Showing papers by "Forest Research Institute published in 2009"

Nanocellulose reinforced PVA composite films: Effects of acid treatment and filler loading

Abstract: Nanocellulose was prepared by acid hydrolysis of microcrystalline cellulose (MCC) at different hydrobromic acid (HBr) concentrations. Polyvinyl alcohol (PVA) composite films were prepared by the reinforcement of nanocellulose into a PVA matrix at different filler loading levels and subsequent film casting. Chemical characterization of nanocelluloses was performed for the analysis of crystallinity (Xc), degree of polymerization (DP), and molecular weight (Mw). The mechanical and thermal properties of the nanocellulose reinforced PVA films were also measured for tensile strength and thermogravimetric analysis (TGA). The acid hydrolysis decreased steadily the DP and Mw of MCC. The crystallinity of MCC with 1.5 M and 2.5 M HBr showed a significant increase due to the degradation of amorphous domains in cellulose. Higher crystalline cellulose showed the higher thermal stability than MCC. From X-ray diffraction (XRD) analysis, nanocellulose samples showed the higher peak intensity than MCC cases. Reduction of MCC particle by acid hydrolysis was clearly observed from scanning electron microscope (SEM) images. The tensile and thermal properties of PVA composite films were significantly improved with the increase of the nanocellulose loading.

The influences of forest stand management on biotic and abiotic risks of damage

Abstract: • This article synthesizes and reviews the available information on the effects of forestry practices on the occurrence of biotic and abiotic hazards, as well as on stand susceptibility to these damaging agents, concentrating on mammal herbivores, pest insects, pathogenic fungi, wind and fire. • The management operations examined are site selection, site preparation, stand composition, regeneration method, cleaning and weed control, thinning and pruning, and harvesting. For each of these operations we have examined how they influence the occurrence of biotic and abiotic damaging agents, the susceptibility of European forests, and describe the ecological processes that may explain these influences. • Overall, we find that the silvicultural operations that have the largest influence on both biotic and abiotic risks to European forest stands are closely related to species composition and the structure of the overstorey. Four main processes that drive the causal relationships between stand management and susceptibility have been identified: effect on local microclimate, provision of fuel and resources to biotic and abiotic hazards, enhancement of biological control by natural enemies and changes in individual tree physiology and development. • The review demonstrates an opportunity to develop silvicultural methods that achieve forest management objectives at the same time as minimising biotic and abiotic risks. Mots-cles : sylviculture / peuplement / occurrence / sensibilite /

Host niches and defensive extended phenotypes structure parasitoid wasp communities

Abstract: Oak galls are spectacular extended phenotypes of gallwasp genes in host oak tissues and have evolved complex morphologies that serve, in part, to exclude parasitoid natural enemies. Parasitoids and their insect herbivore hosts have coevolved to produce diverse communities comprising about a third of all animal species. The factors structuring these communities, however, remain poorly understood. An emerging theme in community ecology is the need to consider the effects of host traits, shaped by both natural selection and phylogenetic history, on associated communities of natural enemies. Here we examine the impact of host traits and phylogenetic relatedness on 48 ecologically closed and species-rich communities of parasitoids attacking gall-inducing wasps on oaks. Gallwasps induce the development of spectacular and structurally complex galls whose species- and generation-specific morphologies are the extended phenotypes of gallwasp genes. All the associated natural enemies attack their concealed hosts through gall tissues, and several structural gall traits have been shown to enhance defence against parasitoid attack. Here we explore the significance of these and other host traits in predicting variation in parasitoid community structure across gallwasp species. In particular, we test the “Enemy Hypothesis,” which predicts that galls with similar morphology will exclude similar sets of parasitoids and therefore have similar parasitoid communities. Having controlled for phylogenetic patterning in host traits and communities, we found significant correlations between parasitoid community structure and several gall structural traits (toughness, hairiness, stickiness), supporting the Enemy Hypothesis. Parasitoid community structure was also consistently predicted by components of the hosts' spatiotemporal niche, particularly host oak taxonomy and gall location (e.g., leaf versus bud versus seed). The combined explanatory power of structural and spatiotemporal traits on community structure can be high, reaching 62% in one analysis. The observed patterns derive mainly from partial niche specialisation of highly generalist parasitoids with broad host ranges (>20 hosts), rather than strict separation of enemies with narrower host ranges, and so may contribute to maintenance of the richness of generalist parasitoids in gallwasp communities. Though evolutionary escape from parasitoids might most effectively be achieved via changes in host oak taxon, extreme conservatism in this trait for gallwasps suggests that selection is more likely to have acted on gall morphology and location. Any escape from parasitoids associated with evolutionary shifts in these traits has probably only been transient, however, due to subsequent recruitment of parasitoid species already attacking other host galls with similar trait combinations.

