Molecular characterization and biological response to respiration inhibitors of Pyricularia isolates from ctenanthe and rice plants

The molecular profile and the biological response of isolates of Pyricularia oryzae Cavara obtained from ctenanthe to two strobilurins (azoxystrobin, kresoxim-methyl) and the phenylpyridinamine fungicide fluazinam were characterized, and compared with isolates from rice plants. Five different isozymes (alpha-esterase, lactate, malate, isocitrate and sorbitol dehydrogenases) and five random decamer primers for RAPD-PCR were used to generate molecular markers. Using unweighted pair-group with arithmetic average analysis, ctenanthe isolates were found to form a separate group distinct from that of the rice isolates for both sets of markers. Amplified polymorphic sequences of mitochondrial cytochrome b that were digested with Fnu4HI or StyI revealed no differences among Pyricularia isolates at amino acid positions 143 or 129 which confer resistance to strobilurins in several fungi. In absence of the alternative respiration inhibitor salicylhydroxamic acid (SHAM) the three fungicides showed inferior and variable efficacy, with a trend toward the rice isolate being less sensitive. The addition of SHAM enhanced the effectiveness of all fungicides against isolates regardless of their origin. Appressorium formation was the most vulnerable target of action of the respiration inhibitors and azoxystrobin the most effective. This is the first report of a comparison between the molecular profiles and sensitivities to respiration inhibitors for Pyricularia oryzae isolates from a non-gramineous host and from rice.     

Research Progress of Alternative Splicing and Its Application in Livestock and Poultry Breeding

Alternative splicing(AS) refers to the process of selective splicing across exons or splice junctions during individual development or cell differentiation to produce tissue-or development-stage specific mRNA. Through AS process, organisms can produce many different protein isomers from a single gene and finally increase the proteome diversity. Therefore, AS plays an important role in the regulation of animal growth, development and physiological metabolism. This article not only summarized the types and the detection methods of alternative splicing, but also highlighted its impact on various economic traits of livestock and poultry, and prospected its application prospects in livestock and poultry breeding. This article could provide new ideas for the improvement of livestock and poultry breeding.     

Soil solarization in various agricultural production systems

Soil solarization is a natural, hydrothermal process of disinfesting soil of plant pests that is accomplished through passive solar heating. Solarization occurs through a combination of physical, chemical, and biological mechanisms, and is compatible with many other disinfestation methods to provide integrated pest management. Commercially, it is used on a relatively small scale worldwide as a substitute for synthetic chemical toxicants, but its use is increasing as methyl bromide, the major chemical fumigant, is phased out due to its ozone-depleting properties. Solarization currently is an important and widespread practice for home gardeners. In production agriculture, the principal use of solarization (on a treated area basis), is probably in conjunction with greenhouse grown crops. Another application for which solarization has come into common use is for disinfestation of seedbeds, containerized planting media, and cold-frames. Around the world, solarization for disinfesting soil in open fields is being implemented at a relatively slow but increasing rate. It has been mainly used for commercial production in areas where air temperatures are very high during the summer and much of the cropland is rotated out of production due to excessive heat. As global concerns regarding environmental quality grow along with the human population in the 21st century, concepts such as solarization and other uses of solar energy in agriculture will likely become increasingly important.     

Theorems of The Alternative for Nearly Convexlike Set-Valued Maps

In this paper, we obtain some theorems of the alternative for nearly convexlike and nearly subconvexlike set-valued maps in linear topological spaces were obtained by the authors.     

The use of an alternative food source (red clover) as a means of reducing slug pest damage to winter wheat: towards field implementation

Slugs are major pests of many crops in the UK, including winter wheat, yet current methods of control are often unreliable. The aim of this study was to investigate three issues key to the successful field implementation of a control strategy that uses red clover as an alternative food source to reduce the amount of damage caused to winter wheat by the field slug, Deroceras reticulatum (Müller). A series of three experiments was designed to assess this aim. Firstly, under laboratory conditions, red clover was consumed in greater quantities than wheat, even when wheat was presented as a novel food. Secondly, red clover had no significant effects on the emergence and early growth of wheat in a polytunnel experiment. Both these results are crucial to the successful implementation of a strategy that uses red clover as an alternative food source. Lastly, the results of a field experiment were consistent with the results of the polytunnel experiment, in that red clover did not significantly affect wheat emergence. However, plots in which red clover was left to grow until the time of wheat harvest resulted in significantly lower (43%) wheat yields than plots without red clover. These results suggest that red clover must be removed from the field after the wheat has passed its vulnerable seedling stage. Recommendations for the potential use of red clover as an alternative food source for reducing damage to winter wheat in field conditions are discussed and opportunities for further work are suggested.     

