草莓的保鲜现状研究   总被引：7，自引：0，他引：7  

张喜才  谢晶  韩志 《农产品加工．学刊》2006,(5):36-39

草莓味道鲜美,受到人们的喜爱,但是却难以保藏。目前,草莓的保藏方法主要是控制温度,并使用保鲜剂进行贮藏。控制温度一般通过冷藏库实现。草莓控温在冰点以上进行冰温贮藏比普通的冷藏效果要好。而使用气调库、气调包装则能更好地保持草莓的新鲜度。  相似文献   

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   

Field evaluation of insect-resistant transgenic Populus nigra trees     

J.J. Hu  Y.C. Tian  Y.F. Han  L. Li  B.E. Zhang 《Euphytica》2001,121(2):123-127

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   

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  

陈学珍  李欣  杨建宇  谢皓  韩天富 《中国农学通报》2003,19(6):64-68

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   

竖向荷载下弹性支承直墙拱反弯点理论分析     

韩永帅  周健南  金丰年  孔新立  范华林 《保鲜与加工》2015,(3):42-47

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   

对精选种子精量与半精量播种的试验研究     

王长春  韩宇环  荻荣伟  王者 《农业工程学报》1997,13(4):98-100

利用精选机械设备，对玉米种子进行精选，并按照农作物区域试验方法进行试验应用研究。结果表明，机械精选种子采用精量与半精量播种，产量表现优异，增产数量十分显著。  相似文献   

强非线性水平混沌振动台     

龙运佳  苏元升  欧阳怡  侯长革 《农业工程学报》1996,12(1):109-113

该文研究了一种水平混沌振动台,机构的运动微分方程是强非线性的,数值仿真和实验结果表明,该振动台的动态响应是混沌的,且敏感依赖于初始条件。  相似文献   

产流积水法测量坡地降雨入渗动态过程及其精度估计   总被引：1，自引：0，他引：1  

刘汗  雷廷武  潘英华  袁建平  毛丽丽  赵军 《农业工程学报》2006,22(9):6-10

坡地土壤的降雨入渗性能对于水文过程、土壤侵蚀、水资源相关方面的研究和实践非常重要。产流积水法采用由实验得到的数据，分析了不同坡位土壤入渗率及累积入渗量随降雨时间的变化过程。结果表明不同坡位入渗过程曲线反映了坡面径流到达前后，实际入渗率从降雨强度控制阶段跃升到入渗性能控制阶段，并最终趋于稳定入渗率的全过程。入渗区不同坡位的累积入渗量从坡顶至坡底逐渐减少，而且径流在坡面上推进速度越快不同坡位上的累积入渗量差值越小。通过理论分析，确定了观测径流推进距离误差所引起的测量结果的误差。用水量平衡原理对产流积水法实验结果进行精度估计，并提出了由实测入渗率求入渗水量的解析方法，并将此与实际降雨量进行比较，间接地估计了测量结果的精度。结果表明，产流积水法测量坡地降雨/径流入渗性能具有很高的精度。  相似文献   

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  

李丽萍  韩涛 《农业工程学报》1996,12(4):189-193

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   

Selection of Tolerant Plants and Their Arrangement to Restore a Forest Ecosystem Damaged by Air Pollution     

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