Insect pests are often the major constraint for exportation of sweet basil. This study revealed the abundance of insect pests on sweet basil under organic, good agricultural practice (GAP) and conventional production systems in central Thailand from February 2010 to January 2011. In total, 6,886 pest specimens from 8 species were collected from all fields while only 2 species of natural enemies were recorded. In total, 4,119 individual insect pests were recorded in the organic field while the numbers in GAP and conventional fields were 1,418 and 1,349, respectively. In every sweet basil production system, thrips (Bathrips melanicornis) were the most common pest. In general, 8 out of 12 monthly diversity indices from the organic system were higher than those from either the GAP or conventional systems. The highest diversity index recorded from the organic farms was in August (1.63) while the highest diversity index from the GAP system (1.61) was recorded in September and from the conventional system (1.42) in October. Since Thailand is a global exporter of sweet basil, this study provides important reference information for importing countries, and represents a form of protection for sweet basil exports from Thailand to the global market.
Butyrivibrios and Pseudobutyrivibrios represent a significant proportion of ruminal bacteria and large culturable Butyrivibrio strains that contribute to fiber degradation and the utilization of various substrates. Butyrivibrio and Pseudobutyrivibrio are highly adaptable to ruminal conditions and play an important role in fiber fermentation. This study isolated the high potential fibrolytic and non-fibrolytic bacteria Butyrivibrio and Pseudobutyrivibrio from buffalo rumen and studied synergism between fibrolytic and non-fibrolytic bacteria in co-culture. Two mature, rumen-fistulated swamp buffaloes were fed roughage of either rice straw or rice straw plus concentrate. Roughage suspended in the rumen was used as the source of isolates. Six hours after feeding, roughage from the rumen was serially diluted and used for pure culture isolation by the roll tube technique under anaerobic conditions. Fiber degrading and cellobiose utilizing bacteria were collected and screened for further characterization, consisting of Gram-staining, 16S rDNA sequencing, utilization of different carbon sources, digestibility on fiber powders, intracellular fibrolytic enzyme activities, volatile fatty acid production and co-culture digestibility between fibrolytic Butyrivibrio and non-fibrolytic bacteria. A total of 165 Gram-negative fibrolytic bacteria were obtained from 1,125 colonies and then 21 fibrolytic and 20 non-fibrolytic strains were selected that could utilize cellobiose efficiently. Fibrolytic bacteria were identified as 10 strains of Butyrivibrio sp. and 4 strains of Pseudobutyrivibrio spp. and non-fibrolytic bacteria were identified as 4 strains of Butyrivibrio sp. and 3 strains of Pseudobutyrivibrio spp. Isolates of fibrolytic Butyrivibrios sp. and Pseudobutyrivibrios spp., especially B. fibrisolvens KU-F83, showed high digestibility of fiber powder and high intracellular fibrolytic enzyme activity. Co-culture of fibrolytic B. fibrisolvens KU-F83 and non-fibrolytic Butyrivibrios, Pseudobutyrivibrios and S. ruminantium S137 could ehance rice straw digestibility and the propionate portion while reducing cellulose digestibility.
Intensive cultivation of rice is believed to be one of the factors responsible for the outbreak of brown planthopper (BPH). An experiment was conducted to study the reaction of 22 rice genotypes to six populations of BPH collected from rice research centers and from farmers’ fields of central Thailand. The results showed that populations of BPH from rice research centers were relatively more virulent than those from farmers’ fields. Cluster analysis using the mean BPH damage score divided the genotypes into three groups. Group I contained 18 susceptible genotypes including the susceptible check TN1. Group II contained two moderately resistant genotypes, IR64 and RD31, while the third group was made up of the resistant checks, Rathu Heenati and Ptb33. Rathu Heenati and Ptb33 could be used as sources of resistance for BPH in central Thailand. However, it is important to study the reaction of more genotypes by using additional BPH populations. The differential response of genotypes to populations of rice research centers and farmers’ fields of the same province also needs further investigation.
The Water, Nutrient, Light Capture in Agroforestry Systems (WaNuLCAS) model was used to evaluate and understand the impact of crop management on intercropping scenarios and competition between rubber and associated annual crops. The intention was to identify sustainable production systems with economic benefits for small-scale landholders in Thailand. The WaNuLCAS model was used to predict maize and rubber productivity under various management scenarios of intercropping and sole cropping in the Phitsanulok province (16o55' N, 100o32' E), Thailand. Model scenarios were simulated for rubber (clone RRIM600) grown with spacings of 2.5 × 7 m, 3 × 7 m and 3 × 8 m under sole cropping and intercropping with maize. The yield of maize was substantially influenced by rubber-tree spacing in the intercropping systems. After 3 yr, the average yield of maize was decreased from 7 to 3 t.ha-1 by rubber tree growth if organic fertilizer was not applied. Organic fertilizer application mitigated the negative influences of rubber trees until the seventh cropping season. After 8 yr, the maize yield decreased to 0.4 t.ha-1. Hence, rubber intercropped with maize with the application of recommended chemical fertilizer plus organic fertilizer was the best way to mitigate competition between rubber and maize. In the long term, the rubber tree girth and wood volume from sole cropping were higher than from the rubber intercropping systems. With a higher rubber tree density, the rubber tree girth and wood volume increased more slowly.
