Development of integrated pest management for sugarcane borer, Diatraea saccharalis in rice

Rice is grown over an area of approximately 500,000 acres in Louisiana. The lepidopteran stem borer complex attacking rice in the southern U.S includes stalk borer Chilo plejadellus Zincken, sugarcane borer (SCB) Diatraea saccharalis (F.) and Mexican rice borer, Eoreuma loftini Dyar. With the increasing impact of stem borers in Louisiana, an urgent need exists to develop strategies for management. Currently, no IPM program is in place for stem borers in Louisiana rice and research has been initiated to develop an IPM program for these pests. The first objective of this research was focused on host plant resistance. For this objective, oviposition preference and larval performance of sugarcane borer on commonly grown rice cultivars in Louisiana were investigated. Results from the oviposition preference study revealed significant differences among cultivars. Overall females of D. saccharalis preferred ovipositing on the upper sides of the leaves of rice plants. In the performance study, three different measures of performance were used. Results from these studies revealed significant differences among varieties for these measures of performance. Results also revealed a strong correlation between different measures of performance as well as between performance and preference. Results from the compensation study revealed differences in compensatory response of same eight cultivars. In the silicon soil amendment study, a significant increase in silicon content of rice plants supplemented with calcium silicate was observed compared to the control plants. Soil Si amendment led to lower relative growth rates and reduced boring success of sugarcane borer larvae on. Studies were conducted to evaluate the efficacy of Dermacor seed treatment against sugarcane borer. Dermacor seed treatment was the most effective among different insecticides used in a field study and significantly increased larval mortality in lab and greenhouse experiments. These studies will help facilitate scouting for sugarcane borer in the field and improvement in insecticide timing. Potential exists for current use of these (moderately resistant) cultivars in IPM programs and as sources of resistance in breeding programs for stem borer resistance. Soil Si amendment and Dermacor seed treatments has the potential to fit into the IPM program

Canadian Youth Criminality and Identity Formation: A South Asian (Sikh) Perspective

This thesis explores the experiences of second generation Sikh males in Canada, focusing on involvement in criminal activities during adolescence. Using a deeply qualitative autoethnographic approach (Anderson, 2006), I conducted unstructured active interviews (Holstein & Gubrium, 1995) with seven males ranging from 20 to 26 years of age. The interviews consist of a dialogue on how these youths\u27 emerging identities as Sikh and as Canadians contributed to their adolescent experiences with crime. Findings highlight the importance of engaging youth at the level of personal experience and at the level of institutional and community influences. Specifically, an interplay of parental, cultural, institutional, and societal processes impacted participants\u27 identities and subsequent actions, including desistance from crime as the youth emerged from adolescence. The major conclusion of the thesis is that while ethnic cultural influences and ethnic pride contributed to youths\u27 involvement in various criminal activities, ethnic and especially family influences and pride also contributed to transitions to desistance. This speaks to the need for an inclusive environment that encourages integration of immigrant populations in ways that allow them to actively participate as full citizens within their families, communities and as Canadians

ASCORBIC ACID AS A GROWTH ADJUVANT IN ENCAPSULATED PROTOCORM-LIKE-BODIES OF RHYNCHOSTYLIS RETUSA BL. (ORCHIDACEAE)

In the present study, effect of ascorbic acid, a known growth adjuvant on encapsulated protocorm-like-bodies (PLBs) of Rhynchostylis retusa Bl. was investigated. PLBs were encapsulated in calcium alginate (3.5% sodium alginate and 100mM calcium chloride) prepared in Mitra et al. (1976) basal medium and supplemented with different concentration of ascorbic acid (5, 10, 15, 20mM). The encapsulated PLBs were stored at 25°C. Their germination response and germination potential was evaluated after every 4 weeks on basal media. Control set of encapsulated PLBs, failed to germinate after 32 weeks. However, PLBs with 15mM ascorbic acid in the encapsulated matrix showed the best response; nearly 90% germinated even after 32 weeks of storage. The survival and germination frequency was directly proportional to the level of ascorbic acid in the alginate mix upto 15mM level but declined on further increase. Differentiation of PLBs into plantlet was better in synthetic seeds containing lower concentration of ascorbic acid (5mM) as compared to higher levels (15, 20mM) whereas multiplication of secondary PLBs was more pronounced at higher levels. Chlorophyll content was inversely proportional to the level of ascorbic acid in the nutrient mix; lush green PLBs were observed at low concentration of ascorbic acid (5mM). This study highlights the potential of ascorbic acid as an aid to growth and survival of encapsulated PLBs upon storage

