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991.
节瓜蓟马的新天敌——中华微刺盲蝽   总被引:8,自引:2,他引:8  
首次发现中华微刺盲蝽Campylomma chinensis Schwh捕食节瓜蓟马Thrips palmi Karny且对田间节瓜蓟马种群数量的减少起重要作用。本文研究了该虫的形态特征、捕食过程和取食范围。结果表明中华微刺盲蝽为多食性昆虫,能取食多种小型昆虫及多种昆虫的卵:在田间,中华微刺盲蝽与节瓜蓟马数量的跟随现象明显;通过释入盲蝽,能使节瓜蓟马种群数量减少。  相似文献   
992.
三穗鸭又称三穗麻鸭,是我国五大蛋系地方优良品种之一.三穗鸭主要产于三穗及周边县市境内,它以生长快、成熟早、产蛋多、觅食力强、耐粗放、肉质细嫩、味美鲜香而闻名海内外.三穗县是三穗鸭的泽源地和主产区,鸭源丰富,自然条件优越,群众养鸭历史悠久.稻田坝区,村村寨寨,组组户户立杆牧鸭.1994年以前,该县三穗鸭的饲养量一直是在40万羽上下徘徊,三穗鸭的发展处于徘徊时期.1994年,县委、县政府围绕"八七扶贫攻坚计划",提出建立三穗鸭生产基地,培植支柱产业的发展思路,采取政策鼓励、资金扶持、技术指导、市场引导和个体、集体、国家一齐上,圈养鸭、圈牧养鸭规模化等措施,经过几年的努力,养鸭业迅速发展起来.据县农业部门调查统计,1997年底该县已建立商品肉鸭基地示范村7个,养鸭专业户180户,饲养肉鸭15.3万羽,蛋鸭1.2万羽.通过基地示范村、示范户的带动,全县养鸭户达1.3万户,鸭的饲养量达83万羽,创历史最高水平.周边的天柱、石阡、玉屏、新晃等县的鸭饲养量也成倍增长,1997年,预计三穗及周边县市鸭的饲养量达200万羽.三穗鸭的发展处于兴盛时期.  相似文献   
993.
蔗糖对香石竹切花的保鲜效果   总被引:1,自引:0,他引:1  
保鲜剂中蔗糖浓度分为4个处理,对照(CK):0%蔗糖+50ppm次氯酸钠;A:1%蔗糖+50ppm次氯酸钠;B:2%蔗糖+50ppm次氯酸钠;C:3%蔗糖+50ppm次氯酸钠。把香石竹切花插入不同蔗糖浓度的保鲜剂中,进行切花寿命比较试验。结果表明,蔗糖浓度为3%的保鲜剂对香石竹的保鲜效果最佳,为12.8d,与对照(7.93d)相比明显延长。  相似文献   
994.
磷肥用量对甜玉米磷素吸收利用的影响   总被引:1,自引:0,他引:1  
Understanding the phosphorus (P) absorption mechanism is the premise for high P utilization and high crop yield. In this study, the effects of different P rates (0, 37.5, 75, 150, and 300 kg hm-2, expressed as P0, P1, P2, P3, and P4, respectively) on sweet corn yield, biomass and P accumulation and tissue distribution, P transportation and P utilization were studied using a two-year P gradient positioning field experiment. Our results showed that P application significantly increased the fresh ear yield of sweet corn, but the yield difference among different P application rates (P1-P4) was not significant from 2018 to 2019 compared with P0 treatment. P application significantly increased the biomass and P accumulation of sweet corn plants at jointing, silking and fresh eating stages, respectively. In addition, P accumulation in grain was not significant different, which accounting for 42% of plant P accumulation. With P application, the contribution rate of P assimilation to the ear P accumulation was 57.3%-93.0% after anthesis, while the fresh ear yield per P accumulation, P physiological efficiency, agronomic efficiency, recovery efficiency and partial productivity decreased with P rates. Considering the yield and utilization efficiency of phosphate fertilizer, the supply of 37.5 kg hm-2 of phosphate fertilizer can meet the needs of high yield and efficient utilization of phosphate fertilizer in sweet corn in this experiment.  相似文献   
995.
To study the clinicopathology and histopathology of African swine fever (ASF), and to explore the internal relationship between pathological changes and disease occurrence and development and its pathological mechanism, 13 Landrace pigs with bodyweight about 20 kg were intramuscular injected with African swine fever virus (ASFV), strain Pig/HLJ/18 at a dose of 102HAD50·mL-1. During the experiment, all the dead pigs were systematically dissected and sampled, paraffin sections were produced, and haematoxylin-eosin staining was performed. Clinicopathological evaluation standards for acute ASF were established, then pathological lesions (classification variables) were expressed by counting frequency and percentage, and the lesion degree (continuous variables) was graded and scored according to different pathological changes of various tissues and organs. The results showed that all infected pigs were in line with the clinical characteristics of ASF, including acute, febrile and highly infectious, with a 100% incidence rate and 100% mortality. The dead pigs showed typical characteristics of septicemia, cadavers prone to corruption, blood clotting adverse or hemolysis, rigor mortis incomplete. The main pathological lesions were hemorrhagic necrotizing lymphadenitis, acute inflammatory splenomegaly (septic spleen), cerebral edema, pulmonary edema and lung consolidation et al. The spleen and lymphonodus are the target organs attacked by ASFV, with the most significant lesions, the earliest occurrence time, the longest duration and the highest frequency. The most prominent pathological changes are blood circulation disorders, including multiple pathological manifestations such as edema, hyperemia, congestion, hemorrhage, infarction, disseminated intravascular coagulation (DIC), and the most important characteristics are hemorrhagic lesions. The inflammatory reaction of lymphocytic exudation caused by ASFV runs through the whole process, especially in the middle and later stages of the course. The results suggest that the main pathological process of acute African swine fever is a typical immune/inflammatory cascade reaction and severe systemic blood circulation disorder, which resulted in the high incidence rate and high mortality rate of acute ASF.  相似文献   
996.
