Monomorphism of isoenzyme loci in natural and cultivated amaranth (Amaranthus L.) populations

Starch gel electrophoresis was used for isozyme analysis of ADH, GDH, MDH, IDH, and ME in populations of amaranth. Experiments were performed with 93 populations and 4 cultivars. Some populations proved to be polymorphic, and this fact allowed analysis of the genetic control of the enzymes listed. The populations examined showed poor allozyme variability. Monomorphism for all loci studied was observed in 73 populations and 4 varieties. Starch gel electrophoresis was used for isozyme analysis ofADH, GDH, MDH, IDH, and ME in populations of amaranth. Experiments were performed with 93 populations and 4 cultivars. Some populations proved to be polymorphic, and this fact allowed analysis of the genetic control of the enzymes listed. The populations examined showed poor allozyme variability. Monomorphism for all loci studied was observed in 73 populations and 4 varieties. Only some populations demonstrated rare polymorphism for a single locus each: Adh, Mdh 2, Gdh, Idh 1, Idh 2, or Mod 2. The results demonstrate genetic monomorphism of amaranth for the studied loci.     

Estimation of the genetic variability of an amaranth collection (Amaranthus L.) by RAPD analysis

The genetic variability of an amaranth collection was studied by RAPD analysis. A high level of polymorphism of the studied samples was detected. It was about 85% on average. Unique fragments characteristic of only definite accessions and 18 monomorphic loci proper for all amaranth accessions were detected using several primers. The genetic distances of Nei and Li were calculated. This index varied from 0.0009 to 0.0141. A cluster analysis was carried out. The amaranth accessions were classified into two clusters according to the species affiliation.     

In vitro culture of lavenders (Lavandula spp.) and the production of secondary metabolites

Lavenders (Lavandula spp., Lamiaceae) are aromatic ornamental plants that are used widely in the food, perfume and pharmaceutical industries. The large-scale production of lavenders requires efficient in vitro propagation techniques to avoid the overexploitation of natural populations and to allow the application of biotechnology-based approaches for plant improvement and the production of valuable secondary metabolites. In this review we discuss micropropagation methods that have been developed in several lavender species, mainly based on meristem proliferation and organogenesis. Specific requirements during stages of micropropagation (establishment, shoot multiplication, root induction and acclimatization) and requisites for plant regeneration trough organogenesis, as an important step for the implementation of plant improvement programs, were revised. We also discuss different methods for the in vitro production of valuable secondary metabolites, focusing on the prospects for highly scalable cultures to meet the market demand for lavender-derived products.     

Primary structure and specificity of the major serine proteinase inhibitor of amaranth (Amaranthus caudatus L.) seeds

A novel of the potato inhibitor I family of serine proteinase inactivating proteins has been isolated from seeds of grain amaranth (Amaranthus caudatus L.) and characterized. The mature form of the amaranth trypsin/subtilisin inhibitor (ATSI) with pI ≈ 8.3 and molecular mass 7887 Da contains 69 amino acids in a sequence showing 33–51% identity with members of the inhibitor I family from other plant families. A minor form with pI ≈ 7.8 and same inhibitory properties lacked the N-terminal dipeptide Ala-Arg. In accordance with the reactive-site bond Lys⁴⁵-Asp⁴⁶, which was identified by specific cleavage on a subtilisin column, ATSI is a potent inhibitor of trypsin (K_i ≈ 0.34 nM) and more weakly of plasmin (K_i ≈ 38 nM) and Factor XII_a (K_i ≈ 440 nM). However, ATSI also inactivates chymotrypsin (K_i ≈ 0.41 nM), cathepsin G (K_i ≈ 122 nM) and several alkaline microbial proteinases, including subtilisin NOVO (K_i ≈ 0.37 nM). Interestingly, ATSI contains a Trp residue instead of the highly conserved Arg in position 53 (P′_B), which is assumed to play a central role in stabilization of the active-site loop during complex formation. ATSI was immediately inactivated by peptsin and hardly represents an antinutritional component in foods or feeds.     

Species differences in courtship acoustic signals among five Lake Malawi cichlid species (Pseudotropheus spp.)

