赤霉素产生菌的激光,化学复合诱变育种研究

采用激光和氯化锂复合诱变赤霉菌,对其产生的赤霉素中活性最高的ＧＡ３含量作为效价测定。结果表明与出发菌株相比,激光诱变,ＬｉＣｌ诱变,复合诱变效价分别提高为１１３．７％,４０．２％,１８９．６％。展