Stimulation of ovarian growth by methyl farnesoate and eyestalk ablation in penaeoidean model shrimp,Sicyonia ingentis Burkenroad, 1938

The effect of methyl farnesoate (MF) administration on the vitellogenesis of the penaeoidean shrimp, Sicyonia ingentis, was studied. The short‐ and long‐term treatment effects as well as the effect of two MF injection regimens (0.1 and 1.0 μg MF/injection) were evaluated. The studies were also carried out to understand the pattern of vitellogenesis in eyestalk ablated adult and juvenile shrimps. A combination of endpoints, haemolymph vitellogenin (Vg) levels, gonadosomatic index (GSI) and histology, was used to study the effect of these treatments. The GSI increased in all the MF‐treated shrimp compared with the control shrimps. Although haemolymph Vg levels declined over the experimental period in all the treatments, the Vg levels decreased significantly only in the short‐term treatment with 1.0 μg MF. Similarly, haemolymph protein level also declined over the experimental period in all the treatment groups. However, except in the long‐term treatment with 0.1 μg MF, all treatments showed a significant decrease in haemolymph protein level. Conversely, in all eyestalk ablated adults and juveniles, haemolymph Vg, total protein and GSI increased over the experimental period, all of which were higher than the concurrent control. The discrepancy in the vitellogenic pattern between MF‐treated and eyestalk ablated shrimp was possibly due to the difference in the ovarian phase of the initial control. Although unilateral eyestalk ablation failed to induce vitellogenesis in juveniles, bilateral ablation induced vitellogenesis, which indicates that juveniles are competent to undergo vitellogenesis.     

与辣椒抗CMV相关的数量性状位点(QTL)的鉴定

在辣椒(Capsicum annuum)种内进行抗CMV QTL分析.从感病品种Maor与抗病品种Perennial杂交获得180个F3.在美国和以色列的三个试验中用两个病毒株系接种.大部分RFLP和AFIP标记被用作构建遗传图谱,区间分析被用作QTL检测.有4个QTL与抗CMV显著相关.检测到了两个标记对CMV抗性的双基因互作,没有检测到单基因效用.3个试验中检测到控制表现型变异(cmy11.1)的QTL,其变异最大百分比为16%～33%,该QTL与双基因互作有关.这个QTL与L位点连锁,并证实该QTL与抗TMV有关.在Perennial上早期非常有趣的观察到抗CMV感TMV的现象.来自于不相关的种群的一个高世代的回交育种株系3990,被选择用来分析对CMV的抗性,标记覆盖整个基因组,检测到来自Perennial的基因渗人.这些基因渗入的区域中包括4个与抗CMV相关的QTL.在两个基因区域的标记被鉴定与抗CMV的QTL相关.同时也与控制果实重量的QTL相关,另外的育种观察也证实对CMV的抗性来源于Perennial和小果型品种.     

In retrospect: managing an invasive pest,fall armyworm,Spodoptera frugiperda,in maize in India through digital and conventional networking pays off rich dividends towards crop sustainability

Journal of Plant Diseases and Protection - Faced with onslaught of an invasive pest, the fall armyworm, Spodoptera frugiperda, detected first on maize crop in the Indian state of Karnataka in May...     

Shock and vibration data acquisition system for off-road vehicle operator health and safety assessment

A data acquisition software and hardware system was developed for acquiring geo-referenced shock and vibration data using National Instruments' LabView graphical programming language. This was used in conjunction with a modular data acquisition and signal conditioning system and a Differential Global Positioning System (DGPS) receiver. A prototype vehicle obstacle course, which introduced spatially varying shock events to vehicles as they traversed the course, was constructed. Obstacles consisted of both repetitious and single discrete events. A series of investigations was conducted on the obstacle course to evaluate the performance and characteristics of the DAQ system and the tractor when exposed to shock and vibration events. Spectral and time domain plots obtained from the geo-referenced data acquisition system (GDAQ) system under static, highway, and off-road obstacle course conditions were evaluated to demonstrate that the system performed as expected. The migration of experiments from laboratory to field gave confidence that this system could be used to collect shock and vibration data over a wide range of frequencies. The use of geo-referenced data records proved beneficial in isolating and extracting data segments of interest from a continuous data record.     

