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1.
The pectin is a backbone of the plant cell wall, its network structure will systemicly resolve when the plant cell splits up and forms. The pectinase produced by Rhizoctonia mainly acts on the pectin of cell wall, and causes the maceration of tissue and the death of protoplast. Polygalacturonase (PG) can decompose the galacturonic acid of disease tissue. The research defined the PG activities of extracellular metabolite of the different virulence Rhizoctonia isolates, and testifid the e…  相似文献   

2.
苹果(品种“Quettaamri,“Kulu”,“Kashmiriamri”)幼芽(茎)培养在含不同水平(0~2.0mg/L)IBA,NAA或IAA的1/2MS培养基上时,可以分化出根.与其它品种相比,“Kashmiriamri”最易生根.各品种在低浓度生长素水平下的生根效果较好.IBA比NAA和IAA对生根的促进作用大,在不含生长素的培养基上幼芽(茎)不能生根  相似文献   

3.
The palm, Elaeis guineensis, has its origins in Africa but is planted on a commercial basis in several countries Statistics for 2002 showed that in the lead for land mass under oil palm cultivation is Indonesia, at 3,769,000 ha, followed by Malaysia at 3,376,000 ha; however, the world‘s leading  相似文献   

4.
The working principle of radio remote controlling of construction machinery should be that signals of the radio wave from the transmitter obtained in the receiver were controlled and then changed into electronic analog or digital signals which can be used to drive different actuators and mechanisms of the vehicle. The vehicle could be acted by following the controlling instructions sent by the operator. The best operation mode of construction machinery is suitable not only to manual operating but also to remote controlling in the same vehicle. The design methods of the hydraulic system used for the radio remote controlling of construction machinery are discussed. The design methods of hydraulic circuits for the actuators controlled by solenoid on-off type valves ,hydro-electronic multi-way proportional valves,closed loop proportional servo driver or threeway proportional reducing valves are discussed in detail (with real example). The design methods of the power shift transmission of electro-hydraulic controlling,the devices of braking and the directional streering are discussed in this paper.  相似文献   

5.
To investigate the mechanism of action of Chinese herbal medicine, the immunocells of Harder's glands were observed. The healthy Hy-Line Brown chickens of 12-day-old were divided into three groups randomly. The chickens in group 1 and 2 drank the water with 0.5% and 1% Chinese herbal medicine immunopromoter every day. The chickens in group 3 as control drank pure water. The Harder's glands of the chickens from 0.5% group, 1% group and control group at 24, 36 and 48 d after drinking medicine respectively were made into histological section. And then the histological sections were observed histologically. The results showed that Chinese herbal medicine could increase the quantity of the immunocells in glandular organs conspicuously. Immunopotentiator of Chinese herbal medicine could promote the amount and growth of secreted immunoglobuline and elevate the immune level of the orgamsm, and the effect of 1% group was higher than that of 0.5% group.  相似文献   

6.
Field experiment was conducted on mature tea bushes of Qi-Men variety at two different altitudes from sea level i.e. at National Tea Research Institute Shinkiari (1000 m) and on farmer's field in Konsh valley at village Battal (1500 m). Different levels of nitrogen with constant dose of phosphorus and potassium were applied to observe the optimal dose of nutrients for highest yield under local edaphic conditions. The experiment was repeated for three consecutive years. The highest yield of fresh tea leaves were obtained by the application of 420 kg ha^-1 N followed by the application of 360 kg ha^-1 N at 1000 masl. The highest dose of nitrogen also reduced significantly the soil pH in the upper (0-15cm) layer depth during 1998 and 1999. During the year 2000, the reduction in soil pH was observed by the application of highest dose of nitrogen but was non-significant at 5% level. The lower soil depth (15-30 cm) showed the reduction in pH with the highest dose of nitrogen during the experimental year but was statistically non significant. At the higher altitude of 1500 masl the highest yield of fresh tea leaves was obtained by the application of 420 kg ha^-1 during the experimental years but the increase was significant during the year 1999 and 2000. The yield of the fresh tea leaves was positively correlated with the amount of nitrogen application at both the altitudes. The increasing amount of nitrogen decreased the soil pH at both the depths of 0-15cm and 15-30cm. Unlike the lower altitude (1000 m) there was no any significant reduction in the soil pH during 1998 and 1999. A significant reduction in soil pH was found in the year 2000.  相似文献   

7.
Three strains of Trichoderma spp. TV112, TX003, TY009 obtained from previous experiments could inhibit the sclerotial formation of two strains of Rhizoctonia salani AG1 (-1A) isolated from the rice paddies in Hanzhou of China. However, it is unclear if there are the antagonism and mycoparasitism of the Trichoderma strains tested against the mycelial growth of R. solani . The objective of this research was to evaluate the ability of the Trichoderma strains to inhibit the mycelial…  相似文献   

