapIIl was initially selected and applied in the higher latitude areas of China in accord with the long day season and longer grain filling stage in these areas. Moreover, the frequency of HaplII in recent modem varieties was still quite low (19.29-26.67%). It indicated a high application potential of TaSAP1-A 1 HapIII for improving grain yield in wheat breeding.  相似文献   

7.
可可(Theobroma cacao L.)为世界三大饮料作物之一,在全球热带地区广泛种植。可可豆是可可树的种子,经加工形成的可可脂、可可粉是生产巧克力、糖果、糕点的主要原材料。利用联合国粮农组织统计数据库数据,通过对全球可可的种植面积、产量等的发展变化,可可豆及其加工产品、巧克力全球与国内进出口贸易数据的对比、分析,揭示可可的种植、加工和产品的发展变化趋势。同时结合我国的可可研究、种植现状与市场需求提出了我国可可发展的建议。  相似文献   

8.
In order to study morphological diversity of codling moth, Cydia pomonella (L.) using thin-plate spline analysis, nine geographical populations from four north western provinces of Iran namely East Azarbayjan, West Azarbayjan, Ardebil and Zandjan were collected during 2003 and 2004. 575 and 564 images were prepared from fore and hind wings, respectively. Then 15 and 11 landmarks were determined from fore and hind wings, respectively. With transforming of landmark's two dimensional coordinate data into partial warp scores, 26 and 18 scores were generated for fore and hind wings, respectively. Cluster analysis based on wing shape variables using Ward's algorithm assigned nine geographical populations into two groups. The pattern of grouping based on fore and hind wings was different in both sexes. Principal component analysis revealed discrimination between geographic populations and confirmed the result of cluster analysis. Among environmental parameters, wind speed showed the highest correlation with wing shape variables. Non significant correlation was observed between geographic and morphological distance matrices as revealed by Mantel test.  相似文献   

9.
Transgenic crops having alien genes from different sources are getting popularity. A Rice (Oryza sativa L.) containing gene from Bacillus thuringiensis, a soil bacterium, was assessed to study the potential risks of transgenic plants on environment. The crop was found resistant to target insect pests. Rice variety Basmati-370 transformed with two insecticidal genes, crylAc and cry2A, was grown under field conditions for several years. Data were collected at different stages of the plant growth. Fate of Cry protein in soil, effect of Bt protein on non-target insects, risks of vertical and horizontal gene flow were evaluated. No potential hazard was found at all levels. Bt protein was unstable and degraded significantly in soil within 30 days after harvesting the crop. No harmful effects were found on non-target insects (insects other than order lepidoptera). Maximum gene flow of 0.02% was observed at close spacing and no evidence of horizontal gene transfer to Rhizobium spp. was found. In conclusion, the transgenic rice plants transformed with Bt genes have no harmful effects on the environment.  相似文献   

10.
Chenopodium album L. (bathu) leaves and roots were selected to evaluate their antifungal potential against the Ascochyta rabiei responsible for chickpea blight that causes destructive yield losses. Methanolic extract of C. album leaves and roots was prepared and their various applied concentrations, viz., 1%, 2%, 3%, 4% and 5% were tested against A. rabiei. Leaf extracts were found more effective and showed significant antifungal activity over the root extracts. C. album leaf was found effective in screening bioassays, so this was subjected for fractional guided bioassays. Different various organic fractions of leaf extract were isolated, viz., n-hexane, chloroform, ethyl acetate and n-butanol. These isolated fractions were serially diluted to check their minimum inhibitory concentration (MIC) along with a synthetic fungicide (72% WP, Puslan). The MIC of various concentrations from 500 mg/mL to 1.95 mg/mL was recorded after 24 h and 48 h intervals. Ethyl acetate and synthetic fungicides were found most effectual in retarding conidial germination with MIC of 1.95 mg/mL after 48 h incubation periods. Chloroform fraction also inhibited the fungal growth whereas n-hexane and n-butanol fraction were found to be ineffective.  相似文献   

11.
F.  C.  L.  Zapico  C.  H.  M.  Aguilar  J.  M.  Aujero  B.  Y.  Disca 《农业科学与技术》2010,(5):101-105
Investigation into the paternity of four abaca (Musa textilis L, Nee) hybrids was done to ascertain the mode of transmission of selected morpho-agronomic traits and to detect possible heterosis. In situ morphological characterization was undertaken using twenty five qualitative and six quantitative characters. Results revealed that a great majority of the qualitative traits were shared by both parents and their hybrids. For the rest, the qualitative traits were inherited from one or the other parent though some variant phenotypes (i.e. chimerism) were also noted in the hybrids. Cases ofheterosis were also observed and this could be exploited to increase fiber yield in the hybrids. Though inconclusive due to factors such as the heterogenous nature of abaca plants in the field and the susceptibility of morphological traits to environmental fluctuations, this study has provided baseline information on abaca hybridity that can be verified using more robust technologies as molecular markers.  相似文献   

