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101.
分析木霉菌MM35、MM7、MM8、MM9、ZT1、ZT2对大豆幼苗生长的影响,其中MM7、ZT1和ZT2的孢子悬浮液在104cfu·mL-1和105cfu·mL-1的浓度下对大豆发芽不会产生影响,其代谢产物对大豆发芽没有抑制作用.盆栽试验表明:木霉菌MM7不对大豆幼苗产生致病性,且使株高增加13%.盆栽灭菌条件下研究木霉MM7在大豆根部定殖能力表明:木霉菌MM7可随大豆主根和侧根的生长而不断繁殖,且在土壤表面以下0~5 cm大豆根际土壤中MM7孢子数量明显高于5~10 cm和10~15 cm的土层,随着生育时间的延长,不同土层大豆主根和侧根表面木霉菌数量均可在12 d~22 d之间达到最高值,在根的表面形成保护层,对于大豆苗期病原菌起到一定抑制作用. 相似文献
102.
103.
针对目前黑龙江垦区的水位监测现状,以及测点分散、距离远等特点,采用集散结构,以计算机为主控机,单片机为下位机采集水位数据,采用GPRS无线通信模块完成数据远程传输。利用C#语言编程将下位机获取的数据通过串口进行读取、转换、读取并实时显示。通过VS2008.NET编程环境中的Serial Port类和Thread类,大大提高了程序的运行效率。通过实际应用表明,基于GPRS模块进行远程地下水水位监测是一种经济、可靠、便捷的监测系统。 相似文献
104.
棕榈藤作为一种重要的生物质材料,其利用对部分替代木材和保护森林资源发挥着重要作用。以黄藤和单叶省藤为研究对象,通过对其改性处理前后主要物理力学的性质变化进行研究,提高我国棕榈藤资源高附加值加工利用水平。研究结果表明,两种藤材通过改性处理后,除部分吸湿率升高之外,其他物理力学性质均有所改善,如抗弯弹性模量、抗弯强度、抗压弹性模量、抗压强度、密度、体积干缩率、吸水体积膨胀率以及材质均匀度等。 相似文献
105.
鲁西牛和秦川牛体尺性状与胴体性状间典型相关分析 总被引:1,自引:0,他引:1
为揭示肉牛体尺性状与胴体性状两组变量之间相关本质,对鲁西牛和秦川牛的4个体尺性状和7个胴体性状分别进行典型相关分析,结果表明:鲁西牛和秦川牛的体尺性状和胴体性状间都存在较强的相关,其第1典型相关系数均达到极显著相关水平(P0.01),典型相关系数分别是0.886和0.985,占到总相关信息的66.00%和92.92%,第2典型相关系数分别是0.738和0.802,累积占到总相关信息的87.73%和98.16%。鲁西牛体尺性状和胴体性状间第1对典型相关主要由胸围(A4)与胴体重(B1)引起,第2对典型相关主要由体高(A1)与后腿长(B5)引起,而秦川牛体尺性状和胴体性状间第1对典型相关主要由管围(A3)、胸围(A4)与胴体重(B1)、后腿长(B5)、胴体长(B7)引起,对2个品种牛两组性状的选育应侧重于这几个性状的表现,可以达到较理想的效果。 相似文献
106.
Chemical fertilizer reduction and soil fertility maintenance in rice-fish coculture system 总被引:1,自引:0,他引:1
Jian Xie Xue Wu Jianjun Tang Jiaen Zhang Xin Chen 《Frontiers of Agriculture in China》2010,4(4):422-429
In the long run, whether the use of chemical fertilizers could be reduced and soil fertility could be maintained through rice-fish
coculture is less well known. At the pilot site of the rice-fish coculture system, which is one of the five “globally important
agricultural heritage systems” (GIAHS), we conducted a 4-year study to compare fertilizer use, rice yield, and soil fertility
in rice-fish coculture and rice monoculture. Based on the survey data from 21 villages, rice yield did not differ between
rice monoculture and rice-fish coculture, but less chemical fertilizers were used in rice-fish coculture than in rice monoculture.
Survey data from 145 farms also showed that rice-fish coculture farms with high input of feed for fish used less chemical
fertilizers for rice production than farms with low input of feed for fish. In the 4-year field experiment, although less
fertilizer was used in rice-fish coculture, rice yield, soil organic matter, soil total nitrogen, and soluble phosphorus did
not differ between rice-fish coculture and rice monoculture. Our results suggest that rice-fish coculture can reduce chemical
fertilizers application, enhance land productivity, and maintain soil fertility. Our results also suggest that rice-fish coculture
could reduce the risk of non-point source pollution by reducing the input of chemical fertilizers. 相似文献
107.