8.
The picked pear is often ripened naturally or artificially in ethylene solution to put the pear into market earlier.When Qiuxiang pear are ripened,a great deal of ethylene is produced,the content of soluble solid,total sugar and titrable acidity are increased.The flesh is softened,the skin of fruit turns yellow,and the fruits are of aromatic favor.At differnet harvest time,respiration intensity appears different changing trends;the fruit qualities and the storage period are influenced too.Artificial ripening promotes fruit ripe and has a better effect than natural ripening.And Qiuxiang pear ripened artificially in earlier the middle or late of August can achieve better fruit qualities and higher economic value.  相似文献   

9.
The even degree of animal population is generlay measured by the coefficient of variation of major economic characters.Facing the coefficient of variation,a statistic with complex properties,we achieved indirectly the determination of confidence interval for even degree of an animal population by analysing the reciprocal of the statistic.The sample size which is suitable to the determination of the even degree of an animal population was probed into within the extent of permissive estimation error.  相似文献   

10.
籽粒苋是一种富钾植物,同时也是一种生物量很大的绿肥和营养价值较高的保健类植物。笔者综述了目前国内外对籽粒苋的生理生化特征、分子生物学基础、富钾机理、矿质营养特点及在食品、药用、饲料、绿肥等方面的研究进展,并对今后籽粒苋的研究提出了建议。  相似文献   

11.
A series of highly taxonomically diverse Trichoderma strains were investigated using proteomic approaches, to investigate the utility of protein profiles as taxonomic markers and to identify proteins of potential economic importance. Initial studies have focused on a comparison of single strains of T. aureoviride, T. saturnisporum, T. polysporum, T. longbrachiatum and T. spirale, along with two strains of T. harzianum. All seven strains were grown in synthetic medium supplemented wi…  相似文献   

12.
As an important plant species with high protein contents,wild soybean(Glycine soja),has drawn much attention and appeared to be useful for the genetic improvement of soybean germplasms.Since temperature is one of the numerous environmental factors affecting the germination of most plants,an experimental study was carried out to determine the effect of temperature on germination of wild soybean(G.soja)seeds.Germination test was conducted by setting up thirty-six constant and alternating temperature regimes,ranging from 5 to 40 ℃(16 h night/8 h day).Responses in germination rate to these temperature regimes were then used to construct a quadratic response surface,giving estimated germination rates with confidence intervals at P ≤ 0.05.The results showed that germination capacity was significantly greater while exposed to constant temperatures of 25 ℃,and under the alternating temperature regime the optimum temperature occurred at the 20/25,25/25,25/30 ℃ regime(16 h/8 h)with the amplitude widened from 0 to 5 ℃.Together with regional monthly climate data,these results could be used to improve and promote the cultivation of wild soybean(G.soja),making it available to develop the location-specific optimum seeding time and to apply weed-control treatments.  相似文献   

13.
通过测定加有黑麦草的土壤样品在不同培养时间产生的硝态氮、亚硝态氮、铵态氮和氨态氮数量的变化,研究了有机氮在二种红壤(红砂土和黄筋泥)中的矿化动态.有机氮在红壤中的矿化结果主要是铵的生成和氨的挥发,培养后5d,明显发生铵的释放,红砂土在培养后15~20d,铵的释放达到最大值,黄筋泥则是在培养后30~35d.在培养的前20d,红砂土中铵的释放多于黄筋泥,但在30d后,情况相反.培养期间有机氮矿化释放的氨用2%硼酸溶液吸收,以这种形式损失的有机氮,红砂土多于黄筋泥  相似文献   

14.
Wheat dwarf bunt, caused by Tilletia controversa Kühn (TCK), is an important quarantine wheat disease throughout the world. Based on published research results of the biology and the epidemiology of the disease, the main factors including temperature, humidity, snow cover, and their parameters relating to teliospore germination, infection and epidemics of TCK were determined. The geophytopathological models for the risk analysis of wheat dwarf bunt establishment were modified. Fifty-year meteorologic data from about 500 weather stations in China were used to calculate the probabilities of TCK establishment in different geographic sites with the models. The map that displays the establishment risk of TCK in winter wheat growing regions in China was generated by using geographical information system (GIS). The zones showing high, moderate, low, and very low, including no risk, of TCK establishment accounted for 27.33, 27.69, 38.12, and 6.86% of total winter wheat growing areas in China, respectively. These results will provide useful information to formulate quarantine regulations and wheat importation policy in China.  相似文献   

15.
Interferon (IFN) is certain protein with extensive antiviral activities that is secreted from leucocytes in- duced by virus or other inducing reagents. IFNs play a key role in inducing cells against virus and adjust- ing immune response[1.] IFNs include t…  相似文献   

