Comment on "Disentangling the drivers of β diversity along latitudinal and elevational gradients"

Kraft et al. (Report, 23 September 2011, p. 1755) analyzed two data sets and concluded that "there is no need to invoke differences in the mechanisms of community assembly in temperate versus tropical systems to explain these global-scale patterns of β diversity." We show that their conclusion is based on inappropriate data and inadequate methods of analysis.     

Genetic diversity center of cultivated soybean(Glycine max) in China——New insight and evidence for the diversity center of Chinese cultivated soybean

Information on the center of genetic diversity of soybean(Glycine max) will be helpful not only for designing efficient strategies for breeding programs, but also for understanding the domestication and origin of this species. Here, we describe an analysis of genetic diversity based on simple-sequence repeat(SSR) variations within a core collection of 2 111 accessions of Chinese soybean landraces. Prior to the diversity assessment, the geographic origin of each accession was mapped. The map was then divided into grids each 2.5° in latitude and 5° in longitude. We found two regions that had higher number of alleles(NA) and greater polymorphic information content(PIC) values than the others. These regions are adjacently located within grid position of 30°–35°N×105°–110°E, which includes the valley of the middle and lower reaches of the Wei River, and the valley of the upper reaches of the Hanjiang River. It was also observed that in many regions, genetic diversity decreased with the increase in distance from the center. Another region, in northern Hebei Province(115°–120°E×40°–42.5°N), was observed having higher diversity than any surrounding regions, indicating that this is a sub-center of soybean diversity. Based on the presented results, the domestication and origin of soybean are also discussed.     

Cloning α and β chains of SLA-DR loci and reconstruction of their complex in vitro

In order to investigate the prompt conformations of swine major histocompatibility complex (MHC), a swine MHC-II protein complex (SLA-II) was reconstructed in vitro. DRA and DRB were cloned from a crossbred commercial pig (Changbai-Dalan). Subcloned extracellular parts of DRA and DRB were linked together by a linker containing rich glycine/serine (G4S)3, and the whole length of two genes, named DRA-linker-DRB, was amplified by splicing overlap extension PCR (SOE PCR). DRA-linker-DRB was inserted into pMAL-p2X prokaryotic system and expressed. The expressed fusion protein MBP-DRA-(G4S)3-DRB was identified by Western-blot, purified and cleaved to obtain the protein of interest DRA-(G4S)3-DRB. The secondary structure of this protein was determined in circular dichroism (CD) apparatus. The results indicated that the subsequent protein MBP-DRA-(G4S)3-DRB was soluble and its molecule weight was 83.4 ku in consistent with the Western-blot. Cleaved by Factor Xa, the protein of interest was separated with a molecular weight of 40.9 ku. The CD spectrum demonstrated that the protein displayed a favorable α-Helix structure, and the contents of α-Helix, β-sheet, turn, and random coil were 80 aa, 121 aa, 101 aa and 80 aa respectively. The identical ratios of α-Helix, β-sheet, turn, and random coil between MBP-DRA-(G4S)3-DRB and DRA-(G4S)3-DRB were 95%, 96.7%, 91.1% and 93.0%, respectively. The results also suggested that the reconstructed SLA-II complex presented an ideal conformation and can be used for studying its structure and function in vitro. __________ Translated from Journal of China Agricultural University, 2006, 11(3): 21–26 [译自: 中国农业大学学报]     

Effect of soil type and overgrowth time on agrochemical parameters of fallow lands located along the accumulation trend of material–energy flow

It has been shown that changes in agrochemical parameters of fallow lands depend on the type of soil and the time of overgrowth. A gradual acidification of the postagrogenic layer, its differentiation into two sublayers by the contents of humus and total exchangeable bases, and a decrease in the content of mineral nutrients are observed in overgrown agrosoddy-podzolic soils. In agrogray soils, these processes are less intense.     

Study on the Effect of ESR and FSH β Genes on Litter Size in Local Northeast Three Pig Breeds

The method of PCR-RFLP was used to analyze the effects of ESR and FSH β genotypes on the litter size, especially the corresponding changes with the difference of genotype distributions in the Min, Sanjiang and Junmu I pigs. The results show that the ESR and FSH β genes are the major genes of litter size ; the heterozygous genotype for ESR as well as for FSH β locus has a more litter size than others. However, the combined genotype ABDD means a more litter size than other genotypes,the frequencies of the heterozygous genotypes in Sanjlang and Junmu I are lower than in Min which maybe one of the most important reasons for the little litter sizes of those two breeds.     

