抗生素对根癌农杆菌抑制作用及对大豆子叶节再生的影响分析

以周豆12大豆子叶节为材料,研究了头孢呋辛钠、头孢曲松钠、头孢噻肟钠和头孢唑林钠4种抑菌抗生素对农杆菌的抑制作用和对大豆子叶节再生的影响,以及卡那霉素对大豆子叶节再生的影响。结果表明:随着卡那霉素浓度的增加,子叶节分化率逐渐降低,当浓度达到45 mg/L时,分化芽的生长几乎完全受到抑制,植株出现白化现象;4种抑菌抗生素中,头孢曲松钠对农杆菌的抑制作用最好,头孢呋辛钠和噻肟钠抑菌效果次之,结合抑菌抗生素对子叶节再生的影响作用,确定在大豆子叶节的遗传转化中,使用头孢曲松钠或头孢噻肟钠作为抑菌抗生素,临界浓度分别为200 mg/L和300 mg/L。而卡那霉素使用的临界浓度为45 mg/L。     

玉米灌浆期抗旱性鉴定形态指标的筛选

以9个玉米品种为试验材料,在大田设置自然干旱胁迫试验与正常灌水试验,对叶面积、株高、干物质、穗位高等8个形态指标进行测定,用8个指标的相对值与抗旱指数进行相关分析.结果表明:叶面积可作为抗旱性鉴定的一级指标;株高、干物质、雄穗分支数、雄穗大小可作为抗旱性鉴定的二级指标;其余指标可作为抗旱性鉴定的三级指标.     

突变体蛋用黑羽鹌鹑生产性能研究

将48只突变体蛋用黑羽鹌鹑进行单笼饲养,并对其开产日龄、开产蛋重、产蛋率、平均蛋重及饲料利用情况等进行了研究。结果表明,突变体蛋用黑羽鹌鹑开产日龄为53d,相对于其他品系稍晚;其开产蛋重量为8.9g;开产至开产15周龄的平均产蛋率为81%,平均蛋重为10.9g,符合鹌鹑蛋的加工要求;开产1～15周龄的平均料蛋比为3.01±0.31。     

谷氨酰胺替代饲用抗生素对黄羽肉鸡生产性能和屠宰性能的影响

[目的]研究基础日粮中添加谷氨酰胺替代饲用抗生素对黄羽肉鸡生产性能及屠宰性能的影响.[方法]将180只1日龄的黄羽肉鸡随机分为5个处理组(每个处理组3个重复,每个重复12只).分组情况:阳性对照组在基础日粮中添加饲用抗生素(0.03;那西肽+0.025;硫酸粘杆菌素预混剂);阴性对照组饲喂基础日粮;试验Ⅰ组在基础日粮中添加0.1;谷氨酰胺;试验Ⅱ组在基础日粮中添加0.2;谷氨酰胺;试验Ⅲ组在基础日粮中添加0.3;的谷氨酰胺.[结果]81 d时各组平均体重分别为2.72、2.66、2.62、2.84、2.68 kg,差异不显著(P＞0.05),试验Ⅱ组平均体重比阳性对照组高4.41;.8～81 d料重比分别为2.67、2.66、2.80、2.64、2.62,差异不显著(P＞0.05),日粮中分别添加0.1;谷氨酰胺、0.2;谷氨酰胺及0.3;谷氨酰胺替代饲用抗生素,黄羽肉鸡81 d体重、饲料转化率、胴体品质等指标上各组间无显著差异(P＞0.05).[结论]从黄羽肉鸡81 d体重、料重比、死亡率等指标综合来看,用添加0.2;谷氨酰胺替代黄羽肉鸡饲用抗生素是可行的.     

金坛地区螟虫发生概况与防治对策

分析了1995年以来江苏省金坛市二化螟Chilo suppressalis(Walker)、三化螟Tryporyza incertulas(Walker)的发生动态与防治方法,从冬后基数、灯诱数量、秧田期与大田期的防治、成熟期考察等几方面分析了螟虫种群在江苏省金坛市的消长动态,总结了螟虫的防治经验.     

江西省阳际峰自然保护区苔藓植物区系研究

对江西省阳际峰自然保护区3000号标本进行鉴定,发现该地区共有苔藓植物57科133属297种(含种下级单位),其中藓类植物33科94属207种,苔类植物24科39属90种;≥10种的苔藓植物优势科有细鳞苔科Lejeuneaceae、灰藓科Hypnaceae、蔓藓科Meteoriaceae、锦藓科Sematophyllaceae、丛藓科Pottiaceae、绢藓科Entodontaceae、曲尾藓科Dicranaceae、青藓科Brachytheciaceae、真藓科Bryaceae、提灯藓科Mniaceae、羽藓科Thuidiaceae等11科,占该区苔藓植物总科数的19.30%,该优势科所含种数为157种,占总种数的52.86%;该区苔藓植物区系成分以东亚、北温带和热带亚洲成分为主,分别占总种数的34.70%、19.03%和14.18%.通过与中国其他9个山地苔藓植物区系的相似性比较,发现阳际峰自然保护区苔藓植物区系与金佛山、马头山、古田山亲缘关系较近,具有较明显的过渡性质.     

