8种山蚂蝗种子萌发期耐盐耐旱性差异分析

为比较不同山蚂蝗（Desmodium Desv.）种子萌发期耐盐耐旱性差异,本研究选用8种山蚂蝗种子为材料,采用培养皿纸上发芽法观测了NaCl和聚乙二醇（Polyethylene glycol,PEG）处理对其发芽率、发芽势、发芽指数、胚根和胚芽的影响,并探讨了8种山蚂蝗种子在萌发期耐盐耐旱性能差异。结果表明山蚂蝗种子对NaCl胁迫较敏感。当NaCl浓度为50 mmol·L^-1时,发芽指数均明显下降;当NaCl浓度为100 mmol·L^-1时,胚根和胚芽生长均受到明显抑制;当NaCl浓度≥150 mmol·L^-1时,胚根胚芽均不能正常生长,甚至出现腐烂。低浓度的PEG胁迫对山蚂蝗种子发芽无显著影响,但可促进胚根和胚芽生长。在PEG浓度≤15%时,山蚂蝗种子均能正常萌发且生长良好;当PEG浓度为20%时,种子萌发和生长均显著受到抑制;当PEG浓度为25%时,仅糙伏山蚂蝗发芽率为86.00%,其它种子不能萌发。在8种山蚂蝗种子中,山蚂蝗、赤山绿豆和异果山绿豆耐盐性较好,糙伏山蚂蝗和异叶山蚂蝗抗旱能力较强,南美山蚂蝗耐盐性和抗旱均较差。     

毛竹林边际扩展促控制施对新鞭生长的影响

通过对毛竹林外侧的扩鞭试验研究表明,竹鞭的平均直径随抚育措施力度和加大而有加大的趋势,竹鞭长度以深翻垦复和锄草松土的单鞭较短,但鞭段数增加,新鞭总长以竹蔸施肥的最长（７．７５ｍ,比锄草松土、深翻垦复两措施均长１．４ｍ）,组合措施的新鞭总长均比单一措施的长,竹蔸施肥有利于竹鞭范围的扩展。随着坡位的降低（即立地的变好）,有鞭段增长、鞭段数减少、竹鞭增粗、扩鞭范围增大的趋势。     

坡度、坡长变化与水土流失量之相关性分析

通过对天然径流小区的观测试验,研究了坡度、坡长与水土流失间的关系。结果表明试验区径流冲刷量、养分流失量、农作物产量与坡度和坡长存在着密切的关系。同时对该地区水土流失的成因进行了一定的分析,并提出了一系列水土流失防治措施,以便为当地的水土流失整治工作提供一定的科学依据。     

新疆博尔塔拉河干流段地表水地下水转化关系的分析研究

通过对博尔塔拉河干流段地质、水文地质及水文诗性的调杏分析，揭示了水资源的转化关系。合理地划分了计算区段，利用水均衡法和水资源系统分析法，计算求得了地下水资源量、转化量及重复利用量，对水资源科学配置具有重要意义。     

3种杂草种子对紫花苜蓿种子化感作用的研究

为研究杂草种子对紫花苜蓿种子萌发的影响,用藜、反枝苋、骆驼蓬3种杂草种子与紫花苜蓿种子按比例进行混合发芽试验,分析紫花苜蓿的发芽率、根长和芽长,研究藜、反枝苋、骆驼蓬对苜蓿种子萌发和幼苗生长中的影响.结果表明,藜种子和紫花苜蓿种子混播使紫花苜蓿种子发芽率提高,藜与苜蓿种子10∶50混播处理与对照组有显著差异(P＜0.05).根长与对照组均有显著差异(P＜0.05),藜种子对苜蓿根长和芽长总体呈现抑制趋势;反枝苋与紫花苜蓿种子混播后紫花苜蓿的发芽率与对照均有显著差异(P＜0.05),随着反枝苋种子密度的增加,紫花苜蓿种子发芽率除反枝苋与苜蓿10∶50混播处理外均有升高的趋势.根长与对照相比均表现出增长的趋势,反枝苋与苜蓿种子混播比例为40∶50、50∶50时与其他处理差异显著(P＜0.05).对芽长的影响总体上呈现抑制趋势;骆驼蓬与紫花苜蓿种子混播后紫花苜蓿种子发芽率均低于对照,骆驼蓬与紫花苜蓿混播比例为30∶50、40∶50时与其他处理和对照差异显著(P＜0.05),根长、芽长均比对照有所减小.骆驼蓬与紫花苜蓿种子混播比例为50∶50时,发生死亡.     

