磁场处理对根瘤菌(USDA110)和(USDA191)数量及世代时间的影响

本试验通过室内培养方法,研究了磁场处理后根瘤菌USDA110(慢生型)和USDA191(快生型)的数量和生长速度的变化.结果表明:磁场对根瘤菌菌落的生长有影响,所有处理均起正效应,但磁场强度和磁处理时间对其影响的效果不同.磁场强度表现为 300 mT效果最显著;磁处理时间以5 min效果最显著.经磁场处理后,根瘤菌的生长速度加快,世代时间缩短.     

金坛地区稻纵卷叶螟大发生年份的发生动态及其防治对策

回顾了1995~2008年江苏省金坛地区稻纵卷叶螟的发生与防治情况,并依据田间赶蛾量、虫卵量划分出大发生代次,总结并分析了各大发生代次的发生动态与防治次数、防治药种。最后,对稻纵卷叶螟的测报与防治提出了相应的建议。     

墨白962穗分化对混合选择的响应

以墨白962的不同世代为材料,研究了混合选择对热带玉米群体穗分化的选择响应。结果表明,在混合选择过程中,雄穗的穗分化阶段I、IV和V所用时间在的C0、C2和C4等3个世代之间无显著性差异;但是雄穗的分化阶段II和III所用时间在世代C0和C4之间有显著差异。而穗子的穗分化阶段I和II在C4、C0和C2世代之间有显著差异。对于雄穗和穗子相同穗分化阶段的时间差,在不同世代之间无显著差异。     

Toxic effects of acephate on Paramecium caudatum with special emphasis on morphology, behaviour, and generation time

The continuous increase in the number of new chemicals as well as the discharges of solid and liquid wastes triggered the need for simple and inexpensive bioassays for routine testing. In recent years, there has been increasing development of methods (particularly rapid tests) for testing environmental samples. This paper describes the quick toxic evaluation of an organophosphorus insecticide, acephate (O,S-dimethyl acetylphosphoramidothioate) on Paramecium caudatum for acute and sub-acute toxicity studies with reference to morphology, behaviour, and its generation time. The lethal concentrations for 10 min and 2 h were determined by probit method, as 500 mg L⁻¹ and 300 mg L⁻¹, respectively. Higher concentrations of 10 min exposure caused cell lysis with disintegration of cell membrane and precipitation of protoplasm. Combination of conventional light microscopy and computerized video tracking systems were used to study the locomotor behaviour of paramecia. The test organism was under stress and exhibited an initial increase and subsequent decrease in the swimming speed when exposed to 1/4, 1/2, 3/4, and LC₅₀ concentrations for 10 min (125, 250, 375, and 500 mg L⁻¹, respectively). Similar changes were also noticed when paramecia were exposed to LC₅₀ for 2 h. In a separate set of experiments, the number of generations and generation time in 24 h was evaluated with respect to the different sub-lethal concentrations (30, 60, 120, and 240 mg L⁻¹). The number of generations decreased and generation time extended significantly in a concentration dependent manner. The results indicate that the Paramecium toxicity assay could be used as a complimentary system to rapidly elucidate the cytotoxic potential of insecticides. The major advantages associated with these tests are: they are inexpensive, simple, user-friendly, space saving, and seem to be attractive alternatives to conventional bioassays.     

球根秋海棠"金正日花"的微体快速繁殖试验

试验表明:球根秋海棠在诱导外植体分化形成愈伤组织的过程中以BA、NAA较为适宜;经MS 6-BA(0.8~1.2)mg/L NAA0.1mg/L 糖30mg/L 琼7g/L为增殖培养基,有利于提高球根秋海棠的分生倍数;以1/2MS IAA0.5mg/L 糖20g/L 琼脂7g/L为根培养基,则有利于提高生根率。     

玉米丝黑穗病的发生与防治及对抗病育种的一些探讨

研究结果表明 :①选育和推广抗丝黑穗病玉米杂交种是当前抗御晋东南地区玉米丝黑穗病既经济又有效的重要措施。在杂交选育中 ,应尽可能用优质高抗自交系作亲本 ,决不能用高感材料。②带菌土壤是玉米丝黑穗病的主要侵染源 ,药剂拌种可有效地防治玉米丝黑穗病的发生。③玉米丝黑穗病是土壤、粪肥传病 ,土壤中病菌厚垣孢子越多 ,发病越重 ,因此因地制宜采取栽培措施 ,促进幼苗健壮生长 ,并有效地减少侵染来源 ,可减轻发病。     

稻纵卷叶螟发生与太阳射角关系的初探

经调查研究资料分析，正常的气候情况下，我国东半部稻纵卷叶螟主害代蛾是处于中午太阳光线与地面或坡地斜面成７０￣８０度幅射角时出现的，其中上半年是随太阳７０￣８０度的射角从南到北出现时，其主害代蛾就从南到北逐代水平迁飞，下半年随太阳７０￣７８度射角从北回南出现时，其主害代蛾也从北到南逐代水平回迁，高山地区随太阳７０￣８０度射角在不同时期、不同海拔高度的出现，稻纵卷叶螟主害代蛾也发生７月上山，８月下山的     

气候变化对沈阳地区亚洲玉米螟发生世代的影响

对沈阳地区亚洲玉米螟落卵情况进行多年系统调查。结果表明,沈阳地区亚洲玉米螟年度落卵结束时间明显延长,已出现第三代卵,该世代幼虫可安全越冬,沈阳地区亚洲玉米螟由传统二代区转变为二、三代混生区。