Fumigant antitermitic activity of plant essential oils and components from Ajowan ( Trachyspermum ammi ), Allspice ( Pimenta dioica ), caraway ( Carum carvi ), dill ( Anethum graveolens ), Geranium ( Pelargonium graveolens ), and Litsea ( Litsea cubeba ) oils against Japanese termite ( Reticulitermes speratus Kolbe).

Abstract: Plant essential oils from 26 plant species were tested for their insecticidal activities against the Japanese termite, Reticulitermes speratus Kolbe, using a fumigation bioassay. Responses varied with source, exposure time, and concentration. Among the essential oils tested, strong insecticidal activity was observed with the essential oils of ajowan ( Trachyspermum ammi ), allspice ( Pimenta dioica ), caraway ( Carum carvi ), dill ( Anethum graveolens ), geranium ( Pelargonium graveolens ), and litsea ( Litsea cubeba ). The composition of six essential oils was identified by using gas chromatography-mass spectrometry. The compounds thus identified were tested individually for their insecticidal activities against Japanese termites. Responses varied in a dose-dependent manner for each compound. Phenol compounds exhibited the strongest insecticidal activity among the test compounds; furthermore, alcohol and aldehyde groups were more toxic than hydrocarbons. The essential oils and compounds described herein merit further study as potential fumigants for termite control.

Dispersal and flight behaviour of the spruce bark beetle Ips typographus in relation to sex, size and fat content

Abstract: Experiments and observations were made to study the flight behaviour and dispersal of I. typographus at a hibernation size, inside a forest area and between forest areas, respectively in relation to sex, size and fat content. The following results and conclusions are reached. Ips typographus beetles grown up in standing trees leave the tree to hibernate in the soil. The beetles hibernate in the soil 0–5 m from the tree in which they has grown up. During hibernation the beetles' fat content reduces with about 50% and when the beetles emerge at springtime, they may react directly to pheromones. In one day Ips typographus beetles can disperse over long distances (up to 750 m), and a homogenous distribution of the beetles over the forest area is reached as long as no pheromone sources exist that aggregate the beetles. The beetles are able to disperse over long distances (> 8 km) outside forest areas. The flight intensity of the beetles is positively correlated with temperature; at wind speeds over 1 m sec−1 the beetles fly mostly with the wind, at lower wind speeds they tend to fly against the wind after contact with pheromones. The dispersal and flight behaviour is not affected by the beetle's sex, size or fat content. The adult beetles that re-emerge from a tree to establish a second brood are at average larger than the beetles that remain in the tree; the males have built up a new fat reserve before they re-emerge. It is suggested that the dispersal and flight behaviour of the beetles reduces the effectiveness of mass trapping as a control strategy. It is hypothesized that a decreasing I. typographus population suffer a high mortality caused by predation and parasitism. Zusammenfassung Zerstreuung und Flugverhalten des Fichtenborkenkafers Iyps typographus in Beziehung zu Geschlecht, Grose und Fettgehalt Experimente und Beobachtungen uber das Flugverhalten und die Zerstreuung der Kafer von I. typographus am Uberwinterungsort sowie allgemein innerhalb und auserhalb von Waldern unter Berucksichtigung des Geschlechts, der Grose und des Fettgehalts fuhrten zu folgenden Ergebnissen. Die I. typographus-Kafer, die sich in stehenden Baumen entwickelten, verlassen diese, um im Boden in 0–5 m Entfernung von ihrem Entwicklungsbaum zu uberwintern. Wahrend der Uberwinterung verringert sich ihr Fettgehalt um etwa 50%. Wenn die Kafer im Fruhjahr den Boden verlassen, konnen sie direkt auf Pheromone reagieren. Innerhalb eines Tages konnen die Kafer von I. typographus sich uber ein groseres Areal (bis zu 750 m) zerstreuen. Solange sie nicht von Pheromonen aggregiert werden, ist ihre Verteilung im Wald homogen. Auserhalb des Waldes sind die Kafer imstande, lange Distanzen (uber 8 km) zu fliegen. Die Flugintensitat war mit der Temperatur positiv korreliert. Bei Windgeschwindigkeiten uber 1 m/s flogen die Kafer meist mit dem Wind; bei geringerer Windstarke zeigten sie die Tendenz, nach Rezeption von Pheromonen gegen den Wind zu fliegen. Die Zerstreuung und das Flugverhalten wurden vom Geschlecht, der Grose und dem Fettgehalt des Kafers nicht beeinflust. Die adulten Kafer, die einen Baum verlassen, um eine 2. Brut anzulegen, waren im Mittel groser als solche, die im Baum verblieben. Die Weibchen hatten einen neuen Fettkorper aufgebaut, bevor sie den Stamm verliesen. Es ist anzunehmen, das die Zerstreuung und das Flugverhalten der Kafer die Wirksamkeit des Massenfangs als Bekampfungsmasnahme verringert. Es wird die Hypothese aufgestellt, das eine abnehmende I. typographus-Population eine hohe Mortalitat durch rauberische und parasitische Feinde erleidet.

