Effect of Environment and Genetic Recombination on Subspecies and Economic Trait Differentiation in the F_2 and F_3 Generations from indicajaponica Hybridization

indica and japonica are the two most important subspecies of Asian cultivated rice. Identifying mechanisms responsible for population differentiation in these subspecies is important for indica-japonica hybridization breeding. In this study, subspecies and economic trait differentiation patterns were analyzed using morphological and molecular （InDel and Intron Length Polymorphism） data in F2 and F3 populations derived from indica-japonica hybridization. Populations were grown in Liaoning and Guangdong provinces, China, with F3 populations generated from F2 populations using bulk harvesting （BM） and single-seed descent methods （SSD）. Segregation distortion was detected in F3-BM populations, but not in F3- SSD or in F2 populations. Superior performance was observed with respect to economic traits in Liaoning compared with that in Guangdong and 1 000-grain weight （KW）, seed setting rate （SSR） and grain yield per plant （GYP） were significantly correlated with indica and japonica subspecies types. Analysis of molecular and morphological data demonstrated that the environment is the main factor giving rise to population differentiation in indica-japonica hybridization. In addition, we also found that KW, SSR and GYP are related to subspecies characteristics and kinship, which is possibly a significant factor resulting in economic trait differentiation and determining environmental adaptability. Our study has provided new insights into the process of population differentiation in these subspecies to inform indica-japonica hybridization breeding.

Correlation and Regressive Model Between Spikelet Fertilized Rate and Temperature in Inter-Subspecific Hybrid Rice

To study the sensitivity of inter-subspecific hybrid rice to climatic conditions, the spikelet fertilized rate （SFR） of four types of rice including indica-japonica hybrid, intermediate hybrid, indica and japonica were analyzed during 2000-2004. The inter-subspecific hybrids showed lower SFR, and much higher fluctuation under various climatic conditions than indica and japonica rice, showing the inter-subspecific hybrids were sensitive to ecological conditions. Among 12 climatic factors, the key factor affecting rice SFR was temperature, with the most significant factor being the average temperature of the seven days around panicle flowering （T7）. A regressive equation of SFR-temperature by T7, and a comprehensive synthetic model by four important temperature indices were put forward. The optimum temperature for inter-subspecific hybrids was estimated to be 26.1-26.6℃, and lower limit of safe temperature to be 22.5-23.3℃ for panicle flowering, showing higher by averagely 0.5℃ and 1.7℃, respectively, to be compared with indica and japonica rice. This suggested that inter-subspecific hybrids require proper climatic conditions. During panicle flowering, the suitable daily average temperature was 23.3-29.0℃, with the fittest one at 26.1-26.6℃. For an application example, optimum heading season for inter-subspecific hybrids in key rice growing areas in China was as same as common pure lines, while inferior limit for safe date of heading was about a ten-day period earlier than those of common pure lines.

Effect of Temperature on Pollen Fertility in Inter-Subspecific Rice Hybrids

Seventeen rice varieties and hybrids of different types (indica, japonica, javanica, indica hybrid, japonica hybrid and inter-subspecific hybrid) were evaluated to determine the effect of temperature on pollen fertility in inter-subspecfic hybrids. The pollen fertility of inter-subspecific hybrids was greatly reduced when average daily temperature dropped to 22.0 - 23.0℃ at meiosis stage, and the extent of pollen fertility reduction varied greatly with respect to different hybrids. However, the pollen fertility reduction of indica and japonica hybrids and conventional varieties was not obvious under the same regime of temperature conditions. When the average daily temperature dropped to 20℃, the pollen development of conventional varieties and hybrids was also affected. Correlation analysis revealed that there existed a positive correlation between pollen fertility and average daily temperature. A significant difference (P<0.01) was also found between the two correlation coefficients i.e. inter-subspecific hybrids and conventional varieties. Temperature at meiosis stage of pollen mother cell was a key factor in pollen developing, and the pollen fertility of inter-subspecific hybrids was more sensitive to low temperature than that of traditional variety.

