刺槐单株生物量动态研究   总被引：3，自引：0，他引：3  

毕君  黄则舟  王振亮 《河北林果研究》1993,(4)

本文依据420株刺槐生物量及23株树干解析资料,应用灰色Verhulst模型,对太行山坡地刺槐林单株干、枝、叶、根生物量动态进行了研究,分别建立了预测模型,预测了各器官生长的速生期和停止生长林龄,为实现刺槐林的多目标经营提供决策依据。  相似文献   

Reproductive biology of the female Japanese mantis shrimp Oratosquilla oratoria (Stomatopoda) in relation to changes in the seasonal pattern of larval occurrence in Tokyo Bay, Japan     

Keita  KODAMA  Takamichi  SHIMIZU  Takashi  YAMAKAWA  Ichiro  AOKI 《Fisheries Science》2004,70(5):734-745

ABSTRACT:   The reproductive traits and the monthly larval abundance of the mantis shrimp Oratosquilla oratoria were investigated in Tokyo Bay, Japan, in 2002. The goal of the study was to elucidate the cause of changes in the monthly pattern of larval abundance from the 1980s to the 1990s as these changes relate to variation in the stock size of the adult shrimp. Oogenesis was divided into 10 stages by histological observation. The developmental stage of oocytes in an individual's ovary was synchronous, suggesting that almost all the oocytes in an ovary are spawned at the same time. The size at first maturity was estimated to be 7 ≤ body length ( BL ) < 8 cm. Fecundity was expressed as a function of BL , ranging from 19 300 eggs for 8 cm BL to 92 100 eggs for 14 cm BL . Small female shrimps (<10 cm BL ) spawned around August. Most large female shrimps (≥10 cm BL ) spawned around May, and some large female shrimps also spawned until September. Although most large female shrimps spawned in spring, the larval abundance was low before July and high from August onwards. The results suggest that a substantial decrease in the stock size of large individuals causes the low larval abundance before July.  相似文献   

Issues and Some Strategies of Sustainable Development of Black Soil Resources in Black Soil Zone in Northeast China     

贾利 《勤云标准版测试》2005,(4)

黑土资源是世界的稀缺资源,黑土带的水土流失、环境污染、土地流转、土地退化问题成为黑土资源可持续发展的障碍。根据实地调研结合资料,分析了东北黑土带土地资源可持续发展的主要问题;提出了黑土资源的可持续发展对策,即:加强农业发展规划;保护黑土区耕地,农耕技术上改进,加强农田基本建设等。  相似文献   

通过病毒分离鉴定和基因检测首次发现虎流感   总被引：21，自引：1，他引：20  

夏咸柱  高玉伟  扈荣良  王立刚  刘丹  邹啸环  黄耕  贺文琦  王玮  苏伟林  刘文良 《中国兽医学报》2003,23(2):107-110

应用F81猫肾传代细胞，从高热、拒食和间有神经症状的死亡率病科中分离获得1株病毒，经形态学、理化学、生物学和血清学系统鉴定，证明为流感病毒。采用流感病毒核蛋白基因引物，对分离病毒及该虎病科进行RT－PCR扩增和序列分析，结果从分离病毒和虎病科中均扩增出与理论值大小相符的464bp基因片段；其序列与A、B、C3型流感病毒相比较，同源性分别为84．9％、35．0％、24．8％。由此说明，所分离病毒为A型流感病毒，命名为/蘧／哈尔滨（中国）／01／2002。用此分离病毒静脉接种于3月龄家猫3号，均出现与病虎相似的临床症状，其中1号耐过，2只死亡。死亡猫剖检变化与死虎相似，主要是呈肺炎病变，并可从病科中回收到所接种病毒。从此分离病毒为HA抗原，进行虎与猫血清的HI抗体检测，结果康复虎血清比其病初血清、康复猫血清比其接种前血清HI抗体均增高4倍以上，表明该病毒具有致病性，是引起该虎与试验猫发病甚至死亡的病原。  相似文献   

Comparative pharmacokinetics and bioavailability of oxytetracycline in giant tiger prawn     

Koolvara  SANGRUNGRUANG  Amornthep  CHOTCHUANG  Ryuji  UENO 《Fisheries Science》2004,70(3):467-472

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黑杨无性系日CO2固定总量的测定及与苗木生产潜势的相关性研究   总被引：1，自引：0，他引：1  

滕小锘  赵凤君  韩锦  沈应柏 《河北林果研究》2005,20(1):21-26

通过对不同基因型黑杨无性系植株净光合速率日变化曲线与光合主体叶面积在时间和光强上进行累计积分来计算植株日CO2固定总量P。由于净光合速率日变化曲线不易准确测得，故以光响应曲线和光强的日变化来推测净光合速率日变化。对P值和生物量的相关性研究表明，二者的相关性很高。且认为可以用计算出的P值作为评估苗木生产潜势的指标之一，这为育种中生产力的早期选择提供了有力的证据。  相似文献   