Research and Significance of the Mesolithic Age

Regarding the issue of the Mesolithic, the author has an article published on Acta Anthropologica Sinica in 1995,pointing out that this period relates to most significant issues such as the transition from the Paleolithic to Neolithic and the origin of agriculture. The Mesolithic is a crucial topic to understand cultulal, economic, technological and social changes during this short time span. Unfortunately, up to recently, the concept of the Mesolithic is still a contriversial issue in Chin…     

The Effect of Chintosan and Sodium Alginate on the Growth and Photosynthesis of Soybean

Seed coating can make soybean seedling grow more strongly and reinforce the resistance of soybean plant.Sodium alginate and chitosan are high-molecular compound of two different kind,have the characteristic of promoting the crop growth,Using sodium alginate and chitosan as coating materials under different concentration can improve the growth and photosynthesis obviously and can decrease pollution because of their characteristics.The analysis show that the effects of Sodium Alginate on soybean plant are better than chitosan and the best concentration is 0.5g.kg^-1.     

Status and Perspectives of the Researches on Lawn

There is a rapid development of lawn industry, however, the researches on lawn culture, maintenance and its mechanis mslag behind. Studies of drought-resistance, fertilization, management and maintenance of lawn are discussed in this paper.Besides, problems with the research on lawn culture and its maintenance in China are also analyzed. For example, soil has been destroyed seriously by the production of wrapping sward, but the studies on turf medium are deficient. Besides, the maintenance and management of lawn have not a standard due to the shortage of studies on turf quality assessment;applications of high-technique to lawn sciences are inadequate too. The developing tendency of lawn research in China is suggested at the end of this paper to help for the further studies in this field.     

The Effect of Chitosan and Sodium Alginate on the Growth and Photosynthesis of Soybean

1　Introduction　　Sodium alginate and chitosan are the oceanic natural resources and high molecular com-pound which can promote the plant growth,and protect various plants from harmful organ-isms or prevent plant disease caused by harmful organisms( Makuuch,1 998and Hadwiger,etal. 1 983) .The two materials were used as coating materials,plant promoters,foliar sprayingin soil and so on( Mitchell,1 96 2 ;Brown,982 ;Cuero,1 991 ,Osuji,1 992 ) .Because the two ma-terials are degradable in soil …     

The Study of Relativity between the DNA Conformation and the Canceration

The conformation of DNA in the granuloblast of the human leukaemia(HL) is also different from that of the normal human (HN) was determined by the fluorescence titration.These results show the view that DNA conformation variety is related with the canceration of human cell.     

A Study on the Tryptic Hydrolysis of Proteins in Skim Milk and the Characteristics of the Hydrolysate

Limited enzymatic hydrolysis of skim milk by trypsin was investigated in this paper,and it was found that the degree of hydrolysis (DH) of milk proteins had a relationship of DH^-1=a bt^-1 with the time(t) of hydrolysis at low enzyme concentrations some properties of the protein such as NSI in PI or TCA were changed obviously,It was suggested that mosk milk proteins would be degraded into peptides by trypsin.     

Are we losing diversity? Navigating ecological,political, and epistemic dimensions of agrobiodiversity conservation

Narratives of seed ‘loss’ and ‘persistence’ remain at loggerheads. Crop genetic diversity is rapidly eroding worldwide, we are told, and numerous studies support this claim. Other data, however, suggests an alternative storyline: far from disappearing, seed diversity persists around the world, resisting the homogenizing forces of modern capitalism. Which of these accounts is closer to the truth? As it turns out, crop biodiversity is more easily invoked than measured, more easily wielded than understood. In this essay, I contend that the impasse reveals an error in the asking. We must, instead, look to the ontological, epistemic, and narrative dimensions of agrobiodiversity—and to the science, politics, and cultures of each. How is diversity empirically defined and measured? Who creates and categorizes diversity? Who does not? How is such knowledge mobilized in the accounts and narratives of different interest groups? Where, when, and why does a narrative hold true? This multi-dimensional view of agrobiodiversity makes space for a greater understanding of how diversity is created, maintained, and renewed. It suggests policy and institutional support for systems that engender such renewal of diversity, both in and ex situ.     

Studies on the Extraction Technology and the Application of Chicken Pepsin

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The principle and Application of the Multiple and Partial Coherence Analysis

The basic principles of the partial and multiple coherence ananlysis and their utilization on vibration source idenfification are discussed in detail in this paper,The partial coherence analysis is the effective method of vibration source identification in multiple input-single output systems.Formerly,there was not any this kind of unction in the signal processor,and there was not and special software too.The software which we developed and used in the 7T 17S signal processor has this function.This software can be used not only for the parial and multiple coherence analysis of signal,but also for the correlation analysis,power spectrum analysis,transfer function analysis et al.We used this software to make the identifcation of the vibration source of the car floor board of electrical measuring vehicle,and to find the main factors which effect the vibration of the ear board.The excellent result was obtained.This method can also be used for making the identifications of noise source and other sources.     

