甘蓝与萝卜属间杂交及其胚挽救技术优化

以甘蓝显性雄性不育系C08-11为母本,以萝卜自交系Q07-12为父本进行属间杂交,对杂交子房和胚珠进行离体培养,筛选适合甘蓝与萝卜属间杂种胚挽救的适宜取材时间、培养基及外源添加物。结果表明,胚珠培养优于子房培养;所有处理子房培养仅获得3株杂交苗,取材时间以授粉后第9天为宜,B5培养基中添加合适的生长调节剂、水解酪蛋白和活性炭为子房培养所必需;胚珠培养各处理共获得29株杂交苗,适宜取材时间为蕾期授粉后第14天、花期授粉后第16天,对生长调节剂的需求取决于不同取材时期及培养基。     

敌百虫对鲫鱼的急性毒性研究

通过96h急性毒性实验敌百虫对鲫鱼的LC50为63.97mg/L,95%可信限为1.81±0.048 mg/L,95%可信区间为57.81～72.11 mg/L.分别选取1/2、1/4、1/8及1/16LC50为染毒浓度,于实验开始后24、48、72及96h采样分析,结果表明随着暴露时间的延长,各浓度组实验鱼血浆胆碱酯酶的活性均有一定的升高,但各浓度组间没有表现出明显的区别.实验剂量下的敌百虫对鲫鱼血浆CST活性有一定的影响,呈现出较为明显的先扬后抑的结果.1/2LC50实验组血浆CAT在实验进行至96h活性明显高于对照组,而其他剂量组在实验期间CAT活性没有明显的改变.本实验中敌百虫对鲫鱼的遗传性在微核率上未表现出差异,但高浓度核异常率在实验24、48h明显高于对照组.     

Conserving indigenous crayfish: stock assessment and habitat requirements in the threatened Austropotamobius italicus

• 1. As part of the Austropotamobius pallipes species complex, the crayfish Austropotamobius italicus is a species of community interest whose preservation requires the designation of Special Areas of Conservation (SACs) (Annex II, EU Habitats Directive). This study aimed at (1) assessing the conservation status of this threatened indigenous species by stock assessment in central Italy and (2) identifying some aspects of its elective habitat.
• 2. Surveys were conducted in nine streams harbouring A. italicus (streams WI) and in 10 streams where crayfish populations became extinct at least 5 years before the study (streams WO).
• 3. The results confirmed that A. italicus is a K‐selected species, with a relatively slow growth rate (males: 0.34; females: 0.37) and a long life expectancy (males: 8.2 years; females: 7.8 years). The extant populations are healthy, showing balanced sex‐ratios and well structured age‐class compositions. Mortality is mainly due to fishing, which is illegal in Tuscany.
• 4. Principal Components Analyses showed that the streams WI and WO differ in the abundance of allochthonous plant detritus but not in the taxonomic composition of their macroinvertebrate communities. Age classes were found to be spatially segregated, juveniles mainly using cobbles as substrates and adults seemingly avoiding them.
• 5. The loss of the pristine riverine landscape seems to have been responsible, together with illegal fishing, for the local extinction of the species. As a consequence, retaining, enhancing, and restoring the habitat and its complexity are required for the preservation of A. italicus.
• 6. The designation of SACs might help in this endeavour if accompanied by programmes aimed at publicizing the need for conservation of this species. Unfortunately, crayfish‐focused projects supported by LIFE in Italy since 1992 (4%) and the SACs involved (1.4%) have been relatively few, despite the poor conservation status of this species and its well recognized ecological role.

Copyright © 2008 John Wiley & Sons, Ltd.     

水分亏缺对不同小麦品种N、P、K分布与产量的影响

为明确华北地区不同小麦品种在正常和缺水条件下N、P、K的吸收利用特点,进一步实现资源高效利用,选用3个不同生态类型品种(沧麦6001、邯麦9、济麦22),设置相对含水量分别为60%~80%(正常)和40%~60%(亏缺)两个浇灌水平,进行人工气候室箱体栽培试验,测定各小麦品种不同器官N、P、K含量和分配、干物质积累以及对籽粒产量构成要素的影响。结果表明,N、P、K含量和分配具有明显的器官特性,其中籽粒N和P含量显著高于其他部位,K含量最低。水分亏缺限制了沧麦6001籽粒N和K的吸收,同时促进了N和P向籽粒的转运;限制了邯麦9茎秆K的吸收,促进了P向颖壳的转运;限制了济麦22叶片、籽粒P的吸收,同时促进了N向颖壳和籽粒的转运,从而改变了小麦不同部位养分比例平衡以及干物质积累。N、P含量与干物质积累呈显著正相关,K含量与其呈显著负相关,但均未直接影响产量及其构成要素。亏缺灌溉下(亏缺量为24.39mm),邯麦9穗数、产量及济麦22穗数显著降低,而沧麦6001穗数、穗粒数和产量显著提高。因此,适度控制水分并提高营养元素向籽粒的转运效率是提高小麦产量和品质的重要途径。     

High water content silk protein-based hydrogels with tunable elasticity fabricated via a Ru(II) mediated photochemical cross-linking method

Silk is very promising in the field of biomaterials as a natural biomacromolecule. Silk protein can be made into various forms of materials, including hydrogels. However, silk protein-based hydrogels have not attracted much attention due to its weak mechanical properties. Here, we report high water content silk protein-based hydrogels with tunable elasticity which were fabricated through Ru(II) mediated photochemically cross-linking tyrosine residues in regenerated silk protein. The regenerated silk protein was characterized by Fourier transform infrared spectroscopy (FTIR). The gelation kinetics of the silk protein was studied by rheology measurements. The compressive mechanical properties of the silk protein-based hydrogels was investigated using compressive tests and dynamic mechanical analysis (DMA). Compressive modulus of the hydrogels reached 349±64 MPa at 15 % strain. The fabricated silk protein-based hydrogels were also characterized by Scanning electron microscopy (SEM), revealing an interconnected porous network structure, typical of hydrogels, with an average pore size of approximately 130 μm. Finally, biocompatibility of the silk protein-based hydrogels was demonstrated through cell culture studies using a human fibroblast cell line, HFL1. The reported silk protein-based hydrogels represent a promising candidate for biomaterial applications.     

