Genetic control of the long glume phenotype in tetraploid wheat by homoeologous chromosomes

The Ispahan emmer wheat, Triticum ispahanicum Heslot, was discovered in Iran 1957 by the French expedition of Vinnot- Bourgen. T. ispahanicum has a long glume and a more slender spike than T. turgidum var. polonicum. The objectives of this study were (1) to determine the inheritance and chromosomal location of the gene for long glume, P2, from T. ispahanicum using the near- isogenic line P2-LD222, and (2) to compare the effects of the genes for long glume. The gene for long glume, P2, was located approximately 36.5 cM from the cn-B1 locus, which controls the chlorina trait and approximately 40 cM from the centromere on the long arm of 7B. The location of P2 approximately 29.6 cM from the Pc locus produced additional evidence that the order of loci was cn-B1, P2, and Pc. This raises the possibility of a paralogous gene set conditioning long glumes. A significant deviation from a 3:1 ratio in the F2 of LDN 7D(7B)/P2-LD222 confirmed the location of P2 on chromosome 7B. It is proposed that T. ispahanicum originated as a mutation of a gene affecting glume length on chromosome 7B of T. dicoccum, a spelt type of cultivated tetraploid wheat. This revised version was published online in July 2006 with corrections to the Cover Date.     

磷肥有机替代、秸秆还田对棉花养分吸收和磷肥利用效率的影响

为探究磷肥有机替代、秸秆还田对棉花养分吸收、磷肥利用效率及棉花产量的影响,本研究基于国家灰漠土肥力与肥料效益监测站5年田间微区棉花连作定位试验,以7种施肥措施为样本,于2022年棉花成熟期开展棉田土壤田间调查研究。结果表明,磷肥有机替代和秸秆还田均能提升棉株氮磷钾养分吸收,各器官氮素平均含量在1.75～40.90 g·kg^-1之间,磷素平均含量在1.46～11.28 g·kg^-1之间,钾素平均含量在3.11～25.03 g·kg^-1之间。综合肥料投入和养分吸收,50%的磷肥有机替代和秸秆还田最能增强棉株吸氮能力和促进干物质积累,50%的磷肥有机替代对棉株吸磷能力最强且最有利于实现棉花节肥增钾的效果。棉株各器官N:P变化范围为1.20～12.01,磷肥有机替代和秸秆还田使茎、叶、蕾/铃/壳的N∶P明显降低,棉株生物量、籽棉产量随茎、叶、蕾/铃/壳N∶P的降低而增加,本试验棉花生长更倾向于受N、P共同限制。磷肥利用率随有机替代量的增加从12.54%提升到33.04%,土壤磷素盈余量随有机替代量的增加从28.20 kg·hm<...     

Inheritance and chromosomal location of the homoeologous genes affecting phenol colour reaction of kernels in durum wheat

End-use quality of wheat for noodles is influenced by polyphenol oxidase activity and its corresponding substrates. This study investigated the chromosomal location of genes that determine phenol colour reaction of kernels in tetraploid wheat using aneuploid stocks. Polyphenol oxidase activity was estimated by the colour reaction of kernels to phenol solution. It was found that the genes located on homoeologous group 2 chromosomes have an important effect on the level of phenol colour reaction of kernels. The genes (Tc1 and Tc2) responsible for high phenol colour reaction of kernels were mapped to the long arms of chromosome 2A and chromosome 2B, respectively. The map distances were estimated to be 46.8 cM for Tc1 and 40.7 cM for Tc2 from the centromere using double-diltelosomics of durum wheat.     

Computational chemistry study of the environmentally important acid-catalyzed hydrolysis of atrazine and related 2-chloro-s-triazines

Many chlorine-containing pesticides, for example 2-chloro-s-triazines, are of great concern both environmentally and toxicologically. As a result, ascertaining or predicting the fate and transport of these compounds in soils and water is of current interest. Transformation pathways for 2-chloro-s-triazines in the environment include dealkylation, dechlorination (hydrolysis), and ring cleavage. This study explored the feasibility of using computational chemistry, specifically the hybrid density functional theory method, B3LYP, to predict hydrolysis trends of atrazine (2-chloro-N4-ethyl-N6-isopropyl-1,3,5-triazine-2,4-diamine) and related 2-chloro-s-triazines to the corresponding 2-hydroxy-s-triazines. Gas-phase energetics are described on the basis of calculations performed at the B3LYP/6-311++G(d,p)//B3LYP/6-31G* level of theory. Calculated free energies of hydrolysis (delta h G298) are nearly the same for simazine (2-chloro-N4,N6-diethyl-1,3,5-triazine-2,4-diamine), atrazine, and propazine (2-chloro-N4,N6-di-isopropyl-1,3,5-triazine-2,4-diamine), suggesting that hydrolysis is not significantly affected by the side-chain amine-nitrogen alkyl substituents. High-energy barriers also suggest that the reactions are not likely to be observed in the gas phase. Aqueous solvation effects were examined by means of self-consistent reaction field methods (SCRF). Molecular structures were optimized at the B3LYP/6-31G* level using the Onsager model, and solvation energies were calculated at the B3LYP/6-311++G(d,p) level using the isodensity surface polarizable continuum model (IPCM). Although the extent of solvent stabilization was greater for cationic species than neutral ones, the full extent of solvation is underestimated, especially for the transition state structures. As a consequence, the calculated hydrolysis barrier for protonated atrazine is exaggerated compared with the experimentally determined one. Overall, the hydrolysis reactions follow a concerted nucleophilic aromatic substitution (SNAr) pathway.     

