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971.
972.
973.
Developing gene-tagged molecular markers for functional analysis of starch-synthesizing genes in rice (Oryza sativa L.) 总被引:1,自引:0,他引:1
Xinyan Liu Minghong Gu Yuepeng Han Qing Ji Jufei Lu Shiliang Gu Rong Zhang Xin Li Jianmin Chen Schuyler S. Korban Mingliang Xu 《Euphytica》2004,135(3):345-353
The granule-bound starch synthase(GBSS), starch branching enzymes 1 (SBE1)and 3 (SBE3) are major enzymes involved in starch
biosynthesis in rice endosperm. Available sequences of Sbe1 and Sbe3 genes encoding corresponding SBE1 and SBE3 have been used to identify homologous regions from genome databases of both the
indica rice 93-11 and the japonica rice Nipponbare. Sequence diversities were exploited to develop gene-tagged markers to distinguish an indica allele from a japonica allele for both Sbe1 and Sbe3 loci. With these newly developed gene-tagged markers and available Wx gene markers, the roles of these starch-synthesizing genes (Sbe1, Sbe3, and Wx) in determining amylose content (AC) in the rice endosperm were evaluated using a double-haploid (DH)population derived from
a cross between the indica rice cv. Nanjing11 and the japonica rice cv. Balilla. Only the Wx and Sbe3 loci had significant effects on the AC variation. On average, indica Wx
a genotypes showed ∼9.1% higher AC than japonica Wx
b genotypes, while indica Sbe3
a genotypes showed ∼1.0% lower AC than japonica Sbe3
b genotypes. A significant interaction was also observed between Wx and Sbe3 loci whereby the amylose content was 0.3% higher in Sbe3
a than Sbe3
b genotypes in the presence of the Wx
a allele, but it was lower by 2.3% in the presence of the Wx
b allele. Overall, polymorphisms at the Wx and Sbe3 loci together could account for 79.1% of the observed AC variation in the DH population. The use of gene-tagged markers in
marker-assisted selection and gene functional analysis was also discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
974.
The performance of insect-resistant transgenic poplar trees (Populusnigra) expressing a Cry1Ac gene from Bacillus thuringiensis subsp. Kurstaki HD-1 against poplar defoliators was evaluated in the field at the Manas Forest Station in Xinjiang Uygur
Autonomous Region during1994–1997. The results showed that the average percentage of highly damaged leaves on the transgenic
trees was 10% while that on the control trees in nearby plantations reached 80–90%. The average number of pupae per m2 of soil at 20cm depth in transgenic poplar plantation was 18 which was only 20% of that found in the non-transgenic control
field. The number of pupae and the leaf-damage on transgenic trees described above are all far below the threshold set for
chemical protection measures. The non-transformed poplar trees grown in the same plantation with the transgenic trees were
also protected indicating that cross protection occurred between these two kinds of trees. Insect-resistant transgenic poplar
trees have a potential application value in afforestation.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
975.
夏播大豆品种的生育期特性与农艺性状的关系分析 总被引:2,自引:0,他引:2
从 339个大豆品种中选取生育期小于 1 0 0d的 1 0 3个品种进行生育期结构特性与农艺性状的分析。结果表明 :①R1最长的为华北品种 ,最短的为外国品种 ;②R7最长的为东北品种 ,最短的为南方品种 ;③R1与生育前期即营养生长阶段 ,高纬地区长于低纬地区 ;R7与生育后期即生殖生长阶段 ,低纬地区长于高纬地区 ;④R1、生育前期长的品种 ,单株荚数、单株粒数多 ,株高较高 ;R7、生育后期长的品种 ,百粒重高 ;⑤筛选出一批对光温不敏感的品种 相似文献
976.
