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61.
田间试验结果表明,6%精喹.嗪酸乳油作茎叶处理对马唐、牛筋草、稗草、反枝苋、藜等杂草均有较好的除草效果。推荐应用剂量为有效量45~54 g/hm2(商品量750~900 mL/hm2),药后20 d对杂草的鲜重防效在95%以上。在推荐剂量范围内对花生安全,一次施药即能有效防除花生田全生育期的杂草,除草效果好。  相似文献   
62.
The production of polyunsaturated fatty acids (PUFA) in Tisochrysis lutea was studied using the gradual incorporation of a 13C-enriched isotopic marker, 13CO2, for 24 h during the exponential growth of the algae. The 13C enrichment of eleven fatty acids was followed to understand the synthetic pathways the most likely to form the essential polyunsaturated fatty acids 20:5n-3 (EPA) and 22:6n-3 (DHA) in T. lutea. The fatty acids 16:0, 18:1n-9 + 18:3n-3, 18:2n-6, and 22:5n-6 were the most enriched in 13C. On the contrary, 18:4n-3 and 18:5n-3 were the least enriched in 13C after long chain polyunsaturated fatty acids such as 20:5n-3 or 22:5n-3. The algae appeared to use different routes in parallel to form its polyunsaturated fatty acids. The use of the PKS pathway was hypothesized for polyunsaturated fatty acids with n-6 configuration (such as 22:5n-6) but might also exist for n-3 PUFA (especially 20:5n-3). With regard to the conventional n-3 PUFA pathway, Δ6 desaturation of 18:3n-3 appeared to be the most limiting step for T. lutea, “stopping” at the synthesis of 18:4n-3 and 18:5n-3. These two fatty acids were hypothesized to not undergo any further reaction of elongation and desaturation after being formed and were therefore considered “end-products”. To circumvent this limiting synthetic route, Tisochrysis lutea seemed to have developed an alternative route via Δ8 desaturation to produce longer chain fatty acids such as 20:5n-3 and 22:5n-3. 22:6n-3 presented a lower enrichment and appeared to be produced by a combination of different pathways: the conventional n-3 PUFA pathway by desaturation of 22:5n-3, the alternative route of ω-3 desaturase using 22:5n-6 as precursor, and possibly the PKS pathway. In this study, PKS synthesis looked particularly effective for producing long chain polyunsaturated fatty acids. The rate of enrichment of these compounds hypothetically synthesized by PKS is remarkably fast, making undetectable the 13C incorporation into their precursors. Finally, we identified a protein cluster gathering PKS sequences of proteins that are hypothesized allowing n-3 PUFA synthesis.  相似文献   
63.
Lymphoma is the third most common cancer diagnosed in children, and T-cell lymphoma has the worst prognosis based on clinical observations. To date, a lymphoma model with uniform penetrance has not yet been developed. In this study, we generated a p53 deficient mouse model by targeting embryonic stem cells derived from a C57BL/6J mouse strain. Homozygous p53 deficient mice exhibited a higher rate of spontaneous tumorigenesis, with a high spontaneous occurrence rate (93.3%) of malignant lymphoma. Because tumor models with high phenotypic consistency are currently needed, we generated a lymphoma model by a single intraperitoneal injection of 37.5 or 75 mg/kg N-methyl-N-nitrosourea to p53 deficient mice. Lymphoma and retinal degeneration occurred in 100% of p53+/− mice administered with higher concentrations of N-methyl-N-nitrosourea, a much greater response than those of previously reported models. The main anatomic sites of lymphoma were the thymus, spleen, bone marrow, and lymph nodes. Both induced and spontaneous lymphomas in the thymus and spleen stained positive for CD3 antigen, and flow cytometry detected positive CD4 and/or CD8 cells. Based on our observations and previous data, we hypothesize that mice with a B6 background are prone to lymphomagenesis.  相似文献   
64.