Morphological characterization of the interaction between Diplocarpon rosae and various rose species     

O. Blechert  T. Debener † 《Plant pathology》2005,54(1):82-90

Blackspot, caused by Diplocarpon rosae , is the most severe and ubiquitous disease of garden roses, but information is lacking about genotype-specific forms of resistance and susceptibility of the host. Macro- and microscopic analyses of 34 rose genotypes with a defined monoconidial culture black spot inoculum identified susceptible and resistant rose genotypes and further genotype-specific subdivisions, indicating the presence of partial forms of resistance and different resistance mechanisms. In total, eight interaction types were characterized, five representing compatible (types 1–5) and three representing incompatible interactions (types 6–8). The incompatible interactions were characterized by the lack of any visible fungal structures beneath the cuticle (type 8), single-cell necroses (type 7) or necroses of larger cell clusters (type 6), the latter two types with penetration hyphae and haustoria in epidermal cells.  相似文献   

黑米天然黑(紫)色素的研究     

王景晨  王学增  王亚莉 《信阳农业高等专科学校学报》1992,(1)

特种稻黑米品种的糙米果皮中,含有大量的稀有天然黑(紫)色素。本文研究了这种色素的提取与分离方法、化学结构及其稳定性,并对其药理作用和应用前景作了简要分析。  相似文献   

Pelargonium flower-break and pelargonium line pattern viruses in the Netherlands; purification,antiserum preparation,serological identification,and detection in pelargonium by ELISA     

I. Bouwen  D. Z. Maat 《European journal of plant pathology / European Foundation for Plant Pathology》1992,98(2):141-156

Two viruses, detected frequently in the Netherlands in pelargonium, were identified by serology and test plant reactions. Antisera were prepared and an ELISA procedure was developed to detect the viruses in pelargonium.One of the viruses, PFBV-N, proved to be pelargonium flower-break virus. With the antiserum to PFBV-N, it could be detected reliably throughout the year inPelargonium zonale Springtime Irene.The other virus, PLPV-N, was serologically closely related to pelargonium line pattern virus (PLPV) and to pelargonium ring pattern virus (PRPV), as were an old virus isolate from Saturnus, collected in the Netherlands in 1971 (L128), and PLPV isolates from Yugoslavia (PLPV-Y) and Denmark (PLPV-D). There were only minor differences in host-plant reactions between the virus isolates. Based on these tests, PLPV and PRPV are considered as isolates of the same virus, for which, for practical reasons, the name pelargonium line pattern virus is proposed.PLPV could be reliably detected by ELISA inP. zonale Springtime Irene and Amanda throughout the year with only a few exceptions. InPelargonium peltatum Tavira, however, reslts were erratic due to uneven distribution of virus in the plant. Best results were obtained when petioles of fully expanded leaves were tested.  相似文献   

Detection of Colletotrichum coccodes from soil and potato tubers by conventional and quantitative real-time PCR   总被引：4，自引：1，他引：4  

D. W. Cullen  A. K. Lees  I. K. Toth  J. M. Duncan † 《Plant pathology》2002,51(3):281-292

Colletotrichum coccodes is the causal agent of the potato blemish disease black dot. Two PCR primer sets were designed to sequences of the ribosomal internal transcribed spacer (ITS1 and ITS2) regions for use in a nested PCR. The genus-specific outer primers (Cc1F1/Cc2R1) were designed to regions common to Colletotrichum spp., and the species-specific nested primers (Cc1NF1/Cc2NR1) were designed to sequences unique to C . coccodes . The primer sets amplified single products of 447 bp (Cc1F1/Cc2R1) and 349 bp (Cc1NF1/Cc2NR1) with DNA extracted from 33 European and North American isolates of C. coccodes. The specificity of primers Cc1NF1/Cc2NR1 was confirmed by the absence of amplified product with DNA of other species representing the six phylogenetic groups of the genus Colletotrichum and 46 other eukaryotic and prokaryotic plant pathogenic species. A rapid procedure for the direct extraction of DNA from soil and potato tubers was used to verify the PCR assay for detecting C. coccodes in environmental samples. The limit of sensitivity of PCR for the specific detection of C. coccodes when inoculum was added to soils was 3·0 spores per g, or the equivalent of 0·06 microsclerotia per g soil, the lowest level of inoculum tested. Colletotrichum coccodes was also detected by PCR in naturally infested soil and from both potato peel and peel extract from infected and apparently healthy tubers. Specific primers and a TaqMan fluorogenic probe were designed to perform quantitative real-time (TaqMan) PCR to obtain the same levels of sensitivity for detection of C. coccodes in soil and tubers during a first-round PCR as with conventional nested PCR and gel electrophoresis. This rapid and quantitative PCR diagnostic assay allows an accurate estimation of tuber and soil contamination by C. coccodes .  相似文献