Current status and future strategy in breeding grasspea (Lathyrus sativus)

Efforts in grasspea (Lathyrus sativus) improvement have increased since the development of lines that are very low in the neurotoxin Beta-N-oxalyl-L-alpha-beta-diamino propionic acid (ODAP); also referred to as Beta-N oxalyl-amino-L-alanine (BOAA). Many programs now address several related aspects of improvement simultaneously. These include reduced ODAP concentrations, insect and disease resistance, nitrogen fixation, agronomic practices, fodder and forage production, and components for increased yielding ability. The coordinated, multidisciplinary approach now being applied to the genetic improvement of grasspea should allow the potential of this largely neglected grain legume to be fully realized.     

Evaluation of mechanical properties of jute/glass/carbon fibers reinforced hybrid composites

A study on the tensile and flexural properties of jute-glass-carbon fibers reinforced epoxy hybrid composites in inter-ply configuration is presented in this paper. Test specimens were manufactured by hand lay-up process and their tensile and flexural properties were obtained. The effects of the hybridization, different fibers content and plies stacking sequence on the mechanical properties of the tested hybrid composites were investigated. Two-parameter Weibull distribution function was used to statistically analyze the experimental results. The failure probability graphs for the tested composites were drawn. These graphs are important tools for helping the designers to understand and choose the suitable material for the required design and development. Results showed that the hybridization process can potentially improve the tensile and flexural properties of jute reinforced composite. The flexural strength decreases when partial laminas from a carbon/epoxy laminate are replaced by glass/epoxy or jute/epoxy laminas. Also, it is realized that incorporating high strength fibers to the outer layers of the composite leads to higher flexural resistance, whilst the order of the layers doesn’t affect the tensile properties.     

Salinity tolerance of wild barley Hordeum vulgare ssp. spontaneum

Salinity tolerance of 47 wild barley genotypes and six barley cultivars was evaluated under control and salinity stress (300 mM NaCl) conditions. Shoot and root dry weight (DW), plant height, membrane stability index (MSI), relative water content, survival rate, leaf malondialdehyde (MDA) and proline contents, root and leaf Na, K, Ca and K/Na ratio, and chlorophyll a fluorescence were measured. Salinity stress caused significant increase in the MDA, proline content, Na and Ca concentrations of the roots and leaves, but resulted in a decrease in the other traits. H. spontaneum genotypes were considerably less affected by the salinity than the genotypes of H. vulgare. Plant survivability was negatively correlated with the Na concentration (r =−.66) but positively correlated with the leaf K/Na ratio (r = .67) and MSI (r = .68). Tolerance mechanisms such as ion exclusion (Na) were likely to be present in the wild barley causing K/Na homeostasis as well as the much lower root and shoot Na, resulting in the higher survival rate.     

Genome-wide association analysis for stripe rust resistance in spring wheat(Triticum aestivum L.) germplasm

Stripe rust is a continuous threat to wheat crop all over the world. It causes considerable yield losses in wheat crop every year. Continuous deployment of adult plant resistance(APR) genes in newly developing wheat cultivars is the most judicious strategy to combat this disease. Herein, we dissected the genetics underpinning stripe rust resistance in Pakistani wheat germplasm. An association panel of 94 spring wheat genotypes was phenotyped for two years to score the infestation of stripe rust on each accession and was scanned with 203 polymorphic SSRs. Based on D' measure, linkage disequilibrium(LD) exhibited between loci distant up to 45 c M. Marker-trait associations(MTAs) were determined using mixed linear model(MLM). Total 31 quantitative trait loci(QTLs) were observed on all 21 wheat chromosomes. Twelve QTLs were newly discovered as well as 19 QTLs and 35 previously reported Yr genes were validated in Pakistani wheat germplasm. The major QTLs were QYr.uaf.2 AL and QYr.uaf.3 BS(PVE, 11.9%). Dissection of genes from the newly observed QTLs can provide new APR genes to improve genetic resources for APR resistance in wheat crop.     

Fortification of Bread Wheat Using Synthesized Zn-Glycine and Zn-Alanine Chelates in Comparison with ZnSO4 in a Calcareous Soil

ABSTRACT

Calcareous soils typically suffer from zinc deficiency and zinc sulfate is incorporated in many cultivated soils. Utilization of ZnSO₄ has some kinds of interaction with soil particles and organic matter. In this study, the efficacy of two znic(Zn)-amino acid chelates (Zn-ACs) i.e., Zn-alanine (Zn-Ala) and Zn-glycine (Zn-Gly) on wheat (Triticum aestivum, cv. N91-8) growth characteristics and zinc concentration in wheat was examined under greenhouse conditions and compared to the a commercial ZnSO₄. Results showed that Zn-Ala and Zn-Gly significantly increased the dry weight and shoot length of wheat in comparison to ZnSO₄ treatment. Soil application of Zn-Amino acid chelates proved to be the most influential source of zinc in increasing wheat growth and yield indices. Number of fertile spikelet and grain yield increased significantly respectively compared to ZnSO₄ treatment. Zn concentration and protein content of wheat grain in Zn-ACs treatment was significantly higher than the ZnSO₄ treatment. Soil application of Zn-ACs caused a significant decrease in the grain phytic acid (PA) concentration and also phytic acid to zinc molar ratio in comparison with ZnSO₄ treatment. According to the results, Zn-ACs could be utilized as a zinc fertilizer source for improving the zinc bioavailability in wheat.     

