مجله علوم گیاهان زراعی ایران
سال چهل و هشتم شماره 2 (تابستان 1396)

Due to reduction the crops yield and yield components in water stress condition, a factorial experiment was conducted in a randomized complete block design with three replications to evaluate the effect of water deficite stress and growth improver materials on canola (Brassica napus L.) yield and yield components in research greenhouse of Agricultural Faculty of TarbiatModares University. Treatments includes water deficit stress {Control (50% discharged available water) (S1), average stress (65% discharged available water) (S2) and sever stress (80% discharged available water) (S3)} and foliar application {Control (F1), distilled water (F2), calcium silicate (F3), Hexaconazole (F4), propiconazole (F5), and penconazole (F6)}. Results showed the highest of yield was related to S1F6 that showed 2.1 gr higher than S2F1. Also S1F6 and S3F1 With more than 2-fold difference were the highest and the lowest of thousand seed weight. Also in S2, control and foliar application of F4 were the highest and the lowest of oil percentage respectively with 34.4% difference. S1 and S2 with no significant difference were lower than control with a significant difference proximately 5.8 µmol co2 m-2 Leaf s-1 in photosynthesis rate. S1F2 and S3F1 were the highest and lowest stomatal conductivity with 0.154 mol H2O m-2s-1 difference. Also S1F1 was the highest amount of intercellular Co2 concentration with 229 µmol CO2 mol air -1 difference with S3F2. So foliar application of triazoles (penconazole) and calcium silicate somewhat reduces the water deficit stress damages. So foliar application of triazoles (penconazole) and calcium silicate somewhat reduces the water deficit stress damages.

In this study the relationships between transcription rate of two hypothetical transcription factors (WRKY and bZIP) and TYDC, BBE, COR, T6ODM, CODM, SODM, DBOX and NOS which are involved in benzylisoquinoline alkaloids biosynthesis in Papaver somniferum were surveyed. Sampling was performed during five developmental stages including rosette, bud initiation, pendulous bud, flowering and lancing. Investigated parts were root, bottom part of stem, leaf, upper part of stem, capsule wall and capsule content. The results showed that there were high degree of consistency among the transcription rate of WRKY and the other genes which are involved in benzylisoquinoline alkaloids biosynthesis specially TYDC. Since TYDC is one of the initial genes in benzylisoquinoline alkaloid pathway, it seems that WRKY affect the entire pathway by changing TYDC transcription rate. Surprisingly, a coordinate regulation was seen among transcription rate of bZIP and the genes involved in benzylisoquiniline biosynthetic pathway. Since the modulation of secondary metabolism and defense against pathogens have been respectively attributed to WRKY and bZIP functions and production of benzylisoquiniline alkaloids is related to defense against plant pathogens and avoiding UV injuries, it seems that the transcription rate of these transcription factors and benzylisoquiniline biosynthetic genes are closely related.

To determine the effect of intercropping maize with pearl millet on dry fodder yield and quality an experiment was conducted at research field of Agriculture and Natural Resources College of Tehran University in Karaj in 2011. The experiment designed in a randomized complete block with four replications. Intercropping treatments included replacement series of pearl millet 25%: 75% forage maize, pearl millet 50%: 50% forage maize, pearl millet 75%: 25% forage maize and augment series of pearl millet 20%: 100% forage maize, pearl millet 40%: 100% forage maize, forage maize 20%: 100% pearl millet, forage maize 40%: 100% pearl millet plus pure culture both forage maize and millet. The results showed that sum of two harvest times gave the highest forage yield of millet per plant (dry) from treatment combination of pearl millet 75%: 25% forage maize. Similarly, the highest maize forage yield per plant (dry) from treatment combination of pearl millet 75%: 25% forage, respectively. Different arrangement of intercropping on quality traits, dry mater digestibility, acid detergent fiber and water soluble carbohydrates fodder millet (second harvest) and quality traits dry mater digestibility, acid detergent fiber, total ash, water soluble carbohydrates and crude protein fodder maize put a significant effect. In the experiment, the maximum amount of land equivalent ratio in the dry forage makeup additive intercropping 20% corn: 100% millet with a 60% performance increase allocated.

