جستجوی مقالات مرتبط با کلیدواژه "مراحل رشدی" در نشریات گروه "زراعت"

Two species of common cocklebur (Xanthium strumarium L.) and spiny cocklebur (X. spinosum) are common annual summer weeds in soybean fields and other summer crops. The current research was carried out with the aim of determining the cardinal temperatures of germination and determining the phenology stages of these two species in Sari University of Agricultural Sciences and Natural Resources. In order to determine the cardinal temperatures of germination of seeds of two weed species, the seeds were examined at constant temperatures of 5 to 45 °C in a completely randomized design in 4 replications in a laboratory experiment. Also, the phenology stages of two weed species were investigated in a field experiment. The highest germination% was observed for the spiny cocklebur (51.3%) and the common cocklebur (58.1%) at temperatures of 25 and 35 °C, respectively. According to the different parameters of segmented model, the base temperature, lower optimum temperature and ceiling temperature for spiny cocklebur are 1.4, 23.2 and 54.7 °C, and for common cocklebur are 4.8, 34.6 and 48.4 °C, respectively. Time from emergence to physiological maturity for the spiny cocklebur and common cocklebur were 136 and 128 days, respectively. The results suggested that seed germination of the two weed species occurs in a wide range of temperatures, i.e. of 5 to 45 °C, and the best time to control this weed is late summer (before the beginning of the flowering stage).

NFXL1 and NFXL2 proteins have NF-X1 type zinc fingers domains, DNA binding, and PHD finger motifs, which potentially mediate its protein interactions. NF-X genes play an important role in response to defense signaling using plant hormones.

In this study, 12 NF-X genes were selected in barley, maize and wheat. The gene structures, duplication patterns, phylogenetic tree, developmental of the 12 NF-X transcription factors in nine species were analyzed to further investigate the functions of these factors. In the present study, a comparative analysis was performed to identify orthologs and paralogues of NF-X in the genomes of maize, barley and wheat.

The phylogenetic tree of NF-X from H.vulgare and Z.mays revealed two groups based on their homology and the exon numbers of NF-X genes, ranging from 1 to 13. According to the synteny analysis, NF-X genes of barley, maize and wheat revealed high similarity, which TaNFXL1.2 with HvNFXL1; HvNFXL2 with TaNFXL1.3, TaNFXL2, TaNFXL2.1; TaNFXL1 with TaNFXL1.1, TaNFXL1.3; ZmNFXL1 with ZmNFXL1.1 genes revealed similarity more than %90. Prediction cis-elements showed that NF-YB; NF-YA; NF-YC, bHLH, myb/SANT, WRKY, Dof, and Trihelix had maximum frequency in the promoter region of NF-X genes.  The HvNF-X2, ZmNF-X2 and TaNF-X2 genes had the highest number of cis-elements. Analysis of NF-X genes showed that tandem duplication and segmental duplication play an important role in the development of barley, maize and wheat genomes. NF-X gene expression analysis showed that these genes were up-regulated in almost all developmental stages. However, the number of tandem and segmental duplication showed that these factors are major factors in the evolution of NF-X genes. Since this is the first study to compare NF-X genes in three species, our findings could be considered as useful source for future NF-X genes studies in comparative studies among different plant species.

The aim of this study was to identify and characterize NF-X genes in nine species via in silico genome-wide analysis approach. HvNFX1, HvNF-X2, and ZmNFXL1.1 genes showed that gene expression in all development stages. The gene structure in most proteins in each group was similar, which validated the NF-X transcription factors phylogenetic classification.

Increased global food production has been associated with increased nitrogen fertilizer application, followed by risks such as nitrate accumulation, water resources pollution, and greenhouse gas emissions. It seems that poultry manure is a suitable case for replacing chemical fertilizers in potato cultivation due to high mineralization rate and micro nutrients. For this reason, two field experiments were carried out based on CRD with 11 treatments in three replications at two sites, Azna and Khoramabad in Lorestan province at 2016 on potato (Banba cultivar). Treatments included nitrogen resource from urea fertilizer and poultry manure along with control. According to results of the experiment, mean tuber yield in Khoramabad (43.7 t.ha-1) was higher than Azna (38.9 t.ha-1). This difference can be attributed to the different growth period in the two locations (Khorramabad and Azna, 114 and 147 days, respectively). Although in both locations, the highest tuber yield was obtained with the application of 700 kg.ha-1 urea, application of 10 t.ha-1 poultry manure resulted in yield approximate to the use of chemical fertilizers, especially in Azna region.However, the results of this experiment showed that agronomic nitrogen use efficiency in urea fertilizer was higher than poultry manure, due to the slight differences in yields between the two types of nitrogen sources, it can be concluded that replacement of chemical fertilizers with organic fertilizers to achieve food security and an efficient and sustainable food chain, is reasonable.