Enhancement of beta-glucosidase and beta-galactosidase of Trigonella foenum-graecum by exposure to the allelochemical mimosine

Glycohydrolases assume significance in the metabolism of biological systems and have important industrial applications in the areas of pharmaceuticals, food, and medicine. Glycosidases were screened in germinating seeds, and attempts were made to enhance their levels. Screening of glycosidases in the seedlings during a 72 h germination period revealed higher levels of beta-glucosidase and beta-galactosidase in Trigonella foenum-graecum compared to Cicer arietinum and Vigna radiata. Activity of beta-galactosidase was in general higher than that of beta-glucosidase in all the seedlings tested. During growth, exposure of the seedlings to an allelochemical, mimosine, at 0.1 mM resulted in the enhancement of enzyme levels by 50% in the seedlings of T. foenum-graecum, whereas the addition of mimosine to the assay medium in vitro did not affect the enzyme activities. Hydrolytic activity was enhanced by addition of glycerol in the medium up to 0.1 M in the case of beta-glucosidase and with 0.05 M in the case of beta-galactosidase. In general, the hydrolytic rate was higher by about 30% in the seedlings exposed to mimosine compared to that of the control. Concomitant enhancement in the rates of transgalactosidation by 51% and transglucosidation by 23% was also noted, underscoring the relevance of plant glycohydrolases for appropriate applications.     

De novo transcriptome assembly and development of EST-SSR markers for Pterocarpus santalinus L. f. (Red sanders), a threatened and endemic tree of India

Genetic Resources and Crop Evolution - The endemic and precious tree Pterocarpus santalinus L. f. (Red sanders) is a drought hardy species for conservation in peninsular India due to its...     

A Simple PCR Procedure to Detect White Spot Syndrome Virus (WSSV) of Shrimp, <Emphasis Type="Italic">Penaeus monodon</Emphasis> (Fabricious)

A non-stop, single tube and semi-nested polymerase chain reaction (PCR) technique with simple procedure was developed for simultaneous detection and grading the level of white spot syndrome infection in penaeid shrimp, Penaeus monodon. In this PCR procedure, three sense primers and one antisense primer with uniform annealing temperature of 55 °C were used. These primers amplify three PCR products (500, 300 and 200 base pairs [bp]) depending upon the severity of infection. Quantities of WSSV-DNA at 10 pg and greater gave three PCR products of 500, 300, 200 bp. A moderate concentration of WSSV-DNA, around 100 fg, gave two products of 300 and 200 bp and a low concentration of 1 fg or more gave only one PCR product of 200 bp. This PCR technique was assessed for early detection of WSSV in shrimp. In time-course infectivity experiments conducted on shrimp with WSSV, one PCR product (200 bp) was seen in hemolymph, tail tissue and gill at 3 h post infection (p.i.); two PCR products (300 and 200 bp) were seen in tail tissue, hemolymph, heart tissue and gill at 18 h p.i. At 30 h p.i., three PCR products (500, 300, 200 bp) were seen in all the organs tested. The samples collected from control animals showed negative for WSSV.     

Immunomodulatory effect of Cynodon dactylon against white tail disease of giant freshwater prawn,Macrobrachium rosenbergii (de Man, 1879)

