抗虫杂交棉的制种及推广

近年来,抗虫棉在黄河三角洲(东营)推广速度很快,全市抗虫棉普及率已达到100%,其中抗虫杂交棉达40%。去年11月份,我市又配出新抗虫杂交品种——华棉1号(暂定名),该品种抗病、抗虫、抗寒、耐盐碱等,是抗逆性强的杂交棉。抗虫杂交棉,弥补了常规抗虫棉产量低和常规品种不抗虫的缺陷     

Effect of genetic improvement of grain yield and nitrogen efficiency of mid‐season indica rice cultivars

Genetic improvement (GI) of mid‐season indica rice (Oryza sativa L.) in China has been experienced four typical plant types during the past several decades, i.e., early tall cultivars (ET), dwarf cultivars (DC), semi‐dwarf cultivars (SDC) and super rice cultivars (SR). However, little is known about the changes in fertilizer nitrogen (N) efficiency and their relationships with grain yield during the GI. With 12 representative mid‐season indica cultivars of the four types during GI, the effects of GI on grain yield and nitrogen efficiency were investigated. The results show that GI significantly increased grain yield and agronomic efficiency (AE) of N fertilizer but had no significant effect on recovery efficiency (RE) of N fertilizer. The low percentage of filled grains in modern SR limited its yield potential and the further increase in AE. GI decreased the N uptake from heading to maturity, leading to lower RE in modern rice cultivars. The rapid decline of the activities of root oxidation and nitrate reductase in SR during grain filling might be the physiological reasons for the lower percentage of filled grains and lower N uptake from heading to maturity.     

我国荒漠化评价研究综述

 中国是世界上受荒漠化危害最为严重的国家之一,准确、全面、及时的荒漠化评价有助于人类制订有效的治理措施。从指标体系、评价方法和基准3方面评述了我国近30a来荒漠化评价的研究成果,指出以景观生态学原理和遥感技术为基础的评价指标体系已成为近年来的研究热点,但目前仍存在指标选择标准不明确,分级阈值确定存在主观性和评价结果缺乏可信度等问题。评述了欧氏距离法、沙漠化程度指数等评价模型的优点和不足,指出近年来荒漠化评价方法研究与景观生态学和3S技术结合,逐步向多尺度、定量化和简便快捷发展,但仍需对方法的可靠性进行验证。介绍了荒漠化基准研究中的主要观点,并提出可以将荒漠化治理的目标作为基准。     

The potato R10 resistance specificity to late blight is conferred by both a single dominant R gene and quantitative trait loci

The R10 late blight differential of potato, 3681ad1, exhibits good field resistance. Progeny from the cross between 3681ad1 and the susceptible cultivar ‘Katahdin’ were assessed for late blight resistance to three Phytophthora infestans isolates, using a detached leaf assay. Progeny differed in response to the three isolates. Resistance to isolates IPO‐0 and 99018 was controlled by quantitative trait loci (QTL), whereas resistance to isolate 89148‐9 was inherited as a dominant R gene, designated as R10 in this study. Statistical analysis revealed that one of the resistance QTLs to isolates IPO‐0 and 99018 is linked to the R10 gene, which maps to chromosome 11 in a region where a complex late blight resistance locus has been reported previously. A high‐resolution map of R10 was constructed using a large segregating population, and the gene was delimited to a genetic interval of 0.26 cM. The clustering of the qualitative gene R10 with resistance QTLs could explain the field resistance observed with 3681ad1.     

Matrix modification with silane coupling agent for carbon fiber reinforced epoxy composites

To improve interfacial adhesion between carbon fiber and epoxy resin, the epoxy matrix is modified with N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (YDH602) and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (YDH792), respectively. And the effect of matrix modification on the mechanical performance of carbon/epoxy composites is investigated in terms of tensile, flexural and interlaminar properties. The flexural properties indicate that the optimum concentration of silane coupling agents YDH602 and YDH792 for the matrix modification is approximately 0.5 wt% of the epoxy resin system, and the mechanical properties of the YDH792-modified epoxy composites is better than that of the YDH602-modified epoxy composites at the same concentration. Compared to unmodified epoxy composite, the incorporation of 0.5 wt% YDH792 results in an increase of 4, 44 and 42 % in tensile, flexural and interlaminar shear strength (ILSS) values of the carbon/epoxy composite, respectively, while the corresponding enhancement of tensile and flexural modulus is 3 and 15 %. These improvements in mechanical properties can be considered to be an indication of better fiber/matrix interfacial adhesion as confirmed by SEM micrographs of the fracture surface after interlaminar shear testing. The viscosity of the modified epoxy resin system can be reduced by incorporation of silane coupling agent YDH792, which is beneficial for fiber impregnation or wetting during liquid composite molding process.     