The Studies on the Grunting of Sows during Nursing and the Sucking Behaviour of Piglets

Two experiments were carried out to study the grunting of sows during nursing and the sucking be-haviour of piglets. In experimental I,six Yorkshire sows and their litters were observed and managed in farrowing crates.In experimental Ⅱ,six Harbin White sows and their litters were selected and housed in farrowing pens.The behaviours and activities of the sows during nursing and the actities of piglest during sucking were recorded with a portable video camera (PanasonicNV-VX22EN)The results showed that the characteristic patterns of grunting by the sows consist of an initial period of rhythmic grunting at a fairly constant rate and followesd by a period of more rapid grunting,and then a decline in grunting rate toward the completion of nursing.The pattern of vocalization showed by the mothers bears a reliable synchronization to the sucking behaviour of the piglets.The rate of grunting varied little during jostling for teat and nosing the udder.The beginning of slow sucking usually occurred during of just after the increase in grunt rate.The rapid sucking began 15-25seconds after the period of most rapid grunting,fol-lowingthe decrease of grunt rate.afterwards the nursing ended.There were individualities found in sows‘grunting patterns.It is found that vocalizations attracted the piglets to the sows and synchronized sucking activities of piglets,but the results indicated that the premassaging time and numbers of piglets enagaing massaging influ-enced the grunting pattern and the onset of the milk ejection.As more piglets were involved the massaging,the higher the grunting rate peak,the faster the milk ejection.     

Correlation Analysis of Rice Seed Setting Rate and Weight of 1 000-Grain and Agro-Meteorology over the Middle and Lower Reaches of the Yangtze River, China

The purpose of this study is to reveal the effects of historic climate change on rice yield over the middle and lower reaches of the Yangtze River, China, and to better adapt to climate change in the future. This study presents the relation of temperature and precipitation and rice components from 1981 to 2003 at 48 early rice stations and 30 middle rice stations. It focuses on an analysis of three stages： flowering, pre-milk, and late milk. The results show that mean maximum temperature and mean daily precipitation at the stages of flowering and pre-milk are most related to early rice yield. Yield change of middle rice is mainly because of mean precipitation change at the flowering stage. Furthermore, percentage of undeveloped grain increases as mean maximum temperature rises at the flowering stage. Over-precipitation in the reproductive stage is a major reason for reduction in yield of early rice. Consecutive rainfall and continuous high temperature can have negative effects on middle rice yield. Global warming would affect middle rice more seriously than early rice.     

Assessment of the Genetic Relationship and Diversity of Mango and Its Relatives by cplSSR Marker

Chloroplast inter-simple sequence repeat markers in mango were developed and used to analyze the genetic relationship and diversity of mango and its relatives. Thirty-six mango cultivars （Mangifera indica L.） and its relative species collected from the fruit germplasm collection in the Guangxi Academy of Agricultural Sciences, China, were examined by ISSR-PCR with chloroplast DNA （cpDNA）. Eight better primers for chloroplast DNA that provided reproducible, polymorphic DNA amplification patterns were screened from 50 ISSR primers and used for UPGMA analysis. According to the band patterns with 8 primers for chloroplast DNA, all cultivars tested were distinguished from each other and these showed ample genetic diversity; the average percentage of polymorphism was 77.2%. The 36 samples could be clustered into four groups by UPGMA analysis at the coefficient 0.74. The results indicated that the cplSSR marker was a new powerful tool for the identification of mango cultivars or its relative species, and their genetic relationship analysis and diversity evaluation.     

The Response of Winter Wheat Root to the Period and the After-Effect of Soil Water Stress

To reveal the period and after-effect of soil water stress on winter wheat, the article employs the experiment results carried out in the greenhouse. The results showed that the root-restricted weights varied with stress degrees and stress times during and after water stressing. In the course of stress, the chief reason resticting the weight of root was the stress intensity at this time, and that of severe stress treatment was larger than that of mild stress treatment. After water stress was relieved, the results of the after-effect of soil water stress on root growth were that, the stress intensity of short-time and mild stress was larger than that of long-time and severe stress. Comparing two-stage stress intensities, root-restricted weight resulted from after-effect intensity of stress under all of the short-time treatment, and the mild and the long-time stress treatments, while that resulted from the period stress intensity under the severe and the long-time stress treatments. In general, the effects of water stress on root were attributed to the three factors, a formed basis in the previous stage, the after-effect of water condition before this stage and influence of water in this stage, which lead to the characters of root in the whole growth stage.     

Advances in Research and Development of the Botanical fungicide

概述了目前植物源杀菌剂植物资源、有效成分、构效关系、作用机理的研究现状。总体来讲,在具有抗菌活性植物资源筛选方面已经做了大量工作,但大多停留在植物初提物;有效成分的分离纯化、构效关系及作用机理的研究较少有待进一步深入。