Prospects of utilization of inter-subspecific heterosis between indica and japonica rice

The Asian cultivated rice(Oryza sativa L.) grown worldwide is divided into two subspecies, indica and japonica. It is well known that the heterosis of inter-subspecies is usually stronger than that of intra-subspecies. Since the 1970 s, indica hybrid rice, an intra-subspecific hybrid rice, has being widely used in China and even in the world. However, the inter-subspecific hybrid rice between indica and japonica is still unavailable. The major obstacle is the hybrid sterility of the inter-subspecies. In recent decades, the genetic and molecular basis of indica-japonica hybrid sterility was understood more and more clearly. Some breeding approaches for overcoming inter-subspecific hybrid sterility were proposed and used to develop the indicajaponica hybrid rice. The updated understanding will offer new approaches for development of breeding lines for overcoming indica-japonica hybrid sterility, which facilitates developing of inter-subspecific hybrid rice.

Comparison of agronomic performance between inter-sub-specific hybrid and inbred japonica rice under different mechanical transplanting methods

Mechanical transplanting has been applied to rice cultivation to save labor costs and ease labor shortages in Asian countries, especially in China. However, little information is available related to the characteristics of agronomic performance when comparing inter-sub-specific hybrid rice(IHR) and inbred japonica rice(IJR) under mechanical transplanting method. In 2013 and 2014, field experiments were conducted using IHR(Yongyou 2640) and IJR(Wuyunjing 24) under two cultivation patterns, that is, pot seedlings mechanically transplanted(PS) and carpet seedlings mechanically transplanted(CS). Grain yield, yield components, leaf area index(LAI), leaf area duration(LAD), aboveground biomass, crop growth rate(CGR), nitrogen(N) uptake, and N accumulation were investigated. When compared with CS, PS displayed significantly increased grain yield for both varieties because the larger sink size allowed higher N accumulation from panicle initiation to maturity. Moreover, total aboveground biomass under PS increased significantly compared with that under CS; that is, higher photosynthetic productivity resulted from a greater LAI and higher LAD during the grain filling stage. Higher N absorption capacity in the middle and late growth periods resulted in significantly enhanced total N uptake under PS. When compared with IJR for both treatments, IHR generated 75.2% more grain yield. However, the characteristics creating high yield of IHR were different from those of IJR. Greater aboveground biomass production as well as higher N uptake and accumulation created higher grain yield in IHR than in IJR. These results suggest higher yield could be achieved using PS with IHR, attributing to exploit both yield superiority and productive potential.

Relationships of Panicle Type Index with Subspecies Characteristics and Yield Traits in Filial Generation of Crosses between Indica and Japonica Rice

Two recombinant inbred line （RIL） populations, one derived from a cross between Zhongyouzao 8 （indica） and Toyonishiki （japonica） and the other from a cross between Qishanzhan （indica） and Akihikari （japonica）, were grown in Liaoning and Sichuan Provinces, China, to study the panicle type index （PTI, the ratio of a number of node position on panicle axis where the secondary branch with the most numerous secondary branch grains is located to the number of primary branches） and its relationships with subspecies characteristics and yield traits. With continuous distribution of PTI and numerous of lines with different PTIs in the progenies, indica-japonica hybridization could be a method for breeding cultivars with ideal panicle type. PTI was significantly influenced by environments, with a significant decrease from Liaoning to Sichuan A significantly negative correlation was found between PTI and most of subspecies characteristics. PTI varied remarkably with different subspecies types. As a whole, it showed a trend of indica （H）〉indicalinous （H＇）〉japonicalinous （K＇）〉japonica （K） However, it is not appropriate to regard PTI as a parameter for subspecies classification in rice because it was recombined in the filial generations of cross between indica and japonica rice. The negative correlations were found between PTI and most of panicle characteristics, as well as yield-related traits. Based on PTI, most of lines from the two populations were middle dominant panicle type （the number of grains on the secondary branch is numerous in middle position of the panicle） and lower dominant panicle type （the number of grains on the secondary branch is numerous in lower position of the panicle and becomes less towards the top of panicle） with significant yield advantages.

