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Summary
Helicotylenchus scoticus n. sp. is described. It was found at an altitude of 660 m on the north-west slope of Sgurr Cos na Breachd-laoidh, Scotland,
in a rough grassland consisting predominantly of tufted hair grass (Deschampsia caespitosa). This species is characterized by a relatively long spear and an oesophagus which superficially appears to abut on to the
intestine with virtually no overlap. The number of nominal species in the genus Helicotylenchus has increased considerably over recent years and stands now at 154 species. The task of identifying species in this genus
using dichotomous keys has become increasingly more difficult. As a practical alternative a compendium is given which uses
nine of the most diagnostic characters. 相似文献
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M. Shamim Jairajpuri 《Systematic parasitology》1984,6(2):107-112
Summary A new genusDivittus is proposed in the subfamily Tylenchorhynchinae Eliava, 1964 with only three incisures in the non-areolated lateral fields and the body cuticle without longitudinal ridges or lamellae. It is also proposed to restrictTrilineellus Lewis & Golden, 1981 to its type species only, i.e.,T. clathrocutis which has three incisures in the lateral fields and longitudinal ridges or lamellae on the body, andTylenchorhynchus to species which have four incisures in the lateral fields but no ridges or lammellae.T. divittatus Siddiqi, 1961,T. triglyphus Seinhorst, 1963 andT. sculptus Seinhorst, 1963 which were transferred toTrilineellus by Lewis & Golden (1981) are now included inDivittus with the following species ofTylenchorhynchus which have three incisures in the lateral fields:T. obscurisulcatus Andrássy, 1959,T. chonai Sethi & Swarup, 1968,T. madrasensis Gupta & Uma, 1981 andT. pruni Gupta & Uma, 1981. The synonymy ofT. chonai withT. triglyphus proposed by Tarjan (1973) is not accepted.Divittus labiatus n.sp. from soil around roots of sugarcane from north-eastern Nigeria is described. It is characterized by having the lip region continuous with the body, the spear 14–16 m long, the basal oesophageal bulb with a small overlap over the intestine and the tail with a large post-anal intestinal sac and 20 to 30 annules. A key to species ofDivittus is provided. ac]19830105 相似文献
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Ranjeet R. Kumar Suneha Goswami Mohammad Shamim Kavita Dubey Khushboo Singh Shweta Singh Yugal K. Kala Ravi R.K. Niraj Akshay Sakhrey Gyanendra P. Singh Monendra Grover Bhupinder Singh Gyanendra K. Rai Anil K. Rai Viswanathan Chinnusamy Shelly Praveen 《Functional & integrative genomics》2017,17(6):621-640
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JG Hansen W Gao J Dupuis GT O’Connor W Tang M Kowgier A Sood SA Gharib LJ Palmer M Fornage SR Heckbert BM Psaty SL Booth SUNLIGHT Consortium Patricia A Cassano 《Respiratory research》2015,16(1)
Background
Vitamin D is associated with lung function in cross-sectional studies, and vitamin D inadequacy is hypothesized to play a role in the pathogenesis of chronic obstructive pulmonary disease. Further data are needed to clarify the relation between vitamin D status, genetic variation in vitamin D metabolic genes, and cross-sectional and longitudinal changes in lung function in healthy adults.Methods
We estimated the association between serum 25-hydroxyvitamin D [25(OH)D] and cross-sectional forced expiratory volume in the first second (FEV1) in Framingham Heart Study (FHS) Offspring and Third Generation participants and the association between serum 25(OH)D and longitudinal change in FEV1 in Third Generation participants using linear mixed-effects models. Using a gene-based approach, we investigated the association between 241 SNPs in 6 select vitamin D metabolic genes in relation to longitudinal change in FEV1 in Offspring participants and pursued replication of these findings in a meta-analyzed set of 4 independent cohorts.Results
We found a positive cross-sectional association between 25(OH)D and FEV1 in FHS Offspring and Third Generation participants (P = 0.004). There was little or no association between 25(OH)D and longitudinal change in FEV1 in Third Generation participants (P = 0.97). In Offspring participants, the CYP2R1 gene, hypothesized to influence usual serum 25(OH)D status, was associated with longitudinal change in FEV1 (gene-based P < 0.05). The most significantly associated SNP from CYP2R1 had a consistent direction of association with FEV1 in the meta-analyzed set of replication cohorts, but the association did not reach statistical significance thresholds (P = 0.09).Conclusions
Serum 25(OH)D status was associated with cross-sectional FEV1, but not longitudinal change in FEV1. The inconsistent associations may be driven by differences in the groups studied. CYP2R1 demonstrated a gene-based association with longitudinal change in FEV1 and is a promising candidate gene for further studies.Electronic supplementary material
The online version of this article (doi:10.1186/s12931-015-0238-y) contains supplementary material, which is available to authorized users. 相似文献7.
