堆肥浸提物和堆肥茶抑制爪哇根结线虫的盆栽试验

利用腐熟堆肥的浸提液(1∶3,W/V)和由浸提液制备的堆肥茶作为盆栽番茄的液态肥,以评估其对爪哇根结线虫(Meloidogyne javanica)种群的影响。盆栽番茄苗并于4周龄时接种根结线虫第二期幼虫(J2)。试验期间用30%稀释的堆肥浸提液和堆肥茶原液淋灌。与对照组相比,在接种35 d后,堆肥茶使根部的根结数量约下降56.9%,土壤和根中的线虫数量分别下降了45.5%和33.9%;接种70 d后,根结数量约下降51.4%,土壤和根中的线虫数量分别下降了49.4%和66.3%。随着堆肥浸提物和堆肥茶使用浓度的增加,根结数量和最终种群数量均呈指数降低,堆肥茶的效果略优于浸提液。     

水稻粳爪交杂种优势和配合力研究

以３个粳型光敏核不育系、１个保持系为母本，以３个粳型、４个偏粳型、１个籼型恢复系或广亲和系为父本，按ＮＣⅡ设计配组３２个Ｆ１杂种，以汕优６３为对照，采用程氏指数分类法对１２个亲本分类。研究了播始历期、株高、穗长及产量因素等８个性状的杂种优势和配合力。结果表明：Ｆ１每穗总粒数的优势最强，中亲优势１．０９％～１０７．８６％，平均３３．４６％，竞争优势－１７．０９％～８２．７０％；单株产量竞争优势－３６．８２％～３３．５８％，平均－２．３８％；而结实率的竞争优势仅３个组合为正向，变幅为－２３．４７％～３．４１％，平均为－７．４４％；杂种播始历期、株高、穗长、有效穗４个性状中亲优势和竞争优势都表现为粳×粳＜粳×偏粳＜粳×籼，每穗总粒数的中亲优势也表现为上述趋势，而竞争优势则是粳×粳＜粳×籼＜粳×偏粳；这５个性状的中亲优势和竞争优势都很明显。父本变量对杂种抽穗期、株高、穗长、有效穗、每穗总粒数、结实率及产量的影响大于母本和互作变量。母本变量对千粒重的影响大于父本和互作变量的总和。光敏核不育系４００８Ｓ和恢复系培矮６４、广亲和系ＹＨ１０１具有较好的产量一般配合力，产量特殊配合力最好的是８０－４Ｂ／ＹＨ１０１，其次是８０?     

中药植物鸦胆子提取物对小菜蛾的拒食活性研究

[目的]明确中药植物鸦胆子提取物对小菜蛾的拒食活性,为其防治提供参考.[方法]分别用氯仿、乙酸乙酯和正丁醇对鸦胆子甲醇提取物进行萃取,采用非选择性叶碟法测定各萃取物对小菜蛾的拒食活性.[结果]氯仿、乙酸乙酯和正丁醇对鸦胆子甲醇提取物的萃取率分别为0.50％、0.73％、2.10％;在10 mg/ml质量浓度下,氯仿萃取物对小菜蛾幼虫的拒食活性明显高于其他组分萃取物,其24、48h的拒食率分别为91.95％和92.61％.[结论]试验结果为鸦胆子各种杀虫活性成分的进一步分离提供了理论依据.     

光敏核不育系轮回422S的选育

轮回４２２Ｓ（简称Ｎ４２２Ｓ）是从７００１Ｓ×轮回４２２的后代中系选而成的光敏核不育系。在北京、长沙以及连云港多年的观察表明，在长日低温条件下该不育系育性稳定，并且在北方具有３０ｄ以上的稳定不育期，由于该不育系在分类上属于粳亚种下的爪哇类型［２］，具有较理想的产量配合力，且杂种不落粒，在北方正在逐步替代偏籼的温敏不育系培矮６４Ｓ。     

氮磷钾配施对鸦胆子养分吸收与分配的影响

运用“3414”不完全正交回归设计,采用盆栽试验,研究了氮磷钾配施对鸦胆子养分吸收与分配的影响。结果表明,施氮处理显著提高了鸦胆子叶、茎、根氮浓度,其中叶氮浓度最高,但对磷和钾素的吸收影响不显著。土壤氮亏缺时,植物将较多的氮、磷和钾素分配到根部。供磷和供钾水平对鸦胆子氮、磷和钾素的吸收分配规律的影响均不显著,氮磷、氮钾和磷钾施肥处理之间的交互作用不明显,叶片氮、磷、钾浓度的大小受氮肥施用量的变化影响较大。不同施肥处理条件下,鸦胆子植株对磷的吸收量最多,钾次之,氮最少,其氮、磷、钾的吸收比例平均为1∶1.4     