籼粳亚种间育性位点分型及籼粳杂交稻育性位点模式研究

【目的】了解我国籼稻、粳稻材料及籼粳杂交稻组合中亚种间育性位点的分布,建立实现亚种间育性亲和所需遗传位点模式,探索新的籼粳杂交稻组合模式,为亚种间亲和材料改良和籼粳育性亲和分子设计育种打下基础。【方法】通过筛选得到育性位点的籼粳分型标记对我国水稻材料进行育性位点的籼粳分型检测,挑选部分籼稻、粳稻亲本进行杂交并统计分析F1代花粉育性和结实率。【结果】籼稻和粳稻之间在所有育性位点均存在少量相互渗入。由于籼稻育性位点渗入,粳稻可以分为Ⅰ型(所有位点均为粳型)和Ⅱ型(Sc^(i)、Sd^(i)和Se^(i),上标i代表来自籼稻)。S5不亲和时籼粳杂交稻结实率约为50%,亲和时结实率约为80%。Sa、Sb、Sc或Sd单个位点杂合对于花粉育性影响较小,但Se/pf12/RHS12单个位点杂合时显著降低花粉育性。籼粳杂交稻材料检测结果表明其育性位点的基本模式是S5和部分花粉育性位点纯合/亲和。带有S5^(n)的籼稻两系不育系深08S与粳稻Ⅱ型材料的杂交F_(1)代的花粉育性和结实率正常。【结论】S5是控制雌配子育性的核心位点。影响雄配子育性的位点具有累加效应,其中Se可能是不可缺少的重要位点。S5+Se与Sa、Sb、Sc、Sd任意两个纯合位点可能是实现籼粳亚种间育性亲和的基本遗传位点模式。以广亲和两系籼稻不育系为母本,常规粳稻为父本的“籼不粳恢”籼粳杂交模式是一个可行的亚种间组合模式。

细菌聚酮合酶间的杂合方式及聚酮化合物生物合成逻辑

聚酮化合物(polyketide)是一类来源广泛、结构多样的活性天然产物,聚酮合酶(polyketide synthase,PKS)负责聚酮骨架的生物合成。细菌次级代谢中PKS广泛存在,不同类型的PKS在组成和生物合成机制上各不相同,从而产生截然不同的聚酮骨架。根据细菌PKS功能和生物合成途径的不同,可以将其分为Ⅰ型、Ⅱ型和Ⅲ型。PKS通常能与其他生物合成酶系杂合以产生结构更为复杂的天然产物。同时,不同类型PKS之间也可以形成多种内部杂合,产生更多样的聚酮骨架。本文总结和比较PKS间的内部杂合,包括Ⅰ型PKS内部杂合、Ⅰ型/Ⅱ型PKS杂合以及Ⅰ型/Ⅲ型PKS杂合,归纳各种杂合基因簇的形成方式及其杂合特征。通过比较杂合聚酮化合物的生物合成机制并讨论杂合聚酮工程化改造的进展,展望了多种潜在的聚酮杂合模式,合理假设存在合成过程相反的Ⅰ型/Ⅱ型PKS杂合模式,或随着化合物的挖掘发现迄今未报道的Ⅱ型/Ⅲ型PKS杂合模式等,指出可以充分和全面地利用细菌基因组信息,通过酶和基因的生物勘探,发现更多更特殊的PKS杂合化合物等一系列针对新颖聚酮化合物进行基因组挖掘的方向,同时也提出了工程化改造trans-AT PKS在cis-AT模块中实现不同寻常的骨架修饰等多种PKS的工程化改造设想,为后续PKS内部杂合基因簇挖掘和表征提供一些新思路。