8.
S. Datta R. G. Choudhary Md. Shamim Vishwa Dhar 《Archives Of Phytopathology And Plant Protection》2013,46(6):558-566
Fusarium species causing wilt diseases in different plants were characterised by comparing nonpathogenic and different pathogenic species using rDNA RFLP analysis. The ITS (internal transcribed spacer) region of 12 isolates belonging to the section Elegans, Laseola, Mortiella, Discolor, Gibbosum, Lateritium and Sporotrichiella were amplified by universal ITS primers (ITS-1 and ITS-4) using polymerase chain reaction (PCR). Amplified products, which ranged from 522 to 565 bp were obtained from all 12 Fusarium isolates. The amplified products were digested with seven restriction enzymes, and restriction fragment length polymorphism (RFLP) patterns were analysed. A dendrogram derived from PCR-RFLP analysis of the rDNA region divided the Fusarium isolates into three major groups. Assessment of molecular variability based on rDNA RFLP clearly indicated that Fusarium species are heterogeneous and most of the forma speciales have close evolutionary relationships. 相似文献
9.
Vascular plants have lignified tissues that transport water, minerals, and photosynthetic products throughout the plant. They are the dominant primary producers in terrestrial ecosystems and capture significant quantities of atmospheric carbon dioxide (CO2) through photosynthesis. Some of the fixed CO2 is respired by the plant directly, with additional CO2 lost from rhizodeposits metabolized by root-associated soil microorganisms. Microbially-mediated mineralization of organic nitrogen (N) from plant byproducts (rhizodeposits, dead plant residues) followed by nitrification generates another greenhouse gas, nitrous oxide (N2O). In anaerobic soils, reduction of nitrate by microbial denitrifiers also produces N2O. The plant-microbial interactions that result in CO2 and N2O emissions from soil could be affected by genetic modification. Down-regulation of genes controlling lignin biosynthesis to achieve lower lignin concentration or a lower guaiacyl:syringyl (G:S) ratio in above-ground biomass is anticipated to produce forage crops with greater digestibility, improve short rotation woody crops for the wood-pulping industry and create second generation biofuel crops with low ligno-cellulosic content, but unharvested residues from such crops are expected to decompose quickly, potentially increasing CO2 and N2O emissions from soil. The objective of this review are the following: 1) to describe how plants influence CO2 and N2O emissions from soil during their life cycle; 2) to explain how plant residue chemistry affects its mineralization, contributing to CO2 and N2O emissions from soil; and 3) to show how modification of plant lignin biosynthesis could influence CO2 and N2O emissions from soil, based on experimental data from genetically modified cell wall mutants of Arabidopsis thaliana. Conceptual models of plants with modified lignin biosynthesis show how changes in phenology, morphology and biomass production alter the allocation of photosynthetic products and carbon (C) losses through rhizodeposition and respiration during their life cycle, and the chemical composition of plant residues. Feedbacks on the soil environment (mineral N concentration, soil moisture, microbial communities, aggregation) affecting CO2 and N2O emissions are described. Down-regulation of the Cinnamoyl CoA Reductase 1 (CCR1) gene is an excellent target for highly digestable forages and biofuel crops, but A. thaliana with this mutation has lower plant biomass and fertility, prolonged vegetative growth and plant residues that are more susceptible to biodegradation, leading to greater CO2 and N2O emissions from soil in the short term. The challenge in future crop breeding efforts will be to select tissue-specific genes for lignin biosynthesis that meet commercial demands without compromising soil CO2 and N2O emission goals. 相似文献
10.
Nimra Akram Naheed Khan Mehreen Ameen Shahmeera Mahmood Komal Shamim Marium Amin 《Chronobiology international》2013,30(9):1262-1268
ABSTRACTSeveral studies have focused on determining the effect of chronotype and learning approach on academic achievement separately indicating that morning types have an academic advantage over the evening types and so have the deep learners over the surface learners. But, surprisingly none have assessed the possible relationship between chronotype and learning approach. So, the current study aimed to evaluate this association and their individual influence on academic performance as indicated by the Cumulative Grade Point Average (CGPA) as well as the effect of their interaction on academic performance. The study included 345 undergraduate medical students who responded to reduced Morningness-Eveningness Questionnaire and Biggs Revised Two-Factor Study Process Questionnaire. Morning types indulged in deep learning while evening types in surface learning. Morning and evening types did not differ on academic performance but deep learners had better academic outcomes than their counterparts. The interaction between chronotype and learning approach was significant on determining academic achievement. Our findings gave the impression that chronotype could have an impact on academic performance not directly but indirectly through learning approaches. 相似文献