高毒农药替代防治番茄烟粉虱田间药效试验

为了了解各种试验药剂对番茄烟粉虱防治效果和施药技术,以及对非靶标有益生物的安全性,筛选出高毒农药替代产品或用药组合,为大面积推广和安全、合理使用提供依据,特进行田间农药筛选试验。     

Development of novel pesticides based on phytoalexins: Part 2. Quantitative structure-activity relationships of 2-heteroaryl-4-chromanone derivatives

Phytoalexins are low-molecular-weight chemicals that immune systems of plants produce and accumulate in response to infections, especially those of fungal origin. Although their content is not high in plants, yet they have shown unique fungicidal activity and played an important role in the defence system of plants. In searching for novel environmentally benign fungicides with high activity, the structures of flavanone derivatives, one of the most important phytoalexins groups, have been modified via bioisosteric substitution and a series of 2-heteroaryl-4-chromanones were designed and synthesized. They showed good fungicidal activities against rice blast disease, Pyricularia grisea (Sacc). Their IC50 values were tested in vitro and the relationship between structure and fungicidal activity was analyzed quantitatively using a Hansch-Fujita approach. The results showed that hydrophobicity was very important for fungicidal activity and there is apparently an optimum hydrophobic property for the molecules at a log Pow value of about 2.7. In addition, the results indicated that electronic effects played an important role in binding with the receptor and that the C=O group was probably a electron-accepting site. The quantitative structure-retention correlative equation of the title compounds was also established.     

可持续发展类型与测度的理论探讨

可持续发展的类型划分与可持续发展的测度是可持续发展理论研究的重要内容。科学反应可持续发展的特征 ,有利于可持续发展类型划分 ,是可持续发展测度的依据和目标。本文运用人地关系协调分析法与经济分析法 ,特别是与替代弹性不变生产函数分析法 (C.E.S生产函数 )相结合 ,提出了可持续的人均国内生产总值 ,探讨了可持续发展中人文资本、自然资本相互协调、相互依存的关系特征 ,建立可持续发展测度的指标系统和可持续发展的类型体系     

民族地区旅游地形象认知的替代效应与旅游形象策划

本文从心理认知的角度解释了旅游地形象认知的替代效应的概念和表现 ,结合民族地区旅游业发展的现状 ,对民族地区旅游形象认知的替代效应对旅游地的促进和抑制作用进行了研究 ,并以甘肃省临潭县旅游形象策划为例 ,对民族地区如何利用替代效应促进作用以及消除其抑制作用进行旅游地形象策划提出了意见。     

Variation in kernel characteristics and protein molecular weight distribution of Langdon durum-wild emmer wheat chromosome substitution lines

Triticum turgidum L. var. dicoccoides (DIC) provides a useful source of genes to improve agronomic and quality characteristics of durum wheat. Research was performed to identify DIC chromosomes that carry useful genes for quality improvement. Langdon-T. dicoccoides substitution lines consisting of 13 lines based on DIC accession PI 481521, 10 lines on PI 478742, and 2 lines on Israel A were evaluated for kernel characteristics and protein molecular weight distribution. DIC chromosomes 3A from PI 481521, and 1A and 7A from PI 478742 increased kernel hardness. Chromosome 2A from PI 481521 increased kernel weight, which resulted in increased semolina yield. Some substituted DIC chromosomes also affected grain protein concentration and protein molecular weight distribution. For example, chromosomes 2A, 5B, and 7B from PI 481521, and 6B from Israel A increased total protein concentration, which was primarily attributed to an increase of SDS soluble gliadins. Chromosome 6B from PI 478742 was unique in that it led to an increase in SDS insoluble high molecular weight polymeric proteins, which contributed to increased dough mixing strength. Results from this research indicated that chromosome 6B from PI 478742 is a potential gene source to improve dough characteristics of durum wheat by increasing insoluble high molecular weight polymeric protein concentration.