Influence of Chemical Modification and Filler Loading on Fundamental Properties of Bamboo Fibers Reinforced Polypropylene Composites

Abstract: The effects of chemical modification (silane coupling) and filler loading on the fundamental properties of the bamboo fiber (BF) filled polypropylene (PP) bio-composites were investigated in this study. Mechanical properties of the PP/ BF composites, such as the tensile strength, flexural strength, and impact strength decreased as BF loading increased. However, the tensile modulus, flexural modulus, and water absorption were increased by the increase of the BF loading. The addition of aminopropyltrimethoxysilane (AS) and tetramethoxy orthosilicate (TMOS) after the alkali pretreatment for the BF increased all the tensile, flexural, impact strength, and water desorption of the resultant composites, resulting from the improved adhesion between the BF and PP matrix. This tendency was more obvious with the increase of the BF loading. The melting temperature, melting enthalpy, crystallization enthalpy, and crystallinity were decreased by the increase of BF loading and the AS and TMOS treatments. One the other h...

Measurement of ethanol concentration using solvent extraction and dichromate oxidation and its application to bioethanol production process.

Abstract: A method for measuring the ethanol concentration in a yeast culture broth was developed using both microtubes and a 96-deepwell microplate. The strategy involved first the solvent extraction of ethanol from the yeast culture broth and measurements of the ethanol concentration using the dichromate oxidation method. Particular focus was made on selecting the extraction solvent as well as determining the measurable range of ethanol concentrations using this solvent extraction-dichromate oxidation method. This method was developed as an assay format in 2.0-ml microtubes and 1.2-ml 96-deepwell microplates, and the ethanol concentration in the batch cultures and fed-batch fermentations was measured. Tri-n-butyl phosphate [non-alcoholic solvent, density = 0.9727, solubility in water = 0.028% (w/v)] was used for solvent extraction when measuring the ethanol concentration from the yeast culture broth. The maximum detectable ethanol concentration was 8% (v/v) when 10 g potassium dichromate in 100 ml of 5 M sulfuric acid was used. The concentrations determined from the solvent extraction-dichromate oxidation methods were remarkably similar to those of gas chromatography in which samples were prepared from seven experiments, such as four batch cultures and three fed-batch fermentations.

Comparative transcriptomic characterization of aluminum, sodium chloride, cadmium and copper rhizotoxicities in Arabidopsis thaliana.

Abstract: Background Rhizotoxic ions in problem soils inhibit nutrient and water acquisition by roots, which in turn leads to reduced crop yields. Previous studies on the effects of rhizotoxic ions on root growth and physiological functions suggested that some mechanisms were common to all rhizotoxins, while others were more specific. To understand this complex system, we performed comparative transcriptomic analysis with various rhizotoxic ions, followed by bioinformatics analysis, in the model plant Arabidopsis thaliana.