Phenological growth and development is very important for determination of sowing date and agronomic practices in different climate condition. Quinoa has been cultivated in the Bolivian and Peruvian Andean region for 7000 years. Worldwide interest on this crop is increasing because of high nutritional quality. Quinoa is gluten free peuduo cereal and suitable for celiac patients, and whole grain consumption prevent type 2 diabetes and because of low glycemic index can be replace common cereal in diabetes diet. Of more than 50 000 edible plant species in the world, only a few hundred contribute significantly to food supplies. Just 15 crop plants provide 90 percent of the world's food energy intake, with three rice, maize and wheat - making up two-thirds of this. Quinoa is a facultative halophyte plant species and some varieties are able to complete life cycle at 400 mM salinity. Quinoa growth was stimulated by moderate salinity (10 dS m-1). Quinoa is interest in Iran for high tolerance to abiotic stress and as a new crop for saline area. The aim of this study was selection of the best sowing date for early mature cultivar of quinoa. For evaluation of different climate condition on phenological growth stage and seed yield, quinoa (NSRCQ1) was planted in eight sowing date (22 Aug, 6 Sep, 26 Sep, 7 Oct, 24 Oct, 24 Feb, 7 March and 30 March) with 14 dS m-1 saline water in Yazd, Iran. One of the main pests of the quinoa which was feed leaves during vegetative growth stage in all sowing date was Spodoptera exigua. This pest controlled by Avant and Saypermetrin. Growing degree day of different growth stage was calculated by dent-like function. Data was analyzed with randomized complete block model using SAS. Treatment means were compared using least significant difference (LSD) test at P=0.05. Results showed that quinoa produced 2.34 t ha-1 at the first sowing date and complete life cycle during 108 days. Frost damage occurred at -4.5 °C in 26 Sep sowing date at flowering stage. In Oct sowing date crop can survive during winter but could not produce the seed. Feb sowing date produced 1.6 t ha-1 and crop cycle complete during 132 days. High temperature (above 32 °C) in Feb and March sowing date and low temperature (13.6 °C) in Sep sowing date during grain filling period reduced seed yield and size. Flowering and seed filling stages were sensitive to photoperiod (based on phenological stage response to growing degree day). Quinoa (NSRC Q1) had a short day quantitative response to photoperiod and photoperiod longer than 12 hours prolonged time to flowering. Among the sowing dates 22th Aug was selected because of shorter growing cycle and higher seed production in Yazd provinces. Among the growth stage grain filling period is sensitive to high and low temperature and the best temperature was 20 ºC. Flowering time and grain filling stage is sensitive to photoperiod and day length longer than 12 hours increased GDD requirement. In 22th Aug sowing date 560 mm saline water (14 dS m-1) was applied in Yazd. In spring sowing date growing cycle prolong to 132 days and seed yield and weight were lower than Aug sowing date. Plant produced higher biomass but during seed filling period high temperature reduced seed yield. For Central Plateau of Iran the best sowing date is in the late of Aug. Based on the weather and phenological data and weather data the best sowing date of this genotype for different agroecological zone could be predicted.

In this research, the chromosome 1 of rice was studied to identify QTLs controlling traits associated with drought and salinity tolerance at germination and seedling stages using F2:4 population derived from a cross between two cultivars, Gharib (tolerant to drought and salinity) and Sepidroud (sensitive to drought and salinity). Two hundred and thirty six polymorph markers (105 AFLPs and 131 SSRs) were used to construct genetic map of the rice chromosome 1. Thirteen SSR and seven AFLP markers with length of 216.1 cM were mapped on chromosome 1 and average distance between adjacent markers was 10.8 cM. In total, 17 QTLs controlling germination rate, germination percentage, radicle length, plumule length, coleoptile length and drought and salinity tolerance indices at germination stage under four different conditions (drought stress induced by PEG and sorbitol, salinity stress induced by NaCl and non-stress conditions) and four QTLs controlling shoot potassium concentration, root/shoot length ratio, root dry weight and standard tolerance ranking at seedling stage under salinity stress induced by NaCl were identified on chromosome 1 using composite interval mapping. Seven major QTLs associated with drought and salinity tolerance were mapped in adjacent of RM212 and RM1287 markers at two growth stages. The major QTLs qGR-1 and qSV-1 were detected under both stress and non-stress conditions showing the stability of these QTLs under diverse environmental conditions. Furthermore, the same locations of the QTLs qSKC-1 and qRL/SL at seedling stage with the QTLs of germination related traits showed the same genetic control of these traits at both germination and seedling stages, associated with drought and salinity tolerance controls by the same genomic regions. Also, the location of the QTLs associated with salinity tolerance were very near to the QTLs associated with drought tolerance which indicated that drought and salinity tolerance in rice controls by pleiotropic or tight linked genes. It seems that the rice breeding for one of these stresses can be successful to the other stress.

