Intrinsic advantages of Cheilomenes sexmaculata over two coexisting Coccinella species （Coleoptera：Coccinellidae）

Development, survival and reproductive performance of coexisting ladybird species, viz. Cheilomenes sexmaculata, Coccinella septempunctata, and Coccinella transversalis, of the tribe Coccinellini were studied and compared to assess their coexistence and ecological relationships. High values of life history parameters, viz. developmental rate,immature survival, fecundity, egg viability, reproductive rate and conversion of efficiency of ingested food were recorded for C. sexmaculata followed by C. transversalis and C.septempunctata suggesting that the former has intrinsic advantages over the latter two species. This could possibly counterbalance its disadvantages, like relatively smaller size and weight, thereby making it competitive. The developmental period increased with increase in body size. Exceptionally high fecundity after single mating has been recorded in C. sexmaculata. The egg viability, however, was lower than in both Coccinella species.     

Association of interleukin-10 (A1082G) gene polymorphism with oral squamous cell carcinoma in north Indian population

The functional polymorphism A1082G in the gene (IL10) for interleukin-10 associated with risk of oral squamous cell carcinoma (OSCC). The present case–control study was to evaluate the possible association between IL10 A1082G gene and OSCC in north Indian population. Analysis of IL10 A1082G genotype in 232 OSCC cases and 221 healthy controls of comparable age, gender, smokers, tobacco chewing and alcohol consumption. IL10 A1082G status in cases and controls were evaluated by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The frequencies of IL10 A1082G polymorphism AA, AG, GG genotypes were 29.74, 68.10 and 2.15% in OSCC cases and 57.46, 42.08 and 0.45% in healthy controls. The average frequency of G mutant allele was 36.20% in OSCC cases compared with 21.50% among the controls and this allele was associated with increased risk for OSCC cases. Heterozygous AG genotype was found statistically significant in OSCC cases than in controls (OR = 1.6, 95% CI = 1.1–2.2, P = 0.003), whereas homozygous mutant GG genotype was not found significant (OR = 4.7, 95% CI = 0.55–41.1, P = 0.2). Moreover, we found that G allele was significant in OSCC cases of tobacco chewing. The frequency of IL10 A1082G polymorphism G allele and AG genotype is associated with OSCC cases as compared with controls; this may be due to smoking and tobacco chewing. Our findings showed that in IL10 A1082G gene polymorphism AG genotype and G allele may participate in the progression of OSCC.     

Studies on chromatin-associated nuclease from barley leaves

A nuclease associated with the chromatin of barley leaves hasbeen solubilized and purified 20 fold. The purified preparationhydrolyzes native or denatured DNA and RNA, but exhibits nophosphodiesterase or phosphomonoesterase activity. The ratiosof RNase and DNase activities remain essentially constant throughoutall the steps of purification. The two enzyme activities hadpH optimum of 7.0 and showed similar effects of phosphate, Zn++,Mg++ and other metal cations, EDTA, inhibitors, freezing andthawing, heat treatment and precipitation by protamine sulfateand streptomycin sulfate. RNA and DNA were degraded by the enzymein endonucleolytic fashion. (Received January 30, 1971; )     

Induction of Nitrate Reductase and Peroxidase Activity in the Seedlings of Normal and High Lysine Maize

Steady state levels of in vivo nitrate reductase activity in the endosperm, scutella, roots and shoots of maize seedlings were higher in normal maize than those in high lysine maize. Activity of peroxidase in the roots, however, was higher in the high lysine cultivar. The nitrate reductase activity increased with the supply of nitrate in all parts of the seedlings of both cultivars, although the rates of increment in the endosperm were lower than those in scutella, roots and shoots. In relation to substrate concentration, a saturation was achieved at 5 to 10 mM of nitrate except in the endosperm, where activity increased slowly up to 100 mM at least. Final levels of enzyme activity were significantly higher in the scutella of normal than in that of high lysine seedlings. In vitro enzyme activity in the roots also increased with the supply of nitrate in both cultivars, reaching maximum at 5 to 10 mM nitrate.     

Rapid photometric assay of growth of Mycoplasma mycoides subsp. capri

A new spectrophotometric technique for evaluation of early growth in liquid culture of Mycoplasma mycoides subsp. capri has been developed. As turbidity does not appear until after incubation to 18 h the method utilizes the change in absorbance of the medium at 550 nm to monitor growth. The change in absorbance of the medium (which contains phenol red) occurs when the pH changes due to microbial growth. For measurement of growth at later stages when turbidity is proportional to number of colony forming units, two other wavelengths (450 nm and 700 nm) have been suggested.     

