Turbiscan Lab分散稳定性分析仪研究异丙甲草胺水乳剂物理稳定性

为获得不同因素对异丙甲草胺水乳剂物理稳定性的影响规律,同时验证Turbiscan Lab分散稳定性分析仪预测和评价水乳剂物理稳定性的可行性,利用Turbiscan Lab分散稳定性分析仪,结合加速试验[(54±2)℃,14d]结果,研究了乳化剂用量、体系pH和电解质离子等对磷酸酯盐稳定的异丙甲草胺水乳剂物理稳定性的影响。结果表明:乳化剂三苯乙烯基苯酚聚氧乙烯醚磷酸酯三乙醇胺盐(SCP)用量为6.0%(质量分数)时,水乳剂稳定性最好;过酸或过碱均会破坏水乳剂的稳定性,pH=9时水乳剂可获得较好的稳定性;Mg2+压缩油水界面双电层,导致水乳剂稳定性下降,且Mg2+添加浓度越大,水乳剂越不稳定。Turbiscan Lab分散稳定性分析仪以多重光散射为技术核心,在不破坏样品的前提下,能够准确测定乳状液中浮油、沉淀和液滴粒径大小的变化情况,与加速试验结果吻合度高,不仅能够缩短试验周期,而且可以分析不稳定现象发生的机理。     

乙烯受体ETR1基因同源性分析及乙烯敏感性与植物采后寿命的关系

将37种不同科属植物及5个不同月季品种的ETR1核苷酸、氨基酸序列进行同源性分析并构建了分子系统发生树,并对植物的呼吸跃变类型、乙烯敏感性及采后寿命的关系进行了归纳和分析.结果表明,在核苷酸水平上,分子性状的同源性与形态性状同源性具有一致性,但月季不同品种种间差异大于异源植物的属间差异.氨基酸序列的同源性分析结果与核苷酸相似,但仍存在差异,可能由于氨基酸密码子简并性、翻译起始位置的不同、ETR1片段大小的差异所造成.在蛋白质水平上,所分析的ETR1片段均具有高度保守结构域.植物的呼吸跃变类型虽与内源乙烯的生成有密切的关系,但与外源乙烯的敏感性无直接关系;植物对外源乙烯的敏感性与植物采后寿命的关系更为密切.     

Extending the postharvest life of carnations with nitric oxide—comparison of fumigation and in vivo delivery

The ability of nitric oxide (NO) to extend the postharvest life at 20 °C of carnations (Dianthus caryophyllus L. cv. White-Sim) was investigated using delivery by gas-based fumigation and in vivo release via a solution containing the NO donor compound 2,2′-(hydroxynitrosohydrazino)-bisethanamine (DETA/NO). Treatment with NO gas in air at 1 and 5 μl l⁻¹ produced about a 30% increase in postharvest life while DETA/NO applied in solution at 10 mg l⁻¹ extended postharvest life by about 50% when dissolved in water. For flowers, use of solid delivery appears to offer a more convenient and more effective method of NO treatment than gaseous fumigation to extend postharvest life.     

A relationship between heading date and in vitro tillering propensity in perennial ryegrass (Lolium perenne L.)

Summary In vitro tillers of over 1000 genotypes from nine contrasting Lolium perenne cultivars were cultured on various media containing the synthetic cytokinin, 6-benzylaminopurine (BAP), in order to determine the effect on tillering. The cultures were assessed after seven weeks for survival, tiller production, size and vigour. Added auxins 2,4-dichlorophenoxyacetic acid (2,4-D) and -napthaleneacetic acid (NAA) had no consistent beneficial effects.A significant relationship was found between in vitro tiller production and cultivar heading date. Genotypes of early-heading, less persistent cultivars produced more tillers than genotypes from late heading more persistent cultivars. This was consistent with the generally higher in vitro tiller production in the biennial species Lolium multiflorum cultured on similar media.     

离体条件下玉米籽粒发育动态研究

采用玉米籽粒离体培养的方法研究了不同培养方式对玉米籽粒发育的影响,并对籽粒体积、粒重、可溶性糖、淀粉、蛋白质含量以及呼吸的变化动态进行了测定。结果表明,采用籽粒∶穗轴为3∶10的培养方式较好。离体籽粒的发育与大田玉米相同,该技术可以广泛应用于玉米生理研究。     

Assessment of drought resistance in 20 accessions of Triticum aestivum L. and related species II. Stability in yield components

Summary Stability in yield components was estimated in several species of Triticum grown across a range of soil moisture. The aim was to assess the effect of varying soil moisture on mechanisms leading to grain yield stability, particularly in the accessions identified as having stable yields and drought resistance viz., T. sphaerococcum, T. vavilovii and T. aestivum cv. C 306 (Paper I of this series). The study indicated that number of grains per spike provided stability to the accessions of T. sphaerococcum and T. vavilovii whereas number of spikes per unit area contributed towards the stability of T. aestivum cv. C 306. It is suggested that these accessions could be utilized as the genetic sources for improving specific yield components with regard to grain yield stability under droughted conditions.     

