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.     

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.     

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.     

Quantitative trait loci for seedling and adult plant resistance to Stagonospora nodorum in wheat

Stagonospora nodorum blotch (SNB) caused by Stagonospora nodorum is a severe disease of wheat (Triticum aestivum) in many areas of the world. S. nodorum affects both seedling and adult plants causing necrosis of leaf and glume tissue, inhibiting photosynthetic capabilities, and reducing grain yield. The aims of this study were to evaluate disease response of 280 doubled haploid (DH) individuals derived from a cross between resistant (6HRWSN125) and susceptible (WAWHT2074) genotypes, compare quantitative trait loci (QTL) for seedling and adult plant resistance in two consecutive years, and assess the contribution of QTL on grain weight. Flag leaves and glumes of individuals from the DH population were inoculated with mixed isolates of S. nodorum at similar maturity time to provide accurate disease evaluation independent of morphological traits and identify true resistance for QTL analysis. Fungicide protected and inoculated plots were used to measure relative grain weight (RGW) as a yield-related trait under pathogen infection. The lack of similar QTL and little or no correlation in disease scores indicate different genes control seedling and adult plant disease and independent genes control flag leaf and glume resistance. This study consistently identified a QTL on chromosome 2DL for flag leaf resistance (QSnl.daw-2D) and 4BL for glume resistance (QSng.daw-4B) from the resistant parent, 6HRWSN125, explaining 4 to 19% of the phenotypic variation at each locus. A total of 5 QTL for RGW were consistently detected, where two were in the same marker interval for QSnl.daw-2D and QSng.daw-4B indicating the contribution of these QTL to yield related traits. Therefore, RGW measurement in QTL analysis could be used as a reliable indicator of grain yield affected by S. nodorum infection.     

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.     

Brucellosis among smallholder cattle farmers in Zambia

A cross-sectional study was performed in Southern and Lusaka provinces of Zambia between March and September 2008 to estimate Brucella seroprevalence in cattle kept by smallholder dairy farmers (n = 185). Rose Bengal test (RBT) was used as a screening test followed by confirmation with competitive ELISA (c-ELISA). We investigated 1,323 cattle, of which 383 had a history of receiving vaccination against brucellosis and 36 had a history of abortion. Overall seroprevalence was 6.0% with areas where vaccination was practiced having low seroprevalence. Age was associated with Brucella seropositivity (P = 0.03) unlike cattle breed (P = 0.21) and sex (P = 0.32). At area level, there was a negative correlation (Corr. coeff = −0.74) between percentage of animals with brucellosis vaccination history (vaccination coverage) and level of brucellosis; percentage of animals with history of abortion (Corr. coeff. = −0.82) and brucellosis vaccination coverage. However, a positive correlation existed between brucellosis infection levels with percentage of animals having a history of abortion (Corr. coeff. = 0.72). History of vaccination against brucellosis was positively associated with a positive Brucella result on RBT (P = 0.004) whereby animals with history of vaccination against brucellosis were more likely to give a positive RBT test results (OR = 1.52). However, the results of c-ELISA were independent of history of Brucella vaccination (P = 0.149) but was positively associated with history of abortion (OR = 4.12). Our results indicate a relatively low Brucella seroprevalence in cattle from smallholder dairy farmers and that vaccination was effective in reducing cases of Brucella infections and Brucella-related abortions. Human exposure to Brucella through milk from smallholder farmers could result through milk traded on the informal market since that milk is not processed and there no quality and safety controls.     

