The purpose of this study was to assess the synergistic effects of exogenously applied proline and glycinebetaine (betaine) in antioxidant defense and methylglyoxal (MG) detoxification system in mung bean seedlings subjected to salt stress (200 mmol·L−1 NaCl, 48 h). Seven-day-old mung bean seedlings were exposed to salt stress after pre-treatment with proline or betaine. Salt stress caused a sharp increase in reduced glutathione (GSH) and oxidized glutathione (GSSG) content in leaves, while the GSH/GSSG ratio and ascorbate (AsA) content decreased significantly. The glutathione reductase (GR), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glyoxalase II (Gly II) activities were increased in response to salt stress, while the monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT) and glyoxalase I (Gly I) activities sharply decreased with an associated increase in hydrogen peroxide (H2O2) and lipid peroxidation level (MDA). Proline or betaine pre-treatment had little influence on nonenzymatic and enzymatic components as compared to those of the untreated control. However, proline or betaine pre-treated salt-stressed seedlings showed an increase in AsA, GSH content, GSH/GSSG ratio and maintained higher activities of APX, DHAR, GR, GST, GPX, CAT, Gly I and Gly II involved in ROS and MG detoxification system as compared to those of the untreated control and mostly also salt-stressed plants with a simultaneous decrease in GSSG content, H2O2 and MDA level. These results together with our previous results suggest that coordinate induction of antioxidant defense and glyoxalase system by proline and betaine rendered the plants tolerant to salinity-induced oxidative stress in a synergistic fashion.
This paper studied the variation characters on wheat and corn water consumption and irrigation watersaving amount under different water conditions (ample irrigation level, farmers conventional irrigation level and optimizing irrigation level). The water use efficiency and water saving potential of optimizing treatment and farmers’ conventional irrigation treatment were analyzed respectively. The objective of this study was to provide theoretical supporting for popularization and application of optimizing irrigation measures. Crop water requirement under sufficient water supply was calculated by Penman equation. We obtained crop water consumption under conventional treatment and optimizing treatment by field experiment. The main results showed that the irrigation amount of wheat and corn was too much under farmers’ conventional irrigation level and basically satisfied their water requirement, therefore, the water-saving amount was smaller while water-saving potential was bigger compared with the optimizing irrigation treatment. The grain yield under optimizing irrigation treatment was improved or appreciably reduced compared with that under conventional irrigation treatment, while the water consumption and irrigation amount of optimizing irrigation treatment was lower, with a higher water use efficiency. Therefore, the optimizing irrigation treatment could achieve a stable yield and high water efficiency at the same time. Moreover, when the optimizing irrigation measure was adopted, the grain yield reached 5940 kg/hm2, water-saving amount reached 91mm for winter wheat, and the grain yield reached 7743 kg/hm2, with water-saving amount of 49mm for summer corn in the piedmont region of Taihang Mount. The grain yield got 7710 kg/hm2, with water-saving amount of 20mm for winter wheat in Heilonggang Plain. Therefore, the water-saving amount in the piedmont region of Taihang Mountain was obviously higher than that in Heilonggang Plain. Thus, the piedmont region of Taihang Mountain in the North China Plain is viewed as the key district for water-saving.
Analysis of genetic interactions between rice and its pathogenic fungi Magnaporthe oryzae and Rhizoctonia solani should lead to a better understanding of molecular mechanisms of host resistance, and the improvement of strategies to manage rice blast and sheath blight diseases. Currently, dozens of rice resistance (R) genes against specific races of the blast fungus have been described. Among them, ten were molecularly characterized and some were widely used for breeding for genetic resistance. The Pi-ta gene was one of the best characterized rice R genes. Following the elucidation of its molecular structure, interaction, distribution, and evolution, user friendly DNA markers were developed from portions of the cloned genes to facilitate the incorporations of the Pi-ta mediated resistance into improved rice varieties using marker assisted selection (MAS). However, rice blast is still a major threat for stable rice production because of race change mutations occurring in rice fields, which often overcome added resistance based on single R genes, and these virulent races of M. oryzae pose a continued challenge for blast control. For sheath blight, progress has been made on the exploration of novel sources of resistance from wild rice relatives and indica rice cultivars. A major quantitative trait locus (QTL), named qSB9-2, was recently verified in several mapping populations with different phenotyping methods, including greenhouse methods. The ability to identify qSB9-2 using greenhouse methods should accelerate the efforts on the qSB9-2 fine mapping and positional cloning. [PUBLICATION ABSTRACT
Opium poppy (Papaver somniferum L.), an important medicinal plant, produces several opiate alkaloids including morphine, thebaine, codeine, papaverine and noscapine. Polysaccharides, such as sodium alginate, have been used in depolymerized form as wonderful promoters of plant growth. The present study has revealed that application of alginate oligosaccharides (AO), obtained from sodium alginate irradiated by Co-60 gamma rays, significantly enhances certain physiological/biochemical parameters as well as the overall growth of opium poppy. The highest dose applied was the most effective in increasing the morphine and codeine contents as well as the overall yield of crude opium per plant.
