番茄不同分化潜力的愈伤组织中若干生化成分比较研究

以番茄叶片离体培养为实验系统，比较了不同生长素类（ＩＡＡ、ＮＡＡ、２，４－Ｄ）诱导产生的具不同分化潜力的愈伤组织在过氧化物酶同工酶谱、过氧化物酶和吲哚乙酸氧化酶活性、碳水化合物含量上的差异。

不同光质对喜树愈伤组织形成及分化潜质影响

以喜树无菌苗的茎、叶为外植体,研究了蓝、白、红3种光质下,MS、1/2MS、SH、WPM4种培养基对喜树愈伤组织形成及分化潜质影响。结果表明:蓝光下SH+1.0mg/L NAA+0.075mg/L TDZ培养基上愈伤组织诱导效果最好;愈伤组织继代后在蓝光下第7天时,SOD酶活最高,POD酶活最低,含水量最低,分化的潜力最大。

Studies on the Allelopathic Potential of Corn （Zea mays L.） Aqueous Extracts and Root Exudates

This investigation was carried out at Faculty of Agriculture and Forestry-University of Duhok/Kurdistan-Iraq. Three experiments were included in this investigation： （1） First experiment was a bioassay related to the germination performance, shoot and root development of corn （Zea mays L.） and peanut （Arachishypogaea） at two concentrations of root （3% and 1.5%） and shoot （12% and 6%） aqueous extracts of corn medium; （2） The second experiment dedicated to the intercropping of corn and peanut at four treatments; （3） While the third experiment involved the effect of peanut root exudation on growth of corn. Experiment results revealed that corn shoot and root water extracts highly inhibited seed germination of both corn and peanut, the inhibitory of shoot extract was more than root aqueous extract. While its effect on the seedling growth was vice versa as compared with control treatment, there was an increase in root and shoot length of both corn and peanut when grown in corn aqueous extracts. Intercropping experiment results has stimulated most traits of peanut under studying. Also for corn, there was apparent and significant increase in all characteristics as compared with control. It was further confirmed from the results of peanut root exudates that had all studied characters of corn were stimulated than the control treatment.

Allelopathic Effect of Achillea （Achillea santolina） on Germination and Growth of Crop Plants

In order to investigate the likely allelopathic potential of an aqueous extract and powder of Achillea （,4chillea santolina） on the germination and seedling growth of pea （Cicer arietinum）, safflower （Carthamus tinctorius L.） and wheat （Triticum sativum）, an experiment was carried out at the laboratory and greenhouse of agriculture faculty of Sho3hid Bahonar University of Kerman, Iran, from October 2009 to March 2010. A completely randomized design with three replicates using five extract concentrations of achillea plant including 0, 25, 50, 75, and 100 g Ll and four amounts of powder of it including 0, 7.5, 15 and 30 g kg1 of soil was employed in laboratory and greenhouse experiments, respectively. All extract concentrations of achillea except 25 g Ll inhibited pea and wheat seed germination significantly, but had no inhibitory effect on the germination of safflower, The powder of mature achillea plants affected the fresh and dry weight and shoots length in these crops negatively compared with the control in all levels. Therefore use of this plant should be prevented in rotation or intercropping with these three crop plants. Further research conducted in the analytical laboratory as well as in the field is needed before a practical application of the extract and powder as weed inhibiting agent can be recommended.

Allelopathic Potential of Rice （Oryza sativa L.） Cultivars on Barnyard Grass （Echinochloa crus-galh~

Laboratory and greenhouse studies were conducted to assess the allelopathic potential of 12 rice cultivars on barnyard grass. Polyethylene glycol （PEG） was used to determine the influence of osmotic potential on the bioassay materials. Effect of different concentrations of stem, root, and leaf extracts of rice cultivars on seed germination, radicle and primary shoot length of barnyard grass seedlings, and rate of respiration of root pieces were investigated in the laboratory experiments. Shoot height and dry weight of weed stands were studied in the greenhouse, Also total peroxidase activity, chlorophyll pigment and mitotic index were determined. Results indicated that, among rice cultivars, Mehr, Tarom-mahali, G3, Nemat, and Shahpasand caused the most inhibition effects on investigated factors. Amol-3 showed the least negative effects on growth of seedlings and stands of barnyard grass. In laboratory, the Mehr cultivar demonstrated the maximum inhibitory effects by reducing barnyard grass seed germination percentage （88%）, radicle length （100%）, primary shoot length （83%）, and root respiration （85%） Cell division, expressed as mitotic index, was significantly reduced in the presence of rice aqueous extracts. Mehr cultivar had higher inhibitory effect on mitosis compared to Amol-3. In greenhouse, the same cultivar showed the maximum inhibitory effect by reducing barnyard grass height （45%） and dry weight （64%）. With increase in extract concentration, the inhibitory effect increased. Leaf extract from rice plants was more effective compared with the root and stem extracts. Comparison of rice cultivars and PEG indicated that any reduction in germination and growth of barnyard grass using rice extract concentrations of 5% and 10% must have been the result of allelochemicals in the extracts. Lower extract concentrations showed a more pronounced inhibitory effect in the laboratory as compared to the greenhouse studies. These results suggest that rice leaf extracts may be a source of natural herbicide.

肝源性干细胞及其应用研究

1项目介绍肝干细胞(Hepatic Stem Cells,HSCs)是指具有干细胞特点,并能增殖、分化成为肝细胞和胆管细胞参与肝脏结构和功能重的一类细胞。1956年,Farber等将肝内可能具有分化潜力的细胞描述为卵圆细胞。1958年,Wilson和Leduc提出肝干细胞概念。肝干细胞根据其起源不同,可分为肝源性HSC和非肝源性HSC。肝源性干细胞起源于肝脏胆小管树的小胆管和赫令管,包括肝卵圆细胞和小肝细胞等。