退耕还林还草地鼠类调查及控制对策研究

2002-2003年对青海省大通县退耕还林还草地鼠类组成进行调查研究,捕获鼠类6种728只,以根田鼠Microtus oeconomus和高原鼢鼠Myospalax baileyi为绝对优势种.4种方法进行退耕还林还草地害鼠控制的结果表明:人工置夹和药物控制是地上害鼠控制的有效方法,人工地箭与灭鼠雷可有效控制地下高原鼢鼠的数量.但从长远来看,控制退耕还林还草地鼠害应采取生态治理的原则和方法.     

用最大树种数测度森林群落树种丰富度

目的 试图给出确定森林群落树种丰富度的方法,解决物种丰富度测度问题,完善森林生物多样性研究的方法。 方法 采用Monod模型表达种-面积曲线,通过数学手段确定最小森林群落面积和最大树种数。 结果 用本研究提出的方法对不同气候带森林物种丰富度进行测算,结果表明：热带森林群落具有更高的最大树种数和更大的群落最小面积,物种丰富度随气候带由热带到寒温带逐渐减少。 结论 用最大树种数能够确切表达不同气候带森林群落树种丰富度,克服了现有研究中直接把不同大小调查面积上的树种数量视为树种丰富度的弊端。     

Effects of plane of nutrition on growth,feed intake,digestibility and nitrogen balance in Murrah graded male buffalo (Bubalus bubalis) calves in Nepal

An experiment was conducted using 17 male buffalo calves to assess the effects of plane of nutrition on dry matter intake (DMI), daily gain (DG), body size measurement, apparent digestibility and nitrogen (N) balance. To attain 250 kg BW, the calves were allocated into three groups: H, L‐H and L, receiving the concentrate at 1.50% of BW, 0.75% of BW until 190 kg BW and 1.50% thereafter and 0.75% of BW, respectively. The animals had ad libitum access to urea‐treated rice straw (UTRS). The DMI of UTRS through the experiment was higher in L and L‐H than H, showing 3.52, 2.90 and 2.62 kg/day, respectively (P < 0.01), but the total DMI did not differ among the treatment groups. The DG throughout the experiment was high in the order of H, L‐H and L, showing 0.72, 0.57 and 0.45 kg, respectively (P < 0.01). The digestibility of DM, organic matter, crude protein, neutral and acid detergent fiber and N retention were higher in H than in L (P < 0.05). The findings of this study thus revealed the greater DG has an advantage of shortening the growing period around 3 months, and consequently increasing benefit in fattening of buffalo calves in Nepal.     

土传病害生物防治研究进展

土传病害已成为严重制约我国农牧业发展的主要原因,近年来人们对于食物安全的重视和环保意识的增强,对农业的可持续发展提出了更高的要求。生物防治因其低成本、高效率、环境友好和无药物残留等特点已成为当前国内外植物病害防治的研究热点。本文从农艺措施改良和优化,利用细菌、真菌、放线菌等生防微生物进行生物防治,诱导寄主产生系统抗病性和其他生物防治方法等几个方面对国内外植物土传病害生物防治的研究现状进行了综述,提出了生物防治目前存在的问题,并对生物防治的研究进行了展望。     

A reactive pattern of ischemia-induced nestin protein in the rat brain

AIM:To explore the expressive profile of nestin protein in the focal ischemic brain and to study the recovery mechanism of brain focal infarct.METHODS:Cellular morphology,time-course and distribution pattern of nestin positive response were immunohistochemically examined in different brain regions of 36 adult male SD rats. RESULTS:Nestin positive response of different brain regions in sham operated rats was present in small- and micro-vasculartures and the third ventricle bottom and ependyma. A large number of nestin positive cells were detected in ischemic brain, and were more remarkable in the cortical areas of parietal lobe and preoptic area as well as ischemic caudoputamen. Stellate nestin positive cells were located in the deep layer of ischemic cortex, but fibrillary cells were located in the shallow layer. Nestin positive cells in the ischemic caudoputamen showed the same changes of morphology as those cells in the deep layer of ischemic cortex. Morphological and number alterations of nestin positive cells were the most remarkable at 1 weeks post-ischemia, which showed more hypertrophy and proliferation in morphology, and a marked increase in number was present in the ischemic cerebral cortex and the ischemic caudoputamen. These alterations of nestin positive cells persisted up to 6 weeks post-ischemia, and then, the nestin positive response in the ischemic brain decreased gradually.CONCLUSION:Focal cerebral ischemia induces nestin re-expression on reactive astrocytes, which may be very important to the self-recovery of cerebral infarct.     

塔里木河孔雀河中下游地区棉花膜下滴灌节水技术研究

以合理利用和节约有限的水资源为目标,2002年在尉犁县孔雀农场进行了棉花膜下滴灌节水试验。得出:该区棉花膜下滴灌适宜的灌溉量为3 931.5 m3/hm2,最佳产量为皮棉2 997.75kg/hm2。与当地农民大水漫灌方式比较,节约水量8 070~14 070 m3/hm2,增产皮棉747.75 kg/hm2,膜下滴灌是该区目前最节水的棉花灌溉方式之一。     

青藏扁蓿豆根瘤菌接种效果试验

对青藏扁蓿豆进行了根瘤菌接种试验,结果表明:青藏扁蓿豆的结瘤率接种比对照平均提高52.9%。接种使青藏扁蓿豆的干草产量提高59.6%~69.2%。     

低浓度玉米小斑病菌C小种毒素培养滤液对玉米叶片过氧化物酶活性的诱导作用

分别用不同低浓度玉米小斑病菌C小种毒素培养滤液处理两种基因型(C103和B37)的同核异质系的玉米叶片,以提高玉米叶片内过氧化物酶(POD)的活性;结果说明:过氧化物酶的活性变化与植物抗病性呈正相关,低浓度C毒素培养滤液本身能够作为激发子来诱导玉米获得抗性,故低浓度C毒素培养滤液作为激发子来诱导玉米的系统获得性抗性具有一定的广适性。对CB37和CC103的处理中,1∶60处理组效果均表现为较好,POD酶活性最高。     

应用聚合酶链式反应鉴定新疆棉花落叶型黄萎病菌

用一对棉花落叶型黄萎病菌的特异性引物D1和D2进行PCR扩增,对于落叶型黄萎病菌,该对引物可特异性地扩增产生一段550bp的产物,而非落叶型黄萎病菌则不能被扩增.供试的35个新疆黄萎菌系中,有3个菌系扩增出550bp大小的落叶型黄萎病菌特异性片段,表明目前新疆已存在落叶型黄萎病菌,用此技术可快速、准确地检疫和鉴定落叶型黄萎病菌.     

巫溪红池坝改良草地鼠类调查报告

对重庆巫溪红池坝改良草地中鼠形动物的种类进行抽样调查、室内饲养、解剖鼠胃和洞道研究，结果显示，该改良草地中有鼠形动物2目3科4种，其对草地危害方式和为害程度均不一样。提出了改良草地中鼠害的防治措施。