黑荆树苗期生长节律研究

2013—2014年在广西林业科学研究院苗圃地内对黑荆树幼苗不同月份的苗高和地径生长量进行调查,分析其幼苗的生长节律,并利用Logistic曲线和S曲线拟合黑荆树0．5年生幼苗的生长过程。结果表明,黑荆树0．5年生幼苗的生长进程具有明显的间歇性,苗高和地径均有2次生长高峰,且出现时间基本一致。Logistic曲线更适合描述其苗高和地径的生长过程,拟合的生长曲线可预测黑荆树0．5年生幼苗的生长状况,从而为育苗造林工作提供参考。依据黑荆树0．5年生幼苗地上部分的生长特点,将其生长过程划分为生长前期、速生期和盛末期3个阶段,并根据不同阶段的生长特性提出相应的育苗措施。     

哈茨木霉M-17固体发酵及发酵产物浸提液对镰刀菌的抑制作用

通过平板对峙试验测定哈茨木霉M-17对尖孢镰刀菌、接骨木镰刀菌、木贼镰刀菌、茄病镰刀菌和锐顶镰刀菌的抑制作用;通过抑菌试验测定菌株M-17在添加中药残渣固体培养基中发酵产物浸提液的抑菌作用,筛选对5种供试病原真菌具有抑菌作用的固体发酵培养基配方。结果表明：哈茨木霉M-17对尖孢镰刀菌、接骨木镰刀菌、木贼镰刀菌、茄病镰刀菌和锐顶镰刀菌的菌丝生长抑制率分别为66.39%、66.18%、  57.06%、66.38%和51.29%;在添加中药渣固体发酵培养基上,菌株M-17的发酵产物浸提液对不同病原菌的抑制作用不同,其中配方为甘草∶玉米粉∶木屑的固体培养基对多种病原真菌具有较强抑制作用,配比为5∶4∶1时,M-17发酵产物浸提液对木贼镰刀菌的抑制率最高,为76.89%;配比为3∶5∶2时,对木贼镰刀菌和尖孢镰刀菌的抑制率最高,分别为78.45%和72.20%;配比为7∶2∶1时,对木贼镰刀菌的抑制率最高,为77.19%;配方为板蓝根∶玉米粉∶木屑、配比为3∶5∶2时,M-17发酵产物浸提液对木贼镰刀菌的抑制率最高,为77.99%。不同固体发酵培养基和配方影响木霉M-17发酵产物对不同镰刀菌的抑菌作用,为木霉菌制剂开发和应用提供了基础。     

桉树造林影响土壤物理性状、养分和微生物群落的研究进展

桉树是保障我国木材产业的重要树种,在产生巨大社会及经济效益的同时,桉树造林所引发的生态环境问题不容忽视。综述了桉树林地土壤物理性状、养分和微生物群落发生变化的成因,桉树自身水分消耗特征、土壤容重和孔隙度的变化、林下植被和枯枝落叶以及连栽和炼山等人为生产经营活动,是导致桉树造林过程中林地土壤物理性质变化的重要原因;桉树自身对养分的需求量大、连栽、炼山、翻耕、除草、轮伐以及营造桉树人工混交林、土地利用类型转变是导致桉树造林过程中林地土壤养分变化的重要因素;桉树造林对林地土壤理化性质的影响、凋落物分解和根系分泌物释放以及炼山、翻耕、间伐和施肥等管理行为,都直接或者间接地影响林地土壤微生物群落。通过对桉树造林过程中维护和提升土壤生态系统服务功能的相关措施进行展望,旨在为推进我国现阶段桉树产业可持续发展提供理论参考。     

微量营养源对红曲霉产洛伐他汀开闭环组分的影响

采用HPLC法测定红曲霉液态发酵培养合成开环的酸型莫纳可林K(Monacolin K)及闭环的内酯型洛伐他汀(Lovastatin)的含量,研究生长因子、前体物质和金属离子等微量营养源对红曲霉液态发酵产洛伐他汀开闭环组分的影响。结果表明:红曲霉液态发酵中,添加烟酸、乙酸钠和硫酸锌等微量营养源能促进Monacolin K及Lovastatin的合成,并提高Monacoling K的比例;当烟酸、乙酸钠和硫酸锌的添加量分别为:0.01%、0.15%和0.15%时,产生的开环Monacolin K的比例占79%,开闭环洛伐他汀总质量浓度为57.138mg·L-1。     

Genomic-SSR 和EST-SSR在柱花草种间的遗传差异

为了探讨genomic-SSR与EST-SSR标记在柱花草种间的遗传差异,利用两种SSR标记技术,对来自不同种的12份柱花草种质进行了遗传分析,并对两种不同标记进行比较.结果表明:EST-SSR标记相比genomic-SSR在柱花草不同种间具有更好的通用性,EST-SSR检测到的等位基因数和PIC指数平均值分别是4.6和0.610,genomic-SSR检测到的等位基因数和PIC指数平均值分别是5.6和0.702.聚类结果表明,genomic-SSR和EST-SSR均能有效鉴别所有供试柱花草种质.     