ntegrated Pest Management of Longan (Sapindales: Sapindaceae) in Vietnam

This paper describes the current state of pests and diseases of longan (Dimocarpus longan Lour.) and their management in Vietnam. Longan is the third most cultivated fruit crop and second major fruit crop exported from Vietnam. Brief descriptions of arthropod pests Eriophyes dimocarpi Kuang (Acari: Eriophyidae), Conogethes punctiferalis Guenée (Lepidoptera: Crambidae), Conopomorpha sinensis Bradley (Lepidoptera: Gracillariidae), Conopomorpha litchiella Bradley (Lepidoptera: Gracillariidae), Tessaratoma papillosa Drury (Hemiptera: Tessaratomidae), Eudocima phalonia L. comb. (Lepidoptera: Erebidae), oriental fruit fly Bactrocera dorsalis Hendel (Diptera: Tephretidae), Planococcus lilacinus Cockerell (Hemiptera: Pseudococcidae), Drepanococcus chiton Green (Hemiptera: Coccidae), and Cornegenapsylla sinica Yang & Li (Hemiptera: Psyllidae) and fungal diseases Phytophthora palmivora Butler (Peronosporales: Peronosporaceae), Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. (Incertaesedis: Glomerellaceae), and Ceratocystis fimbriata Ellis & Halsted (Microascales: Ceratocystidaceae) affecting longan are given. The longan witches’ broom syndrome is a major factor causing 50–86% annual crop loss in Vietnam and it has been considered the primary constraint in production. The causative agent of this syndrome has been identified as the eriophyid mite E. dimocarpi. Deployment of Integrated Pest Management strategies for longan production in Vietnam is outlined

TILLING : EMS mutagenesis in Epichloë endophytes and mutation screening using High Resolution Melting analysis and Next Generation Sequencing : this thesis is presented in partial fulfilment of the requirements for the degree of Master of Science (MSc) in Microbiology at Massey University, Palmerston North, New Zealand

Epichloë are fungal endophytes (family Clavicipitaceae) of pasture grasses of the sub family poöideae. These endophytes live in symbiotic association with their hosts and confer resistance to insect and animal herbivory through the production of bioactive secondary metabolites (alkaloids) that are produced in planta. For a number of years endophyte research has been focused at manipulating fungal genes responsible for production of alkaloids which have toxic effects on livestock. However, the techniques used to date involve genetic modification to delete genes responsible for alkaloid production and strict regulations around genetically modified organisms in New Zealand prevent commercialisation of these organisms. Traditional mutagenesis was not practical. To find mutations in secondary metabolite pathways, the mutants had to be inoculated back into plants, which would have been a laborious and time-consuming process. The aim of my research was to develop Targeting Induced Local Lesions In Genomes (TILLING) methodology in Epichloë to disrupt fungal secondary metabolite genes using Ethyl methanesulfonate (EMS) and screen for mutations using high throughput screening techniques such as High Resolution Melting (HRM) analysis and whole genome sequencing, MiSeq. In order to carry out the mutagenesis, uninucleate propagules would be preferred but as most of the filamentous fungi (including Epichloë) are multinucleate in nature, spores were thought to be an ideal alternative for mutagenesis. However, many of the commercially used Epichloë strains, such as AR1 and AR37, do not readily produce spores. Therefore an alternative mutagenesis system using fungal protoplasts was investigated and employed. EMS mutagenesis showed that the number of colonies derived from protoplasts after mutagenesis declined steadily at a reproducible rate as measured by time-course of 0, 15, 30, 45 and 60 minutes to give LD50 values. At 60 minutes there was decline in the number of colonies to the levels of 10% of the initial number. To determine the effectiveness of EMS as a mutagen positive selection, using 5-Fluoroorotic acid (5-FOA), was also performed on the mutagenized protoplasts to derive the mutation frequency of 6 mutations per 1000 mutants compared to 0.002 mutations per 1000 for non-mutagenized protoplasts. This suggests a 3000-fold EMS-induced increase in the frequency of mutations. Having established mutation frequency from the 5-FOA, positive selection and steady decline in number of colonies from EMS mutagenesis, an EMS mutant library was screened using next generation sequencing. . However, high throughput whole genome sequencing (MiSeq) led to the detection of only three verifiable point mutations (1 in 10Mb). Microscopic observations revealed that while individual protoplasts were largely (85%) uninucleate, protoplasts typically formed clumps containing 15-30 protoplasts. In theory, multiple nuclei would lead to an overestimation of the number of mutations since each nucleus would accumulate different SNPs. However, MiSeq sequencing did not detect this, probably due to being filtered out during bioinformatics processing. Thus if methods can be devised for plating single protoplasts, EMS mutagenesis should be applicable to this system. TILLING technology can be used to reduce the time for endophyte discovery and improvement. My research demonstrated that this procedure, although very promising in terms of benefit to fungal improvement, carries certain difficulties with it that we had to address such as mutagenesis using protoplasts and subsequent mutation discovery. I succeeded in establishing TILLING methodology for mutagenesis of E. festucae strain Fl1 as well as optimising protocols to screen mutants

