Agrobacterium tumefaciens mediated transformation may offer a better alternative than the biolistic gun for genetic transformation of maize plants. This gene delivery system results in a greater proportion of stable, low-copy number transgenic events than does the biolistic gun, and is highly efficient. In the present work, we studied maize transformation using A. tumefaciens by identifying some important factors that affect transformation efficiency subsequent tissue culture and regeneration of transgenic plants. Although, all genotypes produced embryogenic calli, S61 and A188 lines had higher percent (75% and 71% respectively) of regeneration than the other ones. Transformant events obtained when immature embryos (1.5-2 mm) were inoculated with A. tumefaciens LBA4404 harboring a standard binary vector pCAMBIA3301 after 72 h pretreatment culture of the embryos. Polymerase chain reaction (PCR) confirmed the presence of the gus and bar genes in the genome of regenerated plants. The transformation frequency (the number of independent, PCR-positive transgenic plants per 100 embryos infected) was 6.45% for S61 genotype. Therefore, our results identified suitable genotype (S61), embryo size (1.5-2 mm), A. tumefaciens strain (LBA4404), pretreatment culture, and appropriate antibiotic (Timentin) for Agrobacterium mediated transformation of Z. MAYS.

Background & Aim: ZEA MAYS leaf used traditionally in Ibibio ethno medicine in Southern Nigeria to treat malaria and other inflammatory diseases. These anti-inflammatory and analgesic properties were evaluated against experimentally induced inflammation and pains using standard models.Experimental: The effects of ethanol leaf extract of ZEA MAYS (170 -510 mg/kg) on experimentally induced inflammation and pain were studied in rats using Carrageenin, egg albumin and xylene-induced inflammation as well as acetic acid-induced writhing and thermal induced pain models. The GCMS analysis of the most active fraction was carried out.Results: The extract (170 -520 mg/kg) inhibited inflammation and pains caused by different phlogistic agents used in a dose dependent fashion. The various degrees of inhibitions were statistically significant (p<0.05, 0.01, 0.001), though incomparable to that of the standard drugs used (ASA and indomethacin). The GC-MS revealed the present of polyunsaturated fatty acids and phenolic compounds which may be responsible for the observed activities of the extract.Recommended applications/industries: The present study demonstrates that leaf extract of ZEA MAYS might to be useful for the treatment of inflammation and pains.

In order to investigate the possibility of integrated weed management in corn fields an experiment was conducted in a split-plot with randomized complete blocks design with four replications in Arak Islamic Azad University Research Center during 2008. Treatments were corn density at three levels 70, 80 and 90 thousand plants per hectare in main plots and weed management at five levels including weed free and weed infested controls, one time cultivation, one and two liters per hectare of Nicosolforon. Results indicated that, there was no significant difference between one and two lit/ha of nicosulfuron treatments in high corn density was treatments. Therefore, the best corn density for reducing the dose of nicosulfuron 90,000 plants per hectare. Based on the results obtained from present research, in organic agricultural system, herbicide could be omitted for controlling weeds in corn using on time cultivation at 4-6 leaf stage of weeds plus corn density at 90,000 plants per hectare.

Iron is an essential microelement for plant growth. Low content of organic matter and excess application of phosphate fertilizer in soils can be affected on availability of iron. In this study the effect of iron, phosphorus and organic matter on growth and iron uptake of MAYS was evaluated. A greenhouse experiment was conducted with two levels of cattle manure (0 and 1 %), three levels of phosphorus (0, 200, 400 kg.ha-1 triple super phosphate) and three levels of iron (0, 20, 40 kg.ha-1 sequestrene 138).The experiment was carried out based on a completely randomized design with a factorial arrangement using two replications. Plants were grown in a sandy loam soil for eight weeks. Results showed that application of cattle manure significantly increased shoot dry weight, iron concentration and iron uptake of maize. The application of phosphorus along with iron treatment increased shoot dry weight at 20 kg.ha-1 iron but it had a negative effect at higher levels of iron. Application of iron increased concentration and total iron uptake of plants. However, phosphorous revealed an opposite effect. Interaction between treatments showed that application of cattle manure can improve the negative effects of excess phosphorus.