3种桉属植物乙醇抽提物对爪哇根结线虫的毒杀活性

采用直接浸泡法,测定了桉属(Eucalyptus)植物柠檬桉(E.citriodora)、杂交桉(E.urophyla×E.grand)和尾叶桉(E.urophyla)小枝条乙醇抽提物对爪哇根结线虫(Meloidogyne javanica)卵孵化的抑制活性以及对2龄幼虫的毒杀活性。结果表明:柠檬桉、杂交桉和尾叶桉乙醇抽提物对爪哇根结线虫卵的孵化均有较强抑制活性,以20 mg/mL乙醇抽提物液处理24、48、72 h后,抑制孵化率均达94%以上;对爪哇根结线虫2龄幼虫也有较强的毒杀活性,3种桉属植物以20 mg/mL乙醇抽提物液处理2龄幼虫72 h后,线虫校正死亡率均达90%以上。将柠檬桉和杂交桉的茎、叶干粉分别拌土盆栽防治空心菜(Ipomoea aquatica)和黄瓜(Cucumis sati-vus)爪哇根结线虫病。结果表明:柠檬桉和杂交桉茎、叶干粉对爪哇根结线虫病均有较好的防治效果,植株根系的根结数、根结内雌虫数和雌虫产卵粒数均下降,植株地上部鲜质量增加,且均与对照差异显著。     

鸦胆子组织培养技术研究

选用鸦胆子健壮幼嫩茎尖作为组培试验材料,进行组培快繁的研究。结果表明:诱导愈伤组织形成的培养基组合为MS+6-BA2mg/L+NAA0.2mg/L,有利于愈伤组织生长;不定芽分化的培养基为MS+6-BA0.5mg/L+NAA0.05mg/L,有利于不定芽的分化;1/2MS+NAA1mg/L有利于组培苗不定根的形成。     

低钾逆境下根结线虫感染所诱导的番茄根巨型细胞的组织病理学反应

 Comparison of histopathological response and quantitative measurement of giant cell(GC) induced by Meloidogyne javanica in tomato root were studied under potassium-deficient(0.2 mmol/L K⁺) and replete conditions(control,6.0 mmol/L K⁺).K⁺-deficient stress did not impede the formation and maintenance of GC.The mean number of GC per feeding site as well as the mean diameter of GC did not differ between the treatments.However,the thickness of cell wall including components resulted from the accumulated polysaccharide and the length of cell-wall ingrowth increased 5-25 d after inoculation in K⁺-deficient as compared with K⁺-replete conditions.An increase of cell-wall ingrowth suggested a kind of compensational response to the potassium stress.     

Antiphytoviral activity of bruceine-D from Brucea javanica seeds

BACKGROUND: Brucea javanica (L.) Merr. is widely distributed throughout the southern parts of China and has been used in traditional medicine to treat a variety of diseases. The objective of the present study was to identify the active antiphytoviral compound in the seeds of B. javanica and evaluate the inhibitory activity of the compound against plant virus. RESULTS: Bioassay-guided fractionation of the most active extract from the seeds led to the isolation of an antiphytoviral compound which was identified as bruceine-D by conventional spectroscopy methods. The compound exhibited significant inhibitory activity against the infection and replication of tobacco mosaic virus (TMV), with IC(50) values of 13.98 and 7.13 mg L(-1) respectively. The compound also showed a strong inhibitory effect on the infectivity of potato virus Y (PVY) and cucumber mosaic virus (CMV). Furthermore, the compound could effectively inhibit systemic TMV infection in the host tobacco plant under glasshouse conditions.CONCLUSION: The results suggested that bruceine-D from Brucea javanica may have the potential to be used as a natural viricide, or a lead compound for new viricides.     

低温下水芹对生活污水中氨氮、正磷酸盐的去除效果

通过设置3组不同浓度(100%、75%、50%)的生活污水,考察水芹(Oenanthe javanica)对污水中氨氮与正磷酸盐的去除效果。结果表明,在9~12℃的低温下,培养6 d时水芹对3种不同浓度污水中的氨氮和正磷酸盐的去除率分别为47.86%、59.34%、55.56%和44.42%、41.74%、32.95%。表明低温下水芹对生活污水中氨氮和正磷酸盐均有较好的去除效果。