PLANT AND ECOSYSTEM
Year:2010 | Volume:6 | Issue:23|Papers Count:9

A morphological investigation was carried out on pollen of 54 allergic species belong to 43 family from Islam Abad area using light microscope (LM) by Erdtman method. Pollen shape, size, exine ornamentation, the presence and number of apertures present powerful characters to distinguish the species. The size of the pollen grains ranged from 17 mm (Chenopodium) to 120 mm (Alcea). Distribution of pollen grain was very different throughout the year, with the maximum variation registered between the end of March and the first two weeks of April and the lowest observed during end of autumn. Pollination of studied plants begins from the first week of February. Pollens were present until the last week of December.

The aerial parts of Satureja hortensis (Labiatae) were collected from Dezful Province of Khozestan, South of Iran in May 2008 at flowering period. The essential oil of each plant was obtained by hydrodistillation using a Clevenger apparatus. The obtained oils were analyzed by GC and GC/MS. The chemical constituents of each oil was characterized by comparison of achieves mass spectra and relative retention indices with authentic references (1). Among the 12 identified constituent in the oil of Satureja hortensis, (representing 99.85% of the total oil), carvacrol (KI= 1299) (58.1%), g- terpinene (KI= 1060) (28.8%), and P-cymene (KI= 1025) (4.2%) were the major constituents.

In order to evaluate the nitrogen (N) requirement of wheat (Triticum aestivum L.) by using leaf color chart (LCC), a greenhouse experiment was conducted using factorial method in completely randomized design, in three replications. In this study, two cultivars (Pishtaz: C1 and Sepahan: C2) and five nitrogen rates (N1:0, N2:40, N3:80, N4:120 and N5:160 mg N/Kg) were studied. Plant sampling (total N was determined in the samples) and LCC reading were done in three wheat's growth stages: Z21, Z31 and Z37 (Zadoks Growth Scale). Results showed that in all growth stages there is a positive significant regression between sample's LCC reading and N content. The highest level of regression was in Z37 (Flag leaf just visible) that make sit possible to determine the N decline by using LCC in the situation of this study. The critical values of LCC reading were 3 for the Pishtaz cultivar and 4 for the Sepahan cultivar for this experiment.

The study chlorophyl a+b amount and extinction coefficient are very important elements of photosynthesis amount and efficiency. In order to study the Effect of Boric acid spraying levels on chlorophyll a+b content and extinction coefficient of winter rapeseed (Brassica napus L.) cultivars an experiment carried out in factorial design in the basis of randomized complete blocks with 4 replications in 2007. Bor spraying treatments from Boric acid source in three levels: 0 , 1.5/1000 and 3.0/1000 and Rapeseed cultivars in 3 levels : Licord, Modena and SLM046 were considered. The Results showed that simple effect of cultivars , bor spraying element and interaction effect of them on chlorophyll a+b content and extinction coefficient had significant difference. In this case Licord cultivar with 6.62 mg/lit produced maximum amount of chlorophyll a+b content and with 0.46 highest amounts of extinction coefficient and SLM046 cultivar with 5.54 mg/lit and 0.34 showed the lowest amounts of chlorophyll a+b content and extinction coefficient in three average bor spraying amounts alternatively.The effect of bor element spraying amounts on mentioned characters showed that 1.5/1000 and 3/1000 Bor spraying with 6.54 and 6.51 mg/lit had the highest amounts of chlorophyll a+b content and with 0.46 and 0.41 produced minimum amounts of extinction coefficient. The interaction effect of experimental factor on mentioned characters showed that, 3/1000 bor spraying in Licord with 7.25 mg/lit and 0.52 gained the highest amount of chlorophyll a+b and extinction coefficient.

This study was done in order to determine the effect of salinity on the germination and early growth of Vigna radiate L. in Botany laboratory of Islamic Azad University – Shahr-e- Rey unite. The Gohar variety which obtained from Research center of Khozestan was used in this study. Experiment was carried in factorial with randomized complete block with four repetitions. Seeds of radiate L. were treated with six levels of salinity including 30, 60,90, 120,150 and 180 mole/L containing of NaCl and CaCl2 (Ca: Na =1) . Seeds were treated in order to study their germination characters in germinator condition. The effect of salinity was studied on germination percentage, seed vigor (vegetation growth potential )r, length of rootlet, length of stem and Results indicated that the effect of salinity on all studied characters was significant (p<0/01). In addition with increasing salt concentration, the characters showed descending trend which was more obvious about seed vigor (vegetation growth potential) and rootlet length.