The formation causes and ecological rebuilding of the "Black Soil Type" degraded alpine grassland are summarized. The formation of the "Black Soil Type" degraded grassland was caused mainly by climate warming, decreasing glaciers, overgrazing, and damage by rats. The ecological restoration of the "Black Soil Type" degraded alpine grassland relies not only on grassland building, but also on reasonable management and planning of grassland resources. Guaranty measures for developing the alpine grassland animal husbandry in a healthy way include intensifying the educational investment in pasture regions, practicing long-term contracts for grassland, and strengthening the grassland legislation. The authors believe that the Qinghai-Tibetan Plateau ecosystem has a special characteristic intertia or "inert gases", which weaken the self-renewing capability of the ecosystem and makes its structure frail. The inertia characteristic may be the important reason that makes ecological rebuilding so difficult in addition, other problems need to be studied deeply to provide scientific bases for the ecological building in the Qinghai-Tibetan Plateau.
With the aim of increasing the grain crop yield and the level of soil nutrition in the fluvo-aquic soil in North China, the effects of long-term application of K fertilizers and straw returning on crop yield and soil nutrient supplying capacity were investigated in the long-term K localization experiment (1992–2009). The results revealed that wheat and maize responded to K fertilizer in an identical manner and the average yield of wheat and maize for 17 years were NPKSr > NPK > NPSr > NP. Application of K fertilizer on the basis of NP fertilizers could increase the yield of wheat and maize while the grain and straw yields in each treatment were significantly higher for maize than for wheat. The yield of wheat and maize was increased by 6.74% and 22.32% respectively when applied with NPK fertilizers compared to NP fertilizers. With the NPSr fertilizing mode, the yield of wheat and maize was increased by 2.84% and 10.62% compared to the NP mode respectively. The NPKSr fertilizing mode gave the best yield for wheat and maize, resulting in 10.34% and 23.81% increase respectively compared to the NP mode. The yield stability of wheat was significantly higher than that of maize. Under the condition of long-term fertilization, the K uptaken by wheat and maize was degressive by the sequence of NPKSr > NPSr > NPK > NP, mainly deposited in the straw but not in the grain. In this work, the soil natural ability for applying K was gradually reduced as the planting years proceeded and the changes were fitted by linear equations. The natural supply ability of K element in land planted wheat was higher than that in land planted maize.
The study was conducted by means of nutrient solution culture to investigate the effects of exogenous nitric oxide (NO) on growth of cucumber seedlings, active oxygen species metabolism and photosynthetic characteristics in cucumber leaves under 50 mmol/L NaCl stress. The results showed that 10–400 µmol/L exogenous sodium nitroprusside (SNP), especially 100 µmol/L SNP, significantly alleviated the injury to seedlings and increased seedling growth. The activity of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and the contents of photosynthetic pigments and proline also increased under 50 mmol/L NaCl stress. Similarly, net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) also increased significantly. However, exogenous nitric oxide application markedly decreased membrane permeability, rate of O 2 .− production, the contents of malondialdehyde (MDA) and H2O2, and intercellular CO2 concentration (Ci) under 50 mmol/L NaCl stress.
