Phylogenetic Analyses of Phytopathogenic Isolates of Verticillium spp

ABSTRACT To better understand the genetic relationships between Verticillium dahliae isolates from lettuce and other phytopathogenic Verticillium spp. isolates from various hosts and geographic locations, the complete intergenic spacer (IGS) region of the nuclear ribosomal RNA gene (rDNA) and the beta-tubulin gene were amplified and sequenced. The sequences of the complete IGS region and the beta-tubulin gene were used alone and in combination to infer genetic relationships among different isolates of Verticillium with the maximum-likelihood distance method. Phylogenetic analyses set sequences into four distinct groups comprising isolates of V. albo-atrum, V. tricorpus, and V. dahliae from cruciferous and noncruciferous hosts. Within the four Verticillium groups, isolates of V. dahliae from cruciferous hosts displayed the closest affinity to V. dahliae from noncruciferous hosts. Isolates of V. dahliae from noncruciferous hosts could be further divided into four subgroups based on sequence similarities within the IGS region. Cross-pathogenicity tests demonstrated that most Verticillium isolates were as virulent on other hosts as on their hosts of origin. A phenogram based on the cross pathogenicity of individual isolates resembled those derived from the IGS and beta-tubulin sequence comparisons. On the basis of the data presented, the potential origin of some isolates of V. dahliae pathogenic on lettuce is proposed.     

Community water management to intensify agricultural productivity in the polders of the coastal zone of Bangladesh

Paddy and Water Environment - Most of the lands of the southern coastal zone of Bangladesh are protected from tidal flooding and storm surges by embankments constructed during the 1960s and 1970s,...     

Elevated CO2 Improves Growth and Phosphorus Utilization Efficiency in Cereal Species Under Sub-Optimal Phosphorus Supply

Cultivars of Triticum aestivum, T. durum, and Secale cereale were grown at low (2 μM) and sufficient (500 μM) phosphorus (P) under ambient carbon dioxide (380 μmol mol^?1; aCO₂) and elevated CO₂ (700 μmol mol^?1, eCO₂) to study responses of cereal species in terms of growth and P utilization efficiency (PUE) under P x CO₂ interaction. Dry matter accumulation increased under eCO₂ with sufficient P. Nevertheless, dry matter accumulated at eCO₂ with low-P was similar to that obtained at aCO₂ with sufficient P. Leaf area was 43% higher under eCO₂ with sufficient P. Significant increase in lateral root density, length and surface area were noted at low-P under eCO₂. Phosphorus use efficience (PUE) increased by 59% in response to eCO_2­ in low-P plants. Thus, eCO₂ can partly compensate effect of low-P supply because of improved utilization efficiency. Among cereals, durum wheat was more suitable in terms of PUE under high CO₂ and limiting P supply.     

Temporal changes in circulating levels of plasma interleukin-8 during peripartum period in Murrah buffaloes (Bubalus bubalis) under subtropical climate

The objective of this study was to elucidate the changes in circulating levels of plasma interleukin-8 (IL-8) during peripartum period in Murrah buffaloes (Bubalus bubalis). IL-8 was estimated in blood plasma of healthy peripartum Murrah buffaloes (n = 6) on days ±30, ±15, ±5, ±3, ±1 and 0 pre- and postpartum with respect to the day of parturition (day 0) in each of the two different seasons (hot–humid and spring). The mean microclimate Temperature–Humidity Index (THI) during spring season was significantly lower (p < 0.01) than the corresponding THI in hot–humid season. In both the seasons, plasma IL-8 remained lower in prepartum period (≤46.56 ± 14.08 pg/ml during spring and ≤ 73.18 ± 18.56 pg/ml during hot–humid season) than in the postpartum period (≥51.41 ± 13.82 pg/ml during spring and ≥ 84.13 ± 16.97 pg/ml in hot humid season). During spring, the IL-8 levels were significantly higher (P < 0.05) on days +5 and +15 postpartum in comparison to the IL-8 levels on days −30, −5, and −3 prepartum. During hot–humid season, IL-8 level was significantly higher (P < 0.05) on day +30 as compared to the IL-8 levels on days −30 and −5 prepartum. The correlation between IL-8 and mean microclimate THI was significant (r = 0.25, P < 0.01). From the results, it is concluded that peripartum period in buffaloes is associated with an inflammatory response leading to significantly higher plasma IL-8 during parturition and postpartum period than in the pre-partum period.     

Effects of ionised or chelated water-soluble mineral mixture supplementation on growth performance,nutrient digestibility,blood characteristics,meat quality and intestinal microbiota in broilers

1. An experiment was conducted to study the effects of dietary supplementation of water-soluble ionised or chelated mineral mixture on growth performance, nutrient digestibility, blood characteristics, relative organ weight, meat quality and excreta microflora in broilers.

2. A total of 408 Arbor Acres broilers (17 birds in 8 replicate pens) were randomly allocated into one of the following three treatments: (1) Control/basal diet (CON), (2) T1 (basal diet + 0.5% ionised mineral mixture solution, pH 3.0) and (3) T2 (basal diet + 0.5% chelated mineral mixture solution, pH 3.0).

3. The body weight gain was greater and feed conversion ratio was lower in broilers supplemented with ionised or chelated mineral liquid complex compared to CON during the grower and overall phase of the experiment.

