氮是水稻生产发育过程中所必须的大量营养元素，但是大量的氮肥投入在提高产量的同时对环境造成了严重危害。选用含有氮高效基因的水稻品种提高水稻自身的氮肥利用效率是减少氮肥使用量降低环境氮污染的最有效途径之一。 NRT1.1B 是一个影响水稻籼、粳亚种间氮肥利用效率的关键基因，主要分布在籼稻品种中。为了筛选携带 NRT1.1B 基因的粳稻资源，根据氮高效基因 NRT1.1B 与其等位基因 nrt1.1b 在功能区域存在的单核苷酸变异，设计和筛选出 NRT1.1B 的等位基因特异 PCR 功能标记 1nrt / 1NRT 。结合测序分析验证， 1nrt / 1NRT 可以准确快速鉴定出 NRT1.1B 的不同基因型。利用 1nrt / 1NRT 对 71 份籼稻品种和 134 份粳稻品种进行 NRT1.1B 基因型检测，结果表明 71 份籼稻品种均携带 NRT1.1B 基因， 134 份粳稻品种均携带 nrt1.1b 基因。进一步对 172 太湖流域地方粳稻资源和 99 份粳稻育种中间品系进行 NRT1.1B 基因型检测，结果发现粳稻品系‘常粳 144 ’携带 NRT1.1B 基因，测序分析也进一步证实了该结果。本研究为利用 NRT1.1B 改良粳稻氮高效育种提供了科学依据。

氮是水稻生产发育过程中所必须的大量营养元素，但是大量的氮肥投入在提高产量的同时对环境造成了严重危害。选用含有氮高效基因的水稻品种提高水稻自身的氮肥利用效率是减少氮肥使用量降低环境氮污染的最有效途径之一。 NRT1.1B 是一个影响水稻籼、粳亚种间氮肥利用效率的关键基因，主要分布在籼稻品种中。为了筛选携带 NRT1.1B 基因的粳稻资源，根据氮高效基因 NRT1.1B 与其等位基因 nrt1.1b 在功能区域存在的单核苷酸变异，设计和筛选出 NRT1.1B 的等位基因特异 PCR 功能标记 1nrt / 1NRT 。结合测序分析验证， 1nrt / 1NRT 可以准确快速鉴定出 NRT1.1B 的不同基因型。利用 1nrt / 1NRT 对 71 份籼稻品种和 134 份粳稻品种进行 NRT1.1B 基因型检测，结果表明 71 份籼稻品种均携带 NRT1.1B 基因， 134 份粳稻品种均携带 nrt1.1b 基因。进一步对 172 太湖流域地方粳稻资源和 99 份粳稻育种中间品系进行 NRT1.1B 基因型检测，结果发现粳稻品系‘常粳 144 ’携带 NRT1.1B 基因，测序分析也进一步证实了该结果。本研究为利用 NRT1.1B 改良粳稻氮高效育种提供了科学依据。

采用压力板法(吸力范围0～1.5 MPa)、滤纸法(0～40 MPa)和盐溶液蒸汽平衡法(吸力范围3～368 MPa)3种方法,对南宁地区残积黏土进行土—水特性试验,获得全吸力范围内的土-水特征曲线.试验结果表明:压实试样初始干密度1.25g/cm3的进气值为10 kPa,当吸力大于进气值点后,土体由饱和状态进入非饱和状态;土体持水量随着吸力的增加而减小,失水后试样发生收缩变形,考虑土体体积变化后的土-水特征曲线,更能反应其真实持水性,当吸力为367 MPa时,试样含水量为0.76％,可认为当吸力增加至106 kPa后,土体持水量趋于0.

Stability of subgrade slope is always a difficulty in road construction because it relates to construction progress,safety and line operation in the future directly.Taking the slope engineering along Hengyang-Nanyue Highway as an example,for the cutting slope and the embankment slope,different methods are used to analyze the stability.The results show that entirety of the cutting slope and the embankment are stable.

The objective of the excavation support system is to provide safe construction and groundwater free spaces for the main structures installations.The lateral earth pressures during the un-loading process and the pore pressures are transferred to the supporting system.This temporary retaining structure provides a safe guard to the adjacent structures and utilities during the construction.This paper presents a case study of a deep excavation of the underground parking garage structures.The deep excavation type selection process and the design analysis are introduced.The change of the stresses in the soil mass during the excavation is monitored by the finite element analysis.

道路路基边坡的稳定性一直道路建设中的难题,路基边坡的稳定与否直接关系到工程的施工进度、施工安全和今后线路的安全运营。介绍了路基边坡稳定性分析的一些方法、基本原理,结合实际工程条件,对湖南衡岳高速公路段路堑、路堤采用不同的边坡稳定性分析方法分析其稳定性。

In order to improve the precision of marker-assisted selection for S5-n,a functional marker S5136 based on the 136 bp deletion in the DNA sequence of S5-n was developed.The sterile line Yuetai A with S5-n has been identified with marker S5136,and conformed by sequencing.There was a SNP in the downstream of the 136 bp DNA deletion region of Yuetai A,which has been discovered in the wide compatible germplasm resources from India.The polymorphism was identified with marker S5136 between the photo-thermo sensitive sterile line Peiai 64S and the parent R986.Therefore S5136 was a perfect marker to test the purity of commercial hybrid seed of Liangyou 986(Peiai64s/R986).Four Peiai 64S plants were identified from the 233 sampled plants with S5136,with self seed setting rate of Peiai64S being 1.72%.The PCR efficiency was compared between the SDS DNA extracting method and the simple-way DNA extracting method.The results showed that the DNA extracted by the simple-way was better,except that the DNA could not be kept for more than 2 weeks at room temperature.Therefore,the functional marker S5136 was a powerful molecular marker in S5-n germplasm screening and seed purity testing for the two line hybrids with Peiai 64S as maternal parent.