普通小麦不同产量优势杂种与亲本苗期叶片基因表达差异的研究

为探讨小麦杂种优势形成的分子机理，本研究选用普通小麦品种系３３３８、６５５４和２４１０ＴＤ及其强优势杂种１（３３３８＊６５５４）和弱优势杂种Ⅱ（２４１０ＴＤ＊６５５４），利用ｍＲＮＡ差异显示方法分析了杂种和亲本幼苗叶片基因表达差异。结果表明：杂种与双亲间基因表达存在数量水平和质量水平的差异，但以量的差异为主。     

DPB滞火剂的配制及其性能的研究

研究由双氰胺、磷酸和硼酸组成的滞火剂配方及其滞火性能。在室温和大气压下将滞火剂溶液注入木材并沉积在木材组织中。测试结果表明,处理后的木材具有优良的滞火性能;并且具有抗沥出、吸湿性低等特点;其体积稳定性和弯曲强度也有改善;对油漆涂饰无不利影响;这种滞火剂易于配制和便于工业利用。     

高羊茅种子发育过程中的生理生化变化

供试高羊茅法恩和赛福瑞两个品种的种子在发育过程中含水量不断下降，由最初的６０－７０％降至最终的１３％左右，种子的鲜重先于干重达到最高值，然后逐渐下降，而干物质重在含水量迅速下降时增加缓慢。法恩和赛福瑞高羊茅种子在含水量分别降至４５．３和４４．１％后进入生理成熟期。淀粉与可溶性糖含量则相反的变化，淀粉在种子发育初期积累迅速，ＡＴＰ和ＴＴＣ含量均达到最高值。     

九孔鲍球状病毒病研究

本文系统报告1999年－2001年间，福建省东山，漳浦人工养殖九孔鲍暴发急性，毁灭性传染病的流行病学，临床症状和病理变化，该病原被分离鉴定为约100nm的球状DNA病毒，无血凝性；本文建立了病毒琼脂扩散诊断法；在5个试验场开展隔离消毒，消灭病原，砂滤水养殖，药浴和应用药物饲料等防治方法，并取得成功。     

泡桐新无性系苗期性状测定

对１２个泡桐无性系苗期性状测定分析表明，苗高、地径、叶面积和材积指数的遗传力分别为７３．５％、８６．２％、８３．４％和８０．４％；遗传变异系数分别为５．４３％、１１．３％、１２．２％和２６．２％。地径、叶面积和材积指数三个性状间的遗传相关、环境相关和表型相关显著。据此，确定以地径或材积指数作为苗期选择性状，初选出２个较优良的的无性系供中试验证。     

浅谈无锡地区高羊茅草坪的养护管理

从灌溉排水、修剪、施肥、病虫害杂草防治等6个方面总结了适合无锡地区高羊茅草坪的养护管理工作方法。     

Infectious bursal disease virus (IBDV) induces apoptosis in chicken B cells

The ability of infectious bursal disease virus (IBDV) serotypes 1 and 2, and the role of VP4 of both serotypes as well as the capacity of three IBDV intermediate serotype 1-specific vaccine strains to induce apoptosis in a chicken B-lymphocyte cell line, DT40, were investigated using the TUNEL technique. It was observed that IBDV serotype 1 infected the DT40 cell line and directly induced apoptosis. In contrast, the non-pathogenic serotype 2 neither infected nor induced apoptosis, but was able to reduce the serotype 1-induced apoptosis when the two viruses were present in combination. VP4 of both serotypes did not induce apoptosis. IBDV VP2 of serotype 2 induced apoptosis in the same proportion and intensity as VP2 of serotype 1. IBDV intermediate vaccines varied in their ability to induce apoptosis in the DT40 cell line, which was also decreased-delayed in presence of serotype 2 IBDV. We hypothesize that both serotypes compete for the same receptor in DT-40 cells, and suggest that IBDV-induced apoptosis is a multistep process involving virus replication, protein expression, and release of virions.     

Effect of replacement of pyruvate/lactate in culture medium with glucose on preimplantation development of porcine embryos in vitro

The effect of glucose supplementation at different times in in vitro culture on the developmental competence of in vitro produced (IVP) porcine embryos was examined. In Experiment 1, when IVP embryos were cultured in modified NCSU-37 supplemented with pyruvate and lactate (IVC-pyr/lac) for 0 h, 24 h, 48 h, 72 h, 96 h, or 118 h and subsequently in modified NCSU-37 supplemented with glucose (IVC-glu) until Day 6 (Day 0=day of in vitro fertilization), the rates of blastocyst formation were significantly higher in embryos cultured in IVC-pyr/lac for 24 or 48 h (24.4% and 23.0%, respectively) than in embryos cultured in IVC-pyr/lac for the whole culture period (14.5%). However, there were no significant differences between embryos obtained after the energy source replacement and embryos cultured in IVC-glu for the whole culture period on the rates (15.2%-24.4%, and 16.8% respectively). Replacement of pyruvate/lactate with glucose at 58 h of culture in Experiment 2 significantly enhanced the rate (31.3%) compared to those after replacement at 48 h, 53 h and 63 h of culture (20.6%, 20.8%, and 21.1%, respectively). In conclusion, replacement of pyruvate/lactate with glucose as the energy substrate was optimal at 58 h of culture for the development of porcine embryos to the blastocyst stage.     

Effects of ovary storage time and temperature on DNA fragmentation and development of porcine oocytes

The present study was conducted to investigate the effects of storage time and temperature of porcine ovaries on the quality and nuclear maturation in vitro of oocytes obtained from stored ovaries and their subsequent development after in vitro fertilization. The ovaries were stored in physiological saline for 0, 3, 6, 9 and 12 h at various temperatures (4, 15, 25 and 35 C). The pH of follicular fluid obtained from the ovaries, DNA fragmentation of the oocyte nucleus and meiotic competence of oocytes were examined. Some oocytes from ovaries stored at 15, 25 and 35 C for 6 h were fertilized in vitro, and then cultured for 7 days to examine the ability of embryos to develop to the blastocyst stage. When the ovaries were stored at 35 C, the pH of follicular fluid decreased and the proportions of oocytes with DNA fragmented nuclei increased as the storage time was prolonged, and the storage of ovaries for 6, 9 and 12 h resulted in lower maturation rates of oocytes. When the ovaries were stored at 4, 15, 25 and 35 C for 6 h, the storage at higher temperatures (> or =15 C) decreased the pH of follicular fluid and induced nucleic DNA fragmentation in higher proportions of oocytes. None of the oocytes from ovaries stored at 4 C reached metaphase II. The storage of ovaries at 15 C reduced the rates of in vitro fertilized oocytes and subsequent embryo development, but there were no significant differences in the rates of fertilization and blastocyst formation between oocytes from ovaries stored at 25 C and 35 C. Our findings indicate that the storage of ovaries at 25-35 C for 6 h is effective for maintaining the developmental competence of porcine oocytes even though the development rates were lower than those of ovaries stored at 35 C for 3 h.