不确定环境下危险货物公铁联运路径优化研究

为使得危险货物公铁联运路径优化更贴合实际,其引入随机机会约束理论,再用决策分析法、理论研究法和算例分析法等,把含有随机变量的不确定式子转换为确定等价形式,考虑集装箱限容、时间窗约束和运输风险等因素,以运输总成本最低、总时间最短和总风险最小为目标,建立不确定环境下的危险货物多式联运路径优化模型。基于随机模拟算法、神经元网络算法和遗传算法,设计一种改进的混合智能算法验证模型的可行性和有效性。参数变化分析表明:设计的混合智能算法比普通的启发式算法求解效率高;选用大载货量的集装箱对运输企业和风险管理部门均有益;运输途中人口密度或风险阈值越小,可使危险货物运输风险降低;花费较多财力来达到客户的时效要求,也可提高客户满意度;在途运输时间越长,风险值也就越高。以此为运输企业和管理部门提供基础理论知识和多样化的决策方案。

蜡梅CpBEAT3启动子克隆及其互作蛋白的初步验证

苯甲醇乙酰基转移酶(benzyl alcohol acetyltransferase,BEAT)能够以苯甲醇和乙酰辅酶A(acetyl-CoA)为底物催化合成乙酸苄酯,是植物乙酸苄酯生物合成代谢途径下游的关键酶。CpBEAT3是蜡梅叶中调控乙酸苄酯生物合成的关键基因,为了解析其在蜡梅乙酸苄酯生物合成中的转录调控机制,本研究克隆得到了CpBEAT3基因启动子区序列,使用生物信息学软件预测分析了该基因核心启动子区、顺式作用元件、CpG岛等结构特征,并通过酵母单杂交技术筛选可能与CpBEAT3结合的上游调控因子。结果表明,2115 bp的CpBEAT3核心启动子区可能位于-1844~-1794 bp处,有一个位于-1869~-1459 bp处且长度为410 bp的CpG岛,含有多种与光响应、激素调节、胁迫响应相关的顺式作用元件及多个转录因子结合位点。通过酵母单杂交技术筛选获得1个MYB类的转录因子,可以与CpBEAT3启动子结合。

The Influence of Inbreeding Depression and Hybrid Superiority on Wood Property and Tree Growth of Eucalypt

With F1 of self pollinated Eucalyptus urophylla, F1 of inter tree pollinated E.urophylla, F1of open pollinated E.urophylla and F1 of E.urophylla×grandis as materials,inbreeding depression and hybrid superiority in growth and wood traits are analyzed and discussed.The results are as follows.①There was a regularity for E.urophylla that F1 of self pollinated was subjected to more intense depression than F1 of open pollinated,and growth traits showed more signifcant depression than wood traits.②As to F1 of self pollinated E.urophylla, height,DBH and volume showed significant or extremely significant depression,while water content of green wood,wood density and bark thickness showed no significant depression.③As to F1 of open pollinated E.urophylla, height,DBH and volume showed depression to a certain degree,but not significant;Here again,water content of green wood,wood density and bark thickness showed no significant depression.④F1 of E.urophylla×grandis showed significant hybrid superiority in height,DBH and volume,but the hybrid superiority percentage of different cross pairs varied greatly;It showed no hybrid superiority in water content of green wood,wood density and fiber length;Its bark thickness and content of 1% NaOH extractives decreased evidently.

