- Wang Yong-chao;Gu Wan-rong;Ye Le-fu;Sun Yang;Li Li-jie;Zhang He;Li Jing;Wei Shi;
At the beginning of silking, maize production began to form, but leaves started senescence and photosynthetic capacity decreased at this time, all of those severely restricted the formation of the production. In order to study the effects of exogenous substances on the process of leaf senescence, 40 mg · L-1 DCPTA and 20 mg · L-1 CCC were mixed in the research. When the maize grew to the six expanded leaves stage, 10 m L compound mixtures(TR) were sprayed on both sides of leaves for per plant, and the control was treated with water(CK). Three plants were selected randomly for determination of physiological index at the 10, 20, 30, 40 and 50 days after silking. The results showed that TR could increase the chlorophyll content signifi cantly, Fv/F m, Fv/F0 and Y(II) values of TR were higher than those of CK while F0 values were opposite. Compared with CK, TR increased SOD and POD activity and soluble protein content, reduced MDA content. Correlation analysis showed that chlorophyll content had negative correlation with F0, and MDA content had negative correlation with other indexes. Compared with CK, TR reduced the negative correlation effect between chlorophyll content and MDA, increased the positive correlation effect between chlorophyll content and Fv/F m, SOD, POD, soluble protein. The study provided theoretical and experimental evidence for the application of the compound mixtures of DCPTA and CCC to the production.
2015年03期 v.22;No.60 1-15页 [查看摘要][在线阅读][下载 336K] [下载次数:61 ] |[网刊下载次数:0 ] |[引用频次:4 ] |[阅读次数:56 ] - Musa A K;Adeyemi A A;
The insecticidal potential of seed powders of Capsicum chinense Jacq.(Solanaceae) and Aframomum melegueta K. Schum.(Zingiberaceae) was tested against Trogoderma granarium(Coleoptera: Dermestidae) in the laboratory at(28±2)℃ and 70%±5% relative humidity. The seed powders were tested at the rates of 0.0%, 0.5%, 1.0% and 1.5%(w/w) of groundnut seeds replicated three times. At the highest rate of treatment, C. chinense caused 56.7% and 76.8% larval mortality at 3 and 7 days post treatment(DPT) respectively while A. melegueta exerted 53.4% and 73.8% larval mortality at 3 and 7 DPT, respectively. Results showed that insecticidal potential of the seed powders against adult mortality of T. granarium and seed damage followed similar trend. The various rates of C. chinense seed powder performed better than A. melegueta seed powder in causing larval and adult mortality and in reducing seed damage. The activity of the seed powders on mortality of the insect, seed weight loss and seed damage were exposure time and rate dependent. A signifi cant reduction(p<0.05) in seed weight loss and seed damage was recorded among the treatments and maximum reduction was observed in the seeds treated with the highest rate of C. chinense seed powder. Percentage seed damage signifi cantly(p<0.05) decreased with increase in the rate of treatment while the highest seed weight loss and seed damage were obtained in the control. The study showed that C. chinense seed powder had higher activity against the test insect pest than A. melegueta seed powder. The two seed powders had high bio-activity against the insect and therefore could be used in formulating environment friendly plant-derived insecticide.
