Artificial neural network for the estimation of soil moisture and surface roughness

Estimation of the soil moisture and soil roughness by using microwave data with less complex and fast method is a significant area of research today. For this purpose an Artificial Neural Network (ANN) based algorithm is used and tested in present study. The ANN model is calibrated and tested with the experimentally obtained data by using X-band scatterometer for different field roughness 3.78, 1.83 and 1.63 cm and at fixed value of soil moisture 22.8%. The measurement of scattering coefficient was carried out over a range of incidence angle from 20° to 70° by 5° steps for both the HH (horizontal transmitter and horizontal receiver) and VV (vertical transmitter and vertical receiver) polarization. Two training algorithm of Feed Forward Backpropagation neural network namely Levenberg-Marquardt (TRAINLM) and Gradient-Descent (TRAINGD) were used for analysis. The performance of the ANN models with different algorithm is evaluated by comparing the direct measured value of soil roughness and soil moisture with the soil roughness and soil moisture estimated by the ANN. Our work suggests that ANN model with training algorithm (TRAINLM) is more suitable for the soil moisture and surface roughness prediction in comparison to (TRAINGD) and ANN modeling may be the promising alternative for the soil moisture and surface roughness estimation. The main advantage of the ANN approach for the surface roughness and soil moisture estimation is its potential for world wide reporting.     

Supra-nutritional dietary intake of selenite and selenium yeast in normal and stressed rainbow trout (Oncorhynchus mykiss): Implications on selenium status and health responses

Commercial salmonid diets are not typically supplemented with selenium (Se) as they naturally contain relatively high levels of this essential trace element; however supplementation may be necessary to meet requirements during physical stress. Adopting an integrated approach by simultaneously determining Se status, various health parameters and interactions with other trace elements, this study aimed to determine the role of supra-supplemented selenite and Se-yeast (Selplex^®) on the growth and health of rainbow trout (Oncorhynchus mykiss), both under normal conditions and after exposure to chronic physical stress. Fish were fed one of seven diets; a basal un-supplemented diet (0.73 mg kg^− 1 Se) or diets supplemented with Se-yeast or sodium selenite to provide 2, 4, or 8 mg kg^− 1 Se for 10 weeks prior to subjection of daily handling and confinement stressors for seven days. Net whole body Se retention was significantly greater for Se-yeast than selenite at all levels. In normal conditions activities of hepatic glutathione peroxidase (GSH-Px) and thioredoxin reductase (Trx-R) indicate that Se requirements were met by the basal diet. Similarly, pre-stress supra-supplementation of selenite and Se-yeast did not affect oxidative status (total antioxidant capacity of serum and hepatic malondialdehyde), immuno-competence (respiratory burst activity, serum lysozyme, and leukocyte counts) or other haematological and growth parameters (nuclear abnormalities in erythrocytes, and specific growth rate). In contrast, the trend towards a higher GSH-Px post-stress in Se supplemented diets over the basal diet, particularly in Se-yeast fed fish, indicates that Se requirements may not be met by the un-supplemented practical diet in stressed fish. Seven days of chronic physical stress decreased whole body Se and increased GSH-Px activity signifying an increased Se utilisation. During stress Se status was more effectively maintained by Se-yeast than selenite. Increased hepatic lipid peroxidation in stressed fish fed 8 mg kg^− 1 selenite indicates a possible pro-oxidant effect of selenite. A positive interaction was observed between dietary selenite and whole body copper, but no such interaction was observed with Se-yeast. This study concludes that physical stressors can result in an elevated Se utilisation and consequently supplementation of commercial diets may be necessary such that Se reserves are available as a contingency for stress.     

Cyhalofop application timing and adjuvant selection for Echinochloa crus-galli control in rice

