• The Plant Pathology Journal
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• v.34 no.2
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• pp.121-125
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• 2018

Maize (Zea mays L.; 2N=20) is major staple food crop grown worldwide adapted to several biotic and abiotic stresses. Maydis leaf blight (MLB) and banded leaf and sheath blight (BLSB) are serious foliar fungal diseases may cause up to 40% and 100% grain yield loss, respectively. The present studies were undertaken to work out the efficacy of chemicals, botanicals and bioagents for the management of MLB and BLSB under field condition for two seasons Kharif 2014 and 2015. Five molecules (propiconazole 25 EC, hexaconazole 25 EC, carbendazim 50 WP, mancozeb 75 WP and carbedazim 12 WP + mancozeb 63 WP), two bioagents i.e. Trichoderma harzianum and T. viridae and three botanicals namely azadirachtin, sarpagandha and bel pathar were tested for their efficacy against MLB. Eight newer fungicides viz., difenconazole 250 SC, hexaconazole 5 EC, carbendazim 50WP, validamycin 3 L, tebuconazole 250 EC, trifloxystrobin 50 WG + tebuconazole 50 WG, azoxystrobin 250 EC and pencycuron 250 SC were evaluated against BLSB. Analysis revealed significant effects of propiconazole at 0.1%, carbendazim 12 WP + mancozeb 63 WP at 0.125% and sarpagandha leaves at 10% against MLB pathogen, whereas validamycin at 0.1% and trifloxystrobin 25 WG + tebuconazole 50 WG at 0.05% were found effective against BLSB. The slow rate of disease control virtually by the bioagents might have not shown instant effect on plant response to the yield enhancing components. The identified sources of management can be used further in strengthening the plant protection in maize against MLB and BLSB.

• Journal of Plant Biology
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• v.37 no.2
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• pp.151-158
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• 1994

Aleurone layers of normal and vp1 mutant maize kernels were extracted and centrifuged at 100,000g to yield a cytosol fraction. Binding of [3H]ABA cis, trans (＋)ABA to a soluble macromolecular components present in the cytosol was demonstrated by Sephadex chromatography and non-denaturing PAGE. The binding component was of high molecular weight and seems to be an aggregate of proteins. A rapid DEAE-cellulose filter method for assaying bound [3H]ABA to a soluble protein was adapted. Binding assays were performed with cytosol that had been preheated or incubated with several enzymes, indicating that heat and protease treatments disrupted the binding. This suggested that binding occurred to proteins. Some properties of the ABA binding proteins were described. The [3H]ABA binding were reduced dramatically when unlabeled ABA was added as a competitor, suggesting a specific binding of [3H]ABA. Gel filtration profiles and autoradiogram of [3H]ABA binding showed no difference in the binding components of Vp1 and vp1/vp1 mutant cytosol, indicating that Vp1 protein is not a sole ABA binding protein.

• Journal of Plant Biology
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• v.36 no.1
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• pp.67-74
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• 1993

Both polar and gravity-induced lateral transport of auxin was markedly reduced in corn coleoptile segments by octanol treatment. Octanol enhance net auxin uptake without affecting that of benzoic acid, suggesting that the effect did not result from a nonspecific action on general membrane permeability. Since naphthylphthalamic acid (NPA) action on both transport and net uptake of auxin was substantially decreased in the presence of octanol, a specific interaction of octanol with the NPA site (efflux carrier) can be postulated. Studies on in vitro binding of NPA to membrane vesicles indicated that octanol did not interfere with NPA binding. When basipetal transport of auxin was impared by plasmolysis, octanol still inhibited auxin transport in the plasmolyzed tissues. The results ruled out the possibility of octanol acting at the plasmodesmata. Kinetic analysis of growth indicated that IAA-sustained growth was rapidly blocked by octanol implicating a common system by which auxin transport is linked to auxin action. Possible mechanisms for octanol action will be discussed.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.106-112
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• 2008

International conferences to block the spread of Avian bird flu occurred in Beijing, 2006 and others warned of the seriousness of the H5N1 strain. The meetings succeeded in generating billions of dollars from USA, EU and World Bank. Migratory birds seem to play a major role in the spread of the aggressive strain globally from Asia to Europe and Africa. Experiences of tolerance breeding of maize (Zea mays L.) for four decades against 20 biotic stresses suggest that the prime cause of the occurrence of H5N1 strain was due to the human beings' counter-efforts against nature. Excessive use of chemicals (spray and injection) in the commercial poultry farms had created high selection pressure on virus. The new strain had mutated for survival. Attempting to eliminate the virus by chemicals for 100% control is a dangerous way to control biotic stresses. This can create more aggressive strains. A solution would be to build up tolerability of the commercial animals against the virus. Improvement of poultry cage environments and respect for nature must be integrated. Potential foes must be watched.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.374-378
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• 1983

As one way of evaluating polymorphism in maize, variation of peroxidase 8 (Px.8) in maize plants was investigated by means of horizontal acrylomide electrophoresis. The specific part of maize plants was stele and other parts of plants were also studied for 34 different maize lines and hybrids. The results obtained indicate that Px.8 has three distinct migrating patterns on gel such as fast, slow and fast-slow. The band pattern varied with materials used. Most hybrids were showing fast-slow band, indicating that those hybrids are heterozygous at least for Px.8 allele. Variation of band pattern was obseerved within a single inbred line. The Px.8 in stele tissue and in young leaf and nodal tissue was found to be identical, indicating the possible use of those tissues as an alternative tissue for Px.8 study. It was also found that there might be some definite relationship between Px.8 and Px.3 activities in the same tissue.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.6
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• pp.818-823
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• 2008

