Assessment of diversity in Podophyllum hexandrum by genetic and phytochemical markers

For successful conservation and domestication of a species, evaluation of its genetic diversity by different markers is important. Morphological characteristics, phytochemical variation and random amplified polymorphic DNA (RAPD) profiles were generated in different accessions of Podophyllum hexandrum in order to determine the genetic diversity. Random amplified polymorphic DNA (RAPD) analysis revealed a high degree of genetic diversity among the accessions used in the study. There was also high diversity in the concentration of marker compounds in the collected samples as revealed by HPLC analysis. It is shown that the approaches used in the work successfully discriminate between the accessions of this species and thus they constitute interesting tools to analyze molecular, biochemical and phenotypic diversity within this species. Similarity measurement using UPGMA followed by cluster analysis resulted in formation of many groups based on geographical distribution that generally reflected expected trends between the genotypes. There were also some important exceptions like PW-S, an accession from Wastoorwan, Khrew showing close resemblance to PG-S and PG-B collected from Gulmarg but grown at two different gene banks at Srinagar and Bonera. Further an accession PSH-B from Keller was significantly diverse from the rest of the native genotypes phytochemically, morphologically and at molecular level. RAPD data analysis was found to be significant predictor of phytochemical markers in cultivated P. hexandrum germplasm. Twelve accessions grown in gene bank repository were subjected to RAPD analysis and were assessed for content of podophyllotoxin and podophyllotoxin β-d-glycoside by HPLC. Individual regressions of podophyllotoxin and podophyllotoxin β-d-glycoside by RAPD analysis against HPLC has been found to determine linear values. Strong correlation and a strong association of values of the phytochemical variables and the DNA polymorphism data has been recorded.     

Comparison of conventional puddling and dry tillage in rice–wheat system

In many parts of Asia, rice is transplanted in puddled fields and after the harvest of this crop wheat is grown. This traditional method of growing rice may have deleterious effect on the growth of the subsequent crop in a rice–wheat cropping system. Wheat crop was planted in the same plots following a rice crop to evaluate the residual effects of various tillage treatments suitable for rice on the growth of the subsequent crop. Rice cultivar Super-basmati was grown in summer and wheat cultivar Auqab-2000 in autumn after rice. Four treatments were used to grow rice viz. transplanting in continuously flooded conditions (TRF), transplanting with intermittent flooding and drying (TRI), direct seeded using dry seeds (DSR) and direct seeded using primed seeds (DSP). Traditional puddling tillage system was followed in TRF and TRI, while for DSR and DSP, dry tillage system was followed. For convenience, the abbreviations of the rice treatments were used to indicate the same plots during the wheat crop. For the rice crop, tiller number, fertile tillers, kernel and straw yield, and harvest index were significantly better with transplanted treatments (TRI and TRF) than the direct seeded treatments. TRI also gave a yield advantage of 5% over TRF. For wheat, crop following direct seeded rice was better than transplanting. This study suggests that intermittent irrigation in the traditional puddling tillage system and DSP dry tillage system are the promising alternatives that may be opted.     

Interaction of Rhizobium and Pseudomonas with Wheat (Triticum Aestivum L.) in Potted Soil with or Without P2O5

The effect of inoculation of Rhizobium or Pseudomonas, or both, in the presence and absence of phosphorus pentoxide (P₂O₅) fertilizer on wheat yield was tested. The experiment was conducted outdoors in potted soil during two consecutive years under natural conditions. Rhizobial strain (Thal 8-chickpea nodulating bacteria) and Pseudomonas strain (54RB), both indigenous P solubilizers were applied in broth culture at seedling stage. Fertilizer in the form of P₂O₅ was an additional treatment applied at sowing time. Results revealed that inoculation of Pseudomonas strain in presence of phosphorus (P) fertilizer increased yield up to 41.8% when it was compared with only P fertilizer applied. Co-inoculation of Rhizobium and Pseudomonas strains with the P₂O₅ treatment however resulted in increased grains yield by 10% over the P₂O₅ treatment alone. It is inferred that inoculation with Rhizobium and Pseudomonas combined with P₂O₅ is not only environmentally beneficial but also economically sound and productive, with wheat yield increases of 10% to 42%.     

