Limited genotype- and ploidy-related variation in the nutritive value of perennial ryegrass (Lolium perenne L.)

Abstract

Water-soluble carbohydrates and fibre fractions are important traits that influence forage utilization by the ruminant. Little is known about the quality variation among perennial ryegrass genotypes within the same maturity group or between near-isogenic diploids and tetraploids. The current study was carried out in the form of two experiments on two successive years (2006–2007) in three sites in Northern Germany. The main aim was to investigate the variation in nutritive value that could be attributed to differences in maturity among 20 intermediate heading perennial ryegrass genotypes or to differences in ploidy between near-isogenic diploids and tetraploids. Results of the first experiment revealed significant variation among the 20 tested genotypes in the investigated quality parameters that were consistent with the discovered variation in the maturity of the genotypes determined in terms of their Mean Stage by Count (MSC). In the second experiment, few but consistent significant differences were detected between near-isogenic diploids and tetraploids. The tetraploid derivatives had always significantly higher water-soluble carbohydrate content and lower neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) than their near-isogenic diploid parents.     

Changes in Growth,Yield, Photosynthetic Pigments,Biochemical Substances,Oxidative Damage,and Antioxidant Activities Induced by Treatment with Different pH of Artificial acid rain in Pumpkin (Cucurbita Moschata)

Acid rain is one of the major environmental problems that causes plant morphological and physiological disorders. But there are few studies about the impact of acid rain on vegetable crops. This work aimed to study the various effects of simulated acid rain (SAR) at different levels of pH (5.0, 4.5, 4.0, 3.5 or 3.0) on growth, yield, pigment content, protein, carbohydrate, water content in leaves, minerals (NPK), oxidative damage and the activity of various antioxidants in pumpkin. The results show that the plant growth, yield, chlorophyll, carotenoids, protein, carbohydrates, leaf water content, NPK in the leaves of the pumpkin crop decreased significantly with increasing levels of acidity of SAR as compared to the untreated set. H₂O₂ and MDA are increased by SAR treatment which depends on the level of pH value of SAR. The highest value of hydrogen peroxide and malondialdehyde was recorded at pH 3.0 and lower at pH 5.0 of SAR treatment on the pumpkin crop. In contrast, superoxide dismutase, catalase, nitrate reductase and proline contents were accumulated at pH 3.0 and degraded at pH 5.0 of SAR treatment on pumpkin as compared to control. In conclusion, our findings suggest that pumpkin produces more reactive oxygen species (ROS) scavenging SAR stress through the production of enzyme and non-enzyme antioxidant compounds at 3.0 pH. Meanwhile, growth inhibition as well as the photosynthesis of pumpkin and the magnitude of oxidative damage increased as acidity increased (pH 3.0 of SAR).

     

Ascorbic Acid Enhances Growth and Yield of Sweet Peppers (Capsicum annum) by Mitigating Salinity Stress

Salinity is a crucial problem which has affected crop productivity globally. Ascorbic acid is considered helpful against abiotic stresses due to its powerful antioxidant potential. In the pot experiment, salinity stress (0, 35, 70, and 105?mM) was applied to sweet peppers in split doses after 20 days of transplantation. To mitigate the adverse effects of salinity, ascorbic acid (0, 0.40, 0.80, and 1.20?mM) was applied as foliar spray after a 6-day interval during vegetative growth. Sweet pepper plants sprayed with distilled water (control) recorded maximum plant height (cm), leaf area (cm²), number of branches, stem diameter (mm), number of fruit plant^?1, fruit diameter (cm), yield plant^?1 (g), and chlorophyll content (mg 100?g^?1), while the maximum polyphenol oxidase (PPO) activity (unit mg protein^?1 min^?1) and ascorbate peroxidase (APX) activity (unit mg protein^?1 min^?1) were recorded in plants treated with 70?mM NaCl application. Salinity stress beyond 70?mM significantly reduced all the studied parameters. An ascorbic acid concentration of 1.20?mM significantly mitigated the negative effects of salt stress and recorded maximum plant height (cm), number of leaves plant^?1, leaf area (cm²), number of branches plant^?1, stem diameter (mm), number of fruit plant^?1, fruit diameter (cm), yield plant^?1 (g), chlorophyll content (mg 100?g^?1), PPO activity (unit mg protein^?1 min^?1), and APX activity (unit mg protein^?1 min^?1). Hence, a 1.20?mM concentration of foliar ascorbic acid could be used in saline conditions up to 70?mM of sodium chloride (NaCl) for better growth, productivity, and enzymatic activity of sweet peppers.

