用稀土,植物单宁提高胶原蛋白热变性温度

稀土或植物单宁与胶原作用都不能使胶原较高的热变性温度。本文研究中，将稀土和植物单宁结合与胶原作用获得了良好的协同效应，使胶原的热变性温度为５５℃上升到１０２℃。     

低产油茶换冠嫁接茶花技术初探

阐述了低产油茶换冠嫁接茶花技术,重点介绍了高枝嫁接的操作步骤,并研究了施用稀土肥料对嫁接后茶花生长的影响。结果表明：施用稀土肥料后,嫁接的茶花成活率有所提高,且对侧芽抽芽生长优势明显;夏季嫁接茶花的成活率高于秋季嫁接。     

四合木水分代谢特性的初步研究

四合木(Tetraena mongolica Maxim)为内蒙古特有的国家二级保护、内蒙古一级保护植物。本文首次报道了四合木的水分状况(总含水量、自由水含水量及束缚水含水量)和水分代谢(水势、蒸腾速率及抗脱水力),并且讨论了这些特性与忍受干旱的关系,为进一步保护这种植物提供科学依据。     

Multiple origins for black-grass (Alopecurus myosuroides Huds) target-site-based resistance to herbicides inhibiting acetyl-CoA carboxylase

We have investigated the process of evolution of target-site-based resistance to herbicides inhibiting acetyl-CoA carboxylase (ACCase) in nine French populations of black-grass (Alopecurus myosuroides Huds). To date, two different ACCase resistant alleles are known. One contains an isoleucine-to-leucine substitution at position 1781, the second contains an isoleucine-to-asparagine substitution at position 2041. Using phylogenetic analysis of ACCase sequences, we showed that 1781Leu ACCase alleles evolved from four independent origins in the nine black-grass populations studied, while 2041Asn ACCase alleles evolved from six independent origins. No geographical structure of black-grass populations was revealed. This implies that these populations, although geographically distant, are, or have until recently been, connected by gene flows. Comparison of biological data obtained from herbicide sensitivity bioassay and molecular data showed that distinct resistance mechanisms often exist in a single black-grass population. Accumulation of different resistance mechanisms in a single plant was also demonstrated. We conclude that large-scale evolution of resistance to herbicides in black-grass is a complex phenomenon, resulting from the independent selection of various resistance mechanisms in local black-grass populations undergoing contrasted herbicide and agronomical selection pressures, and connected by gene flows whose parameters remain to be determined.     

红麻稀有材料分类地位研究

17份红麻稀有材料的研究发现叶、苞片、萼片、花冠、蒴果和种子等形态特征变异丰富。细胞学研究表明,染色体数均为2n=36;栽培材料随休有普通型、较大型和特大型,野生材料均为普通型;野生材料染色体结构较栽培材料对称。野生材料与常规品种杂交,座果率变幅35-50%,结实率3.2-17%,均明显低于对照（分别为69%和30%）,表明     

基于稀土氧化物示踪法探究冻融循环对黑土团聚体周转的影响

为区分土壤团聚体形成和破碎过程,阐明冻融循环对黑土土壤结构的影响,本文利用稀土氧化物（REOs）示踪技术,通过室内模拟实验,探究不同初始含水量（50 %田间持水量（T50） vs. 100 %田间持水量（T100））和冻融循环次数（0次、3次、6次、12次和20次）对团聚体粒径分布、平均质量直径（MWD）以及团聚体周转过程的影响。研究结果表明：同一初始含水量下,随着冻融循环次数的增加,MWD、>0.25 mm和<0.053 mm团聚体含量显著降低,0.25～0.053 mm团聚体含量显著增加（P < 0.05）。6次冻融循环后,T50处理下的MWD显著高于T100处理（P < 0.05）,5～2 mm和<0.25 mm团聚体含量无显著差异。除5～2 mm团聚体外,相邻粒级团聚体之间周转更为激烈;在同一冻融循环次数下,5～2 mm团聚体向0.25～0.053 mm团聚体的破碎量在T100处理下显著高于T50处理（P < 0.05）。冻融循环促进了>0.25 mm团聚体的破碎和＜0.053mm的团聚,表现为0.25-0.053mm团聚体的累积,该变化与土壤初始含水量无关。冻融循环过程中,MWD与各粒径团聚体相对形成量呈显著正相关,与其相对破碎量呈显著负相关（P < 0.05）。随着冻融循环次数的增加,各粒径团聚体周转时间显著增加（P < 0.05）。同一冻融循环次数下,>0.25 mm团聚体的周转时间高于<0.25 mm团聚体,T100处理下的团聚体周转时间显著高于T50处理（P < 0.05）。综上所述,冻融循环次数和土壤初始含水量通过影响团聚体形成和破碎过程改变土壤结构的稳定性。本研究结果可为进一步探究冻融循环下黑土土壤结构变化提供理论依据。     

Genetic structure of a population of Ganoderma boninense on oil palm

Ganoderma boninense (the causal agent of basal stem rot of oil palm in Papua New Guinea) has a tetrapolar mating system with multiple alleles. Investigations into the population structure of G. boninense , using interfertility between isolates as a marker, revealed that the population on oil palm was comprised predominantly of genetically distinct individuals, although a number of isolates were found to share single mating alleles. No direct hereditary relationship was found between isolates on neighbouring or spatially separated diseased palms, indicating that outcrossing had probably occurred over several generations in the founder population prior to colonization of oil palm. In this study, a total of 81 A and 83 B mating type alleles (factors) were detected with 18 allelic repeats at the A locus and 17 at the B locus. Alleles appeared to be randomly dispersed throughout the population in each study block, although there was a significantly ( P  < 0·01) higher proportion of allelic repeats between estates separated by several kilometres compared to within estates. This is the first study on the population structure of this species and confirms that sexual reproduction is a significant component of the epidemiology of this disease.     

Production of all eight genotypes of null alleles at 'waxy' loci in bread wheat, Triticum aestivum L.

Null alleles of the three loci coding for ‘waxy’ proteins in bread wheat have been identified. Plants carrying different null alleles were collected and segregation of the null alleles in both selfed and doubled haploid progeny of plants simultaneously heterozygous for the null alleles at each of the three loci were examined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Mendelian segregation of these alleles in both types of progeny was shown, indicating that they can easily be utilized in breeding programmes. Iodine staining of the eight possible null phenotypes showed that only the triple null type had zero amylose in its endosperm starch.     

稀土拌种对玉米产量的影响

试验表明,玉米使用不同量的农用稀土拌种均有增产效果。以０４ｇ稀土／ｋｇ种子拌种增产率最高,为１５８％。其次,０８ｇ稀土／ｋｇ种子拌种增产率为１０８％。玉米稀土拌种百粒重、穗长、穗粗与产量直接通径作用大。穗长和百粒重的互作效应以及百粒重、穗长、穗粗单效应成为影响产量的主要因素。     

芥黄蜜环菌交配型复等位基因的研究

从大兴安岭长白山采集１７号芥黄蜜环菌,用分离的单孢菌株进行交配型测定,证实中国该种为双因子异宗配合机制,选取各号标本的４种交配型菌株进行循环配对实验,结果发现该种的交配型基因座的多样性很高,共有１３对复等位基因,证明该种在世界分布区域内具有较强的生态适应能力。是目前国际首次用实验测定的蜜环菌交配基因数目。