2015年03期 v.22;No.60 16-22页 [查看摘要][在线阅读][下载 43K] [下载次数:19 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:42 ] - Li Ran;Han Lan-lan;Ye Le-fu;Zhang Hong-yu;Sun Wen-peng;Tong Xin;Zhao Kui-jun;
Aphis glycines(Hemiptera: Aphididae) is considered as a cosmopolitan pest of cultivated soybean, major diffi culties in its control measures may be due to its higher genetic diversity; however, the knowledge about population genetic diversity of this species is limited. This study aimed to represent the genetic differentiation among different geographic populations of soybean aphid in Northeast China. In order to investigate and assess the genetic diversity, genetic differentiation, molecular variance, population structure, ecological importance and evolutionary history of A. glycines, we sequenced a fragment of one protein-coding gene, the cytochrome c oxidaseⅡof mitochondrial DNA gene. The results showed that four haplotypes were defi ned among COⅡ gene of 180 sequences of soybean aphid in Northeast China including H1 shared by all the populations. Lower haplotype diversity(Hd=0.3590±0.0420) and nucleotide diversity(Pi=0.0012±0.0002) were observed and high gene flow was detected in every two populations, while most of the variation(80.81%) arose from variability within A. glycines from individuals. Low genetic differentiation and high gene fl ow(Nm=2.106) indicated a high migration rate between the populations, which might reveal that gene flow in different geographic populations did not affect by geographical distance. The phylogenetic tree and the haplotype network of A. glycines were obtained based on sequences of COⅡ gene, there were no signifi cant genealogical branches or clusters recognized in NJ tree, and no clear distribution, delineation of haplotypes were demonstrated in the haplotype network according to geographical location. This study rejected the vicariance hypothesis: geographic isolation could be a barrier and it restricted A. glycines gene fl ow among 10 populations.
2015年03期 v.22;No.60 23-31页 [查看摘要][在线阅读][下载 146K] [下载次数:46 ] |[网刊下载次数:0 ] |[引用频次:1 ] |[阅读次数:50 ] - Ge Xiao-ying;He Chun-e;Li Tao;Ouyang Zhu;
Bacillus subtilis(B. subtilis) and Pseudomonas fluorescens(P. fluorescens) are two of the most important plant growth promoting rhizobacteria(PGPR) in agriculture. An in situ trial was conducted on greenhouse tomato(Lycopersicum esculentum Mill.) to examine the effect of two bacterial strains, Bacillus subtilis(CGMCC 1.3343) and Pseudomonas fluorescens(CGMCC 1.1802), on tomato growth, gray mold disease control, catabolic and genetic microbial features of indigenous rhizosphere bacteria under lownitrogen conditions. A commercial inoculant(ETS) was also tested as a comparison. Both B. subtilis and P. fluorescens promoted growth and biomass of seedlings, while only B. subtilis was effi cient in reducing gray mold incidence in greenhouse tomato. The two bacterial strains could colonization in tomato rhizosphere soil at the end of experiment(10 days after the last inoculation). Different AWCD trends and DGGE patterns were got in different bacterial treatments; however, analyses of microbial diversities showed that indigenous soil microbes did not seem to have signifi cant differences at either the catabolic or genetic level among treatments. ETS, as a commercial microbial agent, promoted plant growth and gave a higher microbial diversity in rhizosphere soil.
2015年03期 v.22;No.60 32-42页 [查看摘要][在线阅读][下载 145K] [下载次数:48 ] |[网刊下载次数:0 ] |[引用频次:1 ] |[阅读次数:52 ] - Hasnain Alam;Muhammad Razaq;Salahuddin;
Tea(Camellia sinensis L.) represents different ploidy levels. In the present paper, we reviewed the recent data on the diploid, aneuploid and polyploid formed their origin and chemically induced polyploidy and predicted it role in teagenetic improvement for better yield. Different polidy levels had different effects on tea physiology. Tetraploid and triploid had more vigour and hardness due to increased size of cells, while triploid could have even more vigours due to increased size of cells and sterilities. Chemically induced polyploidy had been found an important tool for improving plant physiology and production, therefore, induced polyploids should be produced to overcome the problem of low yield and limited rainfall in tea growing areas.
2015年03期 v.22;No.60 43-47页 [查看摘要][在线阅读][下载 52K] [下载次数:28 ] |[网刊下载次数:0 ] |[引用频次:3 ] |[阅读次数:45 ] - Mohsin S B;Li Yi-jing;Tang Li-jie;Maqsood I;Ting Ma-sun;Han Le-meng;Khalil U R;Andleeb S;Muhammad S K;Saleem M A;
Distinction of predator's diet and prey choice preference is a hot topic of current investigations. Spider being generalist predator and cosmopoliter in nature acts as biological control agent in many agro-ecosystems. In the current study, predatory efficacy of five spiders(Pardosa birmanica, Cyclosa insulana, Thomisus projectus, Plexippus paykulli and Lycosa terrestris) inhabiting the cotton fi eldevaluated in the laboratory conditions maintained at(27±2)℃ temperature, 65%±5% relative humidity and 12 : 12 h of light and dark photoperiod. Four key cotton pests' viz. Bemisiatabaci, Amrascadevastans Thripstabaci and Helicoverpa armigera were utilized in the choice and no-choice predatory studies. The findings of current investigation revealed that each predatory spider utilized at least one pest species. Predation rate was found higher in the no-choice predation because of unavailability of substitutes feeding source. The investigation also indicated each predatory spider killed more pests than consumed. The findings of this study support the predatory role of spiders in controlling the cotton major pests.