Multiple serum enzyme analyses in chronic alcoholics.

Abstract: . Multiple serum enzyme analyses in 100 chronic alcoholics with a history of heavy drinking revealed that most serum enzyme activities were increased in some of these patients. Increased serum creatine kinase activity, characteristic of muscle injury, was found in 43 patients. Since cardiac damage could be excluded by other enzyme tests, skeletal muscle damage seems to be common in alcoholic patients. Elevated serum ornithine carbamoyl transferase (OCT), which is specific for liver damage, was found in 56 patients. Serum GOT, commonly used for detection of liver damage, seems in alcoholics to be partly released from skeletal muscles and should thus be replaced by the more specific OCT, for which there is a simple method. In alcoholics the increased serum activity of the intramitochondrial enzyme, glutamate dehydrogenase, suggests a rather severe liver damage in nearly half of the patients. Serum guanine deaminase (guanase) was pathological less often than the other “liver enzymes”. Heavy increased values were encountered often in serum γ-glutamyltranspeptidase but leucine aminopeptidase and alkaline phosphatase were less often elevated.

Combined Ips/Ceratocystis attack on Norway spruce, and defensive mechanisms of the trees1

Abstract: The spruce bark beetle, Ips typographus, infects Norway spruce trees with blue-stain fungi, amongst which several species of Ceratocystis are found. Artificial inoculation of healthy trees with C. polonica caused in several cases increased water stress of the trees, and complete sapwood staining. The defences of spruce against Ips/Ceratocystis attack appear to depend on 1. the output of constitutive resin from severed resin ducts, and 2. accumulation of secondary resin around the attack sites. Our preliminary studies indicate that the amount of both types of resin may vary considerably between trees, as well as from place to place on the same tree. A dose/response experiment based on artificial inoculation of C. polonica indicated that at a certain dose (i.e. number of infections per unit area), the accumulation of secondary resin decreased, and the fungus was able to overcome the host defence. Zusammenfassung Kombinierter Befall von Ips und Ceratocystis an Fichte und Abwehrmechanismen der Baume Der Fichtenborkenkafer Ips typographus infiziert seine Wirtsbaume mit Blauepilzen, insbesondere verschiedene Arten von Ceratocystis. Kunstliche Infektion gesunder Fichten mit C. polonica fuhrte in mehreren Fallen zu einem gestorten Wasserhaushalt der Baume und vollstandiger Verfarbung des Splintholzes. Die Abwehrmechanismen der Fichte gegen Ips/Ceratocystis-Befall beruhen offenbar auf 1. der Menge des Harzaustritts aus verletztem Gewebe und 2. der Anreicherung von Wundharz im Bereich der Befallsstellen. Unsere Vorversuche weisen darauf hin, das die Menge von Primar- und Sekundarharz von Baum zu Baum und auch innerhalb eines Baumes sehr verschieden sein kann. Ein quantitativer Versuch zur kunstlichen Infektion von Fichte mit C. polonica fuhrte ab einer bestimmten Infektionsstarke zur Abnahme der Wundharzproduktion, so das der Pilz den Wirt erfolgreich besiedeln konnte.

Inhibition of the response in Ips typographus to the aggregation pheromone; field evaluation of verbenone and ipsenol