拟南芥花组织高表达TCP家族转录因子At1g30210的克隆与转录激活活性鉴定

本文从拟南芥中克隆到基因At1g30210的全长读码框。多序列比对结果表明,在推导的氨基酸水平上,该基因编码的蛋白含有特征性的TCP保守结构域,与已知的玉米、金鱼草和水稻的TCP家族基因中都存在显著性的保守性。另外通过酵母单杂交实验证明该基因编码的蛋白在酵母体内具有转录激活功能。同时RT-PCR实验结果表明,该基因在拟南芥花组织中表达量相对较高,具有明显的组织表达特异性。花器官高表达转录因子的克隆将为研究TCP基因调控植物花发育和花形态建成提供新的物质基础。     

Seasonal Changes in Arsenic Concentrations and Hydrogeochemistry of Canadian Creek, Ballarat (Victoria, Australia)

A 10-month study of surface waters in Canadian Creek (Ballarat, Victoria, Australia) showed the significant influence of historic gold mining waste material. The investigation focussed on the hydrogeochemistry of the surface waters and soils in order to: (1) document the levels and seasonal trends in major, minor and trace elements in the creek, (2) identify the process by which As is released from the soil/waste mining material to surface waters. For most dissolved major and trace elements (Na, Ca, Mg, K, and As) in surface waters, the concentrations decreased with the increasing rainfall and flow conditions except for Al and Fe. Two sites selected along the creek (< 1 km apart) allowed evaluation of the possibility that mining waste material is contributing to the elevated As concentrations (up to 145 μg/l) in downstream surface water. Arsenic concentration varied more than 28 fold seasonally and was highest in autumn and lowest in spring. Elevated concentrations of As (up to 1946 mg/kg) at the downstream site indicated the presence of a source of As concentration in both surface and subsurface soils. Oxidation of arsenic sulphides under aerobic conditions with redox fluctuations (7 to 201 mV) could cause elevated As levels in the creek. Significant statistical correlations among the major cations (Ca, Na and Mg) point to a common source(s) resulting in neutral to slightly alkaline (pH ～ 6.5 to 7.8) surface water. Fe and Al secondary phases under oxidising conditions are a significant controlling mechanism for the mobilization of As in highly contaminated soils (> 1500 mg/kg) in the study area. The large As adsorption capacity of Fe and Al could be limiting extreme mobilization into the water. Rainfall with relatively low pH is possibly causing mobilisation of Al, Fe and As from highly alkaline soils (pH ≈ 9.0) into the nearby creek.     

Evaluating Drainage Design Parameters for the Fourth Drainage Project, Pakistan by using SWAP Model: Part II – Modeling Results

This paper presents the results of modelsimulations to evaluate drainage designparameters for the Fourth Drainage Project(FDP), Punjab, Pakistan. The SWAP model wasapplied to compute the effects of landdrainage (12 combinations of drain depthand spacing) on soil moisture conditions inthe root zone and their effect on cropyield and soil salinization. For theconditions considered, the selection ofdrain depth is found to be more criticalthan that of drain spacing. Deeper drainsperform technically better in relation tocrop growth and soil salinization. Theoptimum drain depth for the multiplecropping system of the FDP-area was foundto be 2.2 m. This drain depth will producereasonably good crop yields at rather lowdrainage intensity while keeping the rootzone salinity within acceptable limits.This drainage design also maintained thegroundwater table depth below the root zonethroughout the growing season. The outcomeof this study reveals that the drainagedesign criteria applied for the FDP israther conservative with high drainageintensity. The FDP-area can effectively bedrained with a 25 percent lower drainageintensity (q _drain/h)provided no operational or maintenanceconstraints are present. However, the finaldecision on the optimum combination ofdrain depth and drain spacing would requirea thorough economical analysis. Thenon-steady state approach proved successfulin analyzing the complex interactionsbetween irrigation and drainage components.It is a valuable tool to optimize thedesign of drainage systems against cropyields and soil salinization.     

Foliar Application of Silicon,Sulfur, and Flowering Fruit Set Biostimulant on Canola

This experiment was conducted to study the effects of foliar application of silicon, sulfur, and flowering fruit set biostimulant on canola in the farmer’s condition in Darzian, 12?km from Marivan city in the northwest of Iran. The experimental layout was designed as a split-split plot in a randomized complete-block design, with three replications during two consecutive growing seasons, 2017–18 and 2018–19. The main factor included silicon application at two levels: control (0: non-application) and silicon application at 2?kg ha^?1. Sub-factor was sulfur spraying at three levels (0, 1, and 2?L ha^?1) and sub-sub-factor was Tecamin flower (Agri Tecno Fertilizantes, Valencia, Spain) spraying as a flowering fruit set biostimulant at three levels (0, 1, and 2?L ha^?1). The results of the combined analysis showed that the number of grains per pod and biomass were increased significantly at the 1% level by silicon application. Sulfur application improved 1000-grain weight, grain yield, and biomass. This increase was 7.42% for grain yield. Tecamin also significantly increased all traits, including fertile and infertile pod numbers, grain number per pod, 1000-grain weight, grain yield, and biomass. As the most important economic traits, Tecamin increased grain yield by 14.12% compared to controls. Among the treatments, the effect of Tecamin on increasing grain yield was superior. In this experiment, some traits were significantly affected by interaction effects of treatments.