SHK-6对不同群体下大豆花荚脱落及其产量的调控   总被引:6,自引:1,他引:5  
以"冀豆12"为材料,在大田条件下通过在初花期对不同群体大豆施用SHK-6,研究了植物生长调节剂SHK-6对不同群体条件下大豆产量及其构成因素的调控作用.结果表明:SHK-6能够明显的提高各个群体下的大豆产量(8.0%),在密度水平为30株/m2的条件下施用SHK-6产量达到最高.调节剂SHK一6能够提高单株花数(13.0%)、荚数(14.8%)、粒数(10.9%)、荚重(16.4%)、粒重(12.3%),并且能够提高百粒重(2.4%)、粒茎比(15.0%).虽然SHK-6处理也增加不同密度水平下的花荚脱落数,但对脱落率没有影响.SHK-6能够降低叶面积指数(LAI)、提高下层叶片的光截获率(群体透光率)和下层叶片的叶绿素的含量.可见冠层结构的优化是导致产量提高的根本原因.  相似文献   
65.
为探明长枝木霉T6菌株对美洲南瓜枯萎病菌的作用机理,采用对峙培养、显微观察、孢子萌发、室内防效测定等方法研究其抑制能力和防治效果。结果表明:长枝木霉T6菌株对美洲南瓜枯萎病菌具有较强的抑制作用,对峙培养7 d时,长枝木霉T6菌株对该病菌的抑制率为60.09%;显微形态观察表明:长枝木霉T6菌株菌丝与美洲南瓜枯萎病菌菌丝发生缠绕;长枝木霉T6菌株发酵液对美洲南瓜枯萎病菌分生孢子萌发具有明显的抑制作用,抑制率为31.00%;长枝木霉T6菌株对美洲南瓜枯萎病具有较好的防治效果,室内盆栽防效为69.06%。  相似文献   
66.
AIMTo investigate whether minimally modified low-density lipoprotein (mmLDL) affects the quantity and activity of endothelin (ET) type A (ETA) and type B (ETB) receptors in mouse mesenteric artery by activating p38 mitogen-activated protein kinase (MAPK) inflammatory pathway. METHODSThe KM mice were divided into normal saline (NS) group (injection of NS via caudal vein), mmLDL group (injection of mmLDL via caudal vein), LDL group (injection of LDL via caudal vein), mmLDL+SB 203580 group (injection of mmLDL via caudal vein and intraperitoneal injection of p38 MAPK pathway specific inhibitor SB 203580) and mmLDL+DMSO group (injection of mmLDL via caudal vein and intraperitoneal injection of DMSO). Mesenteric artery ring segment vasoconstriction dose-response curves affected by sarafotoxin 6c (S6c) and ET-1 were recorded by the myography system. The mRNA levels of ETB receptor, ETA receptor and interleukin-6 (IL-6) were detected by RT-qPCR. The protein levels of ETB receptor, ETA receptor, IL-6, p38 MAPK, p-p38 MAPK, NF-κB and p-NF-κB were determined by Western blot. The serum concentration of IL-6 was measured by ELISA. RESULTSThe contractile responses of the blood vessel segments to S6c and ET-1 were significantly increased by mmLDL (P<0.01). The mRNA and protein expression levels of ETA receptor, ETB receptor, and IL-6 significantly increased (P<0.01). The protein levels of p-p38 MAPK and p-NF-κB were significantly increased (P<0.01). The serum level of IL-6 was significantly increased (P<0.01). These effects of mmLDL were inhibited by p38 MAPK inhibitor SB 203580. CONCLUSION mmLDL increses the serum concentration of IL-6, up-regulates the expression of IL-6, ETA receptor and ETB receptor in mouse mesenteric artery, and enhances the vasoconstriction function medi?ated by ETA and ETB receptors, which is related to the activation of p38 MAPK inflammatory pathway and downstream NF-κB pathway.  相似文献   
67.
