Colchicine-induced variation of cell size and chloroplast number in leaf mesophyll of rice

Comparisons were made in the C₁ generation between the untreated controls (2x) and colchicine‐treated diploids (C2x) for variation of leaf mesophyll cell size and chloroplast number. Differences were found in that the cell section area and the number of chloroplasts per cell in all the seven lines investigated were significantly greater in the C2x selections compared with the 2x controls using coded determination. In each case, there was an enhancement of chloroplast number independent of the variation in cell size.     

Transparent Polycaprolactam Electrospun Nanofibers Doped with 1,10-phenanthroline Optical Sensor for Colorimetric Determination of Iron (II) and Vitamin C

A novel optical chemical sensor based on a transparent electrospun nanofibrous scaffold, composed of polycaprolactam (PA6) and 1,10-phenanthroline (Phen), deposited on a glass slide and impregnated with polyvinyl alcohol (PVA) was coupled with UV-vis spectrophotometry and used for colorimetric determination of ferrous ion (Fe²⁺) and ascorbic acid (AA). The electrospun nanofibers were characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) techniques. The main factors affecting performance of the optical sensor (PA6-Phen/PVA@glass) including Phen dosage, pH of sample solution, electrospinning time, polymer solution flowrate, electrospinning voltage, and PVA amount were investigated and the related optimum values were obtained. The analytical merits of the sensor for quantitative determination of Fe²⁺ and ascorbic acid was evaluated. The limit of detection (LOD) and limit of quantification (LOQ) for Fe²⁺ were 1 and 3 μg mL^-1, respectively. The linear dynamic range (LDR) was 3–150 μg mL^-1 with the determination coefficient (R²) of 0.991. The relative standard deviation (RSD %, n=3) for a solution of 60 μg mL^-1 was 5.4 %. For determination of AA, LOD and LOQ were obtained equal to 0.5 and 2 μg mL^-1, respectively. The linear dynamic range was in the 2–200 μg mL^-1 range with a R2 of 0.994. The RSD % at 100 μg mL^-1, n=3) was equal to 7.0 %. The sensor was applied successfully to the detection of Fe(II) and AA in real water samples and aspirin tablets.     

Screening for Differential Gene Expression in Atropa belladonna Leafy Gall Induced Following Rhodococcus fascians Infection

To better characterise at the molecular level the nature of plant responses to infection by Rhodococcus fascians PCR-based differential display patterns of Atropa belladonna leafy gall (LG) and non-infected plant tissues were compared. Six differentially expressed genes were identified and their altered expression was confirmed by RT-PCR. Three of them corresponded to up-regulated genes which encode proteins involved in plant defence. The three remaining cDNA fragments which correspond to down-regulated genes in LG, encoded proteins with similarity to a multicystatin, a miraculin and a methallothionein-like protein, respectively. Upon elimination of the bacteria from infected plant tissue, the expression of up-regulated genes was maintained, whereas expression of down-regulated genes resumed suggesting a potential role of these up-regulated genes in plant growth and development.     

不同土壤水分调控技术对土壤含水量和鸭梨果实品质的影响

以13、20和30年生鸭梨为试材,分别在辛集市新垒头、泊头市苗圃场和曲阳县寺南庄梨园,研究了覆膜、定期浇水和对照3种不同土壤水分调控技术对土壤含水量和鸭梨品质的影响。结果表明,土壤含水量以定期浇水最高,对照和覆膜较低;平均单果重以定期浇水最大,覆膜次之,对照最小;果肉硬度则正相反;可溶性固形物、总糖含量和糖酸比以对照最高,覆膜次之,定期浇水最低;可滴定酸含量以定期浇水最高,对照和覆膜较低;Vc含量以覆膜最高,对照次之,定期浇水最低;果实淀粉和果皮叶绿素含量均表现为对照>定期浇水>覆膜。     