一种基于非线性电流跟踪算法的STATCOM相间电容电压平衡控制策略

针对基于级联H桥拓扑结构的静止同步补偿器在传统控制框架下所产生的相间电容电压不平衡问题,采用一种新型混合调制方法并提出了一种全新的非线性分相电流控制策略。首先,基于六模块十三电平级联H桥拓扑结构,阐明新型混合调制的调制原理,并阐述适用于新型混合调制的相内电容电压均衡策略。其次,推导了静止同步补偿器在两相同步旋转坐标系下的控制模型,并分析指出采用dq解耦控制存在的相间电容电压不平衡问题。针对相间电容电压不平衡问题,提出基于三相静止坐标系下的电流分相控制策略,通过Lyapunov稳定性判据第二法推导并设计实现对交流指令电流无差跟踪的非线性电流控制器。最后,在Matlab/Simulink环境下搭建仿真模型。仿真结果表明,所提控制策略在不同条件下均能保持相间电容电压一致和稳定,且具有良好的动态响应特性。

反渗透海水淡化系统混合膜设计

节能型反渗透海水淡化系统的设计对于进一步降低制水成本,促进海水淡化的普及应用意义深远。混合膜设计(HID)是一种新颖的反渗透系统设计方式,其特色是在同一个压力容器内排列不同类型的膜元件,通过不同膜元件性能互补实现效益最大化。文中采用软件模拟方式,以水质、能耗、配流为考察指标,首先对杜邦(DuPont)、LG、东丽(Toray)、海德能(Hydranautics)四大主流膜产品在HID中的性能差异进行对比,结果表明,Toray膜在平衡流量和节能效率方面具有明显优势。进一步以Toray膜为研究对象,深入探讨温度和配置比例对性能指标的影响,结果表明,温度是影响HID的一个重要因素,在水温低、水质变化较小的北方海域,HID节能效应更突出,效率可达9%,流量平衡效应明显增强。

基于空气源热泵能效提升的物理和数据混合驱动模型研究进展

由于在实际运行中受环境条件和用户行为等多种因素的影响,空气源热泵系统的实际运行能效与理论能效存在较大差异,切实提升其实际运行能效水平是亟待解决的问题。本文首先对基于空气源热泵能效提升的混合驱动模型进行描述,然后从预测和控制以及故障诊断2个方面阐述现有的混合驱动模型,并总结物理信息可融入数据驱动模型的方式,最终提出能效提升应重点关注的混合驱动可解释性建模的研究方向,为进一步提升空气源热泵实际运行能效提供参考。

Genetic Relationships in Advanced Generation Hybrids Derived from Crosses between Texas (<i>Poa arachnifera</i>) and Kentucky (<i>Poa pratensis</i>) Bluegrass Using ISSR Markers

Fertile, advanced generation hybrids derived from crosses between Texas (Poa arachnifera Torr.) and Kentucky (Poa pratensis L.) bluegrass have been selected. The hybrids are currently being evaluated for low-input turf potential. Since they are derived from hand-harvested seed from first-generation hybrids located in field nurseries their exact genetic origin is unknown. This experiment was conducted to determine if there are still genetic relationships among the advanced generation hybrids and some of the Texas and Kentucky parents in their pedigrees. Four Inter Simple Sequence Repeat (ISSR) primer combinations resolved on 6% nondenaturing polyacrylamide gels resulted in 179 polymorphic bands that were scored to create a genetic similarity matrix and dendrogram based on Jaccard’s coefficient. The clustering of the advanced generation hybrids was generally in agreement with what would be expected based on their pedigrees and indicated it was more likely to select a fertile hybrid from an advanced generation, rather than the F1 generation.

Genetic Variation in Picea mariana ×P. rubens Hybrid Populations Assessed with ISSR and RAPD Markers

Interspecific hybridization can result in significant shifts in allele frequencies. The objective of the present study was to assess the level of genetic variation in populations of P. mariana × P. rubens hybrids derived from artificial crosses. Progenies from backcross populations created through a series of controlled pollinations among P. mariana and P. rubens trees across the hybridization index were analyzed. Several Inter Simple Sequence Repeat (ISSR) and Random Amplified Polymorphic DNA (RAPD) primers were used to amplify genomic DNA samples from each population. ISSR primers produced from 30% to 52% polymorphic loci. The level of polymorphism was higher with RAPD markers, ranging from 57% to 76%. Overall, the two marker systems generated similar levels of polymorphic loci for P. mariana and P. rubens populations. No significant differences were found among the P. mariana × P. rubens populations analyzed and between the hybrids and the parental populations regardless of the molecular marker used. This confirms the genetic closeness of P. mariana and P. rubens species.

