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1.
Alfalfa (Medicago sativa L.) is an important forage crop in the world and it is of great signiifcance for the improvement of its salt tolerance. To improve salt tolerance in alfalfa, a rice ascorbate peroxidase gene (OsAPX2) was introduced into alfalfa using Agrobacterium tumefaciens-mediated transformation with marker gene bar. The different T-DNA insertions in T1 transgenic alfalfa were identiifed by Southern hybridization. Three independent T2 transgenic lines were selected for stress analysis and the results showed that all of them were salt tolerant compared with wild-type plants. The transgenic plants had low levels of H2O2, malondialdehyde and relative electrical conductivity under salt and drought stresses. Moreover, the contents of chlorophyll and proline, and APX activity were high in transgenic plants under salt and drought stresses. Taken together, the overexpression of OsAPX2 enhances salt tolerance in alfalfa through scavenging reactive oxygen species.  相似文献   

2.
Understanding the relationship between the timing of N fertilizer applications and crop primary production is crucial for achieving high yield and N use efifciency in agriculture. This study investigated the effects of starting-N plus topdressing N applications (as compared to the common practice of all basal application) on soybean photosynthetic capacity under different planting densities. A ifeld experiment was conducted in two growing seasons (2011 and 2012), and the soybean (Glycine max L. Merrill) cultivar was Dongnong 52, three planting densities (20, 25 and 30 plants m-2), and four N fertilizer application patterns (all N fertilizer of 6 g N m-2 as basal fertilizer, all N fertilizer as topdressing at beginning pod stage (R3), 1.8 g N m-2 as basal fertilizer and 4.2 g N m-2 as topdressing at stage R3 and full pod stage (R4), respectively). The results indicated that under the same planting density, compared to applying all N as basal fertilizer, the application of starter-N plus topdressing N substantially reduced the rate of pod abscission, and enhanced leaf area index (LAI) signiifcantly at beginning seed stage (R5) (P〈0.05), net assimilation rate (NAR) during stages R4-full seed stage (R6) (P〈0.05), contribution rate of post-seed iflling assimilate to seed (CPA) (P〈0.05), and yield (P〈0.05). Applying topdressing N at stage R4 resulted in higher net primary production and yield than applying topdressing N at stage R3. When applying starter-N plus topdressing N at planting density of 25 plants m-2, LAI after stage R5 and NAR after stage R4 were increased by 5.92-16.3%(P〈0.05) and 13.7-26.6%(P〈0.05) with the planting density of 20 plants m-2, respectively, and yield was 8.46-14.0%(P〈0.05) higher than that under 20 plants m-2. When planting density increased to 30 plants m-2, only LAI during stages R4-R5 and NAR during stages R4-R5 increased by applying starter-N plus topdressing N, while the other indexes declined. Ov  相似文献   

3.
Heading date of rice is a key agronomic trait determining cultivated areas and seasons and affecting yield. In the present study, ifve primary single segment substitution lines with the same genetic background were used to detect quantitative trait loci (QTLs) for heading date in rice. Two QTLs, qHD3 and qHD6 on the short arm of chromosome 3 and the short arm of chromosome 6, respectively, were identiifed under natural long-day (NLD). Nineteen secondary single segment substitution lines (SSSLs) and seven double segments pyramiding lines were designed to map the two QTLs and to evaluate their epistatic interaction between them. By overlapping mapping, qHD3 was mapped in a 791-kb interval between SSR markers RM3894 and RM569 and qHD6 in a 1 125-kb interval between RM587 and RM225. Results revealed the existence of epistatic interaction between qHD3 and qHD6 under natural long-day (NLD). It was also found that qHD3 and qHD6 had signiifcant effects on plant height and yield traits, indicating that both of the QTLs have pleiotropic effects.  相似文献   