在工程实践中,直墙拱应用较多。由于拱脚位移的存在,合理假设拱脚约束为转角约束、竖向约束和水平弹性约束,应用力法推导出了在弯矩、剪力和轴力共同作用下直墙拱沿弧长的弯矩公式。研究了竖向均布荷载、竖向三角形荷载和竖向集中力荷载作用下,直墙拱沿弧长的弯矩分布及反弯点形成的规律;发现在3种荷载作用下,使得拱脚弯矩为零时的圆心角依次减小。取弹簧支座刚度为等效的下端固支、上端允许水平位移的直墙的抗推刚度,得出了随着直墙高度增加,圆弧拱拱顶弯矩增大而拱脚弯矩减小的变化规律。在直墙拱的设计中,建议选取合适的直墙高度和使得圆弧拱拱脚弯矩为零的圆心角大小,从而有利于提高结构抗弯承载力及拱脚抗剪承载力。 相似文献
977.
978.
热处理条件对番茄采后冷害的影响 总被引:11,自引:2,他引:11
研究了绿熟番茄采后在33℃和38℃加热2,5,8d及2±1℃下冷藏后的果实品质、冷害程度和生理变化。结果表明,适宜的热处理可降低果实呼吸强度、细胞膜电解质渗出率和丙二醛含量,增加游离脯氨酸含量,减轻果实冷害,且对果实硬度和可溶性固形物含量无显著影响。其中以处理温度时间组合33℃、5d和38℃、2d的效果最好;33℃、2d的处理温度较低、时间较短,因而效果不明显;8d的处理时间过长,使细胞受到伤害,丙二醛含量和细胞膜电解质渗出率增加,果实明显变软,出现异味。番茄果实的冷害指数(CII)与细胞膜电解质渗出率呈正相关,相关系数r=0.9744。 相似文献
979.
Chang Seok Lee Kyu Song Lee Jun Kwon Hwangbo Young Han You Joon Ho Kim 《Water, air, and soil pollution》2004,156(1):251-273
Plants tolerant to polluted environments were selected, based on several criteria, to restore a coastal forest ecosystem severely damaged by air pollutants discharged from an industrial complex. In addition, a restoration plan was prepared synthesizing these results and the diagnostic ecological indicators in the area for which restoration is required. Pollution-tolerant plants of 11 tree and subtree species, 10 herb species and one shrub species were selected from field surveys in the vicinity of two representative industrial complexes in Korea, Ulsan and Yeocheon. Nine species were selected for tolerance to SO2 fumigation and six species were selected for tolerance to Al3+. Growth and photosynthetic responses of sample plants transplanted into polluted and unpolluted sites showed that 15 species out of the 26 sample plants showed a disposition for tolerance. Most of these are endemic plants and they are composed of diverse species in structure and function. This result implies that these tolerant species could play important roles in the restoration of the study area, which has several specific features. On the other hand, results from transplant tests indicate that a field survey is the most reasonable method for selection of tolerant plants to restore a pollution-damaged ecosystem, as was shown in another restoration program. Results of ecological analysis on vegetation map indicate that the spatial range within the first ridge is the sector for which restoration is required. This sector was classified into four zones on the basis of topographic conditions: lower and upper slopes of both slopes facing and opposite the pollution source. Guidelines for soil amelioration and arrangement of tolerant plants were prepared considering the degree of vegetation degradation, leaf damage of major plant species and soil pollution in each zone under the restoration plan. 相似文献
980.
地膜覆盖对土壤中N2O释放的影响 总被引:2,自引:0,他引:2
研究地膜覆盖下土壤中N2O释放可为进一步探明膜下土壤中N2O的传输、消耗和排放到大气的动力学过程提供理论依据。在2001年3月至6月和2001年10月至2002年6月连续两个冬小麦生长季,采用静态漏斗法和揭膜—封闭箱法测定了地膜覆盖下耕层5、10、20 cm土层处和地表处N2O的释放特征及相应土壤性质。结果表明:地膜覆盖下,地表和耕层10、20 cm土层处N2O释放通量显著增加;0~5 cm土层土壤水分和10~20 cm土层土壤硝态氮的浓度的变化分别解释了休闲地和冬小麦地土壤中N2O释放通量85.23%和92.11%的变异,它们是膜下休闲地和冬小麦地土壤中N2O释放通量增加的主要原因。该结论对地膜覆盖下科学地控制农田水分、养分以及地膜覆盖在中国西北地区的科学使用和推行具有实际意义。 相似文献