北方设施条件下辣木及改良品种生长差异性分析

北方地区利用温室栽培辣木(Moringa oleifera Lam.)及其2个改良品种‘PKM1’和‘PKM2’,通过分析表观生长量、养分含量以及光合特性等指标的差异性,筛选适宜北方温室种植的辣木品种。结果表明:PKM1的高生长和增粗生长均显著快于辣木和PKM2(p0.05),在定干前(71 d)三者平均株高依次为115.7、80.2、81.0 cm,地径依次达17.47、13.27、15.08 mm。植株养分季节变化,PKM1养分状况要优于辣木和PKM2,在5月份,PKM1叶片中全氮(44.32 mg/g)、全钾(12.73 mg/g)含量显著高于其它2个品种(p0.05),全磷和可溶性糖含量品种间无显著性差异;7月份,PKM1可溶性糖显著高于其它2个品种;光合特性分析,3个品种在弱光条件下的光量子利用效率及光补偿能力差异不显著(p0.05),随着光强增加,光量子的转化能力出现显著性差异,PKM1的最大净光合速率(A_(max))显著高于辣木和PKM2(p0.05),最高达23.84μmol CO_2/(m~2·s)。可见,北方设施条件下,PKM1的生长速度、养分状况、光合能力均表现最好,较适宜北方温室栽培。     

不同保水剂对土壤特性及烤烟生长的影响

为提高秦巴山区黄棕壤烟田的土壤性能,减少季节性干旱对烤烟生长的影响,以不施保水剂为对照,在烟田整地起垄前分别施入聚丙烯酸钾(K-PAM)、聚丙烯酰胺(PAM)和腐殖酸钾(KHm)3种保水剂,测定施用不同保水剂后的土壤容重、土壤水分和烤烟生长状况、常规化学成分及经济性状。结果表明,聚丙烯酸钾和聚丙烯酰胺保水剂均降低0～40cm土层土壤容重,在烤烟旺长期提高0～40cm土层土壤水分。不同保水剂均可提高烤烟常规化学成分含量,其中腐殖酸钾保水剂显著降低烤烟的糖碱比和氮碱比。聚丙烯酸钾保水剂提高烤烟的产量、产值、上等烟比例及净增产值,而聚丙烯酰胺和腐殖酸钾保水剂处理组则降低烤烟的净增产值。因此,建议秦巴山区黄棕壤烟田选用聚丙烯酸钾类保水剂。     

Shikonin reverses HGF-induced resistance to gefitinib in lung cancer cells HCC827

AIM: To investigate the effect of shikonin on reversing hepatocyte growth factor(HGF)-induced resistance to gefitinib in lung cancer HCC827 cells, and to explore its possible mechanisms.METHODS: The gefitinib-resistant HCC827 cells induced by HGF were treated with shikonin and gefitinibthe alone or in combination. The inhibition rates of cell viability were determined by MTT assay. The invasive ability of HCC827 cells with HGF-induced resistance to gefitinib was determined by Transwell assay. The protein levels of epithelial-mesenchymal transition (EMT) and related signaling pathway in the HCC827 cells were detected by Western blot.RESULTS: The results of MTT assay showed that the cell activity of HCC827 cells was significantly inhibited by shikonin in a dose dependent manner. The IC₅₀ of shikonin in HCC827 cells was 3.06 μmol/L. And the IC₅₀ of gefitinib in HCC827 cells was 0.51 μmol/L. Under the condition of combined treatment with shikonin and gefitinib in the presence of HGF (20 μg/L), the IC₅₀ of gefitinib was 7.36 μmol/L, significantly lower than that treated with gefitinib alone (P<0.01), so did the result of the cell migration (P<0.01). HGF induced EMT, while shikonin reversed this effect. The protein expression level of p-AKT was significantly up-regulated by HGF, while markedly down-regulated treatment with shikonin and gefitinib compared with gefitinib alone (P<0.01).CONCLUSION: Shikonin reverses HGF-induced resistance to gefitinib in lung cancer HCC827 cells, and the mechanism may be likely related to the preventon of EMT and the inhibition of HGF-induced activation of p-AKT signaling pathway.     

Effect of Heat Stress on Grain Growth, Starch Synthesis and Protein Synthesis in Grains of Wheat (Triticum aestivum L.) Varieties Differing in Grain Weight Stability

The effect of heat stress on the components of grain weight was analysed in wheat ( Triticum aestivum L.) varieties differing in grain weight stability. The wheat varieties PBW154, Sonalika and Hindi62 were raised in the field (New Delhi, India; 77°12' E, 28°40' N, 228.6 m a.s.l.) at three dates of sowing: 19 November 1992 (DOS I), 14 December 1992 (DOS II) and 18 January 1993 (DOS III). The late-sown crop (DOS III) experienced 6–8 °C warmer temperatures during grain development than the crop sown at the normal time (DOS I). The heat susceptibility index (S) revealed that grain weight was less susceptible to heat in Sonalika and PBW154 than in Hindi62. Heat stress reduced both the grain growth duration (GGD) and the grain growth rate (GGR). The grain weight reduction in PBW154 and Sonalika was mainly due to a reduction in GGR, while that of Hindi62 was due to a reduction in GGD. In vivo studies on starch and protein synthesis in excised endosperm at 15, 25 and 35 °C revealed that both processes were more thermotolerant in Hindi62 than in PBW154. The grain starch content was stable in Hindi62 while that in PBW154 was significantly reduced under heat stress. The grain nitrogen content at maturity increased in both varieties under heat stress. It was concluded that the heat susceptibility of grain weight in Hindi62 was mainly due to a reduction in GGD, although GGR, starch and protein synthesis were more thermotolerant in developing grains of Hindi62 than in those of PBW154.     

笔管榕榕果发育的初步研究

对温州市区笔管榕榕果的形成时期、着生部位、结果数量、发育温度、生长特性和果实结构进行了初步研究,对进一步开发笔管榕资源提出了建议.     

黄皮的生物学特性研究

通过本试验观察表明:黄皮[Clausena Lansium (Lour.)Skeels]的开花与温度有密切关系,温度高,开花过程短;温度低,开花过程长。花穗中的花轴增长速度也随温度升高而加快,花轴增长快,则花轴长,花穗大;反之,花轴增长速度慢,花轴短,花穗小。黄皮开花的顺序是从花穗基部第1—4个分枝开始,每个分枝则先从基部1—8个二次分枝首先开放。31℃是黄皮花粉萌发最适宜温度。在培养基中加入15—20％蔗糖或2.4—D,三十烷醇等生长调节物质,明显可提高黄皮花粉的萌发力。本试验对黄皮的物候期及植物学特性同时进行了研究。     

有摩擦的高速气体管流

本文以多变热力过程为基础建立了有摩擦管路的计算公式,并对计算方法和有关问题作了分析说明.     

不同遮荫强度对几种苗木生长的影响

以黄金榕、花斑垂叶榕、乳斑榕的苗木为试验材料，来探讨不同遮荫强度苗木生长、水份利用及苗木生长环境的影响，试验表明：一层遮荫网处理的苗木比无遮荫网和二层遮荫网处理的苗木在株高、冠幅、根径以及叶片数目等方面均增长较快，苗木的地下部分、叶和茎含水量均较低。无遮荫处理利用较多水分，以及土壤温度在14：00点左右的时间明显高于所有的遮荫处理。     

治疗图书馆顽症:流程重组

本文将流程重组理论引入图书馆管理，分析了图书馆流程重组的必要性，同时具体阐述了图书馆流程重组的三种方式。