水淹对水芹(Oenanthe javanica)生长的影响

通过对水芹在不同水淹条件下其形态结构改变及生物量变化的研究,揭示不同水淹对情况对其生长的影响.结果表明,在形态上,对照组和半淹组无显著差异,全淹植株在新生叶叶柄长和匍匐枝长度以及新生叶叶柄与地面的夹角显著增大.半淹组植株所产生的不定根数量远远大于全淹组植株;全淹限制了水芹生物量的积累,总生物量及个器官生物量降低,但叶生物量比(LMR)和支持结构比(SBR)明显增大.因此,水芹在全淹条件下,则是通过向上生长和生物量的重新分配,以减轻水淹对植株造成的伤害.     

鸦胆子苦木素对小鼠血清胆碱酯酶和总胆红素的影响

为了探讨鸦胆子提取物苦木素的毒性,实验以小白鼠为研究对象,对血清中胆碱酯酶活性和总胆红素含量进行了测定。70只健康昆明系雌性小白鼠随机分为1个空白对照组和6个药物组,药物组分别以1.25、1.80、2.80、4.00、6.00、8.50 g/kg灌胃,在第7天和第14天分别进行采血,分离血清,测定血清胆碱酯酶活性和总胆红素含量。结果鸦胆子苦木素类提取物具有抑制小鼠血清胆碱酯酶活性的作用,与空白组相比差异显著（P〈0.05,P〈0.01）,并能使血清中总胆红素升高（P〈0.05,P〈0.01）,对两种酶的抑制与促生作用,第14天较第7天明显增强（P〈0.01）。实验表明鸦胆子苦木素对动物机体有一定的毒性作用,并随着浓度的增加而加强,同时呈现出一定的时效性。     

高产杂交稻威优134的选育

威优134是以带爪哇稻亲源的父本yl-34与母本V20A配组选育的高产中熟杂交组合，2000年2月通过湖南省品种审定。介绍了其主要特征特性、栽培和制种技术要点。     

重阳木降解纤维素内生真菌的筛选研究

通过对重阳木茎内皮内生真菌的分离纯化,得到7株内生真菌.采用羧甲基纤维素钠培养基进行纤维素降解能力初步测定,并且结合漆酶酶活测定方法比较其降解力,得到5株具有降解纤维素能力的内生真菌.     

In-plant activation of root-specific expression of a cytotoxic gene disrupts the development of the root-knot nematode,Meloidogyne javanica

Plant hosts can be engineered to disrupt the development of sedentary plant-parasitic nematodes or proper functioning of the feeding sites the nematodes induce. The use of constitutive promoters to express dsRNAs or nematode inhibitor proteins may be unreliable because of possible silencing or yield penalty from continuous expression in a plant host. This ill-effect can be avoided if a root-specific, nematode-responsive promoter (NRP) is used to drive the target nematode-inhibitory message. This study used the In Plant Activation (INPACT) system to express a barstar-controlled barnase in galls of Meloidogyne javanica and assessed how the engineered tobacco lines affected the growth and development of the nematodes. Of the 11 combinations of four NRPs and the CaMV 35S promoter assessed, the AtCel1 and TobRB7 combinations activated specific expression of split β-glucuronidase (GUS) and barnase genes in and around giant cells. The same NRP combination directed expression of the barnase gene in tobacco roots also constitutively expressing the barstar gene (SPBB transgenic lines). On roots of six T₁ SPBB lines, there was up to 94% reduction in the number of galls with significantly smaller adult females compared to those on wild-type plants. Some of the females on lines SPBB4-1 and SPBB-4-2, for example, were not associated with galls. The results indicated the engineered plants disrupted M. javanica development and demonstrate the potential for controlled and localized expression of peptides, such as those that could block specific effectors, to disrupt initiation, formation, establishment, or proper functioning of feeding cells induced by damaging sedentary nematodes.     

Nematicidal efficacy of MCW‐2, a new nematicide of the fluoroalkenyl group,against the root‐knot nematode Meloidogyne javanica

BACKGROUND: The small number of available nematicides and restrictions on the use of non‐fumigant nematicides owing to high toxicity to human and non‐target organisms hinder effective nematode control. The nematicidal efficacy of MCW‐2, a new nematicide of the fluoroalkenyl group, was evaluated against the root‐knot nematode Meloidogyne javanica (Treub.) Chitwood. RESULTS: MCW‐2 showed irreversible nematicidal activity against second‐stage juveniles of M. javanica in vitro, following exposure for 48 h at concentrations as low as 0.5 mg L^?1, in contrast to fenamiphos or cadusafos. When exposed to MCW‐2 for shorter periods, motile juveniles became immobile with time after rinsing in water. MCW‐2 at 8 mg L^?1 inhibited nematode hatching, which, however, recovered after rinsing in water. In pot and plot experiments, 0.5 mg MCW‐2 L^?1 soil and 2 kg MCW‐2 ha^?1, respectively, controlled M. javanica similarly to or better than fenamiphos or cadusafos at the same concentrations or at their recommended doses. In the soil, the nematicidal activity of MCW‐2 was less persistent than that of fenamiphos. CONCLUSION: MCW‐2 has potential to be used as a new non‐fumigant nematicide that probably has a novel mode of action. Copyright © 2009 Society of Chemical Industry     

3种特色野菜食用安全性研究

[目的]探讨3种特色野菜的食用安全性,为消费者食用野菜提供理论支持。[方法]测定了菜芙蓉、水芹菜和婆罗门参3种特色野菜的硝酸盐、亚硝酸盐、重金属含量和小鼠最大耐受量,并对其进行了健康风险和毒性风险评价。[结果]3种野菜硝酸盐和重金属含量都较低,污染程度都在安全级以内,日常食用不会对居民健康造成风险;小鼠给予60.0 g/(kg·d)的剂量(相当于成人每天3.6 kg食用量),未出现急性中毒反应和病理变化。[结论]菜芙蓉、水芹菜和婆罗门参3种野菜日常适量食用是安全的。     

野生水芹急性毒性研究

[目的]研究野生水芹的毒性。[方法]利用野生水芹对试验小鼠进行急性毒理试验,并观察小鼠肝肾功能及脏器变化。[结果]毒理试验表明,小鼠经口最大耐受剂量(MTD)大于15 g/kg(BW),属无毒级;血生化指标正常,病理切片显示野生水芹对小鼠肝肾等器官均无显著影响。[结论]野生水芹是无毒、值得开发的纯天然植物。     

土党参多糖促进小鼠胃肠运动的初步研究

将KM小鼠分组后,分别灌胃给予土党参多糖(100、200、400 mg/kg)及生理盐水,连续给药30 d,以小鼠食物利用率、体重增重率、血清中D-木糖含量及小肠墨汁推进率为检测指标,考察土党参多糖对小鼠胃肠改善作用。结果表明:土党参多糖能够增加小鼠食物利用率及体重增重率,促进D-木糖吸收及明显增加胃肠抑制小鼠墨汁推进率,对小鼠胃肠运动有促进作用。