Fine mapping of the awn gene on chromosome 4 in rice by association and linkage analyses

Awnness is a key trait in rice domestication, yet no studies have been conducted on fine mapping or association mapping of the rice awn gene. In this study, we investigated the awnness and genotype of a core collection of 303 cultivated rice varieties and a BC5F2 segregating population of 200 individuals. Combining association and linkage analyses, we mapped the awnness related genes to chromosome 4. Primary association analysis using 24 SSR markers revealed five loci significantly associated with awnness on chromosome 4. The associated markers cover previously identified regions. Fine association mapping was conducted using another 29 markers within a 4-Mb region, covering the associated marker in34, which is close to the awn gene Awn4.1. Seven associated markers were revealed, distributed over an 870-kb region. Combining the fine association mapping and linkage analysis of awnness in the 200 BC5F2 segregating population, we finally identified a 330-kb region as the candidate region for Awn4.1. The results indicate that combining association mapping and linkage mapping provides an efficient and precise approach to both genome-wide mapping and fine mapping of rice genes.     

河南省公路客流空间运输联系强度分析

根据河南省公路客流的O-D数据,运用运输联系强度模型,对河南省空间运输联系强度进行了模拟.模拟结果与实际情况基本一致,并揭示了空间相互作用规律.结果表明,郑州市在客运联系中地位突出,是河南省公路客流联系的重心.而豫东和豫西、豫南和豫北的联系则较为松散.豫北各地市的内部联系紧密.     

遥操作机器人多关节联动控制算法

直线插补算法易于编程实现,且能使机器人手臂的运动轨迹以较高的精度逼近预定义轨迹。根据基于蓝牙通信的5DOF遥操作机器人的实际要求,采用绝对坐标值法计算各关节电机所需脉冲个数,并且使用MC9S12XDP512单片机的五个输出比较通道来控制机器人手臂的五个关节电机。每次得到上位机发送的关节运动量后,以五个输出比较通道中分配到最多脉冲的通道频率作为其他通道的脉冲频率基准以保证各关节在运动过程中的联动。实验证明,该算法精确有效。     

开口薄壁截面空间曲杆的双力矩

讨论了各向异性材料开口薄壁截面空间曲杆的双力矩,模型、原理、本构方程的变分导出和一般解法。     

石家庄苹果园,杏园中不同生境土壤蜘蛛群落的比较

１９９７年９月,笔者在苹果园、杏园４种生境中,共获土壤蜘蛛１００８头,隶属于１０科２３属,研究表明：杏园、苹果园中的土壤蜘蛛群落组成有很大差异,不同小生境中的土壤蜘蛛群落组成也有异同;多样性指数各异、影响群落组成的主要因子是生境的植被类型和空间异质性。     

Identification of salt-tolerance QTL in rice (Oryza sativa L.)

Quantitative trait loci (QTLs) controlling salt-tolerance at the seedling stage in rice (Oryza sativa L.) were identified by interval mapping (SIM) and composite interval mapping (CIM) using a doubled haploid population ZJDH and its high resolution genetic linkage map. The population was derived from an inter-subspecific cross between an indica variety Zhaiyeqing8 (ZYQ8) and a japonica variety Jingxi17 (JX17). Analysis of survival days of seedlings treated with 0.7% NaCI revealed that a major salt-tolerance quantitative trait locus (QTL), Std, was present between markers RG612 and C131 on chromosome 1 when using both MAPMAKER/QTL 1.1 and PLABQTL 1.0 (SIM). Its allele which contributes to salt-tolerance was from ZYQ8. In addition, seven more QTLs which give additive effect on salt-tolerance are identified when using PLABQTL (CIM), and most of them were from JX17.     

StephensonⅢ型平面六杆机构刚体导引综合

综合运用精确点法和近似法研究了StephensonⅢ型平面六杆机构的刚体导引问题,首先将该机构折分为一个双杆组和一个四杆机构,然后对双杆组进行近似综合,对四杆机构进行精确点综合,最后将得到和双杆组和四杆机构进行组合得到能近似满足给定要求的Stephenson Ⅲ型平面主杆机构,给出了具体实例,得到了满足设计要求的全部机构方案,此方法具有一般性,可用于研究其它平面复杂机构的综合问题研究。     

单亲完全连锁时多基因杂交F2世代方差分量的分解

提出了有M个连锁群时,F2代方差组成的数学模式;以果蝇为材料,研究了F2其腹部刚毛数量遗传方差的组成,对其进行了分解,获得了第二染色体遗传方差VⅡG、第三染色体遗传方差VⅢG、以及雌性X染色体遗传方差VX♀(G)和雄性X染色体遗传方差VX♂(G).     

齿轮四杆组合机构优化设计

分析了齿轮四杆组合机构的运动原理 ,推导出了计算公式 ,并给出了该组合机构尺度综合的优化设计方法。     

配合物的异构现象

通过对配合物异构现象的本质深入探讨,并对其系统归类,澄清了人们对配合物异构方面的模糊认识,解决了教学中的难点和盲点。