12.
Vigna unguiculata L. Walp is a recalcitrant plant in terms of in vitro cell, tissue and organ differentiation, which makes it difficult to apply tissue-culture dependant approaches for obtaining stable genetic transformation in cowpea. Despite this, sporadic efforts have been made to develop regeneration systems in cowpea during the past 40 years. This review presents the considerable progress on cowpea regeneration (organogenesis and embryogenesis) and especially focuses on the regeneration mode of organogenesis, including highlights of the effect of genotypes, explants, medium and plant hormones used in tissue culture. The existing problems and the future research directions were also discussed.  相似文献   

13.
The aim of the present experiment was to study the relationship between the distribution of relative light intensity in canopy and yield and quality of Wanmi peach. The optimum relative canopy light intensity was judged to be 36.3% for high quality peaches, when canopy volumes of Wanmi peach trees with a relative light intensity 〈 30% accounted for 7.7 and 47.9% of the total canopy volume in June and September, respectively. The canopy volume with a relative light intensity 〉 80% was 27.7 and 3.1% of the total canopy volume in June and September, respectively. Peach canopies were divided into 0.5 m × 0.5 m × 0.5 m cubes, with the relative light intensity being measured at different positions of the canopy during the growing season. Yield and fruit quality were also measured at these positions at harvest. The results showed that the relative light intensity decreased gradually from outside to inside and from top to bottom of the tree canopy. Fruit were mainly distributed in the upper and middle portions of the canopy, 1.5-3.0 m above ground. Regression results showed that single fruit weight and soluble solid content were positively related to relative light intensity.  相似文献   

14.
A two-factorial experiment was conducted with two wheat cultivars, SN1391 (large spike and large grain) and GC8901 (multiple spike and medium grain), and two nitrogen (N) application rates (12 and 24 g N m^-2), to investigate the responses of photosynthetic characteristics and antioxidative metabolism to nitrogen rates in flag leaves of field-grown wheat during grain filling. The results showed that the content of N and chlorophyll (Chl) in wheat flag leaves decreased after anthesis and the net photosynthetic rate (Pn), effective quantum yield of PS Ⅱ (Фps n), efficiency of excitation capture by open PS Ⅱ reaction centers (Fv′/Fm′), and photochemical quenching coefficient (qp) began to decrease at 14 days after anthesis. However, the maximal efficiency of PS Ⅱ photochemistry (Fv/Fm) decreased slightly until the late period of senescence and the nonphotochemical quenching coefficient (NPQ) increased during flag leaves' senescence, As a result, a conflict came into being between absorption and utilization to light energy in flag leaves during senescence, which might accelerate the senescence of flag leaves. Compared with GC8901, the lower plant population of SN1391 during grain filling was helpful to maintain the higher content of photosynthetic pigment, activity of PS II, and Pn in flag leaves during senescence, The delayed decrease in antioxidative enzyme activity and the lower degree of membrane lipid peroxidation in the senescing leaves of SN1391 were beneficial to protect the photosynthetic apparatus, which lead to the prolonged duration of CO2 assimilation. With the increase of N application, the Chl content of SN1391 flag leaves and the efficiency of excitation captured by open PS Ⅱ centers increased. At the same time, the thermal dissipation in SN1391 flag leaves at high N (HN) treatment decreased and Фps Ⅱ improved greatly, which were favorable to the increase of Pn. The SOD, POD, CAT and APX activities in the flag leaves of SN1391 increased  相似文献   

15.
The effect of biopreparations, homogenized with the seed (seed treatment before sowing as a dressing), and used as a mixture with mineral fertilizer ANL (ammonium nitrate with limestone), upon both grain production and the health state of the winter wheat were evaluated during 2006-2009. Besides conventional soil cultivation, reduced tillage with incorporated chopped straw, and direct drilling into untilled soil covered with mulch, were also used. The following biopreparations were applied: Supresivit (Trichoderma harzianum), Polyversum (Pythium oligandrum), and Trianum P (a different strain ofTrichoderma harzianum). Attention was focused on the foliar fungi pathogens Drechslera tritici-repentis, Septoria tritici, and Alternaria triticina, as well as on the soil-borne pathogenic fungi of the genus Fusarium.  相似文献   