Rubber seedlings from two early-introduced clones (EIRpsu 1 and EIRpsu 2) in southern Thailand were evaluated for root growth performance under field conditions. The two clones had been screened for white root disease tolerance. Genetic analysis of EIRpsu 1 and EIRpsu 2 was compared to RRIM 600 (the major cultivated variety of Hevea rubber in Thailand) using random amplified polymorphic DNA markers with 10 primers. Results from cluster analysis indicated that EIRpsu 2 was closer to RRIM 600 than EIRpsu 1 with similarity coefficients of 0.850, 0.860 and 0.890, respectively. Root growth of EIRpsu1 and EIRpsu2 was monitored at a rubber plantation in Langsuan district, Chumphon province during 2012–2013. Six-month-old seedlings of each clone were transplanted into a rhizobox. The experiment was designed as a randomized complete block design with four replications, with one plant per rhizobox. Shoot growth and root proliferation of the seedlings were recorded at two-monthly intervals from October 2012 to March 2013. The shoot growth was monitored by measuring plant height, trunk diameter and the number of compound leaves. It was found that RRIM 600 exhibited the highest shoot growth under field conditions, and it was significantly different from the other two clones. The root length density was measured by scanning the root systems of each seedling from a panel in the rhizobox. Results showed that the seedlings of EIRpsu 1 and EIRpsu 2 had better root growth than RRIM 600. The spatial distribution of roots indicated a rather deeper root system for the two selected clones.
Cellular automata and Monte Carlo simulation techniques were employed to study the spread of mealybugs (a major cassava insect pest) in a cassava field. There are various recommended instructions on how often farmers should release green lacewings (a biological control agent) to control the spread of mealybugs. In this study, the effects of different release frequencies of green lacewings in controlling the spread of mealybugs were investigated. Keyword: Cellular automata, cassava, mealybugs, green lacewings, biological control
Detection of validated and confirmed quantitative trait loci (QTLs) is essential to conduct more successful marker-assisted selection breeding programs. The objectives of this study were to determine the QTLs controlling seed size traits in soybean (Glycine max L.) and to compare those identified with the previously reported QTLs. One hundred thirty-five F2:3 lines derived from the cross MJ0004-6 × R18500 were evaluated in the experimental fields of Kasetsart University, Kamphaeng Saen, Nakhon Pathom, Thailand in a randomized complete block design with two replications each in the 2011 and 2012 growing seasons. The population was genotyped by 149 polymorphic simple sequence repeat markers and the genetic map consisted of 129 simple sequence repeat loci which converged into 38 linkage groups covering 1156 cM of soybean genome. There were 16 quantitative trait loci (QTLs) significantly associated with seed size traits across two seasons with single QTLs explaining between 7.4% and 18.4% of the phenotypic variation. One novel QTL (SL6) on linkage group K was consistently mapped in both seasons. Most QTLs were environment-sensitive, revealing that the genotype × environment interaction played an important role in expression of seed size traits in soybean. The majority of QTLs detected in the research were consistent with earlier QTLs reported by previous researchers.
The objectives of this research were: 1) to study the effect of sucrose replacement with alternative sweeteners on the qualities of vanilla-flavored ice cream, freezing points and raw material cost; and 2) to produce a low sugar, yoghurt-flavored ice cream containing sucralose and inulin. The outcome of this research provided broader information for ice cream manufacturers that intend to apply a sweetener and inulin to their ice cream production lines. For vanilla-flavored ice cream, five ice cream formulas were produced in this work comprised of the control sample using sucrose and the other four samples applying erythritol, maltitol, sucralose and xylitol as the sweeteners, respectively. In order to achieve the equivalent sweetness value to sucrose, the applied weights of erythritol, maltitol, xylitol and sucralose were 125, 111, 100 and 0.17% compared with sucrose. It appeared that the viscosity of samples after the mixing step was higher than after the other steps for all recipes except for the samples using xylitol. The addition of xylitol increased the overrun value and lightness whereas maltitol resulted in the reverse effects. Rapid melting was found in the sample substituted with xylitol. The freezing temperatures of all samples were higher than that of the control. The sensorial characteristics of samples with sucralose were not significantly different from the control while the mouthfeel and smoothness of the maltitol and xylitol recipes significantly differed from the control. The sucrose replacement sucralose led to the lowest cost as it was the least applied. Four yoghurt-flavored ice cream formulas were prepared made from whey protein powder or buffalo milk with or without sucralose replacement and added inulin. The results showed that the overrun of buffalo yoghurt ice cream was lower than for the whey protein powder formulas by an estimated 1.5 times. All sensorial scores of both types of yoghurt ice cream with sucralose substitution and added inulin were similar to samples without sweetener and inulin.