4. No significant effect in the concentration of Ca and P in the blood was observed in birds supplemented with ionised or chelated mineral mixture solution. No adverse effects were observed in organ weight and meat quality with ionised or chelated mineral mixture supplementation.

5. Regarding intestinal microbiota counts there was a reduction of Escherichia coli counts in the small intestine in ionised mineral supplemented birds. In the large intestine, E. coli as well as Salmonella populations were reduced in ionised mineral supplemented birds.

6. In conclusion, ionised or chelated minerals have partial positive effects in improving growth performance and reducing pathogenic bacteria load in the gastro-intestinal tract.

     

Herd-level risk factors for bovine viral diarrhea infection in cattle of Tamil Nadu

A cross-sectional study was carried out to identify risk factors for bovine viral diarrhea virus (BVDV) infection in 62 randomly selected dairy herds which were tested for BVD serum antibodies by using an indirect ELISA kit (IDEXX). Results from the chi-square test analysis were interpreted by analyzing by chi-square test. A sum of 500 sera samples were screened and 66 animals (13.20%) showed positive for BVDV antibody. Within herd, BVD seroprevalence was 12–65%. This study concluded that epidemiological risk factors like location, herd size, housing patterns like, tail to tail system, roofing pattern, distance between the manure pit and farm, and distance between farms were significantly associated with BVDV serological status (P?<?0.05).     

Changes in chemical composition,minerals and amino acids during seed growth and development of four safflower cultivars

Investigation of four safflower ( Carthamus tinctorius L.) cultivars (S208, S400, S541 and S303) showed that when the seeds were harvested at different stages of growth and development (10, 20, 30, and 40 days) after flowering, moisture content significantly decreased with time. Oil, protein, ash and crude fiber were increased up to day 30. Thereafter, these parameters started to decline gradually with time. The cultivars differed in their final values; oil content of the seeds varied from 10.90 to 45.40%, moisture varied from 4.20 to 8.10% and from 8.50 to 11.10%, protein from 12.10 to 20.30% and from 13.40 to 29.60%, ash from 2.30 to 5.40% and from 2.80 to 6.50%, for the seeds and defatted meal, respectively. Crude fiber for the defatted meal was found to vary from 29.50 to 38.60%. Carbohydrate for all cultivars decreased rapidly up to day 40 with final values varying from 28.10 to 63.30% and from 56.70 to 70.30% for the seeds and defatted meal, respectively. Mineral content (Cu, Zn, Fe, Mg, Mn) fluctuated while phosphorus content significantly increased with time for all cultivars. Amino acid content of the defatted meal increased with time up to day 30 after which it started to decline gradually for all cultivars.     

Marker-assisted breeding to develop the drought-tolerant version of Sabitri,a popular variety from Nepal

Sabitri is a rice variety grown in a large part of the rainfed areas of Nepal. It was originally developed for irrigated condition; hence, this variety suffers high yield decline under drought. Two QTLs, qDTY _3.2 and qDTY _12.1 , with large effects on grain yield under drought were identified in the Sabitri background in separate QTL mapping studies. The present study reports the development of Sabitri near isogenic lines (NILs) with combinations of these two QTLs and their characterization under drought. To do so, marker-assisted backcross breeding (MABB) was combined with phenotypic selection to develop high-yielding drought-tolerant NILs with Sabitri grain type. Apart from this, drought-tolerant variants for grain type with high yield under non-stress were identified among the developed NILs. Early days to flowering of up to 13 days and reduction in plant height of up to 13 cm as compared to Sabitri were observed in the developed NILs. Some of these NILs showed higher yield compared to Sabitri and relatively higher tolerance to drought, indicating the capture of positive alleles and interactions during the course of selection. The developed NILs possessed high yield potential which make them suitable materials for the testing of water-saving technologies in irrigated areas. Based on their performance, these NILs can be deployed in rainfed areas in Nepal and other countries of South Asia to increase yield stability.     

Reactions of hard red spring wheat to common root rot under field conditions of Northern United States of America

Common root rot (CRR), primarily caused by Cochliobolus sativus, is one of the important soil borne diseases of wheat (Triticum aestivum L). To gain information about resistance of hard red spring wheat (HRSW) to the disease, forty HRSW cultivars and advanced breeding lines were grown and evaluated in a completely randomized block design for reaction to CRR from 2000 to 2002 in a field plot with high natural inoculum of C. sativus at Williston, ND. Plant root samples during the soft to mid-dough stage were collected and CRR incidences and severities were scored using the subcrown internode index method. Disease severities (DS) varied from 24–61% in 2000 and 2002, but were relatively low in 2001 (19–40%). None of the wheat cultivars was immune to CRR. The genotypes Canon, Forge, Dandy, Ember, Butte 86, Oxen, AC Barrie, Parshall, and 2371 had higher DS (>45%) and exhibited susceptible disease reactions. However, the genotypes ND 722, AC Cadillac, HJ 98, Argent and Scholar had lower levels of DS throughout the study period, and these were better than, or similar to Amidon, the resistant check. The HRSW cultivars with consistent resistance to CRR during the three year evaluation could be valuable resistance sources for use in breeding programs.