Male courtship acoustic signals from five Lake Malawi cichlid fish species of the Pseudotropheus zebra complex were recorded and compared. Sounds made by males of P. zebra , Pseudotropheus callainos and the undescribed species known as Pseudotropheus 'zebra gold' from Nkhata Bay, and Pseudotropheus emmiltos and Pseudotropheus faizilberi from Mphanga Rocks, differed significantly in the number of pulses and in pulse period. The largest differences in acoustic variables were found among the sympatric Mphanga Rocks species that, in contrast to the other three species, show relatively minor differences in male colour and pattern. These findings suggest that interspecific mate recognition is mediated by multimodal signals and that the mass of different sensory channels varies among sympatric species groups. This study also showed that sound peak frequency was significantly negatively correlated with male size and that sound production rate increased significantly with courtship rate.     

Evaluation of responses of five cowpea (Vigna unguiculata (L.) Walp.) varieties to field infestation by major insect pests of cowpea

The study was conducted to evaluate yield response of five cowpea (Vigna unguiculata (L.) Walp.) varieties to field infestation and damage by major insect pests of cowpea. Three local varieties of cowpea, namely, Sokoto, Oloyin and Drum, and two International Institute of Tropical Agriculture (IITA) varieties, IT 90K-277-2 and IT90K-76, were planted on the Teaching and Research Farm of University of Agriculture, Abeokuta (UNAAB), Ogun State, Nigeria in September, 2006 and repeated in September, 2007. The experiment was laid out in Randomised Complete Block Design in split plots arrangement. Insecticidal spray constitutes the main plot while variety was the sub-plot. The main plot size was 19.4 m × 19 m and each of the sub-plot was 2.4 m × 3 m. The space between sub-plots was 1 m. Data from the sprayed plots were significantly (P < 0.05) higher than the unsprayed ones in the two seasons. Irrespective of season, the unsprayed plot of IT 90K-277-2 has a significantly (P < 0.05) high incidence of Ootheca mutabilis. The local variety, “Drum” has the highest incidence of flower thrip – Megalurothrips sjostedti in the two planting seasons. The highest mean number of peduncles/plant and pods/plant was in “IT 90K-277-2”. In both seasons, “IT90K-76” has a significantly (P < 0.05) lower number of damaged seeds and pods and “Oloyin” a significantly (P < 0.05) higher mean number of total pod sucking bugs. The grain yield was in the order IT90K-76 > Oloyin > IT 90K-277-2 > Sokoto > Drum.     

Genetic variation in outcrossing rate and correlated floral traits in a population of grain amaranth (Amaranthus cruentus L.)

The genetic control of breeding system in a population of grain amaranth is described here by the estimates of outcrossing rate variation among individuals and their response to mass selection. In the first generation (S₀), a single morphological marker locus(R/r) controlling plant pigmentation was used for the estimation of outcrossing rate. A mixture of genotypes RR (red) and rr (green) mixed in equal proportions was grown and all rr plants were progeny-tested for estimating the outcrossing rate (t), using the relationship t=H/p, where H = proportion of heterozygotes (Rr) in the progeny, and p = frequency of alleleR. A full range (0 to 100%) of outcrossing rates was found in the first generation, % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabeiDayaara% Gaeyypa0JaaGimaiaac6cacaaIZaGaaGymaiaacYcacqGHGaaicqGH% GaaicuaHdpWCgaqcamaaBaaaleaacaqG0baabeaakiabg2da9iaaic% dacaGGUaGaaGOmaiaaiwdaaaa!441B!\[{\text{\bar t}} = 0.31, \hat \sigma _{\text{t}} = 0.25\], and the distribution was significantly skewed toward high outcrossing.A bidirectional mass selection experiment was initiated for high and low outcrossing rates. In the Hi and Lo lines (Generation S₁), the rate of outcrossing was estimated using the R locus in addition to two other completely dominant morphological markers(B, G1). Relative sex ratios in the monoecious inflorescences of selected lines were estimated by the number of male flowers per glomerule. Outcrossing rate was significantly different between the Hi and Lo lines, and Lo line exhibited much higher male fertility than the Hi line. Such a response to selection indicated a polygenic control of sex expression, and consequently, of the potential for outcrossing in this population. In the second generation (S₂), selection was based on the number of male flowers/glomerule as an index of outcrossing ability. Differences in sex expression between the Hi and Lo lines in S₂ generation had 1.0 male flower/glomerule, while the Hi selection individuals had more or less rectangular distribution from 0.1 to 1.0 male flowers/glomerule.Thus, breeding system in amaranth, as represented by the sex ratios within glomerules and the outcrossing rate parameters, responded to bidirectional selection. Such a genetic component of variation in breeding system has significant implications in the evolution of amaranth species and landraces under domestication.     