A recent study has demonstrated that XagP in xagP of Xanthomonas axonopodis pv. glycines 12-2 )Xag 12-2), the causal agent of soybean bacterial pustule, is required to induce a hypersensitive response (HR) in tobacco (Nicotiana rustica). Until now, its role in virulence on soybean was unknown and whether the general secretion pathway (GSP) is different from other bacteria. To understand the possible relationship between functions, xagP and T4P operon-corresponding to XagP secretion and type IV pili of Xag 12-2, respectivelywere mutated using the site-directed method. XagP secretion into media associated with ΔxagP and ΔT4Pmutants was reduced by 100 and 24.8% respectively. Pili mutants were less reduced in the Pel secretion than by other GSPs which might be necessary for an XagP transporter. Both mutants elicited HR-like typically necrotic symptoms which were the same as the wildtype, that is, within 48 hr after infiltration on susceptible soybean cv. Spencer. On this same host plant, disease severity induced by ΔxagP and ΔT4P mutants was highly reduced by 82.8 and 55.9%, respectively. It is also interesting to note that the HR and disease symptoms produced by the mutants were different from the wildtype. The mutants neither expressed haloes surrounding the HR nor scattered lesions over spray-inoculated leaves but revealed pustules around the leaf margin at hydathode pores. Complemented mutants showed enhanced secretion, transportation, HR and disease severity similar to the wildtype. This is the first report of a co-regulation mechanism of xagP and type IV pili secretion pathway in Xag 12-2 with bacterial pustule disease in soybean. Details involved in these interactions are discussed. The minimal translocation of XagP that is less coincident with the pili transporter should be further elucidated to determine if it is more dependent on other GSPs and can suppress secretion output of other virulence factors associated with Xag 12-2 pathogenesis.
A study was conducted on a farmer’s field on a 35 % slope in the humid forest zone, Nigeria on the use of a green structure that performed some engineering functions on cultivated steep lands to help curtail soil and water losses. Treatments consisted of a vetiver grass strip as a green buffer structure at different surface spacings of 5, 15, 25 m with no vetiver as the control and were laid out in a randomized complete block design with three blocks. Twelve erosion plots each measuring 50 m long and 3 m wide were used for the study. The plots were planted with cassava and maize in a simple crop mixture. The runoff, soil loss and crop yield were assessed under the four treatments. The rainfall lost as runoff with no vetiver (control plot) was 24.8 % compared to 7.7, 11.5 and 11.6% lost on the green structure plots at spacings of 5, 15 and 25 m, respectively. Soil loss on the no vetiver plot was 40 times higher than the acceptable soil loss limit of 12 t.ha-1 yr-1 for the tropics, whereas the soil loss on plots under vetiver at spacings of 5, 15 and 25 m was 1.4, 6.8 and 6.5 times higher than the acceptable limit. The maize grain yield and the fresh cassava tuber yield were significantly lower in the control plots and highest with the 5 m spacing. A vetiver strip as a green structure was more effective at a spacing of 5 m as it reduced soil and water losses and increased crop yield. This spacing was also adequate for traditional pre- and post-farming activities.
The physicochemical characteristics were evaluated of eight wood vinegars from the carbonization of five wood species—Leucaena leucocephala (Katin), Azadirachta indica (Sadao), Eucalyptus camaldulensis, Hevea brasiliensis (rubber wood) and Dendrocalamus asper (bamboo). The vinegars were produced by heating wood samples up to 400 °C in a Thai-Iwate kiln and were compared with two commercial products. The quality assessments of all wood vinegars were determined according to criteria from the Charcoal Handbook. The results showed that all wood vinegar samples appeared to be good quality in terms of odor, color and transparency. The pH (2.9–3.5) and total soluble tar (0.325–0.963 % by weight) also met the standard criteria for the pH (around 3) and total soluble tar (not more than 3%). The values of the specific gravity of only two products, from rubber wood (1.012 g.mL-1) and bamboo (1.010 g.mL-1) were within the acceptance criteria of 1.010–1.050 g.mL-1. Chemical compositions of wood vinegars as determined qualitatively by gas chromatography/mass spectrometry and quantitatively by gas chromatography/flame ionized detector consisted of acetic acid as the largest component (30.45–70.60 mg.mL-1). A high number of phenol derivatives (16 compounds) were found and those in higher concentrations were 4-propyl-2-methoxyphenol (5–11 mg.mL-1) followed by 2-methylphenol (2–4 mg.mL-1). An acetic acid concentration from the eight samples whose presence was indicated by pKa at 4.7 was mainly responsible for the pH values as shown in the good correlations of plots between pH and acetic acid concentrations (Correlation coefficient, R = 0.92). The total acid contents of the ten wood vinegars as determined by titration with 0.1 N sodium hydroxide showed poor correlations with pH (R = 0.65) due to the presence of a variety of organic acids and phenolic compounds which may have affected proton transition. The specific gravity showed good correlations with total soluble tar and degree Brix (R = 0.87 for both); in turn the degree Brix showed good correlation with the total soluble tar (R = 0.87). Thus, the degree Brix which was easy to determine could be used as a general indicator of total soluble tar. The amount of total soluble tar signified the presence of phenolic compounds, of which previous studies suggested antifungal activity and usefulness as wood preservatives. Phenolic compounds were also confirmed by the ultraviolet absorption maximum (λmax) at 268–274 nm.
