抗杀螟硫磷二化螟的抗性遗传力研究

应用数量遗传学的方法分析了水稻二化螟(chilo suppressalis)对杀螟硫磷抗药性的遗传力,并就遗传力和杀虫剂的杀死率对抗性发展速率的影响进行了预测。研究结果表明：二化螟对杀螟硫磷抗性的遗传力较低(h²＝0.277),产生高抗性的潜力不大。即使在室内选择的条件下,要获得10倍的抗性约需要6-12代;在野外条件下则需要更长的时间(15-32代)。因此,结合抗性变化动态的监测结果,我们认为在野外条件下二化螟是不致于产生高抗性,杀螟硫磷仍不失为二化螟抗性治理系统中有效品种之一。     

为害枣树一菱纹叶蝉新种

为害枣树一菱纹叶蝉新种蔡平（安徽农学院园艺系合肥２３００３６）崔士英（河北师范大学生物系石家庄０５００１６）葛钟麟（安徽农学院植保系合肥２３００３６）菱纹叶蝉属（Ｈｉｓｈｉ。。ｏｎｕｓＩｓｈｉｈａｒａ。１９５３）隶属于同翅目（ＨｏｍｏＰｔｅｒａ）ｎ十...     

籼稻的抗冷性与亲本的关系

四个籼稻（Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．）品种幼苗经１℃黑暗或光照２５０ μｍ ｏｌ·ｍ － ２·ｓ－ １处理后,抗冷的“桂山矮选３”比不抗冷的“青华６ 号”幼苗存活率高,其子代是以“桂山矮选３”为母本的比“青华６ 号”为母本的存活率较高。抽穗期剑叶经光照低温处理１２、２４ 和３６ ｈ 后,光合作用是“桂山矮选３”和以“桂山矮选３”为母本的子代比“青华６ 号”和以“青华６ 号”为母本的子代下降较少。呼吸作用是前者比后者在处理１２ ｈ 时有明显升高现象。荧光参数Ｆｖ／Ｆｏ和Ｆｖ／Ｆｍ比值在处理２４ ｈ 时前者比后者下降明显,但在常温下恢复则是前者比后者明显较快。自然低温（寒露风）对叶绿素荧光的影响亦有相似的规律。对水稻后代的抗冷性倾向于母本进行了讨论     

应用CTB基因启动子及信号肽序列构建分泌性表达系统

利用霍乱毒素B亚基基因的启动子、信号肽序列及ctx操纵子的转录终止信号构建了分泌性表达的质粒载体pMCOSS。Β－半乳糖苷酶基因克隆至霍乱毒素B亚基基因的信号肽序列下游后能得到高效分泌性表达。不同的宿主菌和培养基成分中对β-半乳糖苷酶的表达产量有较大的影响,以MM2为宿主菌、在玉米浆培养基中β－半乳糖苷酶的表达产量达4 lOOu／ml,产物的大部分分泌至细胞的周质,活力测定的结果与SDS—PAGE电泳测定结果基本一致,说明表达的β－半乳糖苷酶绝大部分都具有酶活性。构建的蛋白质分泌性表达的载体－宿主系统及合适的培养条件为易形成包含体的蛋白质的高效表达提供了一条新的途径。     

峨嵋山冷杉森林衰退状况研究

报道和分析了峨嵋山冷杉森林的衰退状况。对冷杉种群的受害程度、分布规律、症状特点及其与海拔、特定生境、立木径级和林型的关系进行了研究分析。指出峨嵋山冷杉森林衰退是全球森林衰退的组成部份,而不是个别的或偶然的现象;肯定了当地冷杉林衰退具有某些个性特征。由此认为,导致当地冷杉衰退的主要原因可能是某种或某些作用范围广、持续时间长、发生频率高、对全球森林系统构成威胁的因素所致。     

动物鸣叫声计算机分析

动物鸣叫声计算机分析姜仕仁,丁平,施青松诸葛阳（杭州大学生物科学与技术系３１００１２）ＣｏｍｐｕｔｅｒＡｎａｌｙｓｉｓｏｆＡｎｉｍａｌ’ｓＣａｌｌｉｎｇＳｏｕｎｄ￥ＪｉａｎｇＳｈｉｒｅｎ,Ｄｉｎｇ,Ｐｉｎｇ,ＳｈｉＱｉｎｇｓｏｎｇ,ＺｈｕｇｅＹａｎｇ...     

Characterization of (Na+ + K+)-ATPase liposomes: II. Effect of α-subunit digestion on intramembrane particle formation and Na+,K+-transport

The effect of the protein structure of ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ on its incorporation into liposome membranes was investigated as follows: the catalytic α-subunit of ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ was split into low-molecular weight fragments by trypsin treatment and the digested enzyme was reconstituted at the same protein concentration as intact control enzyme. The reconstitution process was quantified by the average number of intramembrane particles appearing on concave and convex fracture faces after freeze-fracture of the ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ liposomes. The number of intramembrane particles as well as their distribution on concave and convex fracture faces is not modified by the proteolysis. In contrast, the ATPase activity and the transport capacity of the ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ decrease progessively with increasing incubation times in the presence of trypsin and are abolished when the original 100 000 molecular weight α-subunit is no longer visible by sodium dodecylsulfate gel electrophoresis. Apparently, functional ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ with intact protein structure and digested, non functional enzyme consisting of fragments of the α-subunit reconstitute in the same manner and to the same extent as judged by freeze-fracture analysis. We conclude that, while trypsin treatment modifies the ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ molecule in a functional sense, it appears not to modify its interaction with the bilayer in producing intramembrane particles. On the basis of our results, we propose a lipid-lipid interaction mechanism for reconstitution of ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$.     