2015年03期 v.22;No.60 48-53页 [查看摘要][在线阅读][下载 167K] [下载次数:14 ] |[网刊下载次数:0 ] |[引用频次:1 ] |[阅读次数:46 ] - Song Ren-ju;Tong Hui-li;Huang Jian-guo;Gao Xue-jun;
Feedstuff intake plays key role in impacting the yield and quality of milk. In this study, we discussed the contents of trace metal elements in cow milk impacted by different feedstuffs. We detected the contents of Pb, Cd, As, Cu, Mg, Ca, Fe and Zn in different feedstuffs and milk by atomic absorption spectrophotometry. The determinations of Pb, Cd and As contents were by graphite furnace AAS and Cu, Mg, Ca, Fe and Zn was by fl ame atomic absorption spectrometry. The results showed that Pb, Cd, As and Cu presented in feedstuffs, but Pb, Cd and As were lowly detected in milk samples, and Cu was not detected in milk samples. The content of Mg in concentrates was lower than that in forages. However, the content of Mg in milk from concentrate feed was higher than that in forage feed. This suggested that the utilization of Mg in concentrate feed was higher than that in forage feed. The contents of Ca and Zn were opposite to Mg, and the utilization of Ca and Zn in forage feed was higher than that in concentrate feed. There was no obviously change law of Fe in different feedstuffs and milk samples. The relationship between the contents of trace metal elements in milk to feedstuffs would provide a theoretical basis for dairy farming. It would be useful for improving the milk yield and milk quality of dairy production.
2015年03期 v.22;No.60 54-61页 [查看摘要][在线阅读][下载 52K] [下载次数:32 ] |[网刊下载次数:0 ] |[引用频次:1 ] |[阅读次数:85 ] - Zhao Xun-wu;Zheng Peng;Huang Zhi-jun;Zeng Yue;Adegoke E O;Zhang Gui-xue;
The experiment was designed to study effects of retinoic acid and ascorbic acid on differentiation of mouse embryonic stem cells to cardiomyocytes. Embryonic bodies(EB) were developed from m ESC in suspension culture, different levels of concentration of retinoic acid and ascorbic acid were used to determine the optimal conditions for EB formation. The results showed that the optimal concentrations were 10-9 mol · L-1 and 0.1 mg · m L-1 for retinoic acid and ascorbic acids, respectively. 50% of EB which was significantly(p<0.05) different from the control group developed to cardiomyocytes. In conclusion, retinoic acid and ascorbic acid had strong ability to promote cardiomyocyte differentiation of mouse embryonic stem cells. 10-9 mol · L-1 retinoic acid and 0.10 mg · m L-1 ascorbic acids were recommended to induce differentiation of mouse ES cells toward cardiomyocytes.