PHYSICOCHEMICAL STUDY OF THERMOPLASTIC STARCH(TPS) USING IONIC LIQUID AS PLASTICIZER

This research investigates the physicochemical and hygroscopic properties of thermoplastic starch (TPS) an alternative biodegradable material. The material is formed from starch, Ionic liquid (IL) as plasticizer and rice straw fibre (RS) as fillers. TPS is synthesised through starch gelatinization process with the presence of plasticizer at elevated temperature. For this study, two types of ionic liquids as plasticizer are compared which are 1-ethyl-3-methylimidazolium acetate [Emim]Ac and 1-ethyl-3-methylimidazolium chloride [Emim]Cl. The best plasticizer will be chosen through thermal analysis by using Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA). From the result, it was found that [Emim]Ac was the better plasticizer. Following towards the second focus of this study which is to investigate the physicochemical properties and the moisture absorption rate of the synthesised TPS. The optimised TPS will be mixed with RS which aims to reduce moisture uptake. From the moisture absorption analysis, it was found that, 40% of RS loading showed the lowest moisture absorption rate for both 50% and 75% relative humidity (RH). Whereas, the FTIR results indicated that there is new bond formation in the synthesised TPS as well as TPS mixed with RS. SEM images clearly shows the interaction between the TPS samples. In addition, the TPS that is formed is more amorphous compared to other samples. The thermal analysis, showed that the TPS synthesised is thermally stable which includes TPS with 40% RS loading. The biodegradability test also proved that indeed [Emim]Ac can withstand microbial attack. The results obtained clearly showed there is a good potential to use [Emim] Ac and RS as plasticizer and fillers respectively to synthesise an alternative biodegradable material

PHYSICOCHEMICAL STUDY OF THERMOPLASTIC STARCH(TPS) USING IONIC LIQUID AS PLASTICIZER

This research investigates the physicochemical and hygroscopic properties of thermoplastic starch (TPS) an alternative biodegradable material. The material is formed from starch, Ionic liquid (IL) as plasticizer and rice straw fibre (RS) as fillers. TPS is synthesised through starch gelatinization process with the presence of plasticizer at elevated temperature. For this study, two types of ionic liquids as plasticizer are compared which are 1-ethyl-3-methylimidazolium acetate [Emim]Ac and 1-ethyl-3-methylimidazolium chloride [Emim]Cl. The best plasticizer will be chosen through thermal analysis by using Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA). From the result, it was found that [Emim]Ac was the better plasticizer. Following towards the second focus of this study which is to investigate the physicochemical properties and the moisture absorption rate of the synthesised TPS. The optimised TPS will be mixed with RS which aims to reduce moisture uptake. From the moisture absorption analysis, it was found that, 40% of RS loading showed the lowest moisture absorption rate for both 50% and 75% relative humidity (RH). Whereas, the FTIR results indicated that there is new bond formation in the synthesised TPS as well as TPS mixed with RS. SEM images clearly shows the interaction between the TPS samples. In addition, the TPS that is formed is more amorphous compared to other samples. The thermal analysis, showed that the TPS synthesised is thermally stable which includes TPS with 40% RS loading. The biodegradability test also proved that indeed [Emim]Ac can withstand microbial attack. The results obtained clearly showed there is a good potential to use [Emim] Ac and RS as plasticizer and fillers respectively to synthesise an alternative biodegradable material

An okadaic acid-sensitive pathway involved in the phenobarbital-mediated induction of CYP2B gene expression in primary rat hepatocyte cultures

ABSTRACT We have previously demonstrated that specific activation of a cAMP-dependent protein kinase A (PKA) pathway resulted in complete repression of phenobarbital (PB)-inducible CYP gene expression in primary rat hepatocyte cultures. In the current investigation, we examined the role of protein phosphatase pathways as potential co-regulators of this repressive response. Primary rat hepatocytes were treated with increasing concentrations (0.1-25 nM) of okadaic acid, a potent inhibitor of serine/threonine-specific protein phosphatases PP1 and PP2A. PB induction responses were assessed by use of specific hybridization probes to CYP2B1 and CYP2B2 mRNAs. Okadaic acid completely inhibited the PB induction process in a concentration-dependent manner (IC 50 , ϳ1.5-2 nM). Similar repression was obtained with low concentrations of other highly specific phosphatase inhibitors, tautomycin and calyculin A. In contrast, exposure of hepatocytes to 1-nor-okadaone or okadaol, negative analogs of okadaic acid largely devoid of phosphatase inhibitory activity, was without effect on the PB induction process. At similar concentrations, okadaic acid produced only comparatively weak modulation of the ␤-naphthoflavone-inducible CYP1A1 gene expression pathway. In additional experiments, hepatocytes were treated with suboptimal concentrations of PKA activators together with phosphatase inhibitors. Okadaic acid markedly potentiated the repressive effects of dibutyryl-cAMP on the PB induction process. Together, these results indicate that both PKA and protein phosphatase (PP1 and/or PP2A) pathways exert potent and complementary control of the intracellular processes modulating the signaling of PB in cultured primary rat hepatocytes