【目的】研究复硝酚钠(CSN)与胺鲜酯(DA-6)2种植物生长调节剂,分别和化肥复配施用对棉花化肥吸收率的影响。【方法】通过复硝酚硝与胺鲜酯分别和化肥复配施用,采集棉花2叶期、4叶期、6叶期各20株,测定棉株鲜重,干重,以及全氮、全磷和全钾含量,计算棉花3个时期的干物质比、氮吸收率、磷吸收率、钾吸收率,与CK相比较,分析复硝酚钠与胺鲜酯对棉花肥料吸收率的影响。【结果】复硝酚钠和化肥复配施肥后,棉花对肥料的吸收率在2叶期时氮、磷、钾吸收率分别提高了10.76%、0.87%和10.4%。4叶期时氮、磷、钾吸收率分别提高了18.5%、2.34%和24.86%。6叶期时氮、磷、钾吸收率分别提高了31.14%、5.33%和35.56%;胺鲜酯和化肥复配施肥后棉花对肥料的吸收率在2叶期时氮、磷、钾吸收率分别提高了8.31%、0.85%和9.25%。4叶期时氮、磷、钾吸收率分别提高了11.51%、1.48%和15.66%。6叶期时氮、磷、钾吸收率分别提高了27.11%、4.49%和30.31%。【结论】复硝酚钠与胺鲜酯与化肥复配施用,对棉花化肥吸收率有明显的促进作用。  相似文献   
68.
DTA-6对两种食用豆生理代谢及产量的影响   总被引:1,自引:0,他引:1  
为探究2-N,N-二乙氨基乙基己酸酯(diethyl aminoethyl hexanoate,DTA-6)对食用豆叶片的生理代谢及产量的调控效应,选用芸豆(英国红)和小豆(龙垦2号)为试验材料,采用大田完全随机试验方法,于芸豆和小豆的初花期叶面喷施DTA-6,以喷施清水为对照(CK),测定各生育时期叶片光合参数、碳代谢产物、干物质、产量及产量构成因素。结果表明:DTA-6提高了2种食用豆各生育期的SPAD值、盛花期和鼓粒期的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2浓度(Ci),显著增加了叶片蔗糖和可溶性糖的含量,促进了叶片淀粉的积累;与CK相比,DTA-6提高了2种食用豆的地上部单株干物质积累量,并且显著提高了芸豆和小豆鼓粒期荚分配率;DTA-6可有效调控2种食用豆的单株荚数、单株粒数和百粒重,从而提高产量,DTA-6处理的芸豆和小豆产量分别较CK增加13.30%和12.91%,增产显著。  相似文献   
69.
为明确不同品种甘薯茎尖培养的最佳NAA/6BA配比,设置0.1 mg/L/2.5 mg/L、0.2 mg/L/2.5 mg/L、0.2 mg/L/1.0 mg/L 3组NAA/6BA浓度配比处理,观测不同浓度激素处理对‘北京553’、‘红香蕉’、‘苏薯8号’、‘烟薯25’、‘安吉芋’、‘济徐23’、‘渝紫7号’、‘商薯19’茎尖培养成苗率、愈伤组织直径、不定根数目、叶片数和植株高度的影响,同时调查不同品种试管苗的移栽成活率。结果表明,‘红香蕉’、‘济徐23’、‘渝紫7号’、‘商薯19’在0.1 mg/L/2.5 mg/L的处理下培养效率最高;‘安吉芋’在0.2 mg/L/2.5 mg/L的处理下培养效率最高;‘苏薯8号’、‘北京553’、‘烟薯25’在0.2 mg/L/1.0 mg/L的处理下培养效率最高。因此,在甘薯茎尖培养过程中,不同甘薯品种适宜的NAA/6BA配比存在显著差异,在实际生产中应根据品种特性来进行调整激素的用量和比例。  相似文献   
70.
沙棘组培快繁技术研究   总被引:5,自引:3,他引:5  
周洁  岳冬梅  陈贵  张立军 《安徽农业科学》2005,33(2):236-237,249
研究了不同取材时间、不同基本培养基和不同浓度的 6 -BA和NAA组合对沙棘组培快繁的影响。结果表明 :以春秋季节休眠芽为外植体获得的沙棘组培苗效果最好 ;B5+ 6 -BA 0 .5mg/L +NAA 0 .5~ 1.0mg/L为适宜的启动培养基 ,对休眠芽的诱导率为 10 0 % ;1/2B5+ 6- BA 0 .5mg/L +NAA 0 .5mg/L为最佳继代增殖培养基 ;1/2B5+ 6 -BA 0 .1mg/L +NAA 1.0mg/L为最佳生根培养基 ,生根率达到 85 % ;试管苗经过驯化移栽成活率达 5 0 %以上。  相似文献   
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