Feeding ecology of dominant demersal fish species <Emphasis Type="Italic">Favonigobius gymnauchen,Repomucenus</Emphasis> spp. and <Emphasis Type="Italic">Tarphops oligolepis</Emphasis> at a sandy beach where larval Japanese flounder settle in the Seto Inland Sea,Japan

ABSTRACT:   Feeding habits of Favonigobius gymnauchen , Repomucenus spp. and Tarphops oligolepis were examined during the period from May to August in 1999, 2000 and 2001 at a sandy beach in the central Seto Inland Sea, Japan. The three species of fish accounted for more than 60% of all fish collected in terms of number of individuals. All three species mainly consumed small crustaceans. However, the major prey of F .  gymnauchen and Repomucenus spp. differed from that of T .  oligolepis . F .  gymnauchen and Repomucenus spp. mainly consumed mysids and small crangonid shrimp (<12 mm in body length), which predominated in the study area. T .  oligolepis actively selected only epifaunal mysids Nipponomysis ornata and avoided crangonid shrimp and gammarids . The frequencies of occurrence of fish in the guts of the three dominant species were very low, and larval and juvenile Japanese flounder were not observed in any of the three fish species. The diet of juvenile Japanese flounder was similar to that of the three species. From these results, it appears that these three fish are competing species for the flounder.     

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.     

Effects of temperature, salinity, desiccation and chemical treatments on egg embryonation and hatching success of Benedenia seriolae (Monogenea: Capsalidae), a parasite of farmed Seriola spp

The effects of temperature and salinity on the embryonation period and hatching success of eggs of Benedenia seriolae were investigated. Temperature strongly influenced embryonation period; eggs first hatched 5 days after laying at 28 degrees C and 16 days after laying at 14 degrees C. The relationship between temperature and embryonation period is described by quadratic regression equations for time to first and last hatching. Hatching success was >70% for B. seriolae eggs incubated at temperatures from 14 to 28 degrees C. However, no B. seriolae eggs embryonated and hatched at 30 degrees C and <2% of eggs hatched when incubated at 24 degrees C after transfer to 30 degrees C for 48 h. Embryonation period was similar for eggs incubated in sea water at 25, 30 and 35 per thousand salinity, but increased for eggs incubated at higher or lower salinities. When incubated at salinities ranging from 25 to 45 per thousand, more than 70% of B. seriolae eggs embryonated and hatched. Hatching success was lower at 20 and 50 per thousand salinity and few or no eggs hatched at 10 and 15 per thousand. Hatching of B. seriolae eggs can be prevented by desiccation for 3 min, by immersion in water at 50 degrees C for 30 s or by treatment with 25% ethanol for 3 min.     

鱼类腐败菌不同生长动力学温度模型的可靠性评价和比较

探讨和比较了Arrhenius方程和Belehradek方程两种腐败菌生长动力学温度模型预测鱼鲜度和货架期的可靠性。结果表明，两种温度模型都能很好地预测罗非鱼中假单胞菌的生长动态和预报货架期，通过假单胞菌生长动力学模型的预测值，与罗非鱼中假单胞菌生长的实测值比较，偏差度在0．95～1．01之间，准确度在1．02～1．06之间，两种温度模型相比，Belehradek温度模型的可靠性更好。罗非鱼在3和8℃贮藏中货架期实测值与利用Arrhenius方程和Belehradek方程建立的假单胞菌生长动力学温度模型求得的预测值的比较，Arrhenius温度模型预测值和实测值的相对误差分别为11．8％和8．00％，Belehradek温度模型预测值和实测值的相对误差分别为3．47％和一7．91％，两种温度模型相比，Belehradek温度模型的结果更为理想。     

Catch and trade bans for seahorses can be negated by non-selective fisheries

1. All seahorse species (genus Hippocampus) are listed under Schedule I of India's Wild Life Protection Act, making all capture and trade of seahorses illegal. In the more than 15 years since the ban, little work has been done to assess its effects on seahorse conservation.
2. Between 2015 and 2017, fisheries and trade surveys were conducted along the south-east coast of India, in the state of Tamil Nadu, historically known to be a hub for seahorse catches and trade.
3. Seahorses were primarily landed as bycatch, although in greater quantities by traditional drag nets than as trawl bycatch. Total annual catches were estimated between 4.98 million and 13.64 million seahorses, 87% of which were caught by active non-selective gear.
4. Generalized additive models revealed that seahorse catch per unit effort had non-linear relations with depth and latitude, and were higher in biogenic habitats, with active, bottom-used, and non-selective gears (e.g. trawls).
5. The illegal nature of the trade in seahorses hampered an understanding of trade routes and trade volumes. Catch estimates indicated that 11.21–30.31 tonnes of seahorses probably entered trade, yet interviews with traders only documented trade of about 1.6 tonnes.
6. Fishers reported a decreasing availability of seahorses. Since most seahorses come from bycatch in persistent fisheries that are not directly affected by the ban on seahorse capture, this decline is likely to represent a population decline.
7. A fishery and trade ban for incidentally caught species, particularly in a poorly regulated fishery, appears to add little conservation value. There needs to be a shift in the management approach, moving from a ban towards spatial and temporal restrictions, and toward enforcing existing fishery regulations.