To evaluate some agronomic and physiological characteristics under drought stress, determining the best quantitative indices for drought resistance, and identifying drought resistant sunflower genotypes, a field experiment with 36 sunflower genotypes was carried out in 2008-2009 at the research farm of Dryland Agricultural Research Institute (Sararood), Kermanshah, Iran.Thirty six genotypes of sunflower were evaluated in a 6´6 lattice design with two replications under normal and drought stress at flowering and seed development stages. Some agronomic and physiological characteristics under drought stress and seed yield under both conditions were measured during the growing season. The results of analysis of variance showed that differences among the genotypes for plant height, relative ionic leakage and cell membrane stability traits were significant at the 1% and for seed yield at the 5% probability levels. Drought tolerance indices MP, GMP, HarM and STI exhibited a high correlation with seed yield in both stress and non-stress conditions and were recognized as the best indices for selecting genotypes with high yield potential and resistant to drought stress. Using biplot method, SIL-237, SIL-218, SIL-210, SIL-206, SIL-240, SIL-140, SIL-42, SIL-96, SIL-238 and SIL-227 were recognized as resistant genotypes. Genotypes that produced higher seed yield and were drought resistant can be used to develop resistant hybrids.

Azoxystrobin is a broad-spectrum, systemic and soil-applied fungicide used for crop protection on more than 80 different crops. Azoxystrobin use has induced water pollution and ecotoxicological effects upon aquatic organisms, as well as heath issues. Such issues may be solved by phytoremediation. Here, we tested Plantago major L., Helianthus ANNUS L. and Glycine max L. to clean soils under laboratory conditions. Results show that the accumulation efficiency of azoxystrobin and azoxystrobin acid in roots was higher than those of leaves. G. max roots were an efficient accumulator of azoxystrobin (25.32 mg/kg), followed by P. major roots (20.62 mg/kg) and H. ANNUS roots (18.29 mg/kg), within 10 days, respectively. In the leaves, azoxystrobin significantly translocated into the P. major leaves and reached the maximum after 10 days of exposure (15.03 mg/kg), followed by H. ANNUS leaves (9.8 mg/kg), while it reached the maximum after 3 days of exposure (3.12 mg/kg) in G. max leaves. Azoxystrobin acid significantly accumulated in P. majorroots more than the G. max and H. ANNUS roots. In the leaves, azoxystrobin acid significantly accumulated in G. max more than P. major and H. ANNUS. The presence of P. major with Tween 80 had effects on azoxystrobin desorption from soil, plant uptake metabolism and translocation more than P. major alone.

Vanadium (V) is a transition metal consistently distributed in the Earth’ s crust. At trace concentrations, it has been described as a beneficial element for some organisms; however, it is toxic at higher concentrations. This study was conducted hydroponically in a complete randomized design to investigate effects of V (0, 3. 25, 7. 5, and 15 mg L-1) on antioxidant system of sunflower. Results showed that all applied concentrations of V significantly decreased the plant growth, but increased the free amino acids, proline, malondialdehyde and H2O2 contents of plants. The antioxidant enzymes activities increased in response to the increase in V concentration. The activity of (Guaiacol) peroxidase showed a significant increase at 15 mg L-1 V while the activities of catalase, glutathione reductase, and ascorbate peroxidase decreased significantly by application of V. There was a slight increase in the superoxide dismutase activity at different concentrations of V. The study concludes that the applied concentrations of V induced oxidative stress in sunflower and (Guaiacol) peroxidase was a more effective antioxidant enzyme in scavenging the free radicals in this plant.

With the culture of various explant under certain cultural conditions, embryogenesis will result. In this research mbryos were obtained from several species of Hyoscyamus: H.arachnoideus H.pusillus, H.niger, from 2 distinct geographical regions, on MS mediums with various hormonal treatments. The results from statistical assessments showed that the highest embryogenesis were obtained with the following conditions: Culture of region 2 biennial H.niger stern segments on mediums of No .I (IAA=0.2mg/L), No. 3 (BAP=1.5mg/L), No. 4 (Kin=1.5mg/L), No. 7 (BAP=1.5, IAA=0.2mg/L), and No. 10 (Kin= 1.5, IAA=0.2mg/L). Culture of region 2 biennial H. niger roots on mediums of No. 4, 7, 10, and (BAP=1.12, IAA=0.09mg/L). Culture of region 2 biennial H. niger leaves on medium contianing Kin (1.5 mg/L). In addition, the highest embryogenesis frequencies were observed with: Culture of H.pusillus sterns on mediums No. 7; and 12. Culture of H.pusillus leaves on medium No. 3. Culture of H.arachnoideus leaves and sterns on mediums No. 7, and 12. Culture of region I biennial H.niger sterns on mediums No. 7, and 12. Culture of region 2 biennial H.niger roots, sterns, and leaves on medium No. 4, 7, and 12. Culture of region 2 biennial Hniger roots, and sterns on mediums No. 1, 3, and 10. The formation of plantlet resulted from the subculture of the obtained embryos on MS medium and MS medium contianing IAA (0.2mg/L).