Halophyte root powder: an alternative biofertilizer and carrier for saline land

ABSTRACT

The present investigation was based on the hypothesis that the endophytes residing in the roots of halophytes have better adaptation to saline conditions. Six halophytic herbs were collected from Khewra salt range (EC = 4.7 dS m^?1 and SAR = 25.7). From these herbs, root pieces of Cenchrus ciliaris were shade dried; finely ground to powder and three plant growth promoting rhizobacteria (PGPR), Bacillus cereus, Pseudomonad moraviensis, and Stenotrophomonas maltophilia, were isolated. Root powder in sterilized and unsterilized forms was added in the saline-sodic field on wheat and mixed with soil in pot experiment with induced NaCl (150 mM). Sterilized root powder increased organic matter NO₃-N and P contents of soil and leaves, fresh weight, sugar content, and yield attributes. The root powder application in unsterilized form significantly decreased EC, SAR, and Na content of field soil with concomitant increase in soil and leaves K, P, and NO₃-N. The farmer’s benefit was increased by 33% at yield. Root powder-induced salt tolerance was mediated by the PGPR (residing inside the root) through increased growth and better physiological adaptations. It is inferred that root powder harboring the PGPR may be an alternative to biofertilizer with longer shelf life and may also serve as carrier for the preparation of effective biofertilizer for saline land using other PGPR bio-inoculants.     

Feed preference and growth response of juvenile Litopenaeus vannamei to supplementation of marine chemoattractants in a fishmeal‐challenged diet

This study compared the feed preference and growth response of Litopenaeus vannamei to chemoattractants. A diet with 3% fishmeal was supplemented with either 3% salmon meal (POS), 3% soy protein concentrate (NEG), 3% krill meal (KRM), 3% squid meal (SQM), 3% shrimp head meal (SHM), 3% shrimp meal (SM), 3% squid liver meal (SLM), or 5% liquid sardine hydrolysate (SAH). Shrimp with a body weight (BW) of 0.99 ± 0.08 g were stocked at 100 animals/m² in 56 tanks of 1 m³ and fed 10 times daily for 74 days. Feed preference was evaluated by feeding shrimp of 10.87 ± 1.82 g in excess twice a day for 10 days in two separate feeding trays allocated in 50 tanks of 0.5 m³. Survival reached 93.3 ± 5.80% and was unaffected by supplementation. Final BW was the highest for shrimp fed the KRM‐supplemented diet (11.97 ± 0.93 g), followed by POS (11.11 ± 0.77 g) and SQM (11.01 ± 1.17 g). Diets SHM, SM, SLM, and NEG showed a lower shrimp BW than POS, but were not statistically different among them. Shrimp fed the SAH diet achieved the lowest BW (10.06 ± 1.02 g). The highest gained yield was obtained with diets KRM and POS. No statistical difference was observed in shrimp yield among other diets. The lowest feed conversion ratio (FCR) was achieved with shrimp fed KRM (1.31 ± 0.05) when compared to diets SHM (1.47 ± 0.05), SAH (1.47 ± 0.07), and SLM (1.45 ± 0.17). Two‐by‐two comparisons indicated that shrimp preferred SHM and KRM, except when these were compared to SQM and SLM. No difference in feed preference was found between diets with SQM and SLM. SAH was the least preferred raw material in all comparisons. Results indicated that KRM acts as a powerful feeding effector and growth enhancer in fishmeal‐challenged diets for whiteleg shrimp. A dietary supplementation with 3% KRM is more effective than the same dose of any other chemoattractant evaluated.     