Abstract: Field bioassay showed that the aggregation of the spruce bark beetle, Ips typographus on traps baited with the attractive synthetic pheromone mixture, was significantly reduced by the addition of verbenone and ipsenol, which act as inhibitors. When both components were added the reduction in trap catches was most significant and the proportion of responding male beetles caught was significantly reduced. It is hypothesized that verbenone released by the boring beetles counteracts the effect of the aggregation pheromone and shifts the attack to uninfested bark areas of the three under attack or to neighbouring trees. Also ipsenol inhibits the response to the aggregation pheromone, but an explanation of the actual biological function of ipsenol may rest until the absolute configuation of ipsenol released by I. typographus has been established. Zusammenfassung Hemmung der Reaktion von Ips typographus auf das Aggregationspheromon; Freilandversuche mit Verbenon und Ipsenol Freilandexperimente zeigten, das die Anlockung des Buchdruckers Ips typographus an Fallen, die mit einer synthetischen Pheromonmischung versehen waren, durch Verbenon und Ipsenol, die beide als Hemmstoff wirken, signifikant reduziert wurde. Wenn beide Komponenten zusammenwirkten, war die Verminderung der Fallenfange am starksten. Es wird die Hypothese aufgestellt, das das von den sich einbohrenden Kafern produzierte Verbenon der Aggregationskomponente entgegenwirkt und damit den Kaferanflug auf die noch nicht befallenen Rindenareale des Befallsbaumes oder benachbarter Baume verlagert. Auch Ipsenol wirkt hemmend, doch wird eine Erklarung seiner aktuellen biologischen Funktion zuruckgestellt, bis seine Rolle im Pheromonspektrum von Ips typographus voll erkannt ist.

Ips/Ceratocystis-infection of Norway spruce: what is a deadly dosage?1

Abstract: At a certain point in time during a bark beetle aggregation on a host tree a deadly number of attacks is reached, provided suitable swarming conditions and beetle abundance. This “threshold of successful attack” was studied in Norway spruce using: 1. pheromone-elicited attacks by Ips typographus, and 2. artificial inoculations of the blue-stain fungus Ceratocystis polonica. The experiments showed that 150–200 beetle attacks or fungal inoculations to trees of 20 cm DBH caused considerable blue-staining of the sapwood, leading to a high tree mortality. The results are discussed in relation to tree and stand characteristics, and to climatic conditions. Zusammenfassung Ips/Ceratocystis-Befall bei Fichte: Zahl der erfolgreichen Angriffe Zu einem bestimmten Zeitpunkt der Borkenkafer-Aggregation in einem Wirtsbaum wird eine todliche Zahl von Angriffen erreicht, geeignete Schwarmbedingungen und Kafer-Abundanz vorausgesetzt. Diese ”Grenze erfolgreicher Angriffe„ wurde bei der Fichte, Picea abies, in folgender Hinsicht untersucht: 1. durch Pheromone bewirkte Angriffe durch Ips typographus und 2. kunstliche Impfung des Blauepilzes Ceratocystis polonica. Die Experimente zeigten, das 150–200 Kaferangriffe oder Pilzimpfungen bei Baumen mit 20 cm BHD eine betrachtliche Verpilzung des Splintholzes verursachten, was eine hohe Mortalitat der Baume zur Folge hatte. Die Ergebnisse werden in Beziehung zu Baum, Standort und Klima erortert.

A review of growth and stand dynamics of Acer pseudoplatanus L. in Europe: implications for silviculture

Abstract: 1 Sycamore (Acer pseudoplatanus L.) is a widespread but minor species throughout Europe but 2 there is a growing interest in using it more widely because of its potentially high economic 3 and ecological values. Silvicultural recommendations for exploiting the potential of the 4 species to the full should aim at producing high quality timber on short rotations. This can be 5 achieved in a number of ways including the creation of mixed-species and structurally diverse 6 stands that will simultaneously increase ecological values. This review synthesises existing 7 knowledge on growth and development of sycamore that may be used as a basis for 8 developing silvicultural recommendations. Sycamore regenerates easily, although competing 9 ground vegetation, damage by browsers and bark stripping by grey squirrels may endanger 10 production of valuable timber. Existing yield models show that sycamore grows rapidly for 11 the first 20-25 years and then slows considerably. Because of its relative scarcity, there has 12 been limited interest in the species for growth model development and this has restricted its 13 inclusion in forest growth simulators. This review shows that there is currently a lack of 14 detailed knowledge about the responses of sycamore to various environmental, ecological and 15 silvicultural factors and this hinders the understanding and management of this valuable 16 broadleaved tree. 17

Host tree and bark beetle interaction during a mass outbreak of Ips typographus in Norway1

