棕榈藤组培苗根的诱导研究

地短叶省藤、黄藤和单叶省藤组培苗根的诱导进行了研究,结果表明：ＮＡＡ含量高低对丛芽苗的生根与否及根系生长起决定生作用。蔗糖浓度不影响芽苗的生根与否,但影响出根快慢、出根条数和根系的生长。ＮＡＡ也在单苗根的诱导中直主导作用但再附加一定量的ＩＢＡ有利于攻苗生根培养基的优化组合为：ＮＡＡ１．０ｍｇ／Ｌ＋ＩＢＡ２．０ｍｇ／Ｌ＋大量元素０．３３ｍｓ＋蔗糖２０．０ｇ／Ｌ。在优化后的生根培养基上诱导一次６０ｄ,     

石梅湾大桥32m箱梁预应力孔道摩阻试验研究

通过海南东环铁路——石梅湾大桥预应力管道摩阻损失的现场试验,测试了简支箱梁的预应力孔道应变值。基于后张法预应力管道摩阻损失的计算理论,利用应变实测值,得出了箱梁两端压力值的关系曲线。应用最小二乘法原理,导出了μ、k值的计算公式,获得了可靠的μ、k值。通过μ、k实测值与设计值的比较μ、k分析,结果表明,关于μ、k值计算公式的推导合理,实测数据可靠。进一步,根据实测值与设计值的互相验证,表明管道成孔质量较好,施工质量达到设计要求。     

黄快杨试管苗生根及移栽成活率的研究

对黄快杨试管苗诱导生根和移栽进行试验研究,结果表明:以1/2MS+IBA0.05+NAA0.01为生根培养基,平均每株生根数为6.9个,根长为1.6 cm,根较粗壮,有侧根,较少产生愈伤组织,移栽后成活率较高。移栽基质分别采用珍珠岩(粗:细为1:1)、蛭石、蛭石:珍珠岩(1:1)、粗珍珠岩、细珍珠岩,其中,以珍珠岩作为基质的移栽成活率较高,尤以粗颗粒的珍珠岩基质最好,移栽成活率可达98.2%。     

把竹主要害虫生物学特性观察

据观察竹笋夜蛾在湖北阳新 1a发生 1代 ,以卵于禾本科杂草下部枯草上或竹基部笋箨上越冬 ,4月中下旬以 2龄幼虫从杂草上转主蛀入把竹笋危害 ;一字竹象和小竹象 1年 1代 ,以成虫于土下 8～1 5cm深的土茧中越冬 ,4月下旬成虫出土上把竹笋吸食笋肉 ,进行补充营养 ,随后进行交尾、咬产卵孔产卵 ,幼虫孵化后取食笋肉危害 ;江苏泉蝇每年 1代 ,以蛹在土中越冬 ,3月下旬为雄虫羽化高峰 ,雌虫的出现高峰在 4月中旬 ,上把竹笋取食、交尾、产卵 ,幼虫危害竹笋 ,发生腐烂 ,造成退笋     

Wood net primary production resilience in an unmanaged forest transitioning from early to middle succession

The mixed deciduous forests of the upper Midwest, USA are approaching an ecological threshold in which early successional canopy trees are reaching maturity and beginning to senesce, giving way to a more diverse canopy of middle and late successional species. The net primary production (NPP) of these forests is generally considered past peak and in decline, but recent studies show a striking resilience in the NPP trajectories of some middle and late successional forests; yet, the mechanisms controlling such temporal changes in NPP are largely unknown. At the University of Michigan Biological Station in northern Michigan, we used a ≥9-year continuous record of wood net primary production (NPP), leaf area index (LAI), canopy composition, and stem mortality in 30 forested plots to identify the constraints on wood NPP as a mixed forest transitions from early to middle succession. Although wood NPP decreased over time in most stands, the rate of decline was attenuated when the canopy comprised a more diverse assemblage of early and middle/late successional species. The mechanism for sustained NPP in stands with more species diverse canopies was the proliferation of LAI by intact later successional tree species, even as stem mortality rates of early successional trees increased. We conclude that projections of carbon sequestration for the aging mixed forests of the upper Midwest should account for species composition shifts that affect the resilience wood NPP.     