杉木不同龄组树冠形态模拟模型研究

为了对杉木不同龄组树冠形态进行数学模拟,运用非线性回归筛选有效变量的方法将相对树冠半径(RCRj)和相对树冠长度(RCLj)确立为树冠形态模型的因变量和自变量。选取福建省顺昌县297株杉木标准木的1 485个树冠半径测量值,基于8大类模型分别建立不同龄组的树冠最优模型。对最优模型进行误差和残差分析、模型检验、生物学意义评估,结果表明:幼龄林、中龄林和近成熟林时期拟合效果最优的模型分别是Cubic、Poly4和GaussAmp。使用本文建立的树冠轮廓模型预估树冠形态时,只需测量全树高、最大树冠半径和最大树冠长度。树冠轮廓模型是生长和收获模型的重要组成部分,同时对于评价林木间的竞争、森林小气候和生物多样性也至关重要。      

中草药对热应激鸡十二指肠黏膜结构的影响（英文）

伊莎褐88日龄雏鸡120只,随机分为6组,3个对照组(常温组、高温组、高温Vc组)和3个中草药高温组(高剂量组、中剂量组、低剂量组)。常温组在14~25℃环境下饲养,其余5组在28~39℃环境下饲养.试验全程共10天,在试验的第1、4、8、10天每组各剖杀5只并取其十二指肠。经常规方法制成组织切片后H.E染色,测定各十二指肠的黏膜厚度、绒毛长度、隐窝深度。结果显示:热应激状态下,十二指肠黏膜厚度和绒毛长度均显著低于常温组,且绒毛稀疏。但是高温条件下,中草药高剂量组、中剂量组各项指标均高于高温组和高温Vc组,特别是在试验的第8天和第10天差异极显著,并且中草药高剂量组各指标显著高于中草药中低剂量组。该处方对热应激鸡十二指肠粘膜的保护作用强于高温Vc组。在热应激条件下中草药有效减弱了十二指肠粘膜的组织损伤。     

水库大银鱼个体生殖力初步研究

对大银鱼个体生殖力及其雌亲体的形态学指标进行了研究。结果表明：大银鱼的绝对生殖力Ｆ随体长、体重增加而增大，体长每增加１ｍｍ，卵粒增加６３６粒；体重每增加１ｇ，卵粒增加１０６８粒。大银鱼存在两群发育程度不同的大型卵母细胞，首批产卵数占生殖力总数的４８．３％，第２批为５１．７％。     