六个猕猴桃品种在六盘水市的品比试验

以国内外较优6个猕猴桃品种为试材,利用引种技术进行品种的引进及筛选,综合评价各品种的物候期、适应性、果实品质等指标,以优化和调整六盘水猕猴桃品种结构,探明并确定贵州猕猴桃主产区六盘水市适应性较好的品种。结果表明:根据各品种的表现和"合理-满意度"分析,在六盘水表现较好的品种有"红阳",成熟期为8月中下旬,总糖含量为11.90%,口味香甜,果肉为红色,667m~2产量742.8kg,"金艳"成熟期为9月,667m~2产量1 018.6kg、单果质量118.43g、香味浓郁、果肉金黄色,"贵长"成熟期较晚,667m~2产量为1 401.7kg,香味较浓、果肉翠绿色;表现不好的品种有"西选2号""楚红",这2个品种产量均较低,果实口感一般;表现相对较好的品种有‘Hort 16A’口感较好,但抗病性较弱,"和平2号"单果质量156.80g,但667m~2产量仅有953.1kg,"海沃德"667m~2产量仅有703.6kg,表现不稳定。"红阳""金艳""贵长"在六盘水地区表现良好,适宜推广种植。     

不同产地‘南果梨’贮藏中糖酸含量变化研究

作者对鞍山坡地和沈阳坡地、平地栽培的‘南果梨’,测定常温贮藏下果实可滴定酸和可溶性固形物的含量,同时比较常温和4℃下1-MCP处理的果实可滴定酸和可溶性固形物的含量。结果表明,原产地鞍山坡地‘南果梨’果实在常温贮藏下的可滴定酸和可溶性固形物含量高于沈阳坡地的,沈阳坡地的高于平地的;常温1-MCP处理能更好地延缓果实可滴定酸分解和可溶性固形物的积累,使‘南果梨’在采后室温贮藏过程中保持良好的风味品质。     

起垄沟播和常规平播下滴灌棉田土壤水盐的运移

为明确滴灌条件下植棉方式对土壤水盐运移的影响,采用田间调查与室内分析相结合的方法,在滨海重度盐碱地开展了起垄沟播和常规平播植棉方式下的水盐运移试验,调查了滴灌前后两种植棉方式不同点位及不同土壤深度的土壤水分、盐分和土壤溶液电导率等指标,分析不同植棉方式土壤水分、盐分和土壤溶液电导率的时空分布特征。结果表明：滴灌条件下起垄沟播的水分入渗深度和盐分淋洗深度均明显大于常规平播植棉方式,起垄沟播植棉膜下(0~20 cm)土壤溶液电导率明显低于常规平播植棉;滴灌对两种种植方式膜外土壤水分和盐分运移未产生明显影响。起垄沟播联合滴灌技术更有利于为棉花生长的水盐环境。研究结果可为盐碱地植棉提供理论参考和实践依据。     

Effect of apple cultivars and storage periods on the virulence of Neofabraea spp.

Bull’s eye rot is a typical quiescent postharvest apple disease in major fruit-growing areas. The susceptibility of different apple cultivars to Neofabraea spp. (N. vagabunda and N. malicorticis) was assessed, with Granny Smith showing the most resistance and Cripps Pink the most susceptibility. To assess the factors involved in conidial germination, Neofabraea spp. were grown on crude protein extracts (CPEs) collected from apple fruits at different storage periods. Fungal germ tube growth rate and pathogenic enzyme (cellulase and xylanase) activity were assessed. Results showed that CPEs collected after 2 and 4 months of storage progressively stimulated conidial germination and germ tube elongation, while a lesser effect was observed from CPEs after 1 month of storage. Xylanase proved to be the main degrading enzyme secreted by all the isolates, while cellulase was produced only by N. vagabunda isolates. Overall, the isolate ID02 was the most virulent, based on more rapid germ tube elongation and greater activity of the lytic enzymes.     

黏虫蛹性别的快速鉴别方法

根据黏虫Mythimna separata(Walker)蛹生殖孔的位置、腹部腹节的外部形态学特征、生殖孔(产卵孔)至排泄孔之间的距离,快速、准确鉴别黏虫蛹性别。雌蛹第8腹节腹面中央的生殖孔与第9腹节的产卵孔连接形成一纵裂缝,裂缝两侧平坦,无突起。生殖孔下端与第9腹节的前缘连接、产卵孔下端与第10腹节的前缘连接,形成2个明显的"人"字纹。雄蛹第8腹节无纵裂缝,在第9腹节腹面中央的生殖孔呈现的纵裂缝连接第10腹节,裂缝两边各有一个半圆形瘤状突起。雌雄蛹排泄孔均在第10腹节腹面,雌蛹产卵孔下端至排泄孔上端之间的距离为(400.85±151.10)μm,雄蛹生殖孔下端至排泄孔上端之间的距离为(178.21±93.59)μm,约为雌蛹相应距离的一半。采用该方法观察的270头羽化蛹的性别鉴别准确率100%。该方法对于快速鉴别黏虫蛹的性别、开展黏虫相关的生物学研究以及预测预报等具有重要的参考价值。