Seasonal population dynamics of dusky cotton bug (Oxycarenus spp.) in transgenic cotton varieties under field conditions

Dusky cotton bug (Oxycarenus spp.) has become a major insect pest for cotton crop in Pakistan. Transgenic cotton varieties provided resistance to a variety of insects pests. But, these are not safe for this emerging potential threat. In present study, nine transgenic cotton varieties (IUB-222, MNH-886, FH-142, CIM-599, A-555, CIM-602, NIAB-777, MNH-786 and Bt-666) were assessed for seasonal population dynamics of dusky cotton bug (DCB) under field conditions. All transgenic varieties showed a differential DCB population over the months and no transgenic variety was free from DCB population throughout the crop duration. DCB population appeared during 3rd week of July and crossed the economic threshold level (10–15 nymph/ adults or both per plant) during August. A substantial increase in DCB population was noted during September-November with its peak population during October, 2014. Among all varieties, three varieties (CIM-599, CIM-602 & IUB-222) showed a significantly lower mean population per plant (37.76, 37.87, 43.84) and two varieties (FH-142, MNH-886) gave highest population (44.71, 46.81), respectively. Correlation matrix revealed that low temperature and high humidity were promoting the DCB population. Cluster analysis revealed interesting findings that IUB-222 with least population fall in a cluster where other two varieties (FH-142 & MNH-886) possessed highest population. Moreover, two varieties (CIM-599 & CIM-602) with least population fall in second cluster regarding DCB population. These findings would be helpful for the farmers to select the varieties that showed relatively higher resistance towards DCB population and to adopt proper management strategies keeping in view the trend of DCB population during the crop season.     

Susceptibility of willow clones (Salix spp.) to herbivory by Phyllodecta vulgatissima (L.) and Galerucella lineola (Fab.) (Coleoptera, Chrysomelidae)

Levels of damage by mixed natural infestations of the leaf-feeding chrysomelid beetles, Phyllodecta vulgatissima (L.) (the blue willow beetle) and Galerucella lineola (Fab.) (the brown willow beetle), were determined in replicated field plots of 24 Salix clones at Long Ashton (Bristol, UK) during 1993–94. Over the same period, the host plant preferences of both chrysomelids were investigated in a standard multiple-choice laboratory procedure, where beetles were enclosed in Petri dishes with leaf discs cut from young pot-grown trees propagated from shoot cuttings taken from 20 of the 24 willow clones represented in the field study. The laboratory experiments indicated that P. vulgatissima and G. lineola had similar host plant preferences in the range of willows examined (r >0.85). In both field and laboratory, the least preferred Salix clones and hybrids were those of 5. eriocephala, followed by S. purpurea, S. burjatica, S. dasyclados and S. triandra. Clones of S. eriocephala and S. purpurea were frequently rejected altogether in laboratory tests. Most preferred were clones of S. viminalis and several hybrids of S. viminalis, S. aurita, S. caprea and S. cinerea. These results substantiate the reports that P. vulgatissima and G. lineola are deterred from feeding on willows which have relatively high concentrations of phenolic (salicylate) glucosides in the leaves. The least preferred willows, particularly S. eriocephala, S. purpurea and S. burjatica, could be of great potential value in plant breeding for resistance to these willow beetle pests.     

Oat (Avena sativa L.) and amaranth (Amaranthus hypochondriacus) meals positively affect plasma lipid profile in rats fed cholesterol-containing diets