The giant freshwater prawn, Macrobrachium rosenbergii, is an economically important and extensively cultured crustacean worldwide. The viral pathogens, Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) are responsible for causing severe mortalities in the hatchery and nursery phases. This study investigates the protection of postlarvae of freshwater against white tail disease (WTD) using plant extract derived from Cyanodon dactylon and the modulation of the prawn non‐specific immunity. To determine the immunomodulatory effect of C. dactylon extract, the prawn was injected with plant extract and various immunological parameters were estimated. The immunological parameters such as proPO, SOD, THC and clotting time were found to be significantly higher in the plant extract‐injected prawn when compared with control groups. The results of real time PCR analysis revealed up regulation on the expression proPO, SOD and lysozyme genes in MrNV and XSV challenged prawn postlarvae treated with C. dactylon extract. Infectivity experiment showed high relative per cent survival in MrNV and XSV‐challenged prawn postlarvae treated with C. dactylon extract. These results strongly indicate that the administration of C. dactylon plant extract enhances immunity of the prawn. Based on the results, this study recommends that the immersion of postlarvae in C. dactylon plant extract is a potential prophylactic agent against WTD.     

Antioxidant Properties of Protein Hydrolysate Obtained from Oyster Saccostrea cucullata (Born, 1778)

The antioxidant activities of enzymatically hydrolyzed (protease from Bacillus cereus SU12) oyster (Saccostrea cucullata) protein were studied. The hydrolysate exhibited a strong antioxidant potential in 1, 1-diphenyl-2-picrylhydrazyl (DPPH, 85.7 ± 0.37%), followed by hydrogen peroxide radical scavenging activity (81.6 ± 0.3%), hydroxyl radical scavenging activity (79.32 ± 0.6%), and reducing power assay (2.63 ± 0.2 OD at 700 nm) at a concentration of 1 mg/mL. Due to the high antioxidant potential, the hydrolysate was purified in Sephadex G-25 gel filtration chromatography. The active peptide fraction was identified by DPPH and reducing power assay. The amino acid content of the purified active peptide fraction was analyzed by high performance liquid chromatography. The active fraction contained a good quantity of both essential and nonessential amino acids. The present study revealed that oyster (S. cucullata) protein hydrolysate is a potential source for natural antioxidants.     

Microbial inoculation of seeds characteristically shapes the rhizosphere microbiome in <Emphasis Type="Italic">desi</Emphasis> and <Emphasis Type="Italic">kabuli</Emphasis> chickpea types

Purpose

Chickpea is generally cultivated after seed treatment with host-specific Mesorhizobium ciceri, the nitrogen-fixing bacterium forming root nodules. Some species of free-living cyanobacteria are capable of nitrogen fixation. We examined the rhizosphere microbiota changes and the potential for plant growth promotion by applying a free-living, nitrogen-fixing cyanobacterium and the biofilm formulation of cyanobacterium with M. ciceri, relative to M. ciceri applied singly, to two each of desi and kabuli varieties of chickpea.

Materials and methods

Denaturing gradient gel electrophoresis (DGGE) profiles of archaeal, bacterial and cyanobacterial communities and those of phospholipid fatty acids (PLFAs) were obtained to evaluate the changes of the microbial communities in the chickpea rhizosphere. Plant growth attributes, including the pod yields and the availabilities of soil macronutrients and micronutrients, were monitored.

Results and discussion

The DGGE profiles showed distinct and characteristic changes due to the microbial inoculation; varietal differences exerted a marked influence on the archaeal and cyanobacterial communities. However, bacterial communities were modulated more by the type of microbial inoculants. Abundance of Gram-negative bacteria (in terms of notional PLFAs) differed between the desi and the kabuli varieties inoculated with M. ciceri alone, and the principal component analysis of PLFA profiles confirmed the characteristic effect of microbial inoculants tested. Microbial inoculation led to increases in the 100-seed weight and differential effects on the concentrations of available nitrogen and phosphorus, and those of iron, zinc and copper, suggesting their increased cycling in the rhizosphere.

Conclusions

Microbial inoculation of chickpea brought out the characteristic changes in rhizosphere microbiota. Consequently, the growth promotion of chickpea and nutrient cycling in its rhizosphere distinctively differed. Further studies are needed to analyse the association and dynamic changes in the microbial communities to define the subset of microorganisms selected by chickpea in its rhizosphere and the influence of microbial inoculation.