Background: Stresses (such as drought, salt, viruses, and others) seriously affect plant productivity. To cope with these threats, plants express a large number of genes, including several members of ERD (early responsive to dehydration) genes to synthesize and assemble adaptive molecules. But, the function of ERD3 gene hasn’t been known so far.Objectives: The purpose of the present study was to clone the stress-resistance gene: ZmERD3, and to analyze its expression pattern in the maize plant organs at different stages and under various stress treatments.Materials and Methods: MaizeGDB database search together with the bioinformatics analysis led to the identification of ZmERD3 gene in ZEA MAYS. The cDNA sequence and promoter of ZmERD3 gene were obtained through PCR. Bioinformatics analysis was performed through online tools. The tissue-specific expression profile of the ZmERD3 gene in maize plant was carried out using the quantitative real time PCR (qRT-PCR) technique and its expression pattern in response to stress treatments (such as PEG, NaCl, ABA, and low temperature) was also analyzed through qRT-PCR method.Results: Based on the homology alignment with AtERD3 (XP_002867953) in MaizeGDB (http: //www. maizegdb.org/), the cDNA sequence and promoter region of the ZmERD3 gene were obtained. The bioinformatic analysis showed that ZmERD3 protein has one specific hit of methyltransferase and a high probability of location in the cytoplasm, and there are many cis-regulatory elements responsive to light, heat, cold, dehydration, as well as other stresses in its promoter sequence. Expression analysis revealed that the amount of ZmERD3 mRNA is different in all indicated organs of the maize plant. In addition, the ZmERD3 expression could be induced by abiotic stress treatments. Compared to the control, treatment with NaCl or PEG-6000 could significantly enhance the expression ability of ZmERD3 gene. As well, its expression level was increased about 20 times above the control after exposure to NaCl and PEG-6000 treatments for 3-6 h.Conclusions: One putative methyltransferase gene, ZmERD3 was cloned. ZmERD3 expression exhibited an obvious tissue-specificity, and its expression could make a significant response to NaCl and PEG-6000 treatments.

The critical period of weed control (CPWC) is a period in the crop growth cycle during which weeds must be controlled to prevent yield losses. In order to determine the critical period of weed control (CPWC) of corn in Hamedan, an experiment was conducted in 2007 at Agricultural Research Station of Bu-Ali Sina University of Hamedan. The experiment was carried out as a randomized complete block design with three replications. The trial included twelve treatments consisted of six initial weed-free periods in which plots were kept free of weeds for 0, 15, 25, 35, 45 and 55 days after crop emergence (DAE), and then weeds were allowed to grow until harvest and six initial weed-infested periods in which, weeds were allowed to grow for 0, 15, 25, 35, 45 and 55 DAE, after which the plots were kept free of weeds until harvest. Each plat consisted of four rows (six meter per row) with a row spacing of 75 cm. . Weed sampling carried out in first series of treatments at the end of growth season and in second series of treatments at the4 end of infested periods. The results showed that beginning of CPWC ranged from 124 to 204 GDD, at 5% and 10% AYL, which equates to 8 and 16 days after crop emergence (3 and 5 leaf), respectively. The end of the CPWC varied from 395 to 289 GDD, at 5% and 10% AYL, which equates to 31 and 24 days after crop emergence (10 and 7 leaf), respectively. Total dry weight of weeds increased as the duration of weed infested period increased and it was decreased with increasing duration of the weed-free period. Grain yield of corn increased with increasing duration of the weed-free period and decreased as the duration of weed infested period increased.

This experiment was conducted to study the effects of water deficit stress on morphological traits, yield and yield components of 60 maize single cross hybrids at Torough Agricultural and Natural Resources Research Center located in Mashhad, Iran on 2013. This experiment was laid out in randomized complete block design with three replications. The irrigation treatments were consisted of two irrigation levels (50 and 80 percent allowed water depletion as normal and drought stress, respectively). The result of ANOVA showed significant differences among single cross hybrids for all of measured traits in both conditions. In non-stress or normal condition, hybrids No.4 and in stress condition, hybrids No.9 were the best hybrids for grain yield with 13.30 and 9.02 ton/ha, respectively. According to the indices MP, GMP, STI and HARM among the studied hybrids the promising hybrids No.1 and No.1, 4 and9 were recommended for water stress condition in Mashhad regions. During periods of lower growth in hybrid and non-treated with high temperatures during pollination can cause lead to the compounds than others. The correlation results showed the positive and significant relation between potential for performance (no stress) indices MP, GMP, STI, TOL and HARM. Most significant and positive correlation between the indices was related to GMP and STI (0.99). In general, hybrids L1×k1263/1, L5×k1263/1, L10×k1263/1 and 14×k1263/1 due to the high level of tolerance can be used in breeding programs.