Resistance against rhizomania disease via RNA silencing in sugar beet

Rhizomania is one of the most damaging and widely spread diseases in major sugar beet growing regions of the world. The causal agent, beet necrotic yellow vein virus (BNYVV), is transmitted via the fungus Polymyxa betae, which retains it in the field for years. In this study, an RNA silencing mechanism was employed to induce resistance against rhizomania using intron‐hairpin RNA (ihpRNA) constructs. These constructs were based on sequences of the BNYVV 5′‐untranslated region of RNA‐2 or the flanking sequence encoding P21 coat protein, with different lengths and orientations. Both transient and stable transformation methods produced effective resistance against rhizomania correlated with the transgene presence. Among the constructs, those generating ihpRNA structures with small intronic loops produced the highest frequencies of resistant events. The inheritance of transgenes and resistance was confirmed over generations in stably transformed plants.     

Intensive observations on the effect of some insecticides on Nephotettix virescens (Distant), a vector of virus and MLO diseases,with special reference to its transmission ability

The effects of some insecticides on Nephotettix virescens (Distant), a leafhopper vector of virus and MLO diseases, were studied with particular reference to their efficacy in affecting vector behaviour and transmission of rice tungro virus (RTV). When 10- and 15-day old seedlings from carbofuran-treated seeds were exposed to viruliferous vectors in cages, the percentages of transmission were 40 and 50, respectively against cent per cent in the control. Spraying of EC formulations of dimethoate, phosphamidon and methamidophos was not effective but decemethrin showed spectacular knockdown effect and gave absolute protection against RTV transmission upto 7 days. Since the transmission threshold of RTV is considerably shorter than of mycoplasmal diseases, the treatments affecting RTV transmission may reasonably be expected to be quite effective against MLO diseases like rice yellow dwarf and sandal spike, transmitted by N. virescens.     

Evaluation of impact of Khushab sub surface pipe drainage project in Pakistan

This paper describes the essential contents of research at a recently completed subsurface pipe drainage project located in the Khushab district of Pakistan. The paper explores the need and decision by Government of Pakistan to install a Sub Surface Pipe Drainage Project near Khushab where an old Surface Drainage System was already installed by the Provincial Irrigation and Power Department, Government of Punjab, Pakistan, since 1960. The new Sub Surface Pipe Drainage Project’s planning and executing agency M/S Euro-Consultant used existing Surface Drains with remodeling for to carry the additional drainage effluent of newly constructed sump pumps of the pipe drainage system connected to the old drains by means of small outfall drains. Until now the new system is working well in lowering the water table as well as increasing the agro-socio-economic status of the local population.     

Effect of Substrate Dependent Ethylene on Cotton (Gossypium hirsutum L.) at Physiological and Molecular Levels Under Salinity Stress

The potential of encapsulated calcium carbide (ECC) in improving growth, yield and physiology of cotton under salinity was evaluated in pot experiment. Salinity was induced by sodium chloride (NaCl) at 0, 1250 and 2000 ppm. The ECC was applied at the rate of 0, 15, and 30 mg kg^?1 soil. The results revealed that ECC improved number of branches, yield, shoot dry biomass, root dry biomass, by 57, 67, 40, 22, and 18% respectively, over control. Similarly, net photosynthesis, stomatal conductance nitrogen, phosphorus and potassium (N, P and K) concentration of shoot were enhanced by 38, 34, 7, 25 and 11% over control, respectively. The induction of new set of proteins ranging from 11 to 26 kDa was also observed at various levels of ECC and salinity stress. These results proved the efficacy of very lower concentrations of ethylene produced by ECC and showed the behavior of different parameters of cotton to it under saline stress.     

Early detection of the effects of compaction in forested soils: evidence from selective extraction techniques

Purpose

Soil compaction resulting from mechanisation of forest operations reduces air permeability and hydraulic conductivity of soil and can result in the development of hydromorphic and/or anoxic conditions. These hydromorphic conditions can affect physico-chemical properties of the soils. However, early detection of these effects on mineralogical portion of soils is methodologically difficult.

Materials and methods

To analyse the effects of soil compaction on iron minerals in loamy Luvisol, three compacted and three non-compacted soil profiles up to the depth of 50 cm were collected from an artificially deforested and compacted soils after 2 years of treatment. Soil was compacted with the help of 25 Mg wheeler’s load to increase the dry bulk density of soil from 1.21?±?0.05 to 1.45?±?0.1 g cm^?3. Soil samples were analysed by X-ray diffraction (XRD) and were treated by citrate bicarbonate (CB) and dithionite citrate bicarbonate (DCB) under controlled conditions. Major and minor elements (Fe, Al, Mg, Si and Mn) were analysed by ICP-AES in the CB and DCB extracts.

Results and discussion

It was found that X-ray diffraction is not an enough sensitive method to detect the quick mineralogical changes due to soil compaction. Results obtained from CB-DCB extractions showed that soil compaction resulted in larger CB and smaller DCB extractable elements as compared to non-compacted soil. Labile Fe was found 30 % of total Fe oxides in compacted soil against 10–14 % in non-compacted soils. Compaction thus resulted in Fe transfer from non-labile to labile oxides (s.l.). Results showed that soil compaction leads to the reduction of Fe³⁺ to Fe²⁺. The effects of hydromorphic conditions due to soil compaction were observed up to the depth of 35 cm in forest soil profile. Furthermore, a close association of Al with Fe oxides was observed in the soil samples, while Mn and Si were mainly released from other sources, Mg showing an intermediate behaviour.

Conclusions

Hydromorphic conditions owing to soil compaction affect the mobility and crystallisation process of iron mineral. CB-DCB selective extraction technique, in contrast to XRD technique, can be effectively used to examine the possible effects of soil compaction on iron minerals.

     

Transformation of the L-Asparaginase II Gene to Potato Hairy Roots for Production of Recombinant Protein

Journal of Crop Science and Biotechnology - Nowadays, transgenic plants are considered as an expression system for therapeutic recombinant proteins. One of the approaches to recombinant protein...     

Effect of β-aminobutyric acid on resistance of tomato against Pectobacterium carotovorum subsp. carotovorum

Journal of Plant Diseases and Protection - Stem rot of tomato caused by Pectobacterium carotovorum subsp. carotovorum (Pcc) results in economic yield loss worldwide. Previous studies have...     

Wetting-drying cycles during a rice-wheat crop rotation rapidly (im)mobilize recalcitrant soil phosphorus

Journal of Soils and Sediments - The residual phosphorus (P) in Hedley’s sequential fractionation procedure is considered to be a relatively stable soil P pool and unavailable for plant...