有机、特别与常规种植体系对小麦土壤养分的影响 总被引:1,自引:0,他引:1
在江苏溧阳设立了田间定位试验,对有机、特别、常规3种种植体系小麦苗期、分蘖期、拔节期及成熟期土壤养分含量进行了比较。结果表明:在小麦的生长期有机种植体系比特别和常规种植体系的土壤肥力性质稳定、变化幅度小,种植前相比,成熟期的土壤有机质、全氮、碱解氮、速效磷含量均有所增加;常规种植体系土壤pH值及基本养分在分蘖期和拔节期变化较有机和特别种植体系大,种植前相比,成熟期的土壤有机质、全氮、速效磷及速效钾均有所减少;特别种植体系各项土壤指标基本介于有机和常规种植体系之间,因此,有机种植体系在小麦生长期中维持了土壤肥力的稳定,并有效提高了土壤养分含量。 相似文献
108.
Zhiping Cheng Anchun Cheng Mingshu Wang Bin Chen Chuang Liu Kun Duan Xue Zhou Xiaoyue Chen 《Frontiers of Agriculture in China》2008,2(3):343-347
In order to study the effect of cell mediated immunity regulation of duck IFN-α eukaryon expression plasmid (pcDNA-SDIFN-α)
on duck plague virus (DPV) attenuated vaccine in ducks, pcDNA-SDIFN-α was administered to 28-day-old ducks at doses of 1,
3 and 6 μg per duck, respectively, by gene-gun. PBS and empty vector pcDNA were used as control. Fifteen days later, all ducks
were injected with DPV attenuated vaccine and blood samples were collected at 3, 7, 14, 21, 28, 35, 49, 63 and 84 days after
injection. T-lymphocyte proliferation tests (MTT) were used to detect the T-lymphocyte proliferation in the peripheral blood
(PBL) of ducks. Blood samples collected at 7, 14, 21, 28, 35 and 49 days after injection were detected by fluorescence-activated
cell sorter (FACS) for recording the number of CD3
+ T-lymphocytes of ducks. Results were as follows: (1) Reaction of T-lymphocytes in PBL to ConA (OD value) of ducks treated with pcDNA-SDIFN-α was higher than that of PBS and pcDNA control groups in 3–84 days. There
were highly significant differences between the 1 μg per duck group and the two control groups in 3–84 days (P ⩽ (0.01), between the 3 μg per duck group and the two control groups in 3–84 days (P ⩽ 0.01, P ⩽ 0.05), and between the 6 μg per duck group and the two control groups in 7–49 days (P ⩽ 0.01, P ⩽ 0.05). The significant difference was also present between the groups of 1, 3 and 6 μg per duck in 3–35 days (P ⩽ 0.05). However, there was no significant difference between the 3 and 6 μg per duck groups (P ⩾ 0.05). The pcDNA control group was higher than PBS control group, but no difference was detected (P ⩾ 0.05). (2) Change of the number of CD3
+ T-lymphocytes in ducks administered with different doses of pcDNA-SDIFN-α was higher than that of PBS and pcDNA control groups
in 7–49 days. The change in the 1 μg per duck group was significantly higher than that in PBS and pcDNA control groups in
14–49 days (P ⩽ 0.01). There were significant differences between the 3 μg per duck group and the two control groups in 21–49 days (P ⩽ 0.01, P ⩽ 0.05) and between the 6 μg per duck group and the two control groups in 7–49 days (P ⩽ 0.01, P ⩽ 0.05). However, no significant differences among the groups of 1, 3, and 6 μg per duck groups (P ⩾ 0.05) and between the two control groups (P ⩾ 0.05) were found. The results indicated that pcDNA-SDIFN-α administered 15 days before injection of DPV-attenuated vaccine
could significantly enhance cellular immunity induced by DPV-attenuated vaccine. pcDNA-SDIFN-α is an excellent DPV-attenuated
vaccine molecular adjuvant and the best result can be obtained with the dose of 1 μg per duck of pcDNA-SDIFN-α inoculated
by gene-gun.
__________
Translated from Acta Veterinaria et Zootechnica Sinica, 2007, 38 (10): 1066–1071 [译自: 畜牧兽医学报] 相似文献
109.
110.
农药残留对食品安全的影响及其对策 总被引:1,自引:0,他引:1
从农药残留和食品安全的定义出发,论述了使用农药的利与弊、农药残留对食品安全的影响,分析了食品中农药残留的来源,有针对性地提出控制农药残留的措施和确保食品安全的对策。 相似文献