Cd2+、Hg2+、Pb2+抑制罗非鱼EOG反应的研究

将不同浓度Ｃｄ２＋、Ｈｇ２＋、Ｐｂ２＋液分别灌注罗非鱼嗅觉器官,研究其对ＥＯＧ反应的影响。结果表明,这３种离子对ＥＯＧ反应均呈抑制效应,抑制作用的大小与金属离子的种类及浓度有关,Ｃｄ２＋、Ｈｇ２＋、Ｐｂ２＋有效ＩＣ５０分别为３３．９１、６７．７３、１９１．４４μｇ／Ｌ;毒性顺序为：Ｃｄ２＋＞Ｈｇ２＋＞Ｐｂ２＋。     

日本黄姑鱼和鮸状黄姑鱼细胞色素b基因序列的比较分析

利用PCR技术对日本黄姑鱼和鮸状黄姑鱼线粒体DNA的细胞色素b基因片段进行了扩增,PCR产物直接测序,分别获得日本黄姑鱼和鮸状黄姑鱼1137bp的序列。通过对两种鱼的Cyth序列的比对分析,得出两种鱼序列的相似性为99．82％;分析了两种鱼序列的碱基组成及碱基变异情况,发现两种鱼的序列差异明显,碱基替换较多,而且有2个位点可以作为区分两种鱼的分子标记。因此,可以将Cyth基因作为种间分子鉴定或更高分类界元遗传分析的分子标记。     

Partial substitution of chemical fertilizers with organic amendments increased rice yield by changing phosphorus fractions and improving phosphatase activities in fluvo-aquic soil

Journal of Soils and Sediments - The aim of this study was to investigate the effect of combined use of chemical fertilizers with wheat straw and swine manure on rice yield and phosphorus...     

基于多特征提取和Stacking集成学习的金线莲品系分类

针对传统中药鉴定、分子鉴定、生物技术鉴定及光谱检测技术的主观性强、耗时、操作复杂等不足,以及金线莲整个叶片形态区分度小、单一分类器鉴别精度不高的问题,该研究提出了基于机器视觉的叶片子区间多特征提取方法和基于多模型融合的Stacking集成学习算法实现金线莲的品系分类。试验采集6个品系的金线莲叶片图像数据,进行图像预处理后提取叶片子区间内纹理、颜色共114个特征,基于这些特征,构建堆叠式两阶段集成学习框架,以逻辑回归、K最近邻、随机森林和梯度提升决策树(Gradient Boosting Decision Tree,GBDT)作为基分类器,GBDT作为元分类器进行学习。试验结果表明,Stacking集成学习模型的整体识别综合评价指标F值达93.91%,分类正确率达94.49%,分别比逻辑回归、K最近邻、随机森林和GBDT这4个单一分类模型高出4.40、11.87、11.01、12.94个百分点和5.36、11.34、6.93、12.13个百分点。因此,该研究能够有效识别金线莲品系,为形状大小相似、形状特征难以利用的植物叶片识别提供参考。     

虎舌红茎尖高频再生体系的建立

以虎舌红(Ardisia mamillata Hance)幼嫩茎尖为外植体,采用正交设计及方差分析对影响虎舌红植株离体培养的因素进行了优化研究。结果表明:最佳愈伤组织诱导培养基为MS 2,4-D0.7mg/L 6-BA0.2mg/L 蔗糖28g/L 琼脂6.0g/L;不定芽诱导最佳培养基为MS NAA0.2mg/L CPPU0.4mg/L 蔗糖30g/L 琼脂6.0g/L,分化率为96%,增殖率为5.5;最佳生根培养基为1/2MS NAA0.4mg/L IBA0.3mg/L 蔗糖26g/L 琼脂5.0g/L,生根率为93%。     

Interspecific hybrids between helianthus PetiolarisNutt. and H. Annuus L.: Effect of backcrossing on meiosis