Variation amongst protoplast-derived moth bean Vigna aconitifolia plants

Summary Protoplasts were isolated from leaves of a single plant of Vigna aconitifolia, a drought resistant grain legume. The protoplasts regenerated and formed colony and calli from which 50 entire plants were regenerated and transferred to field conditions. Only 7 plants survived upto maturity and they flowered and produced pods with seed. The protoplast derived plants showed variation in important characters. Two groups of characters (one with 7 sets and another with 6 sets) were studied in the protoclones. In first group protoclones showed variations in seed germination, maturity age, pod length, pod and seed colour, number of abortive seed per pod and response to field rots, however, not much difference was recorded in pollen stainability and meiotic behaviour in these protoclones. In second group analysis of variants showed significance difference for plant height, rachis-length, length and breadth of mature odd leaflets, seed per pod and weight of seed. The results indicate that protoplast can be source of variation in this crop. However, detailed biochemical and genetical analysis of protoclones are required.     

Efficient In Vitro Shoot-regeneration Systems in Cassava (Manihot esculenta Crantz)

Two different protocols for in vitro regeneration of cassava using zygotic embryos and nodal axillary meristems have been developed. In both cases, buds were regenerated directly from excised explants without an intervening callus phase after a two-step culture procedure. In cotyledonary explants derived from zygotic embryos, prolific shoot formation occurred within 2—3 weeks on MS medium supplemented with 0.5—5 mg/1 BAP alone or in combination with 0.1 mg/1 NAA. Nodal explants with axillary meristems derived from aseptically grown seedlings or stem cuttings were used to initiate a round compact bulb-like structure on MS medium containing 10 mg/1 BAP. These latter structures, when cultured on MS medium supplemented with 0.1 mg/1 NAA, 1 mg/1 BAP and 0.1 mg/1 GA₃, produced multiple shoots. Somatic embryos isolated at the globular/torpedo stage from zygotic embryo explants were also capable of multiple shoot production on medium with 1 mg/1 BAP. Rooting of regenerated shoots exceeded 95 % in phytohormone-free MS medium. No change in their ploidy levels was observed. Therefore, the protocols developed should be of use in the particle gun and Agrobacterium-mediated genetic transformation of cassava.     

Genetic variability in plants regenerated from in vitro culture of sunflower (Helianthus annum L.)

In vitro regenerated sunflower (Helianthus annuus L.) plants (R₁) were self-fertilized and the R₂ generation was evaluated for qualitative traits. A broad range of phenotypic variation was observed and mutation frequencies were calculated. Some in vitro induced variant phenotypes were similar to known spontaneous or induced mutations in sunflower, while others were new. Chlorophyll and carotenoid deficiencies, chimaerical variegation, fasciated stem and capitulum, abnormal shoot development, and other morphological variations, were noted. Substitution of anthers with petaloid structures in a disk-floret mutant indicates a possible homeotic mutation induced by in vitro tissue culture.     

Selection parameters for resistance to Fusarium oxysporum f. sp. cubense race 1 and race 4 on diploid banana (Musa acuminata Colla)

Summary Shoot tip cultures from banana clones susceptible and resistant to Fusarium oxysporum f. sp. cubense (FOC) race 1 and race 4 were grown in vitro in the presence of different concentrations of fusaric acid and fungal crude filtrates or inoculated with a conidial suspension of FOC to assess correlation between in vivo and in vitro behaviour. Explants were susceptible to both filtrate and fusaric acid irrespective to their known field resistance/susceptibility response. No clear linkage between in vivo and in vitro behaviour was observed and our results suggest that the use of crude filtrate or non-host specific toxin (fusaric acid) in a screening programme for selecting a novel resistant genotype of Musa to FOC is not feasible. When peroxidase activity was used as a parameter to discriminate between sesceptibility and tolerance, results were in good agreement with field response of host plant to pathogens. Early enzymatic activity increased in the incompatible host-pathogen interaction but not in the compatible interaction.Abbreviations IBA Indolebutyric acid - 2iP 6-dimethylallylamino-purine - VCG Vegetative Compatibility Group - FOC Fusarium oxysporum f. sp. cubense - IEF isoelectrofocusing