MicroRNAs (miRNAs) are non-coding small RNAs that regulate gene expression by translational repression or transcript degradation. Thus far, a large number of miRNAs have been identified from model plant species and the quantity of miRNAs has been functionally characterized in diverse plants. However, the molecular characterizations of the conserved miRNAs are still largely elusive in wheat. In this study, 32 wheat miRNAs (TaMIRs) currently released in the Sanger miRBase (the microRNA database) were selected to evaluate the expression patterns under conditions of non-stress (CK) and salt stress treatment. Based on the analysis of semiquantitative RT-PCR and quantitative real qRT-PCR, TaMIR159a, TaMIR160, TaMIR167, TaMIR174, TaMIR399, TaMIR408, TaMIR11124 and TaMIR1133 were found to have responses to salinity stress, with an upregulated pattern under salt stress treatment. Based on a BLAST search against the NCBI GenBank database, the potential targets of the salt-inducible wheat miRNAs were predicted. Except for TaMIR399 not being identified to have the putative target genes, other salt-inducible TaMIRs were found to possess 2 to 7 putative target genes. Together, our results suggest that a subset of miRNAs are involved in the mediation of salt stress signaling responses in wheat via their roles on the regulation of acted target genes at post-transcriptional and translation levels.
To investigate the frequency of occurrence and the concentrations of aflatoxins (AFs), deoxynivalenol (DON), zearalenone (ZEN) and fumonisins (FBs) in naturally infected maize, 25 samples of maize collected from fields in Hebei Province, China, were analyzed by high-performance liquid chromatography (HPLC). The maize samples were found to be frequently contaminated with DON (68%), ZEN (60%) and FBs (32%) in the range from 28 to 2533 μg/kg, 60 to 1239 μg/kg and 150 to 4480 μg/kg, respectively. The average concentration found for DON, ZEN and FB1 + FB2 were 605, 238 and 418 μg/kg, respectively. The average concentration of DON (605 μg/kg) in our samples was below the maximum tolerable limit of 1000 μg/kg set as the Chinese standard for maize, while ZEN (238 μg/kg) was almost four times as high as the maximum tolerable limit of 60 μg/kg. The overall level of FB (FB1 + FB2) contamination was relatively low, with an average concentration of 418 μg/kg in 32% (8 of 25) of maize samples from Hebei. AFs were not detected in any of the tested samples. This is the first report on the natural occurrence of multimycotoxin in maize in China.
The adaptation of plants to stressed environments depends greatly upon the metabolic level of antioxidant systems within their bodies. Among the enzymatic antioxidant systems, the AsA-GSH cycle occupies a vital place and has become a hot research field in recent years. The AsA-GSH cycle can directly scavenge H2O2 produced in plants on one hand, and the antioxidants AsA and GSH produced in the cycle can also scavenge other species of active oxygen by means of additional pathways on the other hand. Environmental conditions and exogenous formulations can alter the oxidative and reductive status in plants and mediate the metabolic level of the AsA-GSH cycle within a certain range, thus regulating the resistance of plants to stresses. The present paper reviews the advances in research on the AsA-GSH cycle with respect to horticultural crops, so as to provide some beneficial reference for further studies.
A complete set of chromosome substitution lines with genetic background of Chinese Spring (CS) were used to determine the effects of each chromosome on utilization efficiencies of nitrogen, phosphorus, and potassium in wheat (Triticum aestivum L.). In each line, only one pair of chromosomes in CS genome was substituted by the corresponding one of donor Synthetic 6x. Under normal growth conditions supplied with enough inorganic nutrients, the dry mass per plant and the utilization efficiencies of nitrogen (N), phosphorus (P), and potassium (K) in plants varied largely among CS, Synthetic 6x, and the chromosome substitution lines (1A–7A, 1B–7B, and 1D–7D). Of these, 1A substituted by the chromosome 1A of Synthetic 6x (other lines are the same as 1A hereafter) had the highest plant dry mass and the accumulative amount of N and K, and 1B behaved to have the highest plant accumulative P amount. 1D and 4D had the lowest accumulative P amount and plant dry mass, respectively. 4B showed the lowest plant accumulative N and K. Thus, chromosome 1A of Synthetic 6x contains major genes endowing plant capacities of higher dry mass, accumulative N and K, whereas chromosome 1B of Synthetic 6x carries major genes improving plant accumulative P capacities. The lines, together with CS and the donor, could be classified into three groups including high-efficiency, mid-efficiency, and low-efficiency based on plant dry mass. Regression analysis suggested that there are significantly positive correlations between plant dry mass and the accumulated amount of N, P, and K. Further, there are positively significant correlations among the plant accumulative N amount and some plant traits and physiological parameters, as well as positively significant correlations between the accumulative amount of P and K and the photosynthetic rate (P n).