Abstract: Outbreaks of the spruce bark beetle Ips typographus have caused great damage to the forest of Norway during the recent decade. About 5 million cubic meter of timber have been attacked. The outbreaks were initiated by extensive storm damages in 1969 and extreme drought during the years 1975–77. The most extensive damage occurred in regions with large continuous areas of spruce, on areas of high and medium site class and on geological formations with poor groundwater-retaining properties and thin soil. Reemergence and establishment of sister generations was an important part of the beetles repruduction biology. Brood density is regulated to reduce the degree of overpopulation, thereby preventing the collapse of the population due to food shortage. No correlation could be found between killed trees and occurrence of butt rot. None of 15 different criteria for tree growth and vitality could be used to distinguish between trees that were killed and those which survived attack. It is supposed that the decline in beetle population was a combined effect of cool and wet summer weather, which limited the flight activity of the beetle and restored the resistance of the trees to beetle attack, and an extensive control program where mass trapping of beetles in response to synthetic pheromone was an important part. Zusammenfassung Wechselwirkungen zwischen Wirtsbaum und Borkenkafern wahrend einer Massenvermehrung von Ips typographus in Norwegen Im vergangenen Jahrzehnt verursachte der Fichtenborkenkafer Ips typographus in den Waldern Norwegens ca. 5 Mio. m3 Schadholzanfall. Die Massenvermehrungen wurden durch umfangreiche Sturmschaden (1969) und ausergewohnliche Trockenheit (1975–1977) ausgelost. Am starksten betroffen waren Gebiete mit ausgedehnten Fichtenbestanden guter bis mittlerer Standortsklassen auf flachgrundigen Boden mit geringer Wasserspeicherkapazitat. Fur den Verlauf der Massenvermehrungen spielte die Anlage von Geschwisterbruten eine grose Rolle. Die Brutproduktion war verringert, um die Massenvermehrung zu begrenzen und einen Zusammenbruch durch Nahrungsmangel zu vermeiden. Fur die Absterberate der Fichten infolge Ips-Befall konnte kein Zusammenhang mit Rotfauleschaden festgestellt werden. Nach Kaferbefall abgestorbene Fichten bzw. solche, die sich wieder erholt hatten, konnten auch mit 15 weiteren Merkmalen fur Wuchsigkeit und Vitalitat nicht unterschieden werden. Es wird angenommen, das der Ruckgang der Kaferpopulation im wesentlichen durch zwei Faktoren bewirkt wurde: das kuhle und niederschlagsreiche Sommerwetter, welches die Flugaktivitat der Kafer einschrankte und die Widerstandskraft der Baume wieder herstellte sowie ein umfangreiches Bekampfungsprogramm, in dem Massenfang der Kafer mit synthetischen Lockstoffen eine wichtige Rolle spielte.

An emerging role of mast cells in cerebral ischemia and hemorrhage.

Abstract: Mast cells (MCs) are perivascularly located resident cells of hematopoietic origin, recognized as effectors in inflammation and immunity. Their subendothelial location at the boundary between the intravascular and extravascular milieus, and their ability to rapidly respond to blood- and tissue-borne stimuli via release of potent vasodilatatory, proteolytic, fibrinolytic, and proinflammatory mediators, render MCs with a unique status to act in the first-line defense in various pathologies. We review experimental evidence suggesting a role for MCs in the pathophysiology of brain ischemia and hemorrhage. In new-born rats, MCs contributed to brain damage in hypoxic-ischemic insults. In experimental cerebral ischemia/reperfusion, MCs regulated permeability of the blood-brain barrier, brain edema formation, and the intensity of local neutrophil infiltration. MCs were reported to play a role in the tissue plasminogen activator-mediated cerebral hemorrhages after experimental ischemic stroke, and to be involved i...

Effects of formaldehyde/urea mole ratio and melamine content on the hydrolytic stability of cured urea-melamine-formaldehyde resin

Abstract: The influence of formaldehyde/urea (F/U) mole ratio and melamine content on the hydrolytic stability of urea-melamine-formaldehyde (UMF) resin was investigated. The hydrolytic stability of cured UMF resin was determined by measuring the mass loss and the liberated formaldehyde concentration after acid hydrolysis. A higher F/U mole ratio and greater melamine content of UMF resins resulted in lower hydrolytic stability. These results indicated that higher F/U mole ratio and greater melamine content resulted in more branched network structure, which subsequently increases the susceptibility of cured UMF resin toward acid hydrolysis.