The interaction of fibre degrading microbes and methanogens was studied using two forages, lucerne (Medicago sativa) hay and maize (Zea mays) hay, as substrate and 2-bromoethanesulphonic acid (BES) as an additive in an in vitro gas production test. Gas and methane production (ml/g dry matter) were significantly higher (p<0.05) on lucerne as compared to maize hay. Inclusion of BES in the incubation medium significantly suppressed methane emission irrespective of substrate. The population density of total bacteria, fungi, Ruminococcus flavefaciens and Fibrobacter succinogenes was higher, whereas that of methanogens was lower with maize hay as compared to lucerne as substrate. BES suppressed methanogen population by 7 fold on lucerene and by 8.5 fold on maize at 24 h incubation as estimated by real time-PCR. This suppression was accompanied by almost complete (>98% of control) inhibition of methanogenesis. The proportion of acetate decreased, whereas that of propionate increased significantly by inclusion of BES, resulting in narrowing of acetate to propionate ratio. In vitro true digestibility (IVTD) of lucerne was significantly higher as compared to maize but BES inclusion did not affect IVTD.

• Journal of Plant Biotechnology
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• v.32 no.2
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• pp.91-95
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• 2005

Agrobacterium tumefaciens-mediated immature embryo transformation was used to produce transgenic maize. Immature embryo of Hi II genotype were co-cultivated with strains Agrobacterium tumefaciens (C58C1) containing the binary vectors (pPTN290) carrying with Ubiquitin promoter-GUS gene as reporter gene and NOS promoter-nptll gene conferring resistance to paromomycin as selective agent. Seven embryogenic callus lines transformed showed the resistance in paromomycin antibiotics. Histochemical GUS assay showed that 7 individual lines transformed with the GUS gene were positive response among the transformants. Southern blot analysis revealed that the nptll gene segregated and expressed in their progeny.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.57-63
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• 2007

Due to the strong influence of nitrogen(N) on plant productivity, a vast amount of N fertilizers is used to maximize crop yield. Over-use of N fertilizers leads to severe pollution of the environment, especially the aquatic ecosystem, as well as reducing farmer's income. Growing of N-efficient cultivars is an important prerequisite for integrated nutrient management strategies in both low- and high-input agriculture. Taking maize as a sample crop, this paper reviews the response of plants to low N stress, the physiological processes which may control N-use efficiency in low-N input conditions, and the genetic and molecular biological aspects of N-use efficiency. Since the harvest index(HI) of modern cultivars is quite high, further improvement of these cultivars to adapt to low N soils should aim to increase their capacity to accumulate N at low N levels. To achieve this goal, establishment and maintenance of a large root system during the growth period may be essential. To reduce the cost of N and carbon for root growth, a strong response of lateral root growth to nitrate-rich patches may be desired. Furthermore, a large proportion of N accumulated in roots at early growth stages should be remobilized for grain growth in the late filling stage to increase N-utilization efficiency. Some QTLs and genes related to maize yield as well as root traits have been identified. However, their significance in improving maize NUE at low N inputs in the field need to be elucidated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.432-440
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• 2019

Global climate change exerts adverse effects on maize production. Among abiotic stresses, drought stress during the tasseling stage (VT) can increase anthesis-silking intervals (ASI) and decrease yield. We performed an evaluation of ASI and yield using a drought-sensitive line (Ki3) and a drought-tolerant line (Ki11) to analyze the correlation with ASI and yield. Moreover, the de novo data of Ki11 were analyzed to find putative novel transcripts related todrought stress in tropical maize. A total of 182 transcripts, with a log2 ratio >1.5, were found by comparing drought conditions to a control. The top 40 transcripts of high expression levels in the de novo analysis were selected and analyzed with PCR. Of the 40 transcripts, six novel transcripts were detected by quantitative real-time PCR (qRT-PCR) using seedling and VT stage samples. Five transcripts (transcripts_1, 12, 34, 35, and 40) were up-regulated in the Ki11 shoot at seedling stage, and transcripts_1, 12, and 40 were up-regulated at the re-watering stage after 12 h of drought stress. The transcripts_32 and 34 were up-regulated at the VT stage. Hence, transcript_34 possibly plays a significant role in drought tolerance during the seedling and VT stages. The transcript_32 was identified as chloramphenicol acetyltransferase (CAT) by Pfam domain analysis. The function of the other transcripts remained unknown. Further characterization of these novel transcripts in genetic regulation will be of great value for the improvement of maize production.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.271-276
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• 2017

Waterlogging strongly affects maize (Zea mays L.) growth. It is necessary to find the screening method of waterlogging tolerant maize lines. This study was to investigate the growth characters at V3 stage of maize, when is very sensitive to waterlogging. Six Korean maize inbred lines were subjected to waterlogging at V3 stage for 30 days. The 30 days waterlogging treatment significantly reduced plant height, number of expanded leaves, and SPAD value, compared with the control plants. SPAD values were significantly different among the six inbred lines, KS140 was the highest. The dry matter accumulation of aerial and root part were significantly decreased by 30 days waterlogging. KS140 was the weightiest among inbred lines. The dry matter of adventitious root showed same trend. Waterlogging treatment significantly reduced to ear length and thickness, grains filling length, grain number per ear, and maize grain. Plant height, SPAD value, and number of fully-expanded leave showed high correlation with maize grain yield, but number of senescent leaves, dry matter of adventitious root and TR ratio did not, suggesting that the former three traits may be good indicator for evaluating 30-day waterlogging tolerance of maize inbred lines. KS164 was the highest yield by increasing of grains filling length and grain number per ear of among waterlogging inbred lines. According to the results, evaluation of maize waterlogging should be consider both early growth characteristics and resilience in the later growth stages.