钙肥和砧木对‘岳冠’苹果水心病的影响

该试验以‘岳冠’苹果为试材,研究砧木和叶面喷钙对‘岳冠’苹果水心病发病率的影响.结果表明,以MAC9为砧木的苹果水心病自然发生率最低,为8.75％.叶面喷钙处理发生率最低的是以MAC9为砧木的,为5.65％;次低的是以山定子为基砧、GM256为中间砧的,为8.15％,且喷钙的防效最高.生产上应当选择MAC9为砧木,或山定子作基砧、GM256为中间砧.叶面喷钙对苹果水心病的防效较低,应改叶面喷肥为土壤施用.     

青海省部分规模化奶牛场乳房炎主要病原菌调查分析

为了初步摸清青海省部分规模化奶牛场奶牛乳房炎的发病情况,本研究采集了青海省5个规模化奶牛场共142份样品,进行细菌的分离鉴定、生化实验及耐药性检测。发现在5个规模化奶牛场中都有不同程度的乳房炎发生。鉴定结果显示,在142份样品中共检出大肠杆菌20株,检出率为14.08%(20/142);金黄色葡萄球菌6株,检出率为4.23%(6/142);链球菌2株,检出率为1.41%(2/142)。耐药性检测结果显示,大肠杆菌对氟苯尼考高度敏感,对头孢他啶、丁胺卡那比较敏感,对青霉素、链霉素等其他药物耐药。金黄色葡萄球菌对万古霉素、阿莫西林、氨苄西林、头孢他啶较敏感,对其他药物耐药。链球菌对阿莫西林、氨苄西林敏感,对其他药物耐药。     

水稻磷素对开放式空气CO2浓度增高响应的研究

2001～2003年利用农田开放式空气CO2浓度增高(FACE)系统平台，研究FACE对武香粳11号不同生育时期磷素含量、吸收、分配及其效率的影响。结果表明：①FACE处理使水稻不同生育时期植株磷素含量增加，增幅为2．48％～18．84％；②FACE处理使水稻不同生育时期磷素积累量显著或极显著增加，增幅为28．74％～59．11％，生育前期的增幅明显大于生育中、后期；⑧FACE处理对水稻抽穗前磷素在叶片、茎鞘中的分配比例无显著影响，但使抽穗后磷素在稻穗中的分配比例明显减少，在叶片和茎鞘中的分配比例明显增加；④FACE处理使水稻不同生育时期磷素物质生产效率增加，增幅为2．53％～16．58％；⑤FACE处理使水稻磷素籽粒生产效率和收获指数下降，降幅分别为6．53％～15．51％和1．48％～9．04％。     

配方施肥及氮肥后移对单季稻氮素累积和利用率的影响

为研究配方施肥及氮肥后移对水稻产量和氮肥利用率的影响,采用田间试验的方法,对比分析了常规施肥与配方施肥及氮肥后移条件下水稻产量、氮素累积量和氮肥利用率的差异。结果表明:1)与常规施肥相比,配方施肥使水稻成熟期叶片氮素总累积量和净累积量分别提高了9.43%~29.25%和8.45%~35.21%;水稻产量增加了1.16%~2.86%、氮肥利用率提高了10.12%~18.61%、产出与投入比增加了0.09%~3.8%。2)在相同施氮水平下,与PF1(基∶蘖∶穗=60%∶30%∶10%)处理相比,氮肥后移的PF2(基∶蘖∶穗=40%∶30%∶30%)处理使水稻成熟期叶片氮素总累积量和净累积量提高了17.24%和23.38%;水稻产量、氮肥利用率和产出与投入比分别提高了0.38%、7.06%和0.64%。3)水稻产量和氮肥利用率分别与成熟期叶片全氮含量及氮素总累积量存在显著或极显著正相关,相关系数(R)在0.85*~0.99**之间。这表明,配方施肥和氮肥后移可通过增加水稻生育期叶片氮素含量和累积量,提高水稻产量和氮肥利用率,增加经济效益。     

甘蔗健康脱毒种苗生产技术方法研究初报

利用茎尖离体组织培养与热水处理相结合的技术方法,进行甘蔗脱毒健康种苗生产研究。试验结果表明:该方法生产的无病无毒的健康种苗,在出苗、分蘖、生长速度、株高、茎径、有效茎及产量等方面与对照比有显著差异,蔗茎增产幅度达26.65%～69.39%。     