Field experiments were conducted in Stuttgart, Arkansas, in 2007 and 2008 to evaluate cyhalofop application timing and adjuvant selection for Echinochloa crus-galli L. Beauv. (barnyardgrass) control in drill-seeded rice. In the application timing experiment, cyhalofop was applied at 1 d prior to flooding (PREFL) and at 7, 14, and 21 d post-flood (POSTFL) as single (314 g a.i./ha) or sequential application (first application at 314 g a.i./ha followed by a second application 14 days later at 213 g a.i./ha). In the adjuvant study, the adjuvants evaluated were non-ionic surfactant (NIS) at 0.25% v/v, crop oil concentrate (COC) at 1% v/v, methylated seed oil (MSO) at 1% v/v, 28% urea ammonium nitrate (UAN) at 2.5% v/v, combination of NIS or COC or MSO with UAN, a proprietary blend of MSO/organosilicone (OSL)/UAN at 2.5% v/v, and MSO/OSL/UAN applied with NIS or COC. All adjuvants applied with cyhalofop (314 g a.i./ha at 14 d after flood establishment) resulted in E. crus-galli control and rice yields comparable to cyhalofop alone. In 2007, a single application of cyhalofop controlled E. crus-galli 98–100% by the end of the season, except in the 14-d POSTFL timing (90%). In 2008, E. crus-galli plants were more robust, and control was inconsistent and less than in 2007 (10–91%). At the PREFL timing, sequential applications were needed to improve end-of-season E. crus-galli control. The 7-d POSTFL timing was one of the best single application timings for increased E. crus-galli control and rice yield. Delaying the cyhalofop application to 21-d POSTFL resulted in unacceptable E. crus-galli control of 10 and 46% with single and sequential programs, respectively. Average rice yield was reduced almost three-fold when the first cyhalofop application was at 21-d POSTFL compared with 7-d POSTFL.     

Effects of dietary arachidonic acid on final maturation,spawning and composition of gonad of black sea urchin Diadema setosum (Leske, 1778)

This study investigated the effect of dietary arachidonic acid (ARA, 20:4n‐6) on final maturation, spawning performance and composition of the gonad of black sea urchin (Diadema setosum). Four different dietary ARA levels of 0.3 g/kg (Control diet), 1.4 g/kg (ARA 1.4), 2.5 g/kg (ARA 2.5) and 3.7 g/kg (ARA 3.7) were prepared and tested in this feeding trial for 90 days. The result showed that growth in terms of weight was not relatively affected by dietary ARA. Gonadosomatic Index (GSI) of animals were gradually increased in all the diets throughout the trial. The highest GSI level (25.7 ± 3.16%) was observed in animals fed with the diet ARA 1.4. ARA content in the gonad proportionally increased with dietary ARA levels. The highest larval survival rate (85.5 ± 5.67%) was found in diet ARA 2.5. The results of this study indicate that ARA plays an important role in the reproduction functions of black sea urchin and supplementing an appropriate level of ARA in the broodstock diet could induce the final maturation and improve reproduction of black sea urchin, but a higher level of ARA (3.7 g/kg) seems to have a negative effect on both growth rate and GSI.     

An improved enzyme preparation for rapid mass production of protoplasts as seed stock for aquaculture of macrophytic marine green algae

Preparation of protoplasts and their subsequent applications for both basic and applied research of marine macroalgae remains largely under developed due to lack of development of reliable methods with consistent yields of viable protoplasts. An improved enzyme preparation with a single commercial enzyme, e.g. 2% Cellulase Onozuka R-10 in 1% NaCl solution, was developed to produce protoplasts rapidly from different green algal genera of Ulva, Enteromorpha and Monostroma. The simple dissolution of enzyme powder in 1% NaCl resulted in exclusion of 2% Macerozyme R-10 from the mixture consisting of 2% Cellulase Onozuka R-10 with 3% NaCl earlier reported as superior for the same algae. Optimal conditions for the isolation of maximum yields of viable protoplasts were found to be with 2% Cellulase Onozuka R-10 incubated at 20 °C for 2 h in 1% NaCl solution with 0.8 M mannitol adjusted to pH 6.0. The protoplast yield with optimized enzyme mixture was as high as 102.8 × 10⁶ cells g^− 1 f. wt for M. oxyspermum while it was in the range of 74.4–88.6 × 10⁶ cells g^− 1 f. wt thallus for seven species of Ulva, and 82.5–95.4 × 10⁶ cells g^− 1 f. wt for three species of Enteromorpha. The regeneration rate of protoplasts isolated using this method ranged from 89 to 92% with normal morphogenesis. The seeding of nylon threads with isolated protoplasts of M. oxyspermum was successful and after 3–4 weeks the entire frame with nylon threads became thick green in color with tiny germlings in laboratory culture. Thus, the method described in the present study allow for rapid mass production of viable protoplasts that could be potentially used as a source for seed material for mariculture and for other applied phycological research.     