利用染色体片段置换系定位低温影响水稻萌芽期根长和芽长QTL

根和芽的正常生长和发育对保障水稻产量有重要作用。为探究在低温条件下影响幼芽期根长和芽长的QTL,以9311（受体）和日本晴（供体）染色体片段置换系群体为材料,将萌发种子置于15℃低温处理7d,然后在25℃下恢复生长7d,连续测量根长和芽长,以25℃下根长和芽长作为对照,定位低温条件下影响根长和芽长的QTL。15℃条件下,定位到9个根长QTL,贡献率为8.65%~24.35%,其中qRL15T7.2和qRL15T10.3在根生长不同时期被重复检测到;定位到9个影响芽长的QTL,贡献率为1.73%~28.89%,其中qBL15T6、qBL15T7、qBL15T9和qBL15T10被重复检测到。25℃条件下,定位到9个根长QTL,贡献率为1.73%~28.89%,qRL25T7、qRL25T9.3、qRL25T10和qRL25T12在根生长不同时期被重复检测到;定位到5个影响芽长QTL,贡献率为0.58%~38.26%,qBL25T3.3在芽生长不同时期被重复检测到。其中,第2、7、9和10号染色体上4个Bin标记区域存在既控制根长又控制芽长的QTL。通过比较发现,15℃下定位到的根长或芽长QTL与25℃定位到的根长或芽长QTL均不相同,表明低温条件下控制水稻幼芽期根和芽生长的遗传机制可能与正常温度下不同。     

Aerosols from overseas rival domestic emissions over North America

Many types of aerosols have lifetimes long enough for their transcontinental transport, making them potentially important contributors to air quality and climate change in remote locations. We estimate that the mass of aerosols arriving at North American shores from overseas is comparable with the total mass of particulates emitted domestically. Curbing domestic emissions of particulates and precursor gases, therefore, is not sufficient to mitigate aerosol impacts in North America. The imported contribution is dominated by dust leaving Asia, not by combustion-generated particles. Thus, even a reduction of industrial emissions of the emerging economies of Asia could be overwhelmed by an increase of dust emissions due to changes in meteorological conditions and potential desertification.     

8-羟基喹啉对草鱼急性毒性和遗传毒性的研究

以8-羟基喹啉为诱变剂,研究了其对草鱼(Ctenopharyngodon idellus)的急性毒性和遗传毒性效应.急性毒性实验测得8-羟基喹啉对草鱼的24、48、96 h的LC50分别为32.30、26.93、20.95 mg/L,表现出较强的急性毒性,其安全浓度为11.62 mg/L.遗传毒性结果表明,处理组与空白对照组相比,微核率均达到显著或极显著差异水平(P＜0.05或P＜0.01),并且表现出明显的时间效应和剂量效应.因此,8-羟基喹啉在达到一定浓度和染毒时间以后对草鱼具有一定的遗传毒性,因而推测其大量使用可能对永生生物及生态环境具有一定的毒害作用.     

重庆市城镇化与生态系统健康的时空耦合特征

[目的]研究山地城市城镇化与生态系统健康的时空交互耦合特征以及生态系统健康与城镇化之间的复杂关系,为该地区城镇的科学管理与可持续发展提供科学依据。[方法]以山地城市重庆市为例,运用熵值法和活力—组织力—弹力—服务模型(V-O-R-S)分析了城镇化与生态系统健康亚系统的时空演变特征,探讨2000—2020年重庆市城镇化与生态系统健康亚系统间交互耦合关系的机理。[结果](1)2000—2020年重庆市综合城镇化水平呈逐年上升的趋势,但仍存在空间发展不均衡的问题,核心带及低值区均受地形起伏影响显著;(2)2000—2020年生态系统健康指数一直处于适中状态,城镇化发展迅速的区域生态系统健康状况恶化显著,植被覆盖度较高的渝东南与渝东北生态系统健康状况良好。[结论]城镇化与生态系统健康亚系统间的交互耦合关系呈上升趋势,但是目前未达到高度协调阶段,仍有矛盾存在。重庆市要实现高质量且可持续的发展,仍需走绿色发展路径,解决时空不均的问题。     

NEW PULPING METHOD FOR LINERBOARD

Traditionallykraftwasusedaslinerforlinerboard.Thekrafpulpingyieldwaslow,andairpollutionhigh.SomeresearcheshaveshownthattheyieldofAS-AQpulpwasmuchhigherthanthatofkraft,andthestrengthwasequaltothatofkraft,exceptforasome-whatlowertearstrength.Thewashingprofi-clencyofAS-AQpulpwashigherandairpol-lutionwasmuchlowerthanthoseofkraft.SoAS-AQpulpwasthoughtasapromisingre-placementofkraftforlinerboard.lntheresearchPinuskoraiensiSandLarljgmehniwereusedasrawmaterials,withtheL,(3')experimentaldesignan…