     

Understanding physical clogging in drip irrigation: in situ,in-lab and numerical approaches

Dripper clogging is a major drawback of microirrigation systems that must be addressed to improve their efficiency and durability. Particle-induced clogging is first studied in situ. The experiments consist in observing in real conditions the behavior of a series of drippers fitted on an agricultural plot in the south of France. The plot is supplied from a canal with Durance River water. The latter is loaded with sediments that gradually clog drippers and filters. Water analysis reveal that physicochemical clogging prevails over biological clogging. This characterization helps in setting in-lab experiment protocol. Indeed, besides field observation of clogging, laboratory analyses of both the irrigation water and the clogging material are performed with reactive and inert clay: smectite and an illite–calcite mix. A surprising tendency is observed: Salt concentration in smectite seeded water decreases the clogging, whereas it increases agglomerate size. Computational fluid dynamic simulations are carried out to investigate the impact of particles on flow behavior. Results demonstrate that clay particles interacting with the flow govern the complex structure of the fluid velocity fields inside the dripper labyrinth channel.     

Protein Synthesis in Juvenile Tilapia Oreochromis mossambicus

A method for measuring protein synthesis has been developed for small juvenile fish. A flooding dose of [³H] phenylalanine (Houlihan et al. 1988b) was added to the water containing the animals. Using juvenile tilapia O. mossambicus of approximately 15 mg, stability of the phenylalanine free pool specific radioactivity was achieved within 10 h. A linear increase in the whole body specific radioactivity of protein-bound phenylalanine occurred 3 h after [³H] phenylalanine was added to the water. In larger animals the flooding dose was injected into the peritoneum, and stable free pool phenylalanine specific radioactivities were achieved over 2 h. In the small fish the rate of protein synthesis exhibited a diurnal pattern. Scaling relationships for growth, protein synthesis and protein degradation were similar. The energy cost of protein synthesis in small juvenile animals, determined from the difference before and after the addition of the protein synthesis inhibitor cycloheximide, was close to the theoretical minimal cost.     

Morphological and Genetical Variability among Rhizoctonia solani Isolates Causing Sheath Blight Disease of Rice

Eighteen isolates of Rhizoctonia solani collected from infected rice plants in four different locations of Bangladesh were studied by using morphological characters and molecular markers. Anastomosis study with a reference isolate confirmed that all the isolates belonged to R. solani. Significant variation was observed in sclerotial size, shape and distribution. Un-weighted pair group method with arithmetic mean dendrogram constructed based on the Gower's general similarity coefficient showed that these isolates were grouped into four clusters at the 0.68 similarity coefficent according to morphological characters. Cluster I was a major cluster consisting of 13 isolates, while clusters Ⅱ to Ⅳ consisted of 1 or 2 isolates. Analyses by variable number of tandem repeat and amplified fragment length polymorphism markers showed that the isolates were grouped into five and three clusters at a similarity coefficient of 0.64 and 0.69, respectively. Although most of the variability was found between isolates from different regions as expected, significant variation was observed within the isolates collected from similar agro-ecological regions. Our results suggest the presence of different races of R. solani within the same local geographic regions.     

Functional relationships of nodulation response and biomass production at nursery stages of two fast-growing, leguminousmultipurpose tree species in Bangladesh: Albizia saman and Leucaena leucocephala

This study was carried out to assess the relationship of the status of nodulation （i.e., the number of nodules, their shape and size） in root and biomass production of plant growth parameters （i.e., number of leaves, root and shoot lengths, root biomass and shoot biomass） in Albizia saman and Leucaena leucocephala. The assessment started 60 days after seeding. The study revealed that nodulation response and biomass production in both species showed significant dif- ferences over time （p 〈 0.05） in all variables except in the root-shoot ratio （oven-dry） of L. leucocephala. The study also showed significant differences （p 〈 0.05） in nodule formation and biomass production at the end of the study period be- tween the two species except in the number of nodules and leaves and the green root-shoot ratio. There were strong pos- itive correlations between nodule formation and biomass production, i.e., the number of nodules and the age of plants, the number of nodules and leaves, as well as the number of nodules and biomass （root biomass and shoot biomass） in both species. The results obtained using principal component analysis （PCA） and correlation coefficients of the different characteristics of nodulation and biomass production were similar in both species. The PCA showed that shoot biomass （shoot green weight and shoot oven-dry weight） is positively correlated with PC1 （with an eigenvalue of 7.50） and root length is positively correlated with PC2 （with an eigenvalue of 0.19） in the case of A. saman. In the case of L. leucocephala, the PCA revealed that root biomass （root green weight and root oven-dry weight）, shoot biomass and shoot length are also positively correlated with PC1, while nodule formation and the number of leaves are positively correlated with PC2 （with an eigenvalue PC1 of 6.92 and PC2 of 0.49）.     