2015年03期 v.22;No.60 62-66页 [查看摘要][在线阅读][下载 204K] [下载次数:32 ] |[网刊下载次数:0 ] |[引用频次:1 ] |[阅读次数:47 ] - Ebewore S O;Ovharhe O J;Emaziye P O;
The study examined the acceptability of bush meat to Deltans. The specifi c objectives were to ascertain the consumption pattern of bush meat; identify the major types of bush meat consumed in the area; determine the likely constraints to bush meat consumption; and stipulate the extension implication of the fi ndings. A systematic sampling technique was used to compose a sample size of 410 respondents. Data used for this study were collected using well structured interview schedule and data were analyzed using descriptive statistical techniques such as tables, percentages, means and standard deviation, and inferential statistics(linear regression model). The result of the study indicated that almost all the respondents(402) representing about 98% was formally consuming bush meat. The fi ndings also revealed that as many as 323 individuals, representing 78.8% of the respondents did not consume bush meat currently. Only about 12.7% and 8.5% occasionally and regularly consumed bush meat respectively. It was therefore very obvious that people no longer consumed bush meat in Delta state as before. The results further indicated that the predominant bush meat consumed in the area were cane rat(97.70%) and the African giant snails(Achatina and Archachatina)(94.25%). The result of the multiple regression analyses indicated that the coeffi cient for education(X3), income(X5), Ebola(X6) and availability of game(X7) were signifi cant at 5%, indicating that these variables were important factors infl uencing the consumption of bush meat in the study area. However, the coeffi cients of education level and Ebola factor were negative and signifi cant, suggesting respondents with higher education and aware of Ebola disease were not likely to consume bush meat. As the result, it was concluded that bush meat was now almost unacceptable due to several factors like dread of Ebola disease, unavailability of game, educational level and income, which signifi cantly affected the consumption of bush meat. It was therefore recommended among others that extension delivery services on how to domesticate game species should be available to farmers.
2015年03期 v.22;No.60 67-78页 [查看摘要][在线阅读][下载 141K] [下载次数:15 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:63 ] - Zhou Li;
The social and economic development level of rural areas, the productivity of agriculture and the life quality of farmers were always the greatest concerns of Chinese Central Government. Therefore, the research related to rural areas, agriculture and farmers had remained as the prominent parts for a long period and would continue to be prominent in the future to build China into a moderately prosperous nation in an all-round way. Chinese rural area had constantly experienced three signifi cant system reforms since 1978, namely the reform of rural management system, the rural tax and fee reform and the rural comprehensive reform. This paper attempted to analyze the theoretic framework and the content structure of the comprehensive rural reform since it was the higher stage of rural institutional vicissitude, which had changed the governance and operation system and thus promoted the great changes to fundamental social and economic system in rural areas. The theoretic framework of comprehensive rural reform covered three aspects in its content, namely the rural governance theory, the government function theory and the public finance theory. The comprehensive rural reform was a complicated system engineering with multiple dimensions and targets mainly including rural political restructuring, rural economic restructuring and rural public products allocation restructuring. The reform had focused on enhancing the vitality of agricultural and rural development, breaking through the urban and rural binary system, and further reducing the disparity between cities and countrysides, so as to realize the urban-rural integration. It was necessary to clarify and understand the key mechanism and intrinsic logic of the rural comprehensive reform, which was helpful to establish the foundation constituted by scientifi c methodology to implement the reform and evaluation criterion to judge the reform performance.
2015年03期 v.22;No.60 79-90页 [查看摘要][在线阅读][下载 62K] [下载次数:51 ] |[网刊下载次数:0 ] |[引用频次:4 ] |[阅读次数:38 ] - Zhao Qi;
At present, an automatic-mechanic contact tap-changer is widely used in power system, but it can not frequently operate. In addition, arc will occur when the switch changes. In order to solve these two problems, this paper presented an automatic on-load voltage-regulating distributing transformer which employed non-contact solid-state relay as tap-changer, and mainly introduced its structure, basic principal, design method of each key link and experimental results. Laboratory simulation experiments informed that the scheme was feasible. It was a smooth and effective experiment device, which was practical in application.
2015年03期 v.22;No.60 91-96页 [查看摘要][在线阅读][下载 124K] [下载次数:51 ] |[网刊下载次数:0 ] |[引用频次:4 ] |[阅读次数:45 ] <正>Aims and Scope Journal of Northeast Agricultural University(English Edition)is a comprehensive academic journal on agricultural sciences sponsored by Northeast Agricultural University and distributed worldwide.It is a peer reviewed journal published quarterly and mainly publishes review and research articles that reflect the latest achievements on
2015年03期 v.22;No.60 97页 [查看摘要][在线阅读][下载 12K] [下载次数:5 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:46 ] 下载本期数据