The effect was studied of the lipophilic extract from Lasia spinosa (L.) Thwaites rhizome on the seed germination and seedling growth of the invasive plant, Mimosa diplotricha C. Wright ex Sauvalle during September–November 2012 using five different extract concentrations (0, 10, 20, 30 and 40 mg.mL -1 ). The results revealed that 1 wk after transplanting, the extract had an effect on the seed germination and on seedling growth and characteristics. When the concentration was increased, the shoot and root length decreased significantly (P < 0.05) Thin layer chromatography screening and preliminary testing and detection using different specific reagents showed the presence of terpenoids, phenolic compounds, coumarin, alkaloids and C-glycoside in the extract.
FieldexperimentIwasconductedundermoderatewaterdeficitconditionsatfourdifferent� growth stages (V10 to V13, V13 to V17, V17 to blister and blister to physiological stage) with three maizegenotypes�(Pioneer�30B80,�NK�40�andSuwan�4452)�andfieldexperimentIIwasconducted� underseverewaterdeficitconditionsatthreestages�(V10�toanthesis,�anthesistomilkandmilkto� physiological maturity stage) with two genotypes (NK 40 and Suwan 4452) to evaluate the hypothesis that the translocation of stored stem reserves into the growing grain is an important source of carbon forsupportinggrainfillingunderwaterdeficit.� Significantlyhigherassimilatetranslocation,�assimilate� translocationefficiencyandcontributionofpre-anthesisassimilatestothegrainwereachievedintheV17� toblisterstageundermoderatewaterdeficitandinthemilktophysiologicalmaturitystageundersevere� waterdeficit,� respectively,�withmaximumstemdryweightdepletionandstemdryweightdepletionco- efficients.� NK�40�alwayssustainedasmallerreductioningrainweightunderbothexperiments.�During� grainfilling,� NK�40�exported�43.51�and�28.38%�higherstemreservedrymattercomparedtoPioneer� 30B80�andSuwan�4452�undermoderatewaterdeficitconditionsanda�46.20%�higherstemreserve� contributioncomparedtoSuwan�4452�underseverewaterdeficitconditions.�Assimilatetranslocation� inthetwoexperimentsshowedasignificantpositiverelationshipwithstemdryweightdepletion�(R 2 = 0.81�and�87,�respectively)�andspecificleafweightdepletion�(R 2 = 0.93 and 88, respectively), whereas it showedasignificantnegativerelationshipwiththesource-sinkratio�(R 2 = -0.53 and -0.84, respectively) and chlorophyll content (R 2 = -0.50 and -0.63, respectively).
A Maillard reaction is one of the common non-enzymatic browning reactions in foods subjected to heat treatment and involves an interaction between protein and reducing sugars. Whey protein isolate (WPI) contains at least 90% soluble proteins. It was hypothesized that WPI could interact with glucose (Glu) leading to the formation of Maillard reaction products (MRPs) and the development of antioxidant activities. The results of this study showed that WPI-Glu developed browning MRPs after heating for 20 min at 90 °C and pH 7 or pH 8. Additionally, the generated browning MRPs developed some antioxidant activities. WPI-Glu mixtures heated at pH 8 revealed the highest free radicals scavenging activity among all examined samples. The highest 2,2-diphenyl-1-picrylhydrazyl scavenging activities of heated WPI-Glu mixtures were 18 and 26% at pH 7 and pH 8, respectively. The results also showed a positive relationship between antioxidant quantities and the amount of added glucose. Sodium dodecyl sulfatepolyacrylamide gel electrophoresis results proved that bovine serum albumin and β-lactoglobulin were the main proteins that reacted with glucose. High performance liquid chromatography analysis detected the presence of hydroxy methyl furfural (HMF) at all tested pH values. However, the data showed that the HMF quantity reached the highest value (6.58 ± 1.79 µg.mL -1 ) at pH 8 and a WPI:Glu ratio of 1:3.
