Biocontrol potential of Alternaria sp. PMK2, against a devastating weed: Parthenium hysterophorus L

Parthenium hysterophorus (Asteraceae) is known as one of the most aggressive invasive weeds, causing severe economic, environmental, human and animal health problems in India and around the world. During a series of extensive surveys for natural enemies of P. hysterophorus, a leaf spot pathogen was isolated from the affected parts of the parthenium following the standard isolation techniques using potato dextrose agar (PDA) and parthenium dextrose agar (PeDA) media. Koch's postulates were performed and found satisfactory for the isolate and proved to be pathogenic to this weed. On the basis of cultural, morphological and molecular characteristics, the pathogen was identified as Alternaria sp. PMK2. The growth of the pathogen was studied on eight selected media and it exhibited varying degrees of growth on different media. Phytotoxicity of fungal cultural filtrates was also confirmed on parthenium leaves in laboratory conditions. Due to the virulent nature of the isolated pathogen, it may be selected for further studies to develop mycoherbicide for control of this devastating weed.     

Potential and cost of carbon sequestration in Indian agriculture: Estimates from long-term field experiments

Carbon sequestration in tropical soils has potential for mitigating global warming and increasing agricultural productivity. We analyzed 26 long-term experiments (LTEs) in different agro-climatic zones (ACZs) of India to assess the potential and cost of C sequestration. Data on initial and final soil organic C (SOC) concentration in the recommended N, P and K (NPK); recommended N, P and K plus farmyard manure (NPK + FYM) and unfertilized (control) treatments were used to calculate carbon sequestration potential (CSP) i.e., capacity to sequester atmospheric carbon dioxide (CO₂) by increasing SOC stock, under different nutrient management scenarios. In most of the LTEs wheat equivalent yields were higher in the NPK + FYM treatment than the NPK treatment. However, partial factor productivity (PFP) was more with the NPK treatment. Average SOC concentration of the control treatment was 0.54%, which increased to 0.65% in the NPK treatment and 0.82% in the NPK + FYM treatment. Compared to the control treatment the NPK + FYM treatment sequestered 0.33 Mg C ha⁻¹ yr⁻¹ whereas the NPK treatment sequestered 0.16 Mg C ha⁻¹ yr⁻¹. The CSP in different nutrient management scenarios ranged from 2.1 to 4.8 Mg C ha⁻¹ during the study period (average 16.9 yr) of the LTEs. In 17 out of 26 LTEs, the NPK + FYM treatment had higher SOC and also higher net return than that of the NPK treatment. In the remaining 9 LTEs SOC sequestration in the NPK + FYM treatment was accomplished with decreased net return suggesting that these are economically not attractive and farmers have to incur into additional cost to achieve C sequestration. The feasibility of SOC sequestration in terms of availability of FYM and other organic sources has been discussed in the paper.     

Pathogenic and genetic variability in <Emphasis Type="Italic">Tilletia indica</Emphasis> monosporidial culture lines using universal rice primer-PCR

Tilletia indica Mitra is the causal agent of Karnal bunt of wheat, an important disease prevalent in several countries. The disease is internationally quarantined and the pathogen due to its heterothallic nature shows high variability. In the present study, we compared the pathogenic behaviour of various isolates of T. indica collected from different geographical locations of India and genetically characterized monosporidial (Ms) culture lines raised from these isolates of the pathogen. Pathogenic variability revealed existence of three pathotypes based on aggressiveness on a set of differential host genotypes. Monosporidial culture lines viz., 5 each from KB1, KB2, KB4 and KB5 and three lines of KB3 were established and analyzed genetically using 12 Universal Rice Primers (URPs). Amplification showed 98.44% polymorphism and primer URP 13R produced 100% polymorphic bands. Maximum similarity (83%) was between KB1MsB and KB1MsD as calculated by Jaccard’s similarity coefficient, whereas, minimum similarity was between KB1MsC and KB4MsB; KB1MsE and KB3MsA (46%). Three groups were formed among all Ms culture lines. One major group consisted of 13 lines with approximately 70% similarity, the second group consisted of 7 culture lines showing 55% similarity and the third group consisted of 3 Ms lines. URPs were able to differentiate the Ms culture lines raised from different T. indica isolates and the results indicated heterogeneity in the pathogen population.     

Studies on cisternal and alveolar fractions &; its composition and mammary health of Murrah buffaloes administered oxytocin

The study was conducted on 18 lactating Murrah buffaloes in 83.72 ± 14.75 days after calving. Group I buffaloes were not injected with oxytocin and served as control. Buffaloes of Group II were injected with oxytocin @ 2.5 IU per 0.5 ml intramuscularly at the hip region for a period of 1 month while Group III buffaloes received injection of oxytocin @ 5.0 IU per ml intramuscularly at the hip region for a period of 1 month. Milk samples from three groups of buffaloes were collected after oxytocin injections at 15 days interval on 0, 15, 30 and 45 days. Blood samples were collected in heparinized tubes at 0, 15, 30 and 45 days of experiment from all three groups of buffaloes. There was no significant change in cisternal, alveolar and total milk yield by exogenous oxytocin administration. Fat % in cisternal, alveolar and total milk decreased significantly (P < 0.01) by 11.8% and 21.3% in groups II and III buffaloes, respectively. Protein % increased significantly (P < 0.01) in group III. A significant increase was observed in somatic cell counts of milk by 5.36% and 6.22% in groups II and III, respectively as compared to control group. Part of MV. Sc. Thesis of the first author submitted to National Dairy Research Institute (Deemed University)     