Low complexity hybrid power distribution combined with subcarrier allocation algorithm for OFDMA

To improve the total throughput of the uplink orthogonal frequency division multiple access system,a low complexity hybrid power distribution（HPD） combined with subcarrier allocation scheme is proposed.For the fairness mechanism for the subcarrier,the inter-cell interference is first analyzed to calculate the capacity of the multi-cell.The user selects the subcarrier with the largest channel gain.Based on the above subcarrier allocation scheme,a new kind of HPD scheme is proposed,which adopts the waterfilling-power-distributed scheme and the equal-power-distributed scheme in the cell-boundary and the cellcenter,respectively.Simulation results show that compared with the waterfilling-power-distributed scheme in the whole cell,the proposed HPD scheme decreases the system complexity significantly,meanwhile its capacity is 2% higher than that of the equal-powerdistributed scheme over the same subcarrier allocation.

胶东调水工程年度水量调度方案研究

随着跨流域调水工程的规模逐渐增加,其内部各个组件之间的协调性降低,工程年度水量运行调度的难度和复杂性也随之增加。胶东调水工程年度水量调度方法根据胶东调水工程的工程特性,对沿线的枢纽工程进行概化并构建空间拓扑结构图,综合考虑汇水区水量补偿调节作用及分水口门的反调节作用,构建水量模拟调度模型。通过解构分水口门取用水过程,降低优化问题维度,构建决策空间,耦合水量模拟调度模型,构建胶东调水工程年度水量调度模型,应用混合优化算法(HOA)求解模型,进而编制工程年度水量调度方案。结果表明:胶东调水工程年度水量调度模型通过解构需水侧取用水过程降低优化问题维度,能够克服工程供、需水侧的非过程控制总量边界条件与其年度水量调度方案编制步长、时间尺度不匹配等问题,实现优化问题快速求解,避免分水口门出现极端缺水情况,最大限度满足其用水需求。

基于混合进化算法的卫星网络星间数传方法

星间链路在卫星网络数据传输中发挥着非常重要的作用,可以解决我国地面站布局受限的问题。然而,卫星网络拓扑时变,网络资源有限,使得星间数据传输具有很大的挑战性。为了克服这个难点,首先利用存储时间聚合图建模卫星网络,在考虑网络资源约束的条件下,构建了数据传输整数规划模型。然后,设计了知识型混合进化算法(knowledge-guided hybrid evolutionary algorithm,KGHEA)对模型进行求解,该算法融合了局部搜索算法、路径流量分配算法,以及多种知识型算子。最后,设计了仿真实验,验证了KGHEA的性能,并分析了各项参数对数据传输性能的影响,为星间网络建设提供参考。

Advances in the understanding of inter-subspecific hybrid sterility and wide-compatibility in rice

Hybrid sterility is a major form of postzygotic reproductive isolation and frequently occurs in hybrids between divergent populations, such as the indica and japonica subspecies of Asian cultivated rice (Oryza sativa L.). It has been a major barrier for utilization of the strong heterosis expressed in hybrids between indica and japonica. A large number of loci for rice inter-subspecific hybrid sterility have been identified by genetic analysis. Cytological studies revealed that male and female gamete abortions and reduced affinity between the uniting gametes all occurred in indica-japonica hybrids, suggesting the complexity of the causes for inter-subspecific hybrid sterility. Two genes conditioning embryo-sac and pollen sterility respectively in indica-japonica hybrids have been cloned recently, providing opportunities for molecular characterization of the indica-japonica hybrid sterility and wide-compatibility. Future studies should aim at cloning more genes for indica-japonica hybrid sterility, characterizing the underlying molecular mechanism, and utilization of the findings for the development of inter-subspecific hybrids to increase rice productivity.