Genetic association between milk yield,stayability, and mastitis in Holstein cows under tropical conditions

The objective of this study was to estimate genetic parameters for milk yield, stayability, and the occurrence of clinical mastitis in Holstein cows, as well as studying the genetic relationship between them, in order to provide subsidies for the genetic evaluation of these traits. Records from 5,090 Holstein cows with calving varying from 1991 to 2010, were used in the analysis. Two standard multivariate analyses were carried out, one containing the trait of accumulated 305-day milk yields in the first lactation (MY1), stayability (STAY) until the third lactation, and clinical mastitis (CM), as well as the other traits, considering accumulated 305-day milk yields (Y305), STAY, and CM, including the first three lactations as repeated measures for Y305 and CM. The covariance components were obtained by a Bayesian approach. The heritability estimates obtained by multivariate analysis with MY1 were 0.19, 0.28, and 0.13 for MY1, STAY, and CM, respectively, whereas using the multivariate analysis with the Y305, the estimates were 0.19, 0.31, and 0.14, respectively. The genetic correlations between MY1 and STAY, MY1 and CM, and STAY and CM, respectively, were 0.38, 0.12, and ?0.49. The genetic correlations between Y305 and STAY, Y305 and CM, and STAY and CM, respectively, were 0.66, ?0.25, and ?0.52.     

Acaricidal properties of extracts from the aerial parts of Hypericum polyanthemum on the cattle tick Boophilus microplus

Laboratory tests were carried out on larvae and adults of the cattle tick Boophilus microplus to determine the toxicity of n-hexane and crude methanolic extracts of Hypericum polyanthemum (Guttiferae) using the larval immersion test (LIT) and adult immersion test (AIT). In the AIT, the effectiveness of treatment against engorged females was assessed by measuring egg production: the n-hexane extract was found to have a small effect on the egg laying at the highest concentration (19.2% of egg-laying inhibition) whilst the crude methanolic extract did not affect the egg production. For the LIT the n-hexane extracts were highly toxic to the larvae at all the concentrations (100% of mortality). The crude methanolic extract was also toxic to the larvae at higher concentrations killing 100, 96.7, 84.7 and 52.7% at the concentrations of 50, 25, 12.5, and 6.25 mg/ml, respectively, 48 h after the immersion of the acarus.     

Timing of exposure and nutritional status affect male response to guava volatiles,a known courtship enhancer of Anastrepha fraterculus

Journal of Pest Science - Finding ways to improve the sexual competitiveness of laboratory reared males have proven beneficial for the sterile insect technique. Exposure to essential oils enhances...     

Seaweed polysaccharides and derived oligosaccharides stimulate defense responses and protection against pathogens in plants

Plants interact with the environment by sensing "non-self" molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae) corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA), jasmonic acid (JA) and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i) Pathogenesis-Related (PR) proteins with antifungal and antibacterial activities; (ii) defense enzymes such as pheylalanine ammonia lyase (PAL) and lipoxygenase (LOX) which determine accumulation of phenylpropanoid compounds (PPCs) and oxylipins with antiviral, antifugal and antibacterial activities and iii) enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants.     

Enhancing multi-functionality of agriculture through rainwater harvesting system

The multi-functionality of agriculture was studied from June to December 2005 in an upland community in Central Luzon, Philippines, by looking across the entire basin of two small water impounding systems or SWIP (Maasin and Buted II). Several sub-studies were undertaken, namely (a) the role of dominant vegetative cover on the rate of surface runoff and erosion; (b) rainfall–runoff analysis in a sub-watershed (i.e., through runoff experimental plot) and within the main watershed (i.e., reservoir inflow analysis); and (c) the environmental functions of agriculture across the entire watershed. The results indicated that about 85% (i.e., throughfall) of rainfall could reach the ground as vegetations intercept the rest. The runoff experimental plot covering a sub-watershed revealed a good correlation between throughfall and runoff. On the other hand, monitoring of reservoir inflows through which surface runoff was measured indicated similar behavior. Integrating the result of runoff experimental plot studies and reservoir inflow analysis resulted to a rainfall–runoff relation which can be applied in the development of rainwater harvesting scheme. The result also showed the dominance of surface runoff as the main component of reservoir inflow, confirming the soil and water conservation, and flood prevention functions of the system. Flood analysis conducted in both SWIP confirmed their flood prevention function by reducing flood peak discharge. The difference between with and without the reservoir was also highlighted in the process. In the paddy field, a 5-cm water depth was consistently maintained, contributing in retaining about 0.543 and 0.272 MCM of rainwater in Maasin and Buted II, respectively. The value of fostering groundwater recharge throughout the entire system was almost equivalent to the value of flood prevention function. Moreover, SWIP also trapped sediments, thereby preventing offsite impact downstream and in surrounding areas.This paper is part of the progress report of the project “Multi-functionality of Agriculture in Selected Sites in the Philippines” presented in the 6th Meeting of the Working Group for the ASEAN-Japan Project on Multi-functionality of Agriculture in ASEAN Countries.     

Standardizing resistance screening to Pseudomonas fuscovaginae and evaluation of rice germplasm at seedling and adult plant growth stages

Sheath lesions, grain sterility and grain discolouration of rice caused by Pseudomonas fuscovaginae can cause yield losses of up to 100 %. The most sustainable method of managing this disease is the use of host plant resistance. To identify sources of resistance an inoculation method that is practical, rapid and reliable is needed. We compare three different inoculation methods. Results showed that the pin-prick method is appropriate for identifying sources of resistance to P. fuscovaginae, while the spray method could be useful for mass screening of rice genotypes. The seed-soaking method was also evaluated and has showed potential in detection of early disease resistance. A total of 16 Multiparent Advanced Generation Inter-Crosses and 20 OryzaSNP set varieties from the International Rice Research Institute were evaluated using the pin-prick and seed-soaking methods. All growth stages were susceptible to the pathogen and the 10⁷ cfu mL^?1 inoculum concentration was optimal for discriminating between resistant and susceptible genotypes. For the pin-prick method, a single point assessment of disease severity at 14 days post-inoculation could be used instead of the AUDPC values to classify genotypes. An index of reduction in seedling height 10 days after seed soaking was established for the classification of the genotypes reaction to the disease. Resistant varieties identified using both the pin-prick and seed-soaking methods could be verified for use in disease resistance breeding programs. Of the 36 genotypes evaluated 22 were found to be resistant at the late booting or early panicle exsertion stage by pin-prick method, while 25 were resistant at the seed to germination stage. No correlation was found between the resistance classification of varieties between the two inoculation methods, indicating that there could be different mechanisms of resistance to P. fuscovaginae in rice.