16.
The effects of two culture systems, conventional and no-till combined the previous crop (lentil and wheat) on soil properties were studied in the experimental site of the station Technical Institute for Field Crops (ITGC) Setif (Algeria) during the crop year 2011/2012. The results indicate that the no-till system affects positively the variables of soil properties and the organic matter has a rate of 2.89% compared to 2.44% in conventional tillage. If the conventional system has an infiltration of moisture relatively higher than that observed for no-till throughout the cycle, the no-tillage is distinguished by a higher storage of moisture at the end of cycle wheat cultivation. The results also indicate that the density (1.44 g/cm), permeability (22.79 cm/h) and soil compaction (12.51 kg/cm) in no-till were significantly higher compared to conventional tillage 1.35 g/cm, 14.13 cm/h, 7.40 kg/cm, respectively.  相似文献   

17.
研究椰子间作可可下的可可光合速率(Pn)和环境因子日变化,探讨间作可可Pn与环境因子的关系,为优化可可栽培技术提供理论依据。结果表明,间作和单作可可Pn日变化均呈双峰曲线,有光合"午休"现象。环境因子与Pn的相关性均不显著(p0.05),间作和单作可可环境因子对Pn的直接作用均为TLRHPARTa,对间作可可Pn的影响是PAR、TL和Ta等相互作用的结果。光合有效辐射是影响间作可可Pn的主要环境因子。在可可的栽培管理中,应发挥主导环境因子的作用。  相似文献   

18.
Different strategies of deficit irrigation based on water stress dynamics were applied in an 11-year old citrus trees (Citrus sinensis L. Osb. cv. Navelina) grafted on carrizo citrange (Citrus sinensis L. Osb.×Poncirus Trifoliata L. Osb.). The trees were subjected to two irrigation treatments: (1) sustainable deficit irrigation (SDI) established with water supplied at 60% of the crop evapotranspiration (ETc) and (2) low frequency deficit irrigation (LFDI) irrigated according to the plant water status. In addition, a treatment irrigated at 100% of ETc was included as a control (C). Midday stem-water potential (ψUstem), stomatal conductance (gs), and micrometric trunk diameter fluctuations were measured during the maximum evapotranspirative demand period to evaluate the plant-water status, and establish the main relationships among them. The seasonal pattern of the studied variables had a behavior consistent with the contributions made by the volumes of applied irrigation water. Especially significant close relationships of ψstem with gs, and with the maximum daily shrinkage (MDS) were found. The lowest ψstem and gs values were registered in the treatments with lowest irrigations levels (SDI and LFDI), being the MDS was significative higher than in the C treatment. The LFDI showed an oscillating behavior in these parameters, which was on line with the supplied irrigation restrictions cycles. Thus, according to the results of the present experiment the physiological stress indexes based in MDS or ψstem allow establishing different irrigation restriction cycles, encouraging important water saving without significant impact on yield and the fruit quality parameters.  相似文献   

19.
20.
种植年限对三江平原农田土壤剖面性质及碳、氮含量的影响   总被引:13,自引:0,他引:13  
【目的】系统探讨三江平原湿地开垦后不同种植年限对土壤剖面性质及碳、氮含量变化等的影响规律,分析其相互关系,为该地区现有种植方式下耕地质量建设提供参考依据。【方法】采用野外实地调查方法,系统调查了三江平原宝清县北部、抚远县东南部两个垦区中不同农业利用年限土壤剖面层次、容重、植被组成等的变化,并采集表层和亚表层土壤样品,测定相应的碳、氮含量,分析其含量变化与种植年限的相互关系。【结果】随着种植年限的延长,土体中相应层次的形成和分化愈明显,腐殖质层厚度愈变薄,二者间呈显著负相关;土壤容重则随种植年限延长而增加,且二者间呈直线相关;表层和亚表层土壤有机碳的含量均随种植年限的增加而减少,二者间的相互关系可用二次多项式(Y = b0 + b1x + b2x2)形式表示;表层土壤全氮含量的变化与种植年限间亦呈显著负相关,且亦可用二次多项式形式来表示;土壤C/N比值亦随种植年限而变化,但与其所处的环境条件具有一定关系,且近年来其比值有下降的趋势。此外,还讨论了湿地农业利用后土壤有机碳储量的变化、立地条件对湿地性质的影响及湿地保护等相关问题。【结论】在当前三江平原耕地种植方式下,随着种植年限的延长,土壤耕层变薄、有机质及氮素含量下降的趋势较为明显,必须通过增加有机肥施用量、强化耕地养分管理、改进耕作方式等措施,防止这种趋势的继续,保证区域农业持续、稳定发展。  相似文献   

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