- Cheng Ji-yao;Wang Wan-peng;Li Wen-bin;Jiang Zhen-feng;
Maturity period is a critical trait in soybean breeding and determines the particularly ecological region of a cultivar.In present study,118 soybean varieties spanning three artificial breeding periods(1923-1970,the early breeding period;1971-1990,the mid-breeding period;and 1991-2010,the current breeding period)in northeast China were selected.Fourteen DNA-specified markers including cleaved amplified polymorphic sequences(CAPS),derived CAPS(d CAPS)and fragment length polymorphism(FLP)markers were filtered to analyze the genetic diversity from E1 to E4.The results were as the followings:the soybean varieties with more gene frequencies showed more gene diversities.Among the E genes,E1 and E3 genes showed more allelic diversities than E2,and E4 only had diversity in the early breeding period.During the artificial process,some alleles of E genes disappeared and some new ones were generated.More gene diversities were observed in soybean germplasms,and new excellent germplasms could be explored to improve yield traits in artificial breeding programs.Furthermore,six different E gene combinations were observed in the early breeding period,five in the mid-breeding period and 11 in the current breeding period.Three elite genotypes were identified through a century artificial selection,while new genotypes were also found in different breeding periods.Of them,e1-nle2e3-tr E4 was a new soybean genotype of extremely early maturity in the current breeding period,which was widely suitable for planting in 00 and 000 maturity groups.Moreover,significant correlation was found between E2 and E3,suggesting that light length and light quality were two key factors for soybean maturity in northeast China.The understanding of the E genes variation underlying soybean maturity could facilitate the procession to breed elite varieties adapted for diverse regions.
2020年01期 v.27;No.78 1-11页 [查看摘要][在线阅读][下载 619K] [下载次数：24 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：1 ] - Ren Hong-yu;Tao Pei;Zhuang Zhong;Li Xin;Li Xue-cong;Zhang Xing-wen;
In this paper, three soybean varieties with different qualities were used as experimental materials for potted plants. In the seedling stage and the flowering stage, different concentrations of lanthanum and cerium (120, 150 and 180 mg·L~(-1) LaCl_3; 30, 60 and90 mg·L~(-1) CeCl_3; 30, 40 and 60 mg·L~(-1) LaCl_3+30, 40 and 60 mg·L~(-1) CeCl_3) were sprayed to study the effects of lanthanum and cerium on soybeans (leaf photosynthetic pigment content, yield and the constituent factors). The results showed that chlorophyll contents of different qualities soybean leaves reached the maximum under 120 mg·L~(-1) LaCl_3 treatment. The yield of high protein soybean was the highest under 60 mg·L~(-1) CeCl_3 treatment, the yield of high fat soybean was the highest under 30 mg·L~(-1) CeCl_3 treatment, and the yield ofdual-purposesoybeanwasthelargestunder30mg·L~(-1)CeCl_3treatment.Therefore,thelanthanumandceriumsolutionshadthe effect of"low promotion and high inhibition"on chlorophyll contentof soybeans, and the cerium solution could increase the yields of different quality soybeans.
2020年01期 v.27;No.78 12-24页 [查看摘要][在线阅读][下载 421K] [下载次数：28 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：1 ] - Shan De-xin;Gao Jia-nan;Liu Xiao;Zhao Yue;Sun Meng-rui;Liu Lu;Xu Zhen-xuan;
To reveal patterns in scientific research results and compare differences in studies on fine particulate matter (PM_(2.5)) between China and the USA, 6608 publications from 1992 to 2016 were collected from the Science Citation Index Expanded (SCI-E)databaseandanalyzedbybibliometrics.Histcite~(TM), Bib Excel1.0.0.0, Net Draw and VOSviewer were used for statistical and visual analysis during this study. Publication outputs, journals, institutions, authors and author keywords were all analyzed to identify publication patterns, research hotspots and research trends. Based on this study, the number of publications produced in future years is expected to be at least twice that in 2016. The number of publications in China and the USA increased annually from 1992 through2014, promoted by improved social and economic conditions. Gross domestic product (GDP) was significantly positively correlated with the number of annual articles published in China and the USA (p<0.05). Through comparative analysis, it was observed that the output of publications in the USA before 2014 was larger than that in China. The total output of PM_(2.5)-related publications in China increased rapidly and far exceeded that in the USA after 2014. It is predicted that the leading region for research on PM_(2.5) in the future would be China. Analysis of author keywords indicated that"chemical composition"and"source allocation"were the main research hotspots in China and the USA. This research on exposure would be valuable in the future because of the pollution problem in China.Moreover, patterns and differences in scientific outcomes were revealed in this study and this study might provide potential guidelines for future research and management.