In order to determine the critical period of weeds control in Allstar cultivar of sunflower, an experiment was conducted in experimental farm of Islamic Azad University of Tabriz, Iran, in 2007. The experimental design was a randomized complete block with three replications. The treatments were weed – infested and weed – free at 0, 2, 4, 6, 8, 10 and 14 weeks after sunflower emergence. Studied traits were hull weight to brain weight ratio, 100 grains weight, grain yield, oil percentage and oil yield. Results indicated the significant differences among treatments in most studied traits. Full season weed – infested treatment decreased up to 27.5% and 43% grain and oil yield in comparison to full season weed–free treatment, respectively. Based on fitted equations for weed–infested and weed – free plots, 1 to 9.5 weeks and 2.5 to 7.5 weeks after sunflower emergence were determined as critical periods of weed control with 5% and 10% yield loss, respectively.

When cultured on media containing various amounts of different hormones, plant organ segments can produce neoformed organs. Just like the organs produced from seeds, these neoformed organs can also go on to serve as intact plant organs. In this research, the seeds from three species of Hyoscyamus genus, including H. pusillus, H.  arachnoideus, annual H. niger and biennial H. niger from two different geographical regions, were cultured to obtain sterile seedlings. Then, organogenesis (rhizogenesis, caulogenesis, and leaf production) was assessed with the culture of seeds and organ segments of the obtained sterile plants on media containing various amounts of various hormones. Statistical assessments on the results showed us that the best rhizogenesis was obtained with root culture of biennial H niger, on MS medium containing IAA (0.2 mg/L), and tem culture of biennial H niger, on MS medium containing IAA (0.2 mg/L) and Kin (1.5 mg/L). Also, the culture of H pusillus, H arachnoideus, and annual H niger species on MS medium containing 2,4-D (0.32 mg/L) showed the highest rhizogenesis. The highest caulogenesis in biennial H niger species was obtained when the calli obtained from the stem ulture on MS medium containing IAA (0.09 g/L) and BAP (1.12 mg/L), were sub-cultured on MS medium containing BAP (1.12 mg/L) and GA3 (2.5 mg/L). Also the highest caulogenesis as observed on the calli obtained from the culture of the seeds of H pusillus on MS medium containing BAP (0.5 mg/L) and NAA (0.5 mg/L). The highest leaf production was bserved with the stem culture of H arachnoideus on MS medium containing Kin (1.5 mg/L), and the culture of H pusillus seeds on MS medium containing BAP (0.5 mg/L) and NAA (0.5 mg/L).

In this research cytogenetical and agricultural characteristic of H. tuberosus and H. annuus including chromosomal morphology‚ shape‚ size‚ number of satellite chromosomes were studied. In caryotypic analysis of H. tuberosus it showed that this species with genome formula of 2n = 6x = 102 is a hexaploid. In this species the average length of haploid chromosome set was 230.415±3.311 (m). The biggest chromosome with the length of 5.767±0.019 (m) and relative length of 2.503±0.008 % was determined as sub acrocentric. The smallest chromosome was metacentric with the length of 3.48±0.032 (m). Out of 51 pairs of chromosomes 34 were identified as metacentric‚ 14 Pairs sub metacentric and 3 pairs sub acrocentric. Among them 3 pairs of satellite chromosomes were observed. The biggest arm ratio index was obtained for chromosome number of 33‚ 3.265±0.327 (m). The caryotypic analysis of H. annuus showed that it was a diploid species 2n = 2x = 34. Average length of haploid chromosome set was 75.682±2.995 (m). The chromosome number 1 had the biggest length 6.033±0.341 (m) with the relative length of 7.939±0.285 % and was metacentric. The smallest chromosome was sub metacentric with the length of 3.563±0.208 (m). Out of 17 pairs of chromosomes‚ 11 pairs were metacentric‚ 2 pairs sub metacentric and 4 pairs were sub acrocentric. Among them 2 pairs of satellite were observed. In the study of arm ratio index‚ the biggest arm ratio index was obtained for chromosome 15‚ 5.634±0.544 and was sub acrocentric. The caryotypic analysis of these two species showed that there were some differences in the chromosomes morphology‚ number and kind of metacentric‚ sub metacentric and sub acrocentric‚ number of satellite‚ arm ratio index and chromosomal formula.