Characterization of variation and quantitative trait loci related to terpenoid indole alkaloid yield in a recombinant inbred line mapping population of <Emphasis Type="Italic">Catharanthus roseus</Emphasis>

Improved Catharanthus roseus cultivars are required for high yields of vinblastine, vindoline and catharanthine and/or serpentine and ajmalicine, the pharmaceutical terpenoid indole alkaloids. An approach to derive them is to map QTL for terpenoid indole alkaloids yields, identify DNA markers tightly linked to the QTL and apply marker assisted selection. Towards the end, 197 recombinant inbred lines from a cross were grown over two seasons to characterize variability for seven biomass and 23 terpenoid indole alkaloids content-traits and yield-traits. The recombinant inbred lines were genotyped for 178 DNA markers which formed a framework genetic map of eight linkage groups (LG), spanning 1786.5 cM, with 10.0 cM average intermarker distance. Estimates of correlations between traits allowed selection of seven relatively more important traits for terpenoid indole alkaloids yields. QTL analysis was performed on them using single marker (regression) analysis, simple interval mapping and composite interval mapping procedures. A total of 20 QTL were detected on five of eight LG, 10 for five traits on LG1, five for four traits on LG2, three for one trait on LG3 and one each for different traits on LG three and four. QTL for the same or different traits were found clustered on three LG. Co-location of two QTL for biomass traits was in accord of correlation between them. The QTL were validated for use in marker assisted selection by the recombinant inbred line which transgressively expressed 16 traits contributory to the yield vinblastine, vindoline and catharanthine from leaves and roots that possessed favourable alleles of 13 relevant QTL.     

Prospective role of insecticides of fungal origin: Review

Advances in the application of microbial‐based technology in insect pest management assist us to counter problems created by the application of chemical pesticides. These are mainly strong environmental effects, resistance development and high costs. Among the microbial pesticides, fungal pesticides are now preferred as they are target specific, ecofriendly, lacking in toxic residue and are economical. Being numerous with great diversification, entomopathogenic fungi therefore have great potential to control a large variety of insect pests. Fungi are applied directly in form of spores, mycelia or blastospores or by their metabolites (mycotoxins). Both approaches have very promising roles in insect pest management. However, there are three main obstacles in the development of fungal pesticides: (i) scant production of mycotoxins; (ii) carcinogenic mycotoxicosis in non‐target organisms; and (iii) slow effectiveness. Therefore, to eliminate these problems, attention has recently been paid to a synergistic approach to combating insecticide resistance. Next to synergism, genetic manipulation is also used to enhance the pathogenicity and virulence of fungal insecticides. However, the key risk associated with the release of recombinant microorganisms into the environment is that the novel organism may have unforeseen undesirable characteristics. Therefore, the introduction of synergists in pest control could have great benefit both economically and ecologically. An ideal synergistic approach is the mixing of more than two accelerating components together, i.e. tripartite or multiple synergism to enhance effectiveness. Thus, synergistic approaches have a bright future and require further research and financial support.     

Stream ecosystem responses to spatially variable land cover: an empirically based model for developing riparian restoration strategies

1. The restoration of native, forested riparian habitats is a widely accepted method for improving degraded streams. Little is known, however, about how the width, extent and continuity of forested vegetation along stream networks affect stream ecosystems. 2. To increase the likelihood of achieving restoration goals, restoration practitioners require quantitative tools to guide the development of restoration strategies in different catchment settings. We present an empirically based model that establishes a relationship between a ‘stress’ imposed at different locations along a stream by the spatial pattern of land cover within catchments, and the response of biologically determined ecosystem characteristics to this stress. The model provides a spatially explicit, quantitative framework for predicting the effects of changes in catchment land cover composition and spatial configuration on specific characteristics of stream ecosystems. 3. We used geospatial datasets and biological data for attached algae and benthic macroinvertebrates in streams to estimate model parameters for 40 sites in 33 distinct catchments within the mid‐Atlantic Piedmont region of the eastern U.S. Model parameters were estimated using a genetic optimisation algorithm. R² values for the resulting relationships between catchment land cover and biological characteristics of streams were substantially improved over R² values for spatially aggregated regression models based on whole‐catchment land cover. 4. Using model parameters estimated for the mid‐Atlantic Piedmont, we show how the model can be used to guide restoration planning in a case study of a small catchment. The model predicts the quantitative change in biological characteristics of the stream, such as indices of species diversity and species composition, that would occur with the implementation of a hypothetical restoration project.