4.
Porcine carcass traits and organ weights have important economic roles in the swine industry. A total of 576 animals from a Large White×Minzhu intercross population were genotyped using the Illumina PorcineSNP60K Beadchip and were phenotyped for 10 traits, speciifcally, backfat thickness (6-7 libs), carcass length, carcass weight, foot weight, head weight, heart weight, leaf fat weight, liver weight, lung weight and slaughter body weight. The genome-wide association study (GWAS) was assessed by Genome Wide Rapid Association using the mixed model and regression-genomic control approach. A total of 31 single nucleotide polymorphisms (SNPs) (with the most signiifcant SNP being MARC0033464, P value=6.80×10-13) were located in a 9.76-Mb (31.24-41.00 Mb) region on SSC7 and were found to be signiifcantly associated with one or more carcass traits and organ weights. High percentage of phenotypic variance explanation was observed for each trait ranging from 31.21 to 67.42%. Linkage analysis revealed one haplotype block of 495 kb, in which the most signiifcant SNP being MARC0033464 was contained, on SSC7 at complete linkage disequilibrium. Annotation of the pig reference genome suggested 6 genes (GRM4, HMGA1, NUDT3, RPS10, SPDEF and PACSIN1) in this candidate linkage disequilibrium (LD) interval. Functional analysis indicated that the HMGA1 gene presents the prime biological candidate for carcass traits and organ weights in pig, with potential application in breeding programs.  相似文献   

5.
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   

6.
Citrus canker, an epidemic quarantine disease caused by Xanthomonas axonopodis pv. citri, has brought a great damage in citrus production worldwide. Herein, a rice PRR (pattern recognition receptor) gene Xa21 together with GUS reporter gene and hygromycin phosphotransferase gene (HPT) was introduced into Anliucheng sweet orange (Citrus sinensis Osbeck) via Agrobacterium-mediated transformation of embryogenic callus. The transgenic calluses were screened on MT basal medium containing hygromycin (HYG) and detected by histochemical GUS staining. The transgenic plantlets were recovered through somatic embryogenesis pathway. The regenerated plantlets were accustomed to and maintained in the greenhouse. The transgene integration of recovered plantlets was identiifed by PCR and Southern blot hybridization. It showed that all the transgenic plantlets tested had undergone single copy integration, the expression of Xa21 in eight different transgenic lines detected by qRT-PCR can be divided into three grades, high for T5 and T6, middle for T4 and low for the rest. The tolerance to citrus canker disease of the three recovered transgenic lines T2, T4 and T6 was assessed by in vitro pin-puncture inoculation. The results showed that all the three transgenic lines conferred improved resistance to citrus canker bacterium infection and the T4 transgenic line displayed the highest resistance. The mechanism and feasibility of rice Xa21 in triggering innate immunity in citrus was brielfy discussed.  相似文献   

7.
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   

8.
Irrigation water management has significant economic implications in developing countries like Malaysia. As in many countries, Malaysia is also espousing internet as a platform of new possibilities for information access and sharing. Thus web based decision tools are pertinent in managing water, which is becoming a source of conflict between domestic, industry and agricultural use in this emerging technological and information age. Decision Support System (DSS) created in the past was theoretically acceptable but practically not effective in the transfer of scientific knowledge from research labs to the end-users to support them in decision making. The Web Based Paddy Irrigation Productivity Assessment (WebPIPA) is an example of DSS created to provide an effective conduit for the transfer of scientific knowledge from research labs to the end-users to support them in decision making. WebPIPA serves as an innovative, user friendly and efficient management tool for run-of-river rice irrigation system. It is a web based program that requires users to login through user name and password WebPIPA is developed using Net framework and ASP. Net Programming Languages of Microsoft. Net 2003 environment. A 3-tier architecture framework was carefully studied and was implemented to create the WebP1PA model. Mathematical model developed for aiding irrigation decisions must be oriented towards addressing various issues in addition to the scientific ones for better acceptability. All government and private agencies, researchers, station users, farmers, investors and buyers related to this study area will be able to access and share the database through the internet. By strengthening the involvement of government departments, the database can be very effectively used by all stakeholders at the same time narrowing the gap between the urban and rural communities in the development of country.  相似文献   

9.
A study carried out for assessment of acaricide for control and how to show resistance of hard tick (Ixodidae) with some types of acaricide which available in Sulaimani marked froro February to April 2012, isolated 80 cattle (local breed) naturally infested with hard tick. Six hundred and fifteen ticks min7 tick/cattle including three genera species were collected and identified, the highest Boophilus spp. followed by Hyalomma spp., and Rhipicephalus spp. were less frequent species collected. Experimental cattle divided into four groups each group content 20 cattle, treatment with four types acaricide and their average of infestation in cattle with Boophilus spp. 33 (41.25%) as the commonest, followed by Hyalomma spp. 31 (75.38%), Rhipicephalus spp. 11 (13.75%) and 5 (6.25%) found mixed infested with Boophilus spp. and Hyalomma spp. 65 (81.3%) of cattle samples had emaciation and skin lesions. According to site of infestation, it showed that inguinal region was the most common predilection site for the ticks. Observed the genera Boophilus spp., there were highly significant differences (12.52%) between different tick species when calculated by general test (LSD). The objective of this study was to estimate and compare these acaricide to control hard tick, and there was highly significant relation between different species of hard ticks when treated by these acaricide, according to the chi-square tests. The activities of the acaricide through the time of application were different on the tick genera species. Diazinon (60%) and carbamate (saven 85%) has been a greater degree than other acaricide resistance, while shows the activity of both acaricide injectable ivermactin and cypromethrein through the early time on all species. The results of the study otherwise provide encouraging possibilities for the potential use recommended dose with both acaricide ivermactin-l% and cypromethrine-10%.  相似文献   