Effects of supplemental xylanase and xylooligosaccharides on production performance and gut health variables of broiler chickens

Background:This study evaluated the effects of supplemental xylanase and xylooligosaccharides(XOS)in a cornsoybean meal(SBM)-based diet on growth performance and intestinal health of broilers.A total of 288 day-old chicks(Cobb 500)were allocated to 36 floor pens(8 birds/pen)equally in 9 dietary treatments in a 3×3 factorial arrangement.The treatments were combinations of 3 levels of xylanase(0,0.005% and 0.01% Econase XT)and 3 levels of prebiotics(0,0.005% and 0.01% XOS)added to basal mash diets formulated in three phases(starter,d 0-14;grower,d 15-28;finisher,d 29-42).The feed intake and body weights were recorded weekly.On d 42,ileal sections were collected for histomorphometric and gene expression analysis,and cecal content was collected for determining short-chain fatty acids(SCFA)and microbiota.Results:Xylanase linearly(P<0.01)increased the average daily gain(ADG)in both the finisher and total period and the final body weight gain(FBWG,2940&2932 vs.2760 g)of broilers.XOS did not significantly increase either ADG or FBWG(P>0.05).Supplemental xylanase and XOS did not affect average daily feed intake and feed conversion ratio(P>0.05).Xylanase and XOS did not change villus height(VH)or crypt depth(CD)ratio(P>0.05).However,xylanase exhibited a trend(P=0.097)on VH:CD ratio.The inclusion of 0.01%XOS without xylanase increased the level of IL-10(a marker of anti-inflammatory cytokine)and IL-4(a T-cell differentiation cytokine)genes compared with control(P<0.05).The acetate production was increased by xylanase(P<0.01)and XOS(P<0.05)without an additive effect.Xylanase increased total SCFA(P<0.01)while XOS had a tendency to increase(P=0.052).Alpha and beta diversity of microbiota among treatments were not different(P>0.05).However,the mean proportion of family Ruminococcaceae was increased by the supplemental 0.01% xylanase(P<0.01).Conclusion:It can be concluded that XOS can enhance cecal fermentation,while xylanase can increase the body weight gain along with the fermentation metabolites in the ceca of broilers fed the corn-SBM-based diet but the effects may not always translate into an improved mucosal absorptive capacity and a better feed efficiency.     

Influence of foliar application of mineral nutrients at different growth stages of guava

Foliar application of nutrients enhances efficient use along with quick response. The experiment was undertaken to study the effect of foliar application of mineral nutrients viz., boron (B), zinc (Zn), calcium (Ca), and potassium (K) sprayed at different growth stages viz., at fruit set and at two weeks after fruit set of guava (Psidium guajava L.). Increase in plant canopy and minimum seed index was in Zn (0.03%) sprayed at fruit set. Fruit size, sugar: acid, and organoleptic score were better in K (0.5%) sprayed at two weeks after fruit set. Increased yield in Zn (0.01%) and pectin enhancement with B (0.03%) was found at two weeks after fruit set, respectively. Minimum physiological loss in weight of fruits was with Ca (0.5%) sprayed at two weeks after fruit set. In general, for most of the desirable characters 0.5% potassium (K) spray at 2 weeks after fruit set had better results.     

Nutrients,amino acid,fatty acid and non‐starch polysaccharide profile and in vitro digestibility of macadamia nut cake in swine

The highly variable cost and limited availability of conventional feedstuffs make it imperative to explore alternative feedstuffs to be used in swine. Macadamia nut cake (MNC), a coproduct of the macadamia nut oil industry, has not been well studied. MNC was analyzed for its nutrient profile, gross energy (GE), fibers, amino acids and fatty acids content. Dry matter (DM) and GE digestibility of MNC in swine was determined using an in vitro model. On a DM basis, ash, crude protein, ether extract, NDF, ADF, lignin and GE were found to be 3.7, 25.5, 11.9, 35.8, 28.0, 16.0% and 5581 kcal/kg, respectively. Total and soluble non‐starch polysaccharide content were 32.2 and 11.8%, respectively. The concentration of lysine was found to be 0.7%. The DM and GE digestibility were found to be 75.7 and 71.4%, respectively. Gross energy content of MNC is comparable with that of corn and higher than soybean meal, while protein content is twice as high as corn but lower than soybean meal. In conclusion, MNC is not merely a good source of protein and energy but also has fairly high digestibility in swine. Hence, it can be used as a viable alternative source of energy and protein in swine diets.