Effect of soil pore size distribution on plant-available water and least limiting water range as soil physical quality indicators

Soil pore size distribution(SPSD) is one of the most important soil physical properties. This research investigated the relationships of location and shape parameters of the SPSD curves with plant-available water(PAW) and least limiting water range(LLWR) of the light-textured soils at the Torogh Agricultural Research Station in north-eastern Iran. Soil moisture release curve(SMRC), PAW and LLWR in matric heads of 100 and 330 h Pa for the field capacity and location and shape parameters of the SPSD curves of 30 soils with different texture and organic carbon contents were determined, and the variable relationships were statistically analyzed. The results showed that the median equivalent pore diameter(de), mean de, standard deviation(SD*), and skewness of the SPSD curves were significantly correlated with PAW(PAW330) and LLWR(LLWR330) measured in a matric head of 330 h Pa. Decrease in deand increase in the diversity of soil pore size(SD*) increased PAW330 and LLWR330. The SD* values of all the soil samples were lower than the optimal ranges suggested in literature. Neither PAW nor LLWR values were significantly different in the soils with the optimal modal deand those with non-optimal modal de. Optimal values of median and mean equivalent pore diameters and kurtosis of SPSD curves led to a significant improvement of PAW330 and LLWR330 as soil physical quality indicators. It was recommended to revise the optimal ranges for SD* and modal defor future studies.     

Effect of Dietary Gamma‐irradiated and Fermented Soybean Meal on the Growth Performance,Body Composition,and Digestive Enzymes Activity of Caspian Brown Trout,Salmo trutta caspius,Juvenile

This experiment was conducted to evaluate the feasibility of gamma‐irradiated soybean meal (SBM) as a dietary ingredient on the performance, body composition, and digestive enzyme activity of Caspian brown trout, Salmo trutta caspius, juveniles. Five isonitrogenous and isoenergetic diets were formulated, in which fish meal was replaced by untreated (untreated SBM), gamma‐ray irradiated at 15 (15ISBM) and 30 (30ISBM) kGy, fermented (FSBM), fermented 15 KGy irradiated soybean meal (FISBM), respectively. Juvenile fish (2.1 ± 0.3 g) were fed with the test diets for 6 wk. Final body weight was significantly affected by dietary SBM treatment with highest values in fish fed FISBM and FSBM (P < 0.05). There were no significant differences in hepatosomatic and visceral indexes, condition factor, and survival among experimental groups (P > 0.05). The carcass proximate composition of lipid and protein in Caspian brown trout in FSBM and FISBM groups was higher than that of other groups. Levels of most whole‐body amino acids were not significantly different among Caspian brown trout fed the five diets. Results of this experiment showed that replacing SBM with FSBM and FISBM in the diet significantly increased the activities of proteolytic enzymes activities (P < 0.05). However, no significant differences were observed in both amylase and lipase activities among dietary treatments. Results of this study indicated that the level of gamma radiation used did not work but fermentation of SBM did increase some growth parameters of Caspian brown trout.     

An outbreak of enzootic bovine leukosis in upper Egypt: clinical,laboratory and molecular-epidemiological studies

In 1989, 220 Holstein Friesian cattle (212 heifers and eight bulls) were imported from Minnesota, USA, to form a closed dairy herd in Arab El-Aoumar, Assiut, Upper Egypt. In November 1996, some abnormal signs such as loss of weight, decreased milk yield, external lymphadenopathy and decreased appetite were observed on this farm. Serological screening by enzyme-linked immunosorbent assay revealed a seroprevalence of antibodies directed against bovine leukaemia virus (BLV) of 37.7% in cattle under 2 years old and of 72.8% in animals more than 2 years old. Diagnosis was confirmed by the detection of BLV proviral DNA using polymerase chain reaction with primers amplifying a fragment of the env gene. Out of 21 tested leucocyte fractions from individual animals, 15 were positive showing a BLV-specific amplicon of 444 base pairs. Analysis of the amplicons for restriction fragment length polymorphisms and DNA sequencing results allowed the isolates to be typed. Since this was the first recorded case of enzootic bovine leukosis in Upper Egypt, strict quarantine measures were adopted and all serologically positive animals in the herd were culled.     

Prevalence and infection pattern of Trypanosoma evansi in camels in mid-eastern Sudan

The antigen detection enzyme immunoassay (AgELISA) in conjunction with parasitological examination of blood were used to study the enzootic situation of cameline trypanosomiasis in mid-Eastern Sudan. A one year survey showed that the infection is endemic among pastoral camels with a prevalence of 5.4% based on parasitological examination and 31.3% based on AgELISA. The infection rate was higher during the dry period (November to May) than the wet season. Young camels had a much lower infection rate as detected by parasitological techniques, but not with AgELISA. A lower prevalence of infection was detected by buffy coat technique (BCT) in herds of camels raised by nomads compared with those kept by agropastoralists and in camels located in the southern districts of mid-Eastern Sudan.     

Irritant potential of triterpenoids from Ficus carica leaves

The irritant potential of total methanolic extract and five triterpenoids newly isolated from the leaves of Ficus carica investigated by open mouse ear assay. Total methanolic extract, calotropenyl acetate, methyl maslinate and lupeol acetate showed potent and persistent irritant effects.