Phytophthora spp. from rubbertree plantations in Yunnan Province of China

Phytophthora spp. associated with leaf fall, stem canker and black stripe of rubbertree (Hevea brasiliensis Muell.-Arg.) in Xishuangbanna of Yunnan Province were isolated from leaves, bark, fruit and soil in the plantations. Of a total of 50 isolates, 42 were designated as P. citrophthora (R. E. Sm. & E. H. Sm.) Leonian, while the others were identified as P. palmivora (Butl.) Butl., P. colocasiae Rac. and P. cactorum (Leb. & Conn) Schroet. This appears to be the first report of P. citrophthora on Hevea brasiliensis.     

Effect of aldosterone on incorporation of amino acids into renal medullary proteins

Summary Studies on the effects of pretreatment with aldosterone on the incorporation of³H leucine or³H methionine into proteins in renal slices were carried out in Joklik-modified minimal essential medium. Administration of aldosterone (2 g/100 g body wt) to adrenalectomized rats increased³H leucine incorporation into trichloroacetic acid insoluble fractions of crude homogenates of cortical slices by 15.5±0.4% and of medullary slices by 53.5±1.3%. No increase in isotope incorporation was observed in slices of renal papilla or spleen prepared from the same rats. Aldosterone had no effect on the³H-leucine content of the trichloroacetic acid-soluble fractions of all three renal zones and the spleen. The dose of aldosterone that elicited a half-maximal increase in³H-methionine incorporation into proteins of renal medullary slices (0.45 g of aldosterone/100 g body wt) was indistinguishable from that needed to elicit a halfmaximal increase in the urinary K⁺/Na⁺ ratio (0.35 g of aldosterone/100 g body wt). Dexamethasone, a potent glucocorticoid, at a dose of 0.8 g/100 g body wt did not augment³H-leucine incorporation into renal medullary proteins but was effective at 8 g/100 g body wt. Spirolactone (SC-26304), a potent anti-mineralocorticoid, abolished the effect of aldosterone on amino acid incorporation into medullary proteins when administered at a 100-fold higher dosage [i.e., 80 gvs. 0.8 g (per 100 g body wt)]. These results imply that the action of aldosterone on amino acid incorporation is mediated by the mineralocorticoid rather than the glucocorticoid pathway, presumably the mineralocorticoid receptors. Moreover, pretreatment of the rats with actinomycin D (70–80 g/100 g body wt) erased the effect of aldosterone (0.8 g/100 g body wt) on amino acid incorporation into medullary proteins.In paired experiments with³H and³⁵S methionine, aldosterone (0.8 g/100 g body wt) increased methionine incorporation into trichloroacetic acid precipitable proteins of subcellular fractions of the renal medulla. The effect of aldosterone on incorporation of methionine into medullary cytosol proteins was analyzed further by polyacrylamide gel electrophoresis at pH 8.3 in tris-glycine buffer. The gel profiles indicate that aldosterone significantly increased methionine incorporation into at least one protein (independent of the isotope) with a molecular weight of 31,000. This increase was inhibited by either pretreatment of the rat with actinomycin D (70–80 g/100 g body wt or SC-26304 (80 g/100 g body wt). Dexamethasone (0.8 g/100 g body wt) did not increase incorporation of methionine into the medullary cytosol proteins resolved by polyacrylamide gel electrophoresis.     

Induction of citrate synthase by aldosterone in the rat kidney

Summary The possible induction of renal citrate synthase (E.C. 4.1.3.7), by aldosterone was evaluated in the adrenalectomized rat. Three hours after administration of aldosterone (0.8 g/100 g body wt), renal cortical and medullary citrate synthase activity was significantly increased as reported previously by Kinne and Kirsten (Kinne, R., Kirsten, R. 1968.Pfleugers Arch. 300:244). In contrast, no change in this activity was detected in the renal papilla or the liver, under the same conditions. Kinetic analysis revealed that injection of aldosterone had no effect on theK _m s for acetyl-CoA and oxalacetate but augmentedV _max of renal medullary citrate synthase activity by 40%. The aldosterone-dependent increase in medullary citrate synthase activity was proportionate to the associated increase in the quantity of antiserum (specific for citrate synthase) required for half-maximal immuno-precipitation.The possibility that aldosterone induced the synthesis of citrate synthase was evaluated in two sets of experiments. In the first set, adrenalectomized rats were injected intraperitoneally with either aldosterone (0.8 g/100 g body wt) or the diluent, and simultaneously with³H or³⁵S methionine (500 Ci/rat). The isotopes were reversed in about half of the experiments. Three hours after the injection, renal citrate synthase was isolated by ATP-sepharose column chromatography and immuno-precipitation with the specific antiserum. Aldosterone augmented methionine incorporation into renal citrate synthase by 55% but had no effect on incorporation into the hepatic enzyme. In the second set, adrenalectomized rats were injected with either aldosterone (0.8 g/100 g body wt) or the diluent, the kidneys were removed 1 hr later and medullary slices were incubated in either³H-or³⁵S-methionine at 20° for 2 hr. Mitochondrial citrate synthase was isolated either by ATP-sepharose column chromatography and immuno-precipitation, or by polyacrylamide gel electrophoresis. Aldosterone increased methionine incorporation into the immuno-precipitates by 30% and into the enzyme peak resolved by polyacrylamide gel electrophoresis by 43%. The latter increase was eliminated by prior administration of either actinomycin D (70–80 g/100 g body wt) or spirolactone (SC-26304) (80 g/100 g body wt). An equimolar dose of dexamethasone (0.8 g/100 g body wt) had no effect on the isotope ratio associated with citrate synthase activity in the polyacrylamide gels.