湛江沿海五种石斑鱼线粒体DNA的RFLP分析

In this paper, genetic diversity of intraspecies, and genetic relationship of interspecies in Epinephelus spp. (E. merra, E. fario, E. awoara, E. akaara and E. septemfasciatus) were assessed by using mitochondrial DNA restriction fragment length polymorphisms (mtDNA RFLPs).The samples were collected from the coastal area of Zhanjiang,Guangdong province. MtDNA was extracted from the fresh liver tissue by applying a difference centrifugation procedures. Using 17 restriction enzymes with 5-or 6-bp recognition sites, the purified mtDNA was cleaved by single enzymes. These enzymes included BamH Ⅰ，Bgl Ⅰ，Bgl Ⅱ，Dra Ⅰ，EcoR Ⅰ，EcoR Ⅴ，Hind Ⅲ，Kpn Ⅰ，Mlu Ⅰ，Pst Ⅰ，Pvu Ⅱ，Sal Ⅰ，Sca Ⅰ，Sma Ⅰ，Sty Ⅰ，Xba Ⅰ and Xho Ⅰ. The phylogenetic analysis was done using the Neighbor joining(NJ) method and Unweighted pairgroup method with arithmetic mean(UPGMA) method. Genetic diversity indices such as haplotype diversity (h), average genetic distance between haplotypes (P) and nucleotide diversity (π) were calculated using Nei and Li's segment method to quantify the genetic diversity within species. There were 8, 5, 8, 5 and 2 haplotypes detected within E. merra, E. fario, E.awoara, E.akaara and E. septemfasciatus, respectively. The haplotype diversity (h) was 0.8943, 0.6186, 0.9242, 0.6927 and 0.1820,respectively. The average genetic distance between haplotypes (P) was 0.62%±0.31%, 0.64%±0.37%, 1.12%±0.55%,0.72%±0.42% and 0.45%, respectively. And the nucleotide diversity (π) was 0.22%, 0.13%, 0.46%, 0.17% and 0.04%, respectively. The wild groupers in the Zhanjiang Coastal Area exhibited a relative higher level of genetic diversity. The net genetic distance between species (P_net) was 0.0694（E. merra - E. fario）,0.1337（E. merra - E. awoara）,0.1090 E. merra -E. akaara）, 0.1286（E. merra - E. septemfasciatus）,0.1590（E. fario -E. awoara）,0.0825（E. fario -E. akaara）,0.1153（E. fario - E. septemfasciatus）,0.1131 E. awoara - E. akaara）,0.0724（E. awoara -E. septemfasciatus） and 0.1336（E. akaara - E. septemfasciatus）. Both NJ and UPGMA methods yielded an identical phylogenetic tree for the five species. The E. merra and E. fario first clustered together, then joined with E. akaara, and finally clustered with E. awoara and E. septemfasciatus.     

Immunohistochemical and Taqman real-time PCR detection of mycobacterial infections in fish

Real‐time PCR and immunohistochemistry (IHC) assays were developed to detect fish mycobacterial infections at the genus level, based on the RNA polymerase β subunit (rpoB) gene and polyclonal anti‐Mycobacterium rabbit serum, respectively. The PCR assay positively identified a number of pathogenic mycobacteria including Mycobacterium abscessus, M. avium ssp. avium, M. bohemicum, M. chelonae ssp. chelonae, M. farcinogenes, M. flavescens, M. fortuitum ssp. fortuitum, M. gastri, M. gordonae, M. immunogenicum, M. malmoense, M. marinum, M. montefiorense, M. phlei, M. phocaicum, M. pseudoshottsii, M. salmoniphilum, M. senegalense, M. shottsii, M. smegmatis, M. szulgi and M. wolinskyi. A detection limit equivalent to 10² cfu g^?1 was registered for M. salmoniphilum‐infected fish tissue. The IHC precisely localized both free and intracellular mycobacteria in tissues and detected mycobacterial infections down to 10² cfu g^?1 tissue. Both assays were found to be more sensitive than Ziehl–Neelsen (ZN) staining, where the detection limit was below 8 × 10³ cfu g^?1 tissue. Although specificity testing of the real‐time PCR against a panel of non‐Mycobacterium spp. revealed a degree of cross‐reaction against pure DNA extracted from Nocardia seriolae and Rhodococcus erythropolis, no cross‐reactions were identified (by either real‐time PCR or IHC) on testing of formalin‐fixed paraffin‐embedded (FFPE) tissues confirmed to be infected with these bacteria. The broad applicability of both assays was confirmed by analysis of FFPE tissues from a range of fish species infected with diverse Mycobacterium spp. The results indicate that both assays, alone or in combination, constitute sensitive tools for initial, rapid diagnosis of mycobacteriosis in fish. This should in turn allow rapid application of more specific studies, i.e. culture based, to identify the specific Mycobacterium sp. involved.