The postharvest physiology of strawberry was investigated to study the effects of ozone on weight loss rate, ascorbic acid, respiration rate, peroxdase (POD) activity, catalase (CAT) activity, and malondialdehyde (MDA) content during cold storage. The strawberries were treated with ozone of 0 ppm (control), 2 ppm, 4 ppm, and 8 ppm, respectively. The results indicated that the treatment of 4 ppm ozone could inhibited the decrease of ascorbic acid, POD activity, and CAT activity, and reduced weight loss rate and MDA content. The treatment delayed the senescence of strawberry, with a significantly lower respiration rate. Thus, the best concentration of ozone was 4 ppm, and ozone treatment could be a good candidate for maintaining postharvest quality of strawberry and provide a longer storage life.
This paper describes the chemical composition and antimicrobial activity of the essential oil of Syzygium aromaticum against Vibrio spp. (n = 6), Edwardsiella spp. (n = 21), Aeromonas spp. (n = 2), Escherichia coli (n = 2), Flavobacterium spp. (n = 1), Salmonella spp. (n = 2), Streptococcus spp. (n = 1) and Pseudomonas spp. (n = 1) isolated from aquaculture sites as well as seven reference strains of bacteria, namely, Escherichia coli (ATCC 25922), Citrobacter freundii (ATCC 8090), Aeromonas hydrophila (ATCC 49140), Pseudomonas aeruginosa (ATCC 35032), Streptococcus agalactiae (ATCC13813), Edwardsiella tarda (ATCC 15947) and Yersinia enterocolitica (ATCC 23715). Nowadays, most antibiotics are no longer effective in controlling diseases in aquaculture, especially fish systemic bacterial diseases, due to increasing incidences of antibiotic resistance among pathogenic bacteria. Furthermore, many countries have banned antibiotics in aquaculture use due to public health concerns and environmental hazards. Therefore, this study was carried out to evaluate the potential of the essential oil of S. aromaticum as an alternate commercial antibiotic to antimicrobial agents against fish systemic bacteria in aquaculture. The essential oil of S. aromaticum was prepared using a steam distillation method, and the chemical composition was analysed using Gas chromatography-mass spectroscopy (GC-MS). Minimum inhibitory concentration (MIC) values of the essential oils against the tested bacteria were determined using the broth two fold micro dilution method, with kanamycin and eugenol as positive controls. The MIC values of the essential oil of S. aromaticum ranged from 0.015 ug*mL.sup.-1 to 0.062 ug*mL.sup.-1 against the tested bacterial isolates. A total of nine chemical compounds were detected in the essential oil, with eugenol (49.0%) and caryophyllene (7.5%) being the major compounds. The results of the present study indicate that the essential oil of S. aromaticum shows a huge potential to substitute commercial antibiotics as antimicrobial agents for aquaculture use.
A systematic and comparative study on the frequency and spectrum of chlorophyll mutations induced by ethylmethane sulphonate (EMS) — an alkylating agent, hydrazine hydrate (HZ) — a base analogue and sodium azide (SA) — a respiratory inhibitor, was carried out in two mungbean varieties, namely, PDM-11 and NM-1. Awide spectrum of chlorophyll mutants was obtained in the M2 generation. All these chlorophyll-deficient mutants were lethal except maculata, viridis and virescent. Chlorina followed by xantha types were predominant in both the varieties. EMS treatments induced the highest frequency of chlorophyll mutations followed by HZ and SA. The frequency of chlorophyll mutations was dose-dependent and increased with the mutagen concentration. Based on effectiveness in both varieties, the order of mutagens was HZ > SA > EMS. Two criteria viz., pollen sterility (Mp/S) and seedling injury (Mp/I) were taken into consideration to determine the efficiency of the mutagens. EMS was found to be the most efficient mutagen followed by HZ and SA. Moderate concentrations of the mutagens were the most effective and efficient in inducing mutations.