Boron Nutrition of Four Sweet Pepper Cultivars Grown in Boron-Deficient Soil

ABSTRACT

In a greenhouse study, boron (B) application significantly increased dry-matter yield of sweet pepper (Capsicum annum L.) cultivars (‘California Wonder,’ ‘Anahein,’ ‘Narwala,’ and ‘2573’) grown in a B-deficient (hot-water extractable, 0.28 B mg kg^?1), calcareous soil of the Shujabad series (Typic Ustochrepts). Five rates of B, ranging from 0 to 8 mg B kg^?1 soil, were applied as H₃BO₃ along with adequate basal fertilization of nitrogen (N), phosphorus (P), potassium (K), and zinc (Zn). Four plants of sweet pepper were transplanted in each pot, two of which were harvested after three weeks of transplanting and the other two after six weeks. Maximum crop biomass was produced with ～1 mg B kg^?1, but application of higher rates proved toxic, resulting in dry-matter yield reductions. The four cultivars significantly differed in relative growth rate (RGR) and relative accumulation rate of B (RARB). Cultivar ‘2573’ showed the highest RGR while ‘Anahein’ showed the highest RARB. Relative accumulation rate was positively correlated (R² = 0.83) with dry-matter yield of four cultivars. Critical B concentration in sweet pepper whole shoots was 69 mg B kg^?1 for three-week-old plants and 49 mg B kg^?1 for six-week-old plants.     

Some of the properties of particleboard made from paulownia

The objective of this study was to determine some of the properties of experimental particleboard panels made from low-quality paulownia (Paulownia tomentosa). Chemical properties including holocellulose, cellulose, lignin contents, water solubility, and pH level of the wood were also analyzed. Three-layer experimental panels were manufactured with two density levels using urea–formaldehyde as a binder. Modulus of elasticity (MOE), modulus of rupture (MOR), internal bond strength (IB), screw-holding strength, thickness swelling, and surface roughness of the specimens were evaluated. Panels with densities of 0.65 g/cm³ and manufactured using a 7-min press time resulted in higher mechanical properties than those of made with densities of 0.55 g/cm³ and press times of 5 min. Based on the initial findings of this study, it appears that higher values of solubility and lignin content of the raw material contributed to better physical and mechanical properties of the experimental panels. All types of strength characteristics of the samples manufactured from underutilized low-quality paulownia wood met the minimum strength requirements of the European Standards for general uses.     

Bioavailability of Calcium,Iron and Zinc Fortified Whole Wheat Flour Chapatti

The bioavailability and interactive effects of calcium, iron and zinc fortified whole wheat flour chapattis on female Sprague–Dawley albino rats were determined. The whole wheat flour was fortified with CaCO₃, FeSO₄ and ZnSO₄ at 1000, 40 and 20 mg/kg, respectively and fed to 64 female Sprague–Dawley rats for 4 weeks. Retention of Ca, Fe and Zn was determined in plasma, femur and liver tissues. Ca levels in plasma and liver did not alter significantly while the Ca retention in femur changed significantly with the change in fortificants. The calcium retention was higher in the femur of rats fed on the diet supplemented with Ca + Zn (221 ± 13.61 mg/g) than the rats fed on the diet supplemented with Ca + Fe (219 ± 18.92 mg/g). The iron in plasma, liver and femur ranged from 2.19 ± 0.11 to 2.77 ± 0.10 μg/ml, 203.5 ± 13.24 to 251.5 ± 17.19 μg/g and 43.5 ± 1.05 to 52 ± 2.07 μg/g while zinc content ranged from 1.31 ± 0.089 to 1.55 ± 0.114 μg/ml, 89.5 ± 3.41 to 132 ± 6.10 μg/g and 175 ± 8.29 to 191 ± 10.85 μg/g, respectively. The minerals interacted with each other resulting in decrease of bioavailability among each other. The absorption was higher in the rats fed on fortified diet than those fed on unfortified chapatti diet. Hence, it is concluded that fortification of whole wheat flour is feasible to overcome the Ca, Fe and Zn malnutrition in the vulnerable groups.