Regulation of resin acid synthesis in Pinus densiflora by differential transcription of genes encoding multiple 1-deoxy-d-xylulose 5-phosphate synthase and 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase genes

Abstract: Pinus densiflora Siebold et Zucc. is the major green canopy species in the mountainous area of Korea. To assess the response of resin acid biosynthetic genes to mechanical and chemical stimuli, we cloned cDNAs of genes encoding enzymes involved in the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway (1-deoxy-d-xylulose 5-phosphate synthase (PdDXS), 1-deoxy-d-xylulose 5-phosphate reductoisomerase (PdDXR) and 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (PdHDR)) by the rapid amplification of cDNA ends (RACE) technique. In addition, we cloned the gene encoding abietadiene synthase (PdABS) as a marker for the site of pine resin biosynthesis. PdHDR and PdDXS occurred as two gene families. In the phylogenetic trees, PdDXSs, PdDXR and PdHDRs each formed a separate clade from their respective angiosperm homologs. PdDXS2, PdHDR2 and PdDXR were most actively transcribed in stem wood, whereas PdABS was specifically transcribed. The abundance of PdDXS2 transcripts in wood in the resting state was generally 50-fold higher than the abundance of PdDXS1 transcripts, and PdHDR2 transcripts were more abundant by an order of magnitude in wood than in other tissues, with the ratio of PdHDR2 to PdHDR1 transcripts in wood being about 1. Application of 1 mM methyl jasmonate (MeJA) selectively enhanced the transcript levels of PdDXS2 and PdHDR2 in wood. The ratios of PdDXS2 to PdDXS1 and PdHDR2 to PdHDR1 reached 900 and 20, respectively, on the second day after MeJA treatment, whereas the transcript level of PdABS increased twofold by 3 days after MeJA treatment. Wounding of the stem differentially enhanced the transcript ratios of PdDXS2 to PdDXS1 and PdHDR2 to PdHDR1 to 300 and 70, respectively. The increase in the transcript levels of the MEP pathway genes in response to wounding was accompanied by two orders of magnitude increase in PdABS transcripts. These observations indicated that resin acid biosynthesis activity, represented by PdABS transcription, was correlated with the selective transcriptions of PdDXS2 and PdHDR2. Introduction of PdDXS2, PdHDR1 and PdHDR2 rescued their respective knockout Escherichia coli mutants, confirming that at least these three genes were functionally active. Intracellular targeting of the green fluorescent protein fused to the N-terminal 100 amino acid residues of these genes in the Arabidopsis transient expression system showed that the proteins were all targeted to the chloroplasts. Our results suggest that the MEP pathway regulates resin biosynthesis in the wood of P. densiflora by differential transcription of the multiple PdDXS and PdHDR genes.

A Comparative Analysis of ISSR and RAPD Markers for Study of Genetic Diversity in Shisham (Dalbergia sissoo)

Abstract: Shisham (Dalbergia sissoo) is one of the most preferred timber tree species of South Asia. Two DNA-based molecular marker techniques, intersimple sequence repeat (ISSR) and random amplified polymorphism DNA (RAPD), were compared to study the genetic diversity in this species. A total of 30 polymorphic primers (15 ISSR and 15 random) were used. Amplification of genomic DNA of 22 genotypes, using ISSR analysis, yielded 117 fragments, of which 64 were polymorphic. Number of amplified fragments with ISSR primers ranged from five to ten and varied in size from 180 to 1,900 bp. Percentage polymorphism ranged from 0 to 87.5. The 15 RAPD primers produced 144 bands across 22 genotypes, of which 84 were polymorphic. The number of amplified bands varied from five to 13, with size range from 180 to 2,400 bp. Percentage polymorphism ranged from 0 to 100, with an average of 58.3 across. RAPD markers were relatively more efficient than the ISSR assay. The mental test between two Jaccard’s similarity matrices gave r ≥ 0.90, showing very good fit correlation in between ISSR- and RAPD-based similarities. Clustering of isolates remained more or less the same in RAPD and combined data of RAPD and ISSR. The similarity coefficient ranged from 0.734 to 0.939, 0.563 to 0.946, and 0.648 to 0.920 with ISSR, RAPD, and combined dendrogram, respectively.