16.
The aim of this study was to elucidate the expression and regulation of the c.kit protein in spermatogenesis of locusts. Immunohistochemistry and biological statistics were used to investigate the expression of the c-kit protein in four representative phases of spermatogenesis of three dominant species of locusts of Arcypteridae (Orthoptera: Acridoidea), namely, Omocestus viridulus (Linnaeus), Euchorthippus unicolor (Ikonn.), and Euchorthippus vittatus Zheng, and so on, in Siping area of Jilin Province, China. The results revealed the following: (1) There was weak positive expression of the c-kit protein in spermatogonia and the positive granules were thinner; (2) there was a strong positive expression of the c-kit protein in primary spermatocyte and the positive granules became the largest than in all developmental stages; (3) the c-kit protein positive expression became stronger in secondary spermatocyte, while the positive granules became thinner; (4) there was strong positive expression of the c-kit protein and the positive granules were thinner in mature sperm, which were distributed on its head and tail; (5) there were strong positive protein granules massing at the end of spermary; (6) the positive intensity of the c-kit protein in spermatogenesis was significantly different among different species of locusts. The data suggested that the c-kit protein may play a crucial role in spermatogenesis as well as maintain the physiological action of sperms and fertilization, regulate the developmental speed of spermatogenesis, and/or maintain species isolation, etc.  相似文献   

17.
中国已成为继美国之后的全球第二大能源消费国,能源问题已成为制约一个国家经济发展的首要因素之一。目前,中国在解决能源问题方面,所采取的措施尚不能从根本上解决这一问题。提出能源农业的概念,系统阐述了能源农业的特点以及中国在发展能源农业方面所要采取的能源作物的筛选、培育、标准化栽培管理制度的建设、加工设备和加工工艺、能源转化设备转化效率和转化机制以及区域发展规划制定等一系列的基础及基础应用研究措施。  相似文献   

18.
The effects of salt-stress on plants involve not only the water stress caused by low osmotic pressure, but also the toxicity of excess Na^+. A large amount of Na^+ entering cells would reduce K^+ uptake, which leads to an imbalance of K:Na ratio in cells. One of the reasons for the reduced K^+-uptake is the closure of K^+-channel which is controlled by membrane potential. Calcium is usually applied to improve the growth of plants on saline soils and shows positive influence in the integrality of cell membrane. This study applied glass microelectrode technique to monitoring the NaCl-induced changes of membrane potential of root epidermal cells of maize (Zea mays L., Denghai 11) seedlings at NaCl concentrations of 0, 8, 20, 50, 100, 200 mmol L^-1, respectively. The effect of Ca^2+ on the changes of membrane potential caused by NaCl was also studied. The results showed that: NaCl caused cell membrane depolarization. The depolarization became greater and faster with increasing of NaCl concentration. Moreover, the extent of depolarization was positively correlated with NaCl concentration. The addition of calcium postponed the depolarization, and decreased the degree of depolarization caused by NaCl. High NaCl concentration leads to depolarization of maize root cell membrane, which can partly be counteracted by calcium.  相似文献   

19.
Water stress effects on stem diameter variations (SDV) were studied in a pot experiment on cotton (Gossypium hirustum L. Meimian99B). Water restriction was imposed at the flowering stage and were compared with a well-watered control treatment. The volumetric soil water content (0v) and SDV were monitored continuously. The objective was to determine the feasibility of using the parameters derived from stem diameter measurements, including maximum daily stem shrinkage (MDS), maximum daily stem diameter (MXSD), and minimum daily stem diameter (MNSD) as indicators of plant water stress. The different behavior of SDV was founded at different growth stages. At stem-maturing stage, MDS increased and MNSD decreased in deficit-irrigated plants compared with the control plants, therefore, it appeared that MDS and MNSD ccould be used as available indicators of plant water status. At stem growth stage, there were no significant differences in MDS values between treatments but MXSD and MNSD responded sharply to soil water deficits. Thus, for rapidly growing cotton, the course of MXSD or MNSD with time offered a consistent stress indicator. SDV was also closely related to atmospheric factors, solar radiation (Rs) and vapor pressure deficit (VPD) were found to be the predominant factors affecting MDS, followed by the relative humidity (RH), while air temperature (Ta) and wind velocity had the least effect. A good linear relationship was founded (r^2 = 0.921) between MDS and environmental variables (Rs, VPD, RH, and θv), which can be used to establish a reference value for detecting plant water stress based on the MDS patterns.  相似文献   

20.
Leptin,a protein hormone produced and secreted predominantly by white adipose tissue,has a critical role in the regulation and coordination of energy metabolism.Leptin is produced in the mammary gland by the fat tissue or by the mammary epithelium.In vitro study has shown that leptin triggers apoptosis in mammary epithelial cells.Mammary gland involution is characterized by extensive apoptosis of the epithelial cells.At the onset of involution,STAT3 is specifically activated.Various studies show that leptin act as a paracrine and autocrin factor to influence mammary epithelial cell proliferation and differentiation.This paper reviewed the function of leptin to the involution of mammary gland.  相似文献   

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