Cereals are an important part of diets for hypercholesterolemic patients. However, some of these patients are allergic to these natural products. The purpose of the current study was to compare oatmeal with equal in nutritional values two allergy-free amaranth meals to determine whether this pseudocereal can be a substitute for allergic to cereals individuals. The total phenols of the samples were determined with the Folin-Chocalteu reagent, anthocyanins, and flavonoids spectrophotometrically. The antioxidant activities were estimated with nitric oxide scavenging radical (NO) and by beta-carotene bleaching (beta-carotene). It was found that the contents of different protein fractions, antioxidant compounds, and the antioxidant activities of oatmeal were significantly higher than those of the two amaranth samples. The results of kinetic reactions showed that samples differed in their capacities to quench these radicals, and oats have shown more antioxidant activity than amaranth. High correlation was observed between antioxidant activities and phenols (R(2) = 0.99). In the in vivo part of the investigation, 60 male Wistar rats were divided into five diet groups of 12 animals each; these groups were designated as Control, Chol, Chol/Oat, Chol/AmarI, and Chol/AmarII. The rats of the Control group were fed basal diet (BD) only. To the BD of the four other groups were added the following: 1% of cholesterol (Chol), 10% of oat meal and 1% of cholesterol (Chol/Oat), 10% of amaranth I meal, and 1% of cholesterol (Chol/AmarI) and 10% of amaranth II meal and 1% of cholesterol (Chol/AmarII). After 32 days of different feeding, diets supplemented with oat meal and, to lesser degree, with amaranth I and amaranth II hindered the rise in the plasma lipids: a) TC: 3.14 vs. 4.57 mmol/L, - 31.3%; 3.31 vs. 4.57 mmol/L - 27.6%; and 3.40 vs. 4.57, - 25.6%, respectively b) LDL-C: 1.69 vs. 3.31 mmol/L, - 49.9%; 2.05 vs. 3.31 mmol/L, - 38.1%; and 2.16 vs. 3.31 mmol/L, - 34.8%, respectively; c) TG: 0.73 vs. 0.88 mmol/L, - 17.1%; 0.75 vs. 0.88 mmol/L, - 14.8%; and 0.79 vs. 0.88 mmol/L, -10.2%, respectively. The HDL-PH was increased as follows: 0.79 vs. 0.63 mmol/L, -25.3%; 0.75 vs. 0.63 mmol/L, -23.0%; and 0.71 vs. 0.63 mmol/L, -12.7% for the Chol/Oat, Chol/AmarI and Chol/AmarII, respectively. No significant changes in the concentrations of HDL-C and TPH were found; however the HDL-C in the Chol/Oat group was slightly higher than in other groups. No changes in the Control group were registered. In conclusion, oat and amaranth meals positively affect plasma lipid profile in rats fed cholesterol-containing diets. The degree of this positive influence is directly connected to the contents of the bioactive components and the antioxidant activities of the studied samples. It is suggested that amaranth could be a valuable substitute for hypercholesterolemic patients allergic to cereals.     

Needle nematodes (Longidorus spp.) and stubby-root nematodes (Trichodorus spp.) harmful to sugar beet and other field crops in England

Longidorus attenuatus produces galls at the tips of roots of field crops, including sugar beet, growing in alkaline, sandy soils in eastern England. L. elongatus produces similar, but often larger, galls on the roots of sugar beet and other crops in sandy soils in the W. Midlands and in Fen peats. Trichodorus spp. cause ‘stubby root’ of sugar beet and can feed on many field crops. Seven species of Trichodorus were found in sandy soils in eastern England. L. attenuatus, L. elongatus and Trichodorus spp. aggregate around roots and stunt sugar beet and other crop plants. L. attenuatus is commoner below plough depth than in the topsoil, whereas T. cylindricus, T. pachy-dermus and T. anemones are more abundant in the topsoil. These nematodes cause some forms of ‘Docking disorder’.     

Physiological and behavioral variation in estivation among mud turtles (Kinosternon spp.)

Kinosternid mud turtles, a primarily aquatic group, exhibit variable degrees of terrestrial activity in the Sonoran and Chihuahuan Deserts. We compared behavioral and physiological responses to dry conditions in four populations representing three species, Kinosternon sonoriense, Kinosternon flavescens, and Kinosternon hirtipes. All four groups were subjected to simulated dry season conditions in the laboratory, during which activity was monitored and physiological responses (blood chemistry and rates of resting metabolism and evaporative water loss) were measured. Kinosternon flavescens and K. hirtipes represented extremes in apparent ability to estivate, based on activity and rate of increase of plasma osmolality. Two populations of K. sonoriense exhibited intraspecific differences in behavioral and physiological measures that were related to extant environmental conditions. Large numbers of K. sonoriense from Arizona and K. hirtipes, the poorest estivators, had to be rehydrated after only 30 d out of water. Kinosteron flavescens had the lowest metabolic rates, but no evidence of metabolic depression during dehydration was found for any of the four populations. We conclude that the differences in capacity for estivation among populations are primarily linked to variable behavioral responses to dry conditions, though high rates of evaporative water loss in K. hirtipes represent a probable physiological constraint.     