Effects of dietary microbial levan on growth performance,RNA/DNA ratio and some physio‐biochemical responses of Labeo rohita (Hamilton) juveniles

Six isonitrogenous and isocaloric semi‐purified diets were prepared with different levels of microbial levan: control (Basal), T1 (Basal + 2.5 g kg^?1 diet), T2 (Basal + 5 g kg^?1 diet), T3 (Basal + 7.5 g kg^?1 diet), T4 (Basal + 10 g kg^?1 diet) and T5 (Basal + 12.5 g kg^?1 diet), fed to six groups of fish in triplicate tanks. The results of the 60 days feeding trail showed that supplementation of dietary levan significantly affected the weight gain percentage and specific growth rate of the treatment groups fed at 10 g kg^?1 or more levan. Lowest feed conversion ratio (FCR) value and highest survival percentage among levan fed groups were observed with 12.5 g kg^?1 incorporation (T5) and was comparable with (T4) group. Significant increase in muscle RNA level and RNA/DNA ratio was observed with the increasing dietary levan. Fish fed 12.5 g kg^?1 levan had significantly higher protease, amylase and lipase activities compare with the control group. Lowest Aspartate aminotransferase (AST) activity in the liver and muscle was observed in the T5 group fed with highest level of dietary levan. Overall results conclude that dietary microbial levan incorporation at 12.5 g kg^?1 could be used as potent dietary prebiotic for the culture of L. rohita juveniles.     

Two phenolic glycosides from Curculigo orchioides Gaertn

One new glycoside derivative from syringic acid and one new phenol glycoside, curculigoside E (1) and orchioside D (2), were isolated and characterized from the rootstock of Curculigo orchioides collected in the Nawalparasi District (Nepal). The structures of the new isolated compounds were elucidated by means of spectroscopic methods such as 1D, 2D NMR and MS.     

基于天气预报的参照作物腾发量中短期预报模型研究

以新乡市1970—2011年逐日实测气象资料代入FAO 56 Penman-Monteith(PM)方法算得的ET0作为基准值,对HG、P-T、M-K、M-C模型进行参数修正,将新乡市2012—2014年冬小麦生育期间预见期为1、3、5、7、10d的天气预报数据代入修正后的模型进行ET01~10 d的中短期预报,并以2012—2014年冬小麦生育期间逐日实测气象资料由PM公式算得的ET0为基准值,对天气预报的精度及ET0的预报精度进行评价。结果表明:经过参数修正后HG、P-T、M-K、M-C模型的精度均有提高;最高气温、最低气温、风速、日照时数的预报精度均随预见期的增加呈逐渐下降趋势,最低气温预报的精度稍高于最高气温;不同预见期的ET0预报模型中,P-T模型预报的ET0平均准确率在众模型中较高(95.06%),其次为HG-M模型(94.66%)、PMT1模型(94.34%)、M-K模型(93.89%),且P-T、HGM两种模型计算程序较简单,因此优选P-T、HG-M模型进行ET0的中短期预报。     

Advances in “omics” approaches to tackle drought stress in grain legumes

Grain legumes being affordable sources of proteins, vitamins and essential micronutrients are key to human nutrition worldwide. However, frequent drought episodes present serious threat to grain legume production worldwide. Advances in legume omics in concert with evolving phenotyping and breeding techniques hold great promise to improve drought response of these crops. These resources could underpin prebreeding efforts to expedite discovery and deployment of novel drought tolerance traits into elite backgrounds. Fast-track transfer of traits that confer drought tolerance using marker technologies has been demonstrated in grain legumes like chickpea. However, complex genetic architecture of drought tolerance demands embracing more efficient tools like genomic selection (GS) for accelerated trait improvement. Recent studies on GS for addressing complex traits like drought tolerance have yielded encouraging results in these crops. Recently, speed breeding (SB) protocols have also been optimized for the improvement of long-day/day-neutral grain legumes. Efficacy of SB protocols with regard to complex traits awaits further evidences though. There remains immense scope for integrating SB with GS and gene editing to deliver drought-tolerant cultivars.     

Integrated “omics” approaches to sustain global productivity of major grain legumes under heat stress

Grain legumes serve as key sources of dietary protein to the global human population. Consequence of high‐temperature (HT) stress is increasingly evident as drastically lost production of different crops including grain legumes worldwide, thus putting the global food security under great threat. In a changing climate scenario, cool season‐adapted grain legumes frequently encounter heat stress (HS) during their reproductive phase, thus witnessing serious yield losses. To combat the emerging challenges of HT stress, an integrated approach demanding collaborative efforts from various disciplines of plant science should be in place. This review summarizes major impacts of HT stress on grain legume, and captures the relevance of crop genetic resources to HS tolerance in these crops. Measurement of physiological traits assumes key place in view of ever‐increasing precision of next‐generation phenotyping assays. We also discuss the significance of genetic inheritance and QTL discovery and evolving “omics” science for developing HS tolerance grain legume crops.