啶酰菌胺对草莓灰霉病菌的毒力测定及田间防效

采用菌丝生长速率法和果实活体接菌法分别测定了啶酰菌胺(Boscalid)对草莓灰霉病菌(Botrytis cinereaPers.)的室内毒力和对草莓保护作用。结果表明,啶酰菌胺对草莓灰霉病菌有较强的抑制作用,其EC50值为3.9803μg/mL,对草莓灰有较好的保护作用。50%啶酰菌胺水分散颗粒剂1200倍液药后60 d对草莓灰霉病的防效达91.84%。     

涝洼地“雪莲”硬池藕无公害标准化高产栽培技术

按照莲藕的生态习性,依据农业生态学原理,创新选用硬池浅水栽培模式,引进、试验、示范“雪莲”系列新品种,采用无公害标准化生产技术,取得了较为显著的经济、社会和生态效益。     

Study of Dynamics of Floodwater Nitrogen and Regulation of Its Runoff Loss in Paddy Field-Based Two-Cropping Rice with Urea and Controlled Release Nitrogen Fertilizer Application

The article deals with the effects of urea and controlled release nitrogen fertilizer （CRNF） on dynamics of pH, electronic conductivity （EC）, total nitrogen （TN）, NH4^＋-N and NO3 -N in floodwater, and the regulation of runoff TN loss from paddy field-based two-cropping rice in Dongting Lake, China, and probes the best fertilization management for controlling N loss. Studies were conducted through modeling alluvial sandy loamy paddy soil （ASP） and purple calcareous clayey paddy soil （PCP） using lysimeter, following the sequence of the soil profiles identified by investigating soil profile. After application of urea in paddy field-based two-cropping rice, TN and NHa＋-N concentrations in floodwater reached peak on the 1st and the 3rd day, respectively, and then decreased rapidly over time; all the floodwater NO3--N concentrations were very low; the pH of floodwater gradually rose in case of early rice within 15 d （late rice within 3 d） after application of urea, and EC remained consistent with the dynamics of NH4^＋-N. The applied CRNF, especially 70% CRNF, led to significantly lower floodwater TN and NH4^＋ concentrations, pH, and EC values compared with urea within 15 d after application. The monitoring result for N loss due to natural rainfall runoff indicated that the amount of TN lost in runoff from paddy field- based two-cropping rice with urea application in Dongting Lake area was 7.47 kg ha^-1, which accounted for 2.49% of urea- N applied, and that with CRNF and 70% CRNF application decreased 24.5 and 27.2% compared with urea application, respectively. The two runoff events, which occurred within 20 d after application, contributed significantly to TN loss from paddy field. TN loss due to the two runoffs in urea, CRNF, and 70% CRNF treatments accounted for 72, 70, and 58% of the total TN loss due to runoff over the whole rice growth season, respectively. And the TN loss in these two CRNF treatments due to the first run-off event at the 10th day after application to early rice decreased 44.9 and 44.2% compared with urea, respectively. In conclusion, the 15-d period after application of urea was the critical time during which N loss occurred due to high floodwater N concentrations. But CRNF decreased N concentrations greatly in floodwater and runoff water during this period. As a result, it obviously reduced TN loss in runoff over the whole rice growth season.     

南疆棉花连作对土壤酶活性的影响——以新疆生产建设兵团农一师10团为例

通过田间调查采样和室内分析测试的方法,对新疆南疆棉区不同连作年限的棉田土壤土壤酶活性特征进行了初步研究,结果表明:耕种后的棉田土壤的脲酶、过氧化氢酶、碱性磷酸酶、脱氢酶及转化酶活性都远高于未耕种荒地,连作棉田耕层土壤脲酶和碱性磷酸酶活性随种植年限的增加而逐渐增强,转化酶和脱氢酶活性随种植年限的增长先增加后而降低,过氧化氢酶活性变化不大.土壤剖面自上而下土壤酶活性除过氧化氢酶活性变化不大外,其它4种酶活性都呈现随土壤深度的增加而降低趋势,且土壤酶活性0～40 cm层均显著高于40～60 cm.