驻茄15 号是以自交系P04-11 为母本,以高代自交系驻Q-25 为父本配制而成的中早熟绿茄一代杂种。植株生长势强,果实卵圆形,纵径15.0 cm 左右,横径10.6 cm 左右,平均单果质量0.52 kg,果皮绿色、光亮,肉质硬度中等,商品性好,一般每667 m2 前期产量1 100 kg 左右,总产量5 300 kg 左右,田间对青枯病、绵疫病、黄萎病的抗性强于对照郑研早青茄,适宜河南省及周边省份春、秋设施及露地栽培。  相似文献   
997.
贵州喀斯特地区牧草引种试验评价   总被引:10,自引:0,他引:10  
对国内外引进的6个禾本科牧草品种,9个豆科牧草品种以及喀斯特地区的4个对照品种,在贵州独山地区进行引种试验。结果表明:各参试品种生长良好,能安全越冬、越夏,一年可刈割5~6次,鲜草产量达36558.2~66450.0kg/hm2,干草产量10771.0~19869.0kg/hm2。综合性状表现较好的依次为鸭茅Totter,Wana,Tuoa;多年生黑麦草Nui,Bronsys;白三叶Alice,C6151,Prop,Pitua,Sustain;百脉根Mareb,Lel。  相似文献   
998.
鸡骨型白血病免疫琼扩与放射摄片诊断的比较   总被引:1,自引:1,他引:0  
为了探索特异性免疫学诊断方法对鸡骨型白血病(OP)的检测效果。用双盲法分批采样同时进行羽髓琼脂扩散试验和胫骨X线摄片检查对比,共检834只鸡(433羽属天然自发OP鸡群,401羽属人工诱发实验鸡群)。结果羽髓琼扩试验的OP阳性检出率为3.48%(29/834:)。阳性病理符合率为75.86%(22/29)。阳性误诊(假阳性)率24.13%(7/29),阴性误诊(假阴性)率36.15%(291/805)。而X线摄片检查的OP阳性检出率为38.37%(320/834)。X线阳性完全可获病理组织学证实,不存在假阳性或假阴性。把禽白血病羽髓琼扩试验试用于检测鸡骨型白血病尚属初次报道,其阳性检出率低而误诊率高,尚不宜作OP检测手段。放射摄片诊断的阳性检出率高而误诊率低,可快速诊断,故适用于OP检疫。  相似文献   
999.
加系双肌臀大白猪不同杂交组合性能比较试验   总被引:1,自引:0,他引:1  
本试验选择加系双肌臀大白猪、美系杜洛克、丹麦长白三个品种的公母猪,组成5个杂交组合(双公×双母,双公×长母,双公×杜母,杜公×双母),测定了双×双、长×双、双×长、双×杜、杜×双五个组合猪的繁殖性能与肥育性能。结果表明:杜×双组合在日增重(896.05g)、饲料报酬(2.80∶1)、瘦肉率(66.01%)等主要指标上优于其它杂交组合,且繁殖性能居中、胴体品质优良,是加系双肌臀大白猪二元杂交瘦肉猪生产中的最佳杂交父本品种。试验还表明,双肌臀大白猪产仔多(12.08头)、增重快(851.97g)、瘦肉率高(65.24%)、适应性强,值得大力繁殖推广。  相似文献   
1000.
AIM: To study the mechanism of the effect of NSAIDs on apoptosis in mice hepatoma at anti-inflammatory doses. METHODS: Kunming breed mice were inoculated subcutaneously in the flank with mice hepatoma H22 cell line. The effects of ibuprofen, indomethacin, and nimesulide on apoptosis were determined by using electron microscopy, agarose gel electrophoresis, flow cytometry, and Western blot analysis of the expression of c-myc, bcl-xL and bcl-2 proteins. RESULTS: NSAIDs induced apoptosis of mice implanted hepatoma, which includes the morphological changes such as reduction in the volume, and the nuclear chromatin condensation, as well as the "ladder pattern" revealed by agarose gel electrophoresis of DNA. The apoptotic index was increased to 15%±1.0%, 29.7%±1.5%, 46.3%±3.5% from 3.3%±0.6% by detecting Sub-G1 peaks on flow cytometry. Western blot analysis showed that levels of bcl-2 and bcl-xL were significantly reduced by treatment with nimesulide. Ibuprofen and indomethacin decreased bcl-2 expression but increased bcl-xL expression. C-myc wasn't changed in these groups. CONCLUSION: These results suggest that NSAIDs induces apoptosis of mice hepatoma, which may be due to their regulation on the expressions of bcl-2 family genes.  相似文献   
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