2020年01期 v.27;No.78 25-39页 [查看摘要][在线阅读][下载 1622K] [下载次数：12 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：1 ] - Bai Xiu-juan;Su Hang;Bao Jun;Lv Jing;
Behaviors, immunities and growth performances of suckling calves to either fed milk through barrel feeding or artificial nipple feeding were investigated in this study. Seventy-two newborn female suckling Holstein calves were selected and divided into two treatments which fed regular milk through milk barrels or artificial nipples. The behaviors′parameters were measured on 14,29 and 44 days. Body weight and body size of the calves were recorded on 15, 30 and 45 days. Immune indicators were collected in quiet situation on 15, 30 and 45 days. Compared with the barrel feeding method, calves fed by artificial nipples had less non-nutritive behaviors, stronger growth performances and higher immune levels. Artificial nipples gave calves sucking conditions and reduced the motivation of calves to suck each other, which might promote the development of complex stomachs, allow food to be better digested and more effective. It also reduced cross-infection indirectly which increased the calves'immunities.
2020年01期 v.27;No.78 40-48页 [查看摘要][在线阅读][下载 526K] [下载次数：17 ] |[网刊下载次数：0 ] |[引用频次：1 ] |[阅读次数：1 ] - Zhang Mei-mei;Li Yan-fang;Liu Da-sen;
The purpose of the paper was to study the effects of cellulolytic bacteria (CB) mixed with nitrogen-fixing bacteria (NFB)onfermentationinvitro.NineCBstrainsandsevenNFBstrainswereisolatedfromrumenfluidofthreeHolsteincows.Basedon higher activity of cellulose or nitrogenase, three CB types [CB-2(KT725624), CB-5(KT725623) and CB-6(KT725622)] and one NFB type [NFB-3(KT735054)] were screened out, respectively. Two parts were included in this study. The first part explored the optimal mixed ratio of CB to NFB through inoculating filter paper medium with the bacteria of 2×10~5 cfu·mL~(-1). According to CMCase and FPase activities in the medium, the ratio of 4 to 1 was proven to be more effective. In the second part, rumen fermentation in vitro was conducted at 4:1 of CB to NFB, aiming at studying the effects of mixed bacteria. Six groups were classified, namely, control group(no bacteria), Group 1 (CB-2+NFB-3), Group 2 (CB-5+NFB-3), Group 3 (CB-6+NFB-3), Group 4 (NFB-3) and Group 5 (CB-6). All the experimental groups had the same amount of bacteria (4×10~6 cfu·mL~(-1)) in the fermentation liquid. Samples were collected at 2, 4,8, 12 and 24 h of incubation. Compared with the groups with CB or NFB alone, gas production, dry matter degradability and bacterial protein expressions in the mixed groups increased. However, NH3-N concentration decreased and p H was stable. Meanwhile, related values among three mixed groups were significantly different; values in Group 2 were the best.
2020年01期 v.27;No.78 49-59页 [查看摘要][在线阅读][下载 643K] [下载次数：24 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：1 ] - Liu Da-wei;Cao Shu-xin;Wei Jing-kun;Qin Wen-chao;Liu Yang;Li Jia-ning;Xu Liang-mei;
The aim of this study was to determine the effects of supplementing organic forms of zinc(zinc acetate,ZnA)and inorganic zinc(zinc sulfate,Zn S)on performance,the gain to feed ratio(G:F)and skeletal characters in broilers from the first day to the 42th day.A total of 240-day-old broilers(Arbor Acres)were randomly distributed in four groups.A corn-soybean meal-based control diet containing recommended concentrations of inorganic trace minerals and other nutrients was prepared.On the basal diets,the control goup(CG)was supplemented with Zn S and the treatment group(TG)feeding diets were with different ZnA supplemental levels(80,100 and 150 mg·kg~(-1))of ZnA.Each group was allotted randomly to five replicates and 12 broilers in each replicate and fed ad libitum from the first day to the 42th day.The results showed that supplementation of ZnA significantly increased(p<0.05)energy and phosphorus(P)compared to that fed Zn S on the 21th day.Calcium(Ca),tibia weight,ash weight,tibia Ca and tibia P in TG(80 mg·kg-1 of ZnA)were the highest(p<0.05).The pancreas Zn content of TG was higher than that in CG and increased with the supplementation of ZnA.On the 42th day,the content of energy,crude protein(CP),Ca and tibia Ca in TG(80 mg·kg-1 of ZnA)were the highest(p<0.05),the change of pancreas Zn was the same as the results on the 21th day,but enter extract(EE),tibia weight,tibia length,tibia width and ash weight were not affected(p>0.05)by ZnA.The results of this study showed that ZnA was better than Zn S in improving the early growth performance,nutrient utilization rate in broilers,the length and weight of broiler tibia,it promoted the calcium,phosphorus deposition and normal growth of tibia,and the optimum dietary ZnA level to feed was 80 mg·kg-1.ZnA affected body Zn stores and the apparent metabolic rate of nutrients.