10.
《农业科学与技术》2013,(10):1476-1481
[Objective] The paper was to evaluate effects of peracetic acid (PAA) combined with calcium treatments on storage quality of Ioquat fruits, so as to pro- vide practical techniques to solve the problems of postharvest rot and quality deteri- oration for Ioquat fruits. [Method] With Ioquat fruits of Qingzhong variety as materi- als, 0.2%, 0.4% and 0.8% PAA combined with 0.8% CaCI2 was used to soak Ioquat fruits for 4 min, 0.8% CaCl2 and water treatments were set as two controls; the fruits were dried and packaged by 0.02 mm PE bags, then stored under non-chilling low temperature of (7±1) ℃. The indicators related to storage quality of Ioquat fruits were randomly tested once every 3 d, and their variation situations were analyzed. [Result] Compared with two control treatments and 0.2% PAA, 0.8% PAA combined with calcium treatments, the treatment of 0.4% PAA combined with 0.8% CaCl2 could significantly inhibit rot index, weight loss rate, firmness and cell membrane permeability of Ioquat fruits during storage period, which could also effectively delay the reduction of titratable acid, vitamin C, soluble solid content and juice yield, and maintain respiration intensity of fruits at a low level; the appearance and flavor qual- ity of fruits were good after stored for 25 d. [Conclusion] 0.4% PAA combined with 0.8% CaCl2 treatment is an efficient, safe and economical practice technology in an- ti-corrosion and quality preservation for postharvest Ioquat fruits .  相似文献   

11.
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   

12.
《农业科学与技术》2013,(10):1403-1408
Advanced glycation end-products (AGEs) are products of non-enzymatic glycation of proteins, lipids or nucleic acids and other macromolecules. To be spe- cific, Nε-(carboxymethyl)-Iysine (CML) is one of the most important components of AGEs, which is wildly distributed in the body and can be formed in vivo or in food processing and heating processes. Previous studies have shown that CML is a ma- jor immunological epitope in AGEs and plays an important role in diabetes and its complications, as well as in the development and progression of aging. This review summarized recent advances in major source, toxicological hazard and control mea- sures of CML.  相似文献   

13.
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   

14.
For long-term prediction of occurrence degree of tobacco aphid Myzus persicae (Sulzer), Markov chain method was used to establish prediction model for occurrence degree of tobacco aphid. With 4 levels of occurrence degree, Markov chain model was established based on the data in 1987-2004. The results indicated that the accuracy for total prediction in 2005-2007 and the back prediction in 1987-2004 reached 88.89% and 85.12%, respectively. The method is simple and feasible for long-term prediction of occurrence degree of tobacco aphid.  相似文献   

15.
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   

16.
17.
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   

18.
19.
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   

20.
The effect of agricultural practices on soil organic nitrogen (N) fractions in a cocoa plantation has not been much revealed till now. Despite the fact that soil organic N has been long admitted for its importance to maintain soil fertility. Presented field experiment was conducted in Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institute (ICCRI), Jember, East Java, Indonesia, to investigate the effect of cocoa farm management, namely fertilization, weeding and soil tillage on the content of soil organic N fractions. The design of experiment was arranged in a split-split plot with two levels of weeding as main plots, two levels of soil tillage as subplot and three different fertilizer treatments as sub-sub plot. The analysis of soil N including total N and soil organic N fractions, namely, total hydrolized N, ammonium N, amino sugar N and amino acid N, were performed. The result showed that the effect of fertilization treatment was significant to the content of total N, ammonium N, amino sugar N and amino acid N. No-tillage treatment resulted in total N and amino sugar-N content increasing by 8% and 24%, respectively, over tillage treatment. Slashing treatment caused increase of the total N by 3% from herbicide treatment, whilst decrease of ammonium N and amino sugar N by 7% and 24%, respectively.  相似文献   

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