In order to study the effects of different levels of water logging at different growth stages on yield and yield components of barley WB-79-10, a field experiment was carried out using split plot in randomized complete block design with four replications in Ramin Research Field Station in a growing season (2009-2010) in Ramin Agriculture and Natural Resources University, Ahvaz. Tillering, stem elongation and booting stage were assigned to main plots, and water logging periods, including 0, 7 and 14 days in terms of water logging were randomized in sub–plots. The results showed that between the beginning stages of water logging and various water logging periods for yield and yield components, significant differences exist. The water logging at tillering stage had more damage than stem elongation and booting stages on grain yield and its components. In the tillering stage, grain yield at 7 and 14 days, compared to control water logging 42 and 78.28 percent respectively, to the spikelet, respectively 20.84 and 37.5 percent and to the grain number per ear 22.31 and 41.04 percent respectively, decreased. Overall, the results showed that water logging at each stage of plant growth, even in a short period, led to irrecoverable damage on yield and its components on the leaves.

Iran is located in arid and semi-arid areas and has limited water resources that yield reduction due to low irrigation in these areas can be inhibited by programming and wise facilities usage. Supplemental irrigation is an approach that can lead to satisfactory and sustainable yield in dryland. The effects of supplemental irrigation on growth and yield of rainfed wheat (Var. Azar2) were investigated in at Dryland Research Station of Shirvan, during growing season of 2008-2009. Four sensitive stages of wheat to drought stress are A) germination, B) tillering, C) flowering, and D) seed set. Single or combined irrigation patterns in these four stages created 16 combinations. That it carried out based on randomized complete block design with 4 replications. These treatments included single irrigation in each stage (A, B, C, and D), two times irrigation (AB, AC, AD, BC, BD and CD), three times irrigation (ABC, ACD, ABD and BCD), four times irrigation (ABCD) and control (No irrigation). The results showed that supplemental irrigation had no significant effect on plant height, but its effect was significant on spike length, tillers and fertile tillers number, seed number per spike, 1000-seed weight, grain yield, harvest index and dry weight of wheat. The highest yield was obtained from 2 times irrigation in flowering and seed set stages (CD with 2009.2 kg/ha) which had no significant difference with 2 times irrigation in tillering and flowering stages. The lowest yield was obtained from no irrigation treatment (NO with 1045.2 kg/ha). The highest seed number per spike was obtained from BC and highest 1000-seed weight from AD. According to the result of this study, it could be concluded that supplemental irrigation in dryland wheat had significant effect on yield and can increase dryland wheat yield. So, it seems that enough water in flowering stage can increase the yield to a satisfactory level.

To obtain pathogenic fungal isolates from Physalis divericata L., the plants showing the symptoms of fungal diseases were collected from different areas in Lorestan and were transported to the laboratory in year 2009. The samples, after surface disinfection, were cultured on PDA and V-8 media. Based on fungi keys identification, two species including Alternaria alternata and Fusarium sp. were identified. The pathogenicity and virulence of identified fungal pathogens at 105, 106, 107 and 108 spores per mL of distilled water were tested on Physalis divericata at different growth stages (cotyledon, 4, 6 and 9-11 leaf). Host range tests were conducted on beans, corn, sugar beets and soybeans under greenhouse conditions. Results showed that Alternaria alternata isolate A6 induced more severe disease than other Alternaria isolates and Fusarium sp. Physalis divericata was more sensitive to Alternaria alternata isolate A6 at 6 leaf-stage, especially at 108 spore per ml distilled water. Non of the target crops showed any symptoms due to inoculation by Alternaria alternata isolate A6.