2020年01期 v.27;No.78 60-68页 [查看摘要][在线阅读][下载 527K] [下载次数：11 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：1 ] - Li Wei-qun;Wang Xin;Zhong Ming;Sun Xiao-qi;Zhao Lei;Huang Xiao-dan;Zhang Rui-li;Li Guang-xing;
Avian infectious bronchitis(IB)is an acute and highly contagious disease caused by infectious bronchitis virus(IBV).In the study,according to IBV gene sequences published in Gen Bank,specific primers were designed to clone N gene by RT-PCR,and this gene was inserted into p ET-30a(+)vector resulting in a prokaryotic expression plasma p ET-30a-N.The results of SDS-PAGE and Western Blot analysis showed that the recombinant protein was expressed successfully and had good reactivity with IBV positive serum.Using purified recombinant N protein as a coating antigen,the indirect ELISA protocol was established and optimized,in which N protein was 2.5μg·m L~(-1) of concentration,sample serum of 1:40 dilution.For clinical specimen,the IBV antibodies could be detected by this method efficiently and got nearly the same results as those of IBV-mediated ELISA.It would provide a good tool for rapid diagnosis and epidemiological study of avian infectious bronchitis.
2020年01期 v.27;No.78 69-79页 [查看摘要][在线阅读][下载 737K] [下载次数：45 ] |[网刊下载次数：0 ] |[引用频次：1 ] |[阅读次数：3 ] - Zhang Ying;Chen Hai-tao;Li Long-hai;He Yun-yang;
To obtain high quality raw materials,the optimization of process parameters of corn stalk-based raw material for straw fibre mulching film was studied.A central composite design(CCD)methodology of four factors and five levels was applied to determine the effects of four process variables,i.e.,stalk size,soaking time,working temperature and processing speed;the fibre yield,initial beating degree and fibre aspect ratio were selected as the objective functions.Fibre yield higher than 95%,initial beating degree greater than 9°SR and fibre aspect ratio greater than 45 were established as the expected values meeting the technical requirements of manufacturing stalk fibre mulching film.Response surface analysis methodology was employed.As a result,the optimal ranges of process variables were obtained as the following:the stalk size was from 3 cm to 10 cm,the soaking time was 18 h,the working temperature was 80℃,and the processing speed was 107-117 r·min~(-1).The results could be applied to the design and optimization of the D200 type stalk fibre preparation machine and to the process of making raw materials of corn stalk-based straw fibre mulching film.
2020年01期 v.27;No.78 80-89页 [查看摘要][在线阅读][下载 1073K] [下载次数：28 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：1 ] - Shi Feng-mei;Pei Zhan-jiang;Lu Bin-yu;Wang Su;Gao Ya-bing;Liu Jie;Wang Quan-hui;Huang Bo;
Agrometeorological disasters severely impact agriculture in Heilongjiang Province.Flood is one of the main agrometeorological disasters in Heilongjiang Province.The temporal change in flood events in Heilongjiang Province from 1986to 2015 was studied using Mann-Kendall and Morlet wavelet methods,respectively.The results of Mann-Kendall analysis showed that the disaster rates of flood gradually stabilized from 1986 to 2015 with a confidence level of 99%.The Morlet wavelet variance analysis revealed that disaster rates of flood changed periodically at time scales of 3a,7a and 18a in Heilongjiang Province during1986-2015.The dominant period of the variation of flood disaster rate was about 18a over the past 30 years.The flood disaster rates were indicated in a positive phase during the period of 2016-2020 by the fitting curve of Morlet wavelet analysis.The annual average flood disaster indexes of single station,during 1986-2015 years were calculated,according to the precipitation data at 31 stations in Heilongjiang Province and the GIS software was used to analyze the spatial change in flood disasters in Heilongjiang Province from1986-2015.The results demonstrated that the southwest area of Heilongjiang Province was highly hazardous region of flood.The flood indices in the northern part of Songnen Plain and southwest of Heilongjiang Province presented the increment trends.
2020年01期 v.27;No.78 90-96页 [查看摘要][在线阅读][下载 802K] [下载次数：16 ] |[网刊下载次数：0 ] |[引用频次：1 ] |[阅读次数：1 ] <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
2020年01期 v.27;No.78 97页 [查看摘要][在线阅读][下载 262K] [下载次数：11 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：1 ]