Control of phytophthora leaf blight of taro (Colocasia esculenta) by fungicides and roguing

Six fungicides were evaluated under laboratory and field conditions for control of Phytophthora leaf blight of taro,Coloeasia esculenta, incited byPhytophthora colocasiae. Inin vitro tests Deraosan 65W was the most effective in inhibiting the mycelial growth of the test pathogen followed by Difolatan 80W, Fytolan (copper oxychloride), Apron 35F, Topsin-M 50W and Dithane Z-78 75W. Excellent control was obtained with Demosan 65W and Difolatan 80W, good control with Apron 35F, fair control with Fytolan, and poor control with Topsin-M 50W and Dithane Z-78 75W. Results ofin vivo tests were correlated with those of thein vitro tests. Roguing of infected leaves did not eradicate the pathogen but can only delay epiphytotics.     

Effect of additional vitamin E and zinc supplementation on immunological changes in peripartum Sahiwal cows

This study was conducted to exploit ameliorative effect of additional vitamin E and/or zinc supplementation on immune response of peripartum Sahiwal cows. Thirty‐two pregnant dry Sahiwal cows were blocked into four treatment groups (n = 8), namely control, zinc (Zn), vitamin E (Vit E) and zinc + vitamin E (Zn + Vit E). Feeding regimen was same in all the groups except that the Sahiwal cows in the zinc‐, vitamin E‐ and zinc + vitamin E‐fed groups were additionally supplemented with 60 mg Zn/kg DM, 1000 IU vitamin E and 60 mg/kg + 1000 IU Zn + vitamin E, respectively, from day 60 pre‐partum to day 90 post‐partum. Blood samples were collected on days ?60, ?45, ?30, ?15, ?7, ?3, 0, 3, 7, 15, 30, 45, 60, 90 and 120 with respect to day of parturition and analysed for total immunoglobulin (TIG), immunoglobulin G (IgG), interleukin‐2 (IL‐2), vitamin E (Vit E) and zinc (Zn) status. Before calving, cows showed a decrease in plasma TIG, IgG, IL‐2, Vit E and Zn levels. However, increased levels of plasma TIG, IgG, IL‐2, Vit E and Zn were observed after calving. After calving, Sahiwal cows supplemented with Zn + Vit E had higher plasma TIG, IgG and IL‐2 in comparison with cows of control and Zn + Vit E‐fed groups. In the present study, plasma vitamin E level was higher in Vit E‐fed and Zn + Vit E‐fed cows; however, zinc level was higher in Zn‐ and Zn + Vit E‐supplemented cows. In conclusion, a reduced immune response during peripartum period in Sahiwal cows was ameliorated by dietary vitamin E and zinc supplementation.     

Porcine gammadelta T cells: possible roles on the innate and adaptive immune responses following virus infection

gammadelta T cells recognise different types of antigen in alternative ways to alphabeta T cells, and thus appear to play a complementary role in the immune response. However, unlike alphabeta T cells, the role or function of gammadelta T cells is still unclear. As pigs possess a high proportion of circulating gammadelta T cells, they are suitable large animal model to study gammadelta T cell functions. This as yet has not been fully exploited, leaving porcine gammadelta T cell biology and its role in immunity in its infancy. Foot-and-mouth disease (FMD) high potency "emergency" vaccines are able to induce early protection from challenge and it has been suggested that, in part, there is some involvement of innate immune responses. The antigen component of the vaccine is able to stimulate purified naive pig gammadelta T cells and induce the mRNA of various cytokines and chemokines. This observation suggests that gammadelta T cells probably contribute to the early phase of the immune responses to FMD vaccination, and perhaps infection. A subset of these circulating gammadelta T cells display a phenotype similar to professional antigen presenting cells and are able to take up and present soluble antigen to CD4(+) T cells in a direct cell-cell interaction via MHC class II. This direct interaction between gammadelta T cells and CD4(+) T cells is likely to have a significant influence on the out come of the adaptive immune response.     

Estimation of combining ability in broilers from a full diallel cross

1. A 4 × 4 complete diallel cross involving four broiler strains (two of Cornish stock and two of Rock stock) was made. Twelve males from each strain were concurrently mated to three pullets from each strain in single sire pens.

2. Body weight was measured from 1‐d‐old to 10 weeks of age every two weeks in the 2880 progeny obtained in five hatches.

3. General combining ability was highly significant for all traits except body weight at 1 d old. The specific combining ability was significant for 4‐, 8‐ and 10‐week body weights.

4. Maternal effects were evident for body weights at earlier ages but gradually declined with advancing age and were non‐significant for 8‐ and 10‐week weights.

5. Sex‐linked effects, although smaller in magnitude, were evident for body weights up to 6 weeks of age.