Cytochrome b gene structure and consequences for resistance to Qo inhibitor fungicides in plant pathogens

The cytochrome b (cyt b) gene structure was characterized for different agronomically important plant pathogens, such as Puccinia recondita f sp tritici (Erikss) CO Johnston, P graminis f sp tritici Erikss and Hennings, P striiformis f sp tritici Erikss, P coronata f sp avenae P Syd & Syd, P hordei GH Otth, P recondita f sp secalis Roberge, P sorghi Schwein, P horiana Henn, Uromyces appendiculatus (Pers) Unger, Phakopsora pachyrhizi Syd & P Syd, Hemileia vastatrix Berk & Broome, Alternaria solani Sorauer, A alternata (Fr) Keissl and Plasmopara viticola (Berk & Curt) Berlese & de Toni. The sequenced fragment included the two hot spot regions in which mutations conferring resistance to QoI fungicides may occur. The cyt b gene structure of these pathogens was compared with that of other species from public databases, including the strobilurin-producing fungus Mycena galopoda (Pers) P Kumm, Saccharomyces cerevisiae Meyer ex Hansen, Venturia inaequalis (Cooke) Winter and Mycosphaerella fijiensis Morelet. In all rust species, as well as in A solani, resistance to QoI fungicides caused by the mutation G143A has never been reported. A type I intron was observed directly after the codon for glycine at position 143 in these species. This intron was absent in pathogens such as A alternata, Blumeria graminis (DC) Speer, Pyricularia grisea Sacc, Mycosphaerella graminicola (Fuckel) J Schr?t, M fijiensis, V inaequalis and P viticola, in which resistance to QoI fungicides has occurred and the glycine is replaced by alanine at position 143 in the resistant genotype. The present authors predict that a nucleotide substitution in codon 143 would prevent splicing of the intron, leading to a deficient cytochrome b, which is lethal. As a consequence, the evolution of resistance to QoI fungicides based on G143A is not likely to evolve in pathogens carrying an intron directly after this codon.     

可变剪接在肌肉发育中的作用研究进展

可变剪接发生在DNA转录为前体mRNA后，通过该过程可以使单个基因产生多个mRNA异构体和蛋白质亚型，增加了转录后加工过程中基因的信息多样性和蛋白质丰度。剪接体、剪接因子和其他RNA结合蛋白催化识别剪接位点和可变剪接外显子，参与调节可变剪接，从进化的角度来看，可变剪接在一定程度上为生物进化提供了驱动力。可变剪接作为组织特异性调节剂，参与肌肉发育的整个过程。在成肌细胞分化过程中，多聚嘧啶序列结合蛋白（polypyrimidine tract-binding protein，PTB）和RNA结合蛋白4（RNA-binding motif protein 4，RBM4）分别与原肌球蛋白的内含子多嘧啶序列和富含CU的内含子结合，共同调节α-原肌球蛋白的肌肉细胞特异性外显子选择的活性。RBM4可通过下调PTB表达并颉颃PTB在外显子选择中的活性来协同作用于肌细胞增殖分化的特异性剪接；肌球蛋白Ⅰ亚型通过可变剪接产生4种不同长度杠杆臂的蛋白质，影响肌肉的张力与拉伸激活；可变剪接可能是产生肌肉类型特异性的重要机制，选择性剪接产生具有不同催化动力学的肌球蛋白重链同工型，催化动力学差异地调节收缩性，从而影响肌纤维类型和肌肉功能。作者通过阐述可变剪接事件在肌肉发育及肌纤维形成过程中的主要作用，揭示可变剪接对肌肉发育的作用，以期为后续研究肌肉的发育调控机理提供参考依据。     

甲醇和乙醇作为替代燃料在单缸四冲程柴油机中的应用研究

 分析了甲醇和乙醇作为柴油替代燃料的可行性及应用前景，对甲醇或乙醇、柴油及水的混烧比例提出了建议。同时根据云南农业大学在X195型柴油机上增设的甲/乙醇供给系统提出了改进举措及试验目标。     

茄黄萎病化学防治试验初报

茄黄萎病(Verticillium dahliae Kleb.)是我区露地和保护地茄子的主要病害,由于发生普遍和损失严重,目前成为限制茄子生产的重要影响因子。1987年8～10月,室内对8种杀菌剂毒力测定,证明50%多菌灵可湿性粉剂、40%白霜净胶悬剂、Busan 乳油有很好的抑菌效果.1988年5～8月通过大田防治和测产试验,发现用多苗灵与白霜净交替定植前的苗期喷雾,有防病和增产的作用;定植后用多菌灵或白霜净分别加1%平平加茎杆涂药或稀释灌根,亦有防病和增产的效果.