土壤放线菌生防活性物质的研究进展

放线菌是一类有着广泛实际用途的微生物资源,从土壤放线菌的杀菌活性、除草活性、杀虫、杀螨活性等方面对土壤放线菌生防活性物质研究进行了综述。     

Effects of different stocking densities on the growth performance and antioxidant capacity of Chinese mitten crab (Eriocheir sinensis) in rice crab culture system

This study assessed the effects of stocking density (D02, 0.2 individuals/m²; D03. 0.3 individuals/m²; D04, 0.4 individuals/m²; D05, 0.5 individuals/m²; D06, 0.6 individuals/m²) on Chinese mitten crab (Eriocheir sinensis; 6.25?±?0.11 g) growth performance, tissue indices, antioxidant enzyme activity (total superoxide, catalase, glutathione peroxidase, total antioxidant capacity, and malondialdehyde), and mRNA expression of antioxidant-related genes (SOD, CAT, GPx) in rice crab culture systems. Our results demonstrated that increasing stocking densities decreased the final weight (FBW), weight gain rate (WGR), specific growth rate (SGR), feed conversion efficiency (FCR), and protein efficiency ratio (PER) of the crabs. The hepatosomatic index (HSI) of female crabs in D04 group was higher than that of other groups. The gonadosomatic index (GSI) of the male crabs in the D04 group was significantly higher than that of the other groups(P?<?0.05). The meat yield (MY), total edible yield (TEY), and condition factor (CF) of the female and male crabs in the D04 group were higher than those of the other groups. The antioxidant enzyme activity (T-SOD, CAT, GSH-Px, and T-AOC) of male and female crabs in the D04 group was significantly higher than that of the other groups, and the MDA content of the D04 group was significantly lower than that of the other groups (P?<?0.05). The stocking density of 0.4 individuals/m² effectively promoted the efficient mRNA expression of SOD, CAT, and GPx genes in the hepatopancreas of male and female crabs. In summary, the optimal stocking density of E. sinensis in the rice crab culture system is 0.4 individuals/m².

     

香樟黄化病防治对春季生长发育的影响

香樟是合肥市区栽植最多的行道树,但近年来黄化病发生普遍且严重,成为园林生产中的主要问题之一。本文对该病采用3种不同的试剂注射滴灌,结果表明:3种试剂处理对香樟的落叶与发芽时间、叶面积、新梢长度、叶绿素含量等都有明显增加,尤其试剂3[1.2%FeSO4和0.8%CO(NH2)2]防治后生长增幅最大,复绿效果最为明显,与对照相比:发芽时间提前24d、落叶时间推迟16d;新梢生长增幅230.77%;叶长及叶宽增长率分别为21.81%和31.23%,总叶绿素含量增加130.65%。建议在生产中推广应用。     

Interrelation between the structure and the function of artific ial ribozyme M1GS

AIM:To study the interrelation between the structure and the function of artificial ribozyme M₁GS.METHODS:Ribozyme M₁GS-T₇,which targeted the mRNA segment o f HCMV UL54 gene,was constructed.The secondary structure of M₁GS was simulat ed under different temperatures (20 ℃,37 ℃ or 55 ℃,at which the secondary s tructure of M₁GS was relatively stable) and the interrelation between the seco ndary structure and the cleavage activity of M₁GS was analyzed under different temperature in vitro.To investigate the interrelation between the structur e and the function of ribozyme M₁GS further,mM₁GS-T₇ was designed,in whi ch some mutation sites was added,according to the result of temperature change experiment and the simulated secondary structure,showing that were the same str uctures at 37 ℃ as that of M₁GS-T₇ at 55 ℃.RESULTS:In temperature change experiment,the cleavage activity of M₁GS-T₇ was highest at 55 ℃.The result of mutant experiment showed tha t the mutant type was more active than M₁GS-T₇ at 37 ℃.CONCLUSION:The cleavage activity of M₁GS,which has some cert ain secondary structure,is higher than others.There is some interrelation bet ween the structure and the function of M₁GS.     

江苏直播稻发展历程回顾、弊端分析及其对策探讨

简要阐述了人工栽插、抛秧、机插秧、直播稻等几种稻作方式在江苏的应用情况,以及直播稻在江苏省的发展历程,对江苏省直播稻迅速发展的原因、生产中存在的弊端以及生产效益进行了简要分析,并提出了控制直播稻盲目发展的一些具体措施。