Two approaches of genetic analysis of quantitative traits were compared with a case study on soybean. One approach was the segregation analysis developed by Gai et al. (2003), which utilized information from individuals of one or multiple segregation populations as well as that from parents based on the principles of the major-gene plus polygene inheritance model, mixture distribution, joint maximum-likelihood function, IECM (Iterated Expectation and Conditional Maximization) algorithm, and Akaike’s information criterion and goodness of fit tests. Another approach was quantitative trait locus (QTL) mapping with molecular markers. A recombinant inbred line (RIL) population with 201 families derived from (Kefeng No.1 × 1138-2) F2:7:10 along with their parents were tested in a randomized block design experiment. The 171 RFLP, 60 SSR, and 79 AFLP molecular markers were used to mark the 201 families. The data of nine traits, i.e., number of days to flowering, number of days to maturity, plant height, number of nodes on main stem, number of pods per node, 100-seed weight, protein content, oil content, and plot yield, were analyzed with the segregation analysis procedure of RIL population with parents (Gai et al., 2003; Zhang and Gai, 2000; Zhang et al., 2001) to detect their genetic system, and those along with the molecular marker data were analyzed with WinQTL Cartographer (Basten et al., 1999; Zeng, 1993, 1994) to detect their QTL system. The results showed that both procedures could detect the main major genes or QTLs, and therefore, could be used as a mutual check and supplement. From the results that most of the traits were mainly controlled by three or four QTLs, it was impressed that the segregation analysis procedure of four major-gene plus polygene mixed inheritance model should be developed to fit the requirements. The results also showed that the QTLs of the involved traits concentrated on several linkage groups, such as C2, B1, F1, M, and N. Finally, the results showed that the experimental sample was not necessarily coincident with the theoretical population according to equality test, symmetry test, and representation test, and therefore, the sample should be checked, tested and then adjusted to fit the theoretical requirements through deleting the extra-biased families and markers.
The biomass production (BP), the leaf age (LA), and the plant height (PH) as well as the quantitative trait loci (QTLs) associated with these traits were determined for F2:3 population derived from the cross of two contrasting maize (Zea mays L.) genotypes: 082 and Ye107. By using composite interval mapping, a total of 12 and 12 distinct QTLs were identified at Kaixian and Southwest University under deficient phosphorus. Another 9 and 8 distinct QTLs were identified at two sites under normal phosphorus, respectively. Seven coincident QTLs for two traits (BP and LA) were detected in the interval bnlg1832-P2M8/j (bin 1.05) on Chromosome 1, and four consistent QTLs for one trait (PH) were coincident in the interval umc1102-P1M7/d (bin 3.05) on Chromosome 3. These coincident QTLs in two important genomic regions were identified under different phosphorus levels and two different environments. Therefore, the above two segments one (bnlg1832-P2M8/j) identified in Chromosome 1 and the other (umc1102-P1M7/d) identified in Chromosome 3 may be used in future for marker-assisted selection and high-resolution mapping leading to map-based cloning of QTLs for agronomically important traits under phosphorus deficiency.
Land evaluation is the process of predicting land use potential on the basis of its attributes. In the present study, the physical land suitability evaluation approach was investigated for specific cereal crops including irrigated wheat, barley, grain maize and sorghum, based on FAO land evaluation frameworks (FAO, 1976, 1983, 1985) and the proposed method by Sys et al. (1991) at Mashhad Plain, Northeast Iran. Twenty eight soil profiles were studied on seven land units by a precise soil survey and their morphological and physicochemical properties were determined. Climatic and land qualities/characteristics of four cereal crops were determined using the tables of crop requirements developed by Sys et al. (1993). An interpolation function was used to map values to scores in terms of land qualities/characteristics for land utilization types and the evaluation was carried out according to parametric approaches. The interpolation technique using GIS functions helped in managing the spatial data and visualizing the results. Our results indicated that the most important limiting factors for irrigated wheat and barley cultivations are soil physical and fertility/chemical properties, while the production of irrigated grain maize and sorghum is mainly limited by climatic conditions at Mashhad Plain. It was shown that all land units suitable for irrigated wheat cultivation overlap with that of barley, whereas the same limiting factors resulted in the overlapping of the irrigated grain maize production area with that of sorghum. The results of the physical land suitability evaluation for specific cereal crops indicated the priority of irrigated barley and wheat cultivations over irrigated grain maize and sorghum at the study area.
