Preparation of extracts from tropical plants for· electrophoresis - an analysis of methodology

Electrophoretic analysis of enzymes from tropical plants can be very diffie-ult due to the presence of high concentrations of phenolics in plant tissues. It is believed that these high tannin levels may serve to protect plants from the numerous insect predators present in the tropics. Different methods of extraction of enzymes prior to electrophoresis are suggested. A number of factors which make plant proteins practically unstable and difficult to work with are also mentioned. The occurrence of tannins in plants and the reactions of these phenolic compounds with proteins and enzymes are discussed. Techniques for the extraction of enzymes from tannin-rich plants should involve the removal of phenolic substrates, the inhibition of O-dlfthenol-oxidase activity or the removal of quinones formed from oxidation by reducing the quinones back to the O-dlfthenol. Chemicals added into the extracting medium to overcome the problem of interference by tannins include polymers, copper chelating agents, thiols, ascorbate, metabisulphite, dithionite and b01!ine serum albumin

Genetic variation in the grafted vegetatively propagated mango (Mangijera indica)

The purpose of this project is to study the authenticity of the naming system of the bud grafted mango (Mangifera indica) .. Many type of mango are commonly cultivated, namely, Apple, Malgoa, Harum~anis, Erwin, etc. Regarding the naming system, there are two schools of thought. One suggests that the different types are different' clones'. The other view is that they are different 'varieties'. Since a clone is defined as a group of plants or individuals propagated asexually from a single parent, their isozyme patterns should be uniform or identical. If the isozyme patterns of plants that reputedly belong to the same clone show a high degree of variation between individuals, this would indicate that they are not a true clone. Six'clones' of mango were studied using the electrophoretic technique. The banding patterns of four enzyme systems including esterases, aspartate aminotransferase and acid and alkaline phosphatases were analysed. From the results obtained, it is suggested that the term 'variety', rather than the term'clone' is more appropriate. The results suggested that all the morphologically similar individuals of the same'clone' in fact do not come from the same parent. The present chaotic naming system of mango should be standardised and improved so that it can be used as a basis for plant breeding research

Liver esterase polymorphisms in sepat Siam (Trichogaster pectoralis)

Esterase D and general esterases (which use a- or J3-naphthyl acetate as substrates) were investigated electrophoretically in the paddy field fish, Trichogaster pectoralis. Variants were observed for these enzymes. It is hypothesized that esterase D phenotypes are due to two codominant alleles at an autosomal locus, and that four loci are involved in the control of the general esterases

Hexokinase, Malate Dehydrogenase, Fluorescent Esterase and Malic Enzyme Polymorphisms in the Cocoa Pod Borer, Conopomorpha cramerella (Snellen)

Cocoa pod borers collected in the field from Tawau, Sabah and from Sua Betong, Negeri Sembilan and rambutan fruit borers collected from Puchong and the campus of Universiti Pertanian Malaysia (UPM) in Serdang, Selangor, Malaysia were analysed by polyacrylamide gel electrophoresis. Hexokinase was found to be polymorphic in the UPM population, malate dehydrogenase in the Tawau, Sua Betong and UPM populations and fluorescent esterase and malic enzyme were polymorphic in all four populations

Biochemical polymorphisms in the Malaysian water buffaloes

Ten enzymes and proteins: transferrin, amylase, haemoglobin, esterase D, red cell acid pho.phatau, superoxide dismutase, phosphoglycolate phosphatase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and soluble glutamate oxaloace.tate transaminase, from the serum and red blood cell of 88 water buffaloes, Bubalus bubahs, have been investigated by starch gel or polyacrylamide gel electrophoresis. Four of these: transferrin, amylase, haemoglobin and esterase D show electrophoretic variation at polymorphic proportions

Peptidase Polymorphism in Natural Populations of the Cocoa Pest, Helopeltis theobromae Miller

Helopeltis theobromae caught off cocoa plants in Kuala Selangor and off Acalypha plants in Serdang, Selangor, Malaysia were investigated electrophoretically for nine biochemical markers: peptidase, a -glycerophosphate dehydrogenase, 6-phosphogluconate dehydrogenase, xanthine dehydrogenase, aldehyde oxidase, phosphoglucose isomerase, isocitrate dehydrogenase, glutamate transaminase and adenylate kinase. Only peptidase-2 polymorphism could be easily interpreted

An Electrophoretic Study of Natural Populations of the Cocoa Pod Borer, Canopomorpha cramerella (Snellen) from Malaysia

Cocoa pod borers from Tawau, Sabah and Sua Betong, Negeri Sembilan and rambutan fruit borers from Serdang and Puchong, Selangor and Kuala Kangsar, Perak, Malaysia were subjected to electrophoretic analysis in an effort to find diagnostic electromorphs between these two bio types of Conopomorpha cramerella. Thirty enzymes and general proteins were successfully demonstrated on zymograms but none of them could serve as diagnostic markers between cocoa pod borers and rambutan fruit borers. The allelic frequencies for 8 polymorphic enzymes are presented

Esterase and phosphoglucomutase polymorphism in the rambutan fruit borer, Conopomorpha cramerella (Snellen)

Adult Conopomorpha cramerella collected from rambutan fruit from Serdang, Malaysia were subjected to polyacrylamide gel electrophoresis. Esterase-1, esterase-2 and phosphoglucomutase were found to be polymorphic while NADH dehydrogenase was monophormic. The two esterases and phosphoglucomutase are potentially useful biochemical markers for population genetic studies as each locus had three common alleles in the population analysed

Gc subtyping in Malaysians and in Indonesians from North Sumatra

Malays, Chinese and Indians from peninsular Malaysia; Ibans and Bidayuh from Sarawak state, Northern Borneo; and Bataks, Minangkabau and Javanese from North Sumatra, Indonesia, were subtyped for Gc (group-specific component) by polyacrylamide gel isoelectric focusing. All eight populations investigated were found to be polymorphic for three common alleles, GcIF, GclS and Gc