Crude protein in low‐fish meal diets for juvenile Litopenaeus vannamei can be reduced through a well‐balanced supplementation of essential amino acids

The use of supplemental essential amino acids (EAAs) has been shown to provide an opportunity to minimize excess levels of crude protein (CP) in animal feeds. The present study investigated the effect of reducing the amount of CP in low‐fish meal diets (5%) for juvenile Litopenaeus vannamei. Four sets of diets were prepared containing (% on a fed basis, mean ± SD) 31.24 ± 0.71, 33.70 ± 0.41, 36.90 ± 0.44, and 39.63 ± 0.14% CP, with each protein level containing a total dietary methionine (Met) (Met + Cys) level of 0.56 ± 0.02 (1.07 ± 0.23), 0.71 ± 0.01 (1.22 ± 0.20), 0.88 ± 0.02 (1.38 ± 0.22), or 1.04 ± 0.02% (1.55 ± 0.18%). Shrimp of 1.00 ± 0.08 g were stocked in 84 outdoor tanks of 1 m³ at a rate of 100 shrimp/m² and raised for 75 days. Final survival ranged from 83 to 97% and was unaffected by Met content. Both survival and yield were significantly depressed when shrimp were fed the 31% CP diet. Shrimp grew at a weekly rate of between 0.79 and 0.97 g, achieving a final body weight (BW) in excess of 10.8 g. There was a significant interaction between CP and Met over BW. Shrimp fed 0.56% Met achieved the lowest BW at harvest. Increasing CP beyond 34% did not enhance BW. With a dietary Met content of 0.71%, the highest BW was achieved with 34% CP compared to other levels. There was a significant improvement in Feed Conversion Ratio (FCR) when CP was raised from 31 to 34%. Similarly, dietary Met levels above 0.71% resulted in a significantly better FCR compared to 0.56%. Our study has shown that, if dietary Met (Met + Cys) meets a minimum of 0.71% (1.22%), levels of CP could be reduced from 40 to 34% without adverse effects on shrimp performance.     

Identification of Streptococcus dysgalactiae Strains of Lancefield's group C,G and L by Polymerase Chain Reaction

Streptococcus dysgalactiae serogroup C, G and L strains were investigated by polymerase chain reaction (PCR) using oligonucleotide primers designed according to species‐specific parts of the 16S–23S rDNA intergenic spacer region. The oligonucleotide primers with specificity for the 16S–23S rDNA intergenic spacer region allowed a correct identification of all S. dysgalactiae serogroups C, G and L strains investigated. No cross‐reactivities could be observed with any of the control strains indicating the usefulness of PCR‐technology to identify the serologically heterogeneous species S. dysgalactiae.     

Effects of supplementing broiler diets with coriander seed powder on growth performance,blood haematology,ileum microflora and economic efficiency

A total of 480 one‐day‐old Arbor Acres broiler chicks were randomly assigned to four dietary groups, each including six replicates (n = 20/replicate). Broilers in the first group (G1) were fed a basal diet without any additives (control). Broilers in groups 2, 3 and 4 (G2, G3 and G4) were fed a basal diet supplemented with 0.1%, 0.2% and 0.4% coriander (Coriandrum sativum L.) seed powder (CSP) respectively. Feeding trials lasted for 42 days, and after that growth, carcass traits, haematological parameters, gut microbiota and economic efficiency (EE) were evaluated. Final body weight (FBW), total weight gain (TWG), total feed intake (TFI) and red blood cell (RBC) counts of broilers in the G4 and G3 treatment groups were significantly higher (p < .05) compared with broilers in the G1 treatment group. The feed conversion ratio (FCR) was better (p < .05) in the G4 treatment group (1.72) than in the G1 treatment group (1.84). Broilers in CSP treatment groups had significantly higher haemoglobin (Hb) concentrations, packed cell volume (PCV) and platelet counts, and had lower (p < .05) Escherichia coli and Clostridium perfringens counts compared with broilers in the G1 treatment group. Dressing, liver, pancreas, bursa and thymus percentages were higher (p < .05) in broilers in the G4 (70.30, 3.18, 0.31, 0.10 and 0.32% respectively) treatment group, compared with broilers in the control (G1) group (66.57, 2.37, 0.23, 0.04 and 0.21% respectively). Broilers in treatment groups G4 and G3 had lower percentages of abdominal fat and lower total bacterial counts (p < .05) than broilers in treatment groups G2 and G1. The highest economic efficiency (EE) was found in treatment group G4, and EE in this group was 13.06% greater than in the control (G1) group.