To study the effect of water stress and zinc sulfate application method on maximum leaf area index, yield and yield components of sunflower, an experiment was conducted in 2014 at research station of Bu Ali Sina University as a randomized complete block design with split plot arrangement in three replications. Water stress in four levels (irrigation after 60, 90, 120 and 150 mm evaporation from A pan) was placed in main plots and zinc sulfate application methods (no application, foliar feeding, broadcasting and placement application) were placed as subplots. The results showed that the maximums of leaf area index, head weight, number of seeds per head and grain yield were achieved in low intensity of water stress levels (irrigation after 60 and 90 mm evaporation) plus foliar feeding of zinc sulfate. Nevertheless, at severe water stress conditions, there was not difference between application methods of zinc sulfate fertilizer on measured traits. However, the head diameter and biological yield in severe water stress level (irrigation after 150 mm evaporation) were higher in foliar zinc sulfate application versus other application forms. In this study, seed weight was only affected by water stress treatments and harvest index reduced by reduction in water availability. In this study zinc sulfate especially in foliar application and under water stress improved the most of measured traits and decreased water stress severity on them.

In order to study of interaction between mycorrhizae symbiosis, soil and foliar spary of Flomix on yield and yield components of corn (Zea may L.), an experiment was carried out as factorial based on Randomized Complete Block Design (RCBD) with three replications in Agriculture Research Station of Shahrood University of Technology in 2014. The treatments included mycorrhizae symbiosis at 2 levels (non-application and application of mycorrhizae), foliar spray at 3 levels (non-application, once sprayed and twice sprayed) and soli spray at 3 levels (non-application, once soil application and twice soil application). Results showed that interaction between mycorrhizae symbiosis, soil and foliar spray of Flomix indicate a significant effect on forage yield, protein percent, grain P, chlorophyll a, b and relative water content traits. Also effect of mycorrhizae symbiosis foliar spray and foliar soil spray of Flomix was significant on colonization and increased this trait.Moreover, the result showed that interaction between mycorrhizae symbiosis and foliar spray indicate a significant effect on sugar solution and increased it. Mean comparisons showed treatment of none application of mycorrhizae once foliar spray none soil spray of Flomix increased the relative water content in compare with Application of mycorrhizae twice foliar spray none soil spray.

In order to study the effects of water deficit stress and foliar application of ascorbic acid on some agronomic, physiologic and biochemical traits of corn, an experiment was conducted in research field of Agriculture Faculty of Islamic Azad University, Varamin Branch in Iran during 2014 growing season. The experimental design was laid out in a randomized complete block arranged in split plots with three replicates. Irrigation at four levels (normal irrigation according to the region, irrigation withholding at eight leafy stage, irrigation withholding at silking stage and irrigation withholding at eight leaf stage and silking stages) as the main factor and ascorbic acid foliar application at three levels (0, 50 and 100 ppm) as the sub-factor were allocated to main and sub plots, respectively. The results showed that irrigation withholding at different growth stages significantly decreased seed yield and biological yield, harvest index, oil and protein percentage, oil and protein yield, total chlorophyll content, increased proline content and superoxide dismutase activity in the leaves. Foliar application of ascorbic acid could prevent quantitative and qualitative yield loss and chlorophyll degradation. In addition, ascorbic acid foliar application decreased proline accumulation and superoxide dismutase activity in the leaves. In general, considering the qualitative and quantitative improvement in studied traits, it can be concluded that ascorbic acid application can scavenge reactive oxygen species and reduce antioxidant enzyme activity and proline accumulation, which in turn, leads to increased seed yield and quality with improving growth conditions.

To study the different irrigation treatments on agronomic characteristics of soybean with and without use of triazoles and calcium silicate, an experiment was conducted as split-plot factorial in a randomized complete block design with three replications at the Research Field of Faculty of Agriculture, Tarbiat Modares University. The results showed that three-way interaction among experimental factors significantly influenced all traits, except plant height. Under non-stressed conditions for L17 and under moderate stress for Williams, hexaconazole spraying caused maximum and minimum protein yield with more than fourflods differences between them. Calcium silicate spraying on Williams under non- and moderate- stressed conditions, with 0.23 difference, showed most and least values of harvest index, respectively. Biological and seed yield under stress conditions decreased 9519 and 3328 kg/ha, respectively. According to the findings of these research, water deficit stress can cause reductions in values for quantitative traits and yield components of soybean, and under stress conditions, spraying admendatory materials can mitigate the harm of stress and increase the crop tolerance. Considering different response of soybean cultivars tested in terms of oil yield to spraying under varios conditions, it can be noted that penconazole and calcium silicate spraying on Williams under non-stressed conditions, and penconazole and hexaconazole spraying on L17 under moderate- and severe stressed conditions, exhibited higher efficiency in increasing oil yield.