Summary Interspecific substitutions of the nucleus of Helianthus annuus (2n=34) into the cytoplasm of H. petiolaris (2n=34) were obtained by successive backcrossing using cultivated sunflower, H. annuus, as the recurrent pollen parent.Meiosis in the F₁ was characterized by multivalents, suggesting that 10 of the 34 chromosomes were heterozygous for chromosomal interchanges. An additional pair of chromosomes also contained a paracentric inversion. Continued backcrossing resulted in rapid elimination of the meiotic aberrations evident in the F₁. In the BC₁, 1 of 11 plants had normal meiosis and by the BC₂, only 13 of 54 plants had meiotic aberrations similar to those of the F₁. However, trisomic progeny (2n=35) were found in 3 of the 11 BC₁ plants and 20 of the 54 BC₂ plants. No meiotic aberrations were observed in BC₃ or BC₄ plants. Plants with indehiscent anthers, and considered to be male sterile (M.S.), first occurred in the BC₁ and, by the BC₂, 51 of 54 plants were M.S. All 19 BC₃ and 16 BC₄ plants were M.S. Preliminary investigations suggest that the pollen from such plants is sterile and that the sterility is cytoplasmic rather than genetic.Disc-flower measurements were a useful technique for selecting samples at the correct stage of microsporogenesis, but could not be used to distinguish between successive backcrosses.     

花粉直感对马家柚果实品质的影响北大核心CSCD

【目的】通过对马家柚配置不同授粉组合,探究花粉直感效应对马家柚果实品质的影响。【方法】以江西省上饶市地方优良品种马家柚为杂交母本,以信木柚、四倍体葡萄柚为杂交父本,通过人工授粉进行杂交,比较不同处理下马家柚果实品质差异。【结果】信木柚与四倍体葡萄柚花粉活力分别为94.34%和93.75%,经过异花授粉能显著提高马家柚坐果率,四倍体葡萄柚高于信木柚。在常规品质方面,信木柚授粉能提高果实平均单果质量、横径、纵径、种子质量、果皮质量和固酸比;四倍体葡萄柚授粉能提高果实平均可食率,降低果实平均单果质量、果皮厚度、种子质量和果皮质量,且授粉后种子呈瘪籽状。在代谢物方面,果肉中主要的初生代谢物为氨基酸类、有机酸类、糖类和醇类,不同授粉品种之间初生代谢物含量有明显差异,但与亲本之间没有明显规律。另外在授粉后的果实与亲本果实中共统计到85种挥发性物质,其中醛类11种,萜烯类28种,酯类16种,醇类14种,酮类14种,烷烃类化合物5种和7种酚、羧酸类化合物,不同果实中均以柠檬烯含量最高,含量占比在87.48%~92.57%之间,不同授粉品种的挥发性物质含量存在差异,且信木柚授粉组合中有21种物质表现出明显的花粉直感效应。【结论】异花授粉可以提高马家柚坐果率,可以通过花粉直感效应在一定程度上快速改善马家柚的综合品质,为马家柚实际生产提供理论依据和调控技术支撑。     

浙江太湖稻区稻瘟病菌生理小种变化及毒性分析

】１９９１～１９９６年,从浙江太湖稻区８个县（市）的稻瘟病标样中分离到４８８个有效单孢菌株,经７个中国稻瘟病菌鉴别品种鉴定,共鉴定出７群１８个小种。其中,ＺＤ,ＺＡ,ＺＥ群为优势种群,出现频率分别为３９．３４％,２７．２５％和２４．８０％,优势小种为ＺＤ３,ＺＥ３,ＺＡ４９,ＺＤ１。主栽品种上的小种组成较为复杂,但主要小种与整个稻区的优势小种基本一致,小种与品种之间存在着特定的亲和性关系。病菌对该稻区已被更换或正在被更换的品种的毒力频率较高,对新育成和推广的秀水１７、秀水９３－６３等品种的毒力较弱。病菌小种类型和结构随着栽培品种的更换而发生较大的变化,反映了病原菌与寄主品种的协同进化关系。     

APSA—80对草甘膦增效机制及药效研究

在草甘膦药液中加入φ为０．１％或０．２％的ＡＰＳＡ－８０后,表面张力降低了６１．５６％和６４．８６％;在８种窄叶杂草和９种阔叶杂草叶子上接触角明显降低;药后２０￣３０ｄ,防效在８４．８５％￣９６．５６％,单用仅４４．３３％￣５２．３３％,药后４０ｄ时的杂草干物质积累量被抑制在８３．８５％以上,抑制率比单用提高了２２．２７％￣５４．１１％。结果还表明：ＡＰＳＡ－８０具有延长草甘膦持效期、加快杀草速率