Rapid identification of cyst (Heterodera spp., Globodera spp.) and root-knot (Meloidogyne spp.) nematodes on the basis of ITS2 sequence variation detected by PCR-single-strand conformational polymorphism (PCR-SSCP) in cultures and field samples

Cyst and root-knot nematodes show high levels of gross morphological similarity. This presents difficulties for the study of their ecology in natural ecosystems. In this study, cyst and root-knot nematode species, as well as some ectoparasitic nematode species, were identified using the second internal transcribed spacer (ITS2) sequence variation detected by polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP). The ITS2 region was sufficiently variable within the taxa investigated to allow species to be separated on the basis of minor sequence variation. The PCR primers used in this study were effective for 12 species with three genera within the Heteroderinae (Globodera pallida, G. rostochiensis, Heterodera arenaria/avenae, H. ciceri, H. daverti, H. hordecalis, H. mani, H. schachtii, H. trifolii, Meloidogyne ardenensis, M. duytsi and M. maritima). However, pathotypes of Globodera pallida and G. rostochiensis could not be distinguished. The method was tested at two coastal dune locations in The Netherlands (one in the lime-poor dunes of the north and one in calcareous dunes of the south) to determine the population structure of cyst nematodes. At each site, cyst nematodes were associated with three plant species: two plant species on the foredune (Elymus farctus and Ammophila arenaria) and one plant species occurring further inland (Calamagrostis epigejos). Two species of cyst nematodes, H. arenaria and H. hordecalis, were found. H. arenaria associated with vigorous A. arenaria and H. hordecalis in association with degenerating A. arenaria and C. epigejos. The field survey demonstrated that in coastal dunes abiotic factors may be the important affecting the distribution of cyst nematodes.     

Socially flexible female choice and premating isolation in field crickets (Teleogryllus spp.)

Social influences on mate choice are predicted to influence evolutionary divergence of closely related taxa, because of the key role mate choice plays in reproductive isolation. However, it is unclear whether females choosing between heterospecific and conspecific male signals use previously experienced social information in the same manner or to the same extent that they do when discriminating among conspecific mates only. We tested this using two field cricket sister species (Teleogryllus oceanicus and Teleogryllus commodus), in which considerable information is known about the role of male calling song in premating isolation, in addition to the influence of acoustic experience on the development of reproductive traits. We manipulated the acoustic experience of replicate populations of both species and found, unexpectedly, that experience of male calling song during rearing did not change how accurate females were in choosing a conspecific over a heterospecific male song during playback trials. However, females with acoustic experience were considerably less responsive to male song compared with naïve females. Our results suggest that variation in the acoustic environment affects mate choice in both species, but that it may have a limited impact on premating isolation. The fact that social flexibility during interspecific mate discrimination does not appear to operate identically to that which occurs during conspecific mate discrimination highlights the importance of considering the context in which animals exercise socially flexible mating behaviours. We suggest an explanation for why social flexibility might be context dependent and discuss the consequences of such flexibility for the evolution of reproductive isolation.     

红曲菌次生代谢产物生物合成途径及相关基因的研究进展

红曲菌(Monascus spp.)是我国重要的药食两用微生物资源之一,能够产生天然食品添加剂红曲色素、降血酯活性物质Monacolin K等有益次生代谢产物,但也能分泌真菌毒素桔霉素(Citrinin),红曲菌及其相关产品的安全性由此受到质疑.因此,如何促进红曲菌有益代谢产物的产生,减少或抑制桔霉素的产生成为广大科研工作者研究的重点方向.近年来,红曲菌的分子生物学研究有了较快的发展,红曲菌次生代谢产物生物合成及其调控的研究是热点.本文重点介绍红曲色素、Monacolin K和桔霉素生物合成途径及相关基因的研究进展,以期为有效调控红曲菌次生代谢产物的产生、提高红曲产品的安全性提供参考和借鉴.     

Inter-population variability of secondary metabolites in Hypericum spp. (Hypericaceae) of the Northern Apennines, Italy

Hypericum spp. flowers were collected from different sites of Northern Apennines in Italy and were analysed by HPTLC technique to determine their contents in flavonoids (rutin, hyperosid, quercitrin, isoquercitrin and quercetin) and hypericins (pseudohypericin and hypericin). The H. perforatum and H. richeri composition was evaluated in order to investigate the influence of ecological conditions on secondary metabolites production. The species studied showed some differences in the amounts of investigated metabolites and high variability was observed in populations gathered in different places. No significant effects of environmental factors on active compound production were observed, except for the rutin content which is in positive correlation with the altitude of the growing site. Interesting informations are also given about the morphology of secretory structures found in Hypericum richeri.