This study for identification the portion of effective traits on increasing yields of six monogerm varieties, in sugar beet research institute in the year 1386 on complete randomized block design with three replications had been done. In this trial, at Establishment, Middle vegetative growth, Root growth and harvest stages, destructive sampling took place and besides measuring morphological characters, different growth indices with using different Plant parts dry weights, were determined. At the harvest time, Root Yield, impure Sugar Content and White Sugar Yield had been measured. According to the results, the varieties white sugar yields had significant differentiation at 1 percent statistical level. Evaluating the amount of different trait's effects at different sampling times (except harvest time), on amount of White Sugar Yield, with the help of multiple regression, showed that Average Root Diameter, at establishment and middle vegetative growth level, Specific Leaf Area and Root Dry Weight at establishment level, and Petiole Dry Weight at Root development level had the highest significant influence on White Sugar Yield. Results of Path Analysis showed that, in the studied six monogerm varieties of Sugar beet, the main restrictive factor for White Sugar Yield is shortage of assimilate accumulation in Root, as an important sink, at establishment level. So, according to the results, it can be concluded that, in addition to variety, paying attention to agronomy; especially at the beginning of the growing season can be effective on providing the appropriate situation for saving more assimilates in sugar beet root and as a result achieving the desirable yield.

In order to study the effect of different densities on the morphological traits, oil and protein percentages in three varieties of soybean (Glycine max L.) in climatic conditions of Kermanshah, an experiment in research field Mahidasht, Kermanshah, was conducted in 2002.A factorial experiment was carried out based on randomized complete blocks design with four replications. Varieties were placed in the blocks at 3 levels, including Williams, Zan, and Clark varieties and density at 3 levels, including plant were placed on 3, 5, 7cm intra rows spacing in the blocks (555000, 333000 and 238000 plant/ha, respectively). After harvesting plant height, number of sub branch, distance of the first sub branch from soil surface and inter node length and number of node in main stem, sub stem and per plant were recorded. The results showed that with increasing the planting density, plant height, distance the first sub branch from soil surface, number of node in main stem and inter-node length were increased. Also with decrease of density, number of sub-branch per plant was increased. Therefore, the highest number of node in main stem, plant height, distance the first sub branch from soil surface and inter node length belonged to D1 density. The study of cultivars showed that the Clark cultivar had highest number sub branch and number of node in sub stem and plant. Protein and oil percentages were not affected by cultivar and planting densities. GDD for each stage, was measured based on daily temperatures from planting to that time. Clark cultivar had the highest GDD for stages planting and R8 (physiological maturity).

Some plant species inhibit germination and growth of other plant species by secretion of specific chemical substances. In order to survey the allelopathic effect of five Amaranthus species (which are among the most prominent weed species in Golestan province) residues on Soybean seeds germination, a factorial complete random design experiment was conducted. The extract of Amaranthus species (allelopath) organs were chosen as main factor, water extract with different concentrations and seed germination as factorial and subsidiary factors. The results were analyzed using Mstatc software and the means for each characteristic were compared with Duncan's Multiple Range Test (P>0.01). Water extract of all Amaranthus species surveyed in this experiment had negative effect on Soybean var. DPX seeds germination. In addition, there was a slight difference in the allelopathic effect of surveyed species (effect of the type of allelopath). A. viridis with 62% had the highest and A. blitoides with 52% the lowest effect. There was not a significant difference between A. viridis, A. albus and A. hybridus. Similar results were also obtained between A. retroflexus and A. blitoides. The effect of different water extract concentrations of these species on Soybean var. DPX seeds germination was significant; allelopathic effect increased with the increase of concentration. From the survey of concentration and allelopath type interaction it could be concluded that 100% concentration of A. viridis had the highest allelopathic effect (88% germination decrease) in contrast with A. blitoides 25% concentration which had the lowest effect (28% decrease). To sum up, total plant organ water extract of these Amaranthus species have allelopathic properties on Soybean seeds germination. That is why, it is recommended that during Soybean cultivation as a secondary crop in a field containing weed residues of these species, either weed residues be evacuated from the field or considering the mentioned results, a higher amount of seeds be used, in this way a considerable decline in crop growth could be prevented.

This study focused on considering Hamedan-Bahar area water quality and quantity. To achieve this purpose 30 wells with good dispersion and good quality were selected. Quality variations were studied every month for each well in different years and water table (W.T.) similar Tisane's polygons of wells in 15 years (1991-2006) were determined. The results showed that W.T. of area because of city development, agriculture and incorrect managements was decreased abaut 11m. Head lost in years 1991 to 1996 rather than years of 1996 to 2001 was decreased and in years 2001 to 2006 good precipitations and management were controlled. Wells on based of Wilcox diagram in 2 quality groups (EC<750dSm-1 and EC>750dSm-1) were classified. Considering the correlation between SO42- and Cl1- showed that group 2 is affected by contamination source. Results of quality analyses showed that regarding nearer area to city and industrial region the quality in direction of ground water flow from south of east to north of east to C3S1 ,class was decreased. According to Wilcox diagram, water is used for agriculture without banning. Piper diagram showed that bicarbonatcalcic and bicarbonatsodic are two sources for water. Affections of water quality from time and location with absolute randomized block in several observations on 2 treats (1 and 2) and 30 repetitions (well locations) in 3 blocks were built. In time aspect 1% level was insignificant and in local aspect 1% level was significant. In spite of insignificant of time a significant decrease in water quality was seen. For the validation of results anevaluation on average of data with Duncan-test was done. Duncan test showed that average of parameters was lower in group 1.