百合花粉管粘附与定向生长相关基因SCA的克隆及基因多样性分析

以亚洲百合‘Tresor’、麝香百合‘White heaven’和东方百合‘Caruso’为试材,首次在百合基因组中扩增到SCA基因全长序列,在亚洲百合和东方百合中分别获得4个SCA基因拷贝,在麝香百合中获得3个SCA基因拷贝,各拷贝之间具有72.97%～99.68%相似性。从百合基因组中克隆到的SCA基因均含有两个外显子和一个内含子,推导编码113～115个氨基酸残基的前体蛋白(其中成熟蛋白均含91个氨基酸残基)。SCA蛋白具有典型的LTP蛋白N端信号肽,保守的8个半胱氨酸残基和2个五肽模序,并且氨基酸序列之间的相似性高于基因序列相似性,为87.91%～98.90%。亚洲百合、麝香百合、东方百合SCA氨基酸序列比对发现在某些氨基酸位点存在着明显种系间差异。在系统进化树中,三个杂种系的11个SCA基因的氨基酸序列与单子叶植物LTP亲缘关系较近,与双子叶植物较远,这与植物分类学中亲缘关系的远近相一致。     

Design Approach on Flexural Load-carrying Capacity of Steel Beam to CFST Column Joints with External Stiffening Ring

A 3-D finite element model is established by ABAQUS to simulate the behavior of the joints with concrete-filled steel tubular (CFST) column to steel beam using external stiffening ring.The load versus deformation curves of this type of joints are compared between theoretical and experimental results,and in good agreement.Parametric analysis is performed to study the flexural load-carrying capacity of the joint.The width of external stiffening ring,the steel ratio of CFST column,the ultimate strength of steel beam,the strength of steel tube and beam,the concrete strength,the axial load ratio,and the beam to column linear stiffness ratio are considered as parameters.The simplified practical design approach is proposed based on parameter analysis of the flexural load-carrying capacity of these joints.The practical calculated values are in good agreement with the FEM results.     

Plant regeneration from protoplasts isolated from primary calli using mature embryos of two Brazilian rice cultivars

A plant regeneration system from rice protoplasts using calli derived from mature embryos was established for the two Brazilian modern rice cultivars IAC-201 and IAC-165. After 30 to 40 days of in vitro culture it was possible to obtain on average 6 million protoplasts per gram of callus. Microscopic selection of embryogenic calli was a key step for protoplast isolation. The production of embryogenic calli increased when L-proline and casein hydrolysate were used in the callus induction medium. The Oc or IR52 nurse cell lines were essential for protoplast division. Different regeneration media were studied and 139 plants were regenerated which set seed. Some of the regenerated plants showed morphological variation such as the presence of awns in spite of the short time of the in vitro culture. This revised version was published online in July 2006 with corrections to the Cover Date.     

2010年春季微山湖叶绿素a及初级生产力研究

2010年4月对微山湖不同水域叶绿素a含量和初级生产力进行调查,并就环境因子对其影响进行了研究。结果表明,微山湖叶绿素a平均含量为6.29 μg/L,表现为入湖河道>航道区>养殖区;初级生产力均值为188.67 mgC/(m3?d),表现为入湖航道>养殖区>湖区航道;逐步回归分析发现,总氮、总磷对微山湖叶绿素a含量影响显著;总磷含量对入库河流叶绿素a含量影响显著。总磷含量对微山湖、入湖河流初级生产力影响显著;磷酸盐含量对入湖河流初级生产力影响显著。     

苹果花粉萌发生理影响因子的研究

选用‘红星’、‘美红’、‘荷红’、‘全家红’4个品种的花粉作为试材,分别通过染色法（TTC、过氧化物酶法）和离体萌发法来测定苹果花粉的生活力,并通过花粉离体萌发、生长试验,观察其在不同培养条件下的萌发生长状况。结果表明：染色及离体培养试验中,品种间花粉活力存在较大差异,其中‘红星’花粉生活力最高,‘美红’、‘荷红’次之,‘全家红’最低;离体萌发试验中,不同培养条件下各种花粉的萌发及花粉管生长随温度、浓度的增加均呈先增后减趋势;不同温度条件下,花粉萌发生长最适培养基浓度不同,高浓度（15%、20%）的培养环境对花粉的萌发生长有一定抑制作用;试验还发现,各花粉最高萌发率与花粉管最大长度生长条件不一致,花粉管的生长最适温度及培养浓度均高于萌发最适条件,这可能与花粉管萌发生长时新陈代谢旺盛有关。