A greenhouse experiment was conducted to study the accumulation of selenium by some vegetable crops commonly grown in the Indian Punjab. Eleven vegetable crops were raised in an alkaline clay loam soil treated with different levels of selenate-Se, i.e., 0, 1.25, 2.5 and 5.0 mg*kg.sup.-1 soil. Dry matter yield of both edible and inedible portions of different vegetable crops decreased with increasing Se level in soil except potato (Solanum tuberosum), radish (Raphanus sativus) and cauliflower (Brassica oleracea var. botrytis) which recorded 10%21% increase in inedible dry matter at 1.25 mg*kg.sup.-1 Se soil. Application of 5 mg*kg.sup.-1 selenate-Se soil resulted in complete mortality in the case of radish, turnip (Brassica rapa) and brinjal (Solanum melongena). Some vegetable crops including tomato (Lycopersicum esculentum), cauliflower and pea (Pisum sativum), though, survived the toxic effect at the highest concentration of Se yet did not bear any fruit. Potato and spinach (Spinacea oleracea) proved to be highly tolerant crops. Selenium concentration in the edible as well as inedible portions of all the vegetables increased with an increase in the level of applied Se. Selenium accumulation in the edible portion of vegetable crops in the no-Se control ranged from 2.2 to 4.9 mg*kg.sup.-1 Se dry weight. At 1.25 mg*kg.sup.-1 Se soil, the edible portion of radish accumulated the greatest concentration of Se (38 mg*kg.sup.-1 Se dry weight) with that of onion (Allium cepa) bulb the lowest (9 mg*kg.sup.-1 Se dry weight). Inedible portions of vegetables accumulated Se 25 times more than that absorbed by edible portions. Total Se uptake by edible portions of different vegetables was the greatest at 1.25 mg*kg.sup.-1 Se soil, ranging from 7 to 485 ug*pot.sup.-1. The results suggest that vegetable crops vary in their sensitivity to the presence of selenate-Se in soil. Vegetative portions were several times richer in Se than other parts of vegetable crops.
The APETALA2 (AP2) domain defines a large family of DNA binding proteins. It has been demonstrated that the AP2 proteins have important functions in the transcriptional regulation of a variety of biologic processes related to growth and development in various responses to drought and other abiotic stresses. In this essay, recent researches on the AP2 transcription factors, such as the molecular characterization, expression patterns in responses to drought and other abiotic stresses, the roles of ABA on drought responding which were mediated by AP2 transcription factors, transcription regulation mechanisms, and the roles of overexpression of AP2 transcription factor on plant drought tolerance, etc. have been overviewed. Deepening the understanding of signaling and the corresponding transduction pathways that are initiated via drought stress stimuli will play crucial roles for providing the theoretical basis for variety breeding with promising drought tolerance in the future.
Apriona germari is a destructive stem-boring pest. To date, the control of the pest is still based largely on the chemical insecticides. To meet the needs of people’s high pesticide efficacy and environment safety, the alternative management strategy must be proposed. Beauveria bassiana is one of the most widely studied and used entomopathogenic fungi. The potential of Beauveria bassiana used to control Apriona germari was here evaluated. The result showed that the infective rate of B. bassiana to adults was 20%, with no pathogenicity to eggs. But it showed a high pathogenicity to larvae. The laboratory bioassays showed that the mortality, when concentration was 1 × 108 conidia/mL, was 96.47% ten days after inoculation. LT50 of B. beauveria to Apriona germari larvae was 4.53 d at the concentration of 1 × 108 conidia/mL; LC50 was 6.76 × 105 conidia/mL. The infecting experiments in field showed that, 20 days after control, the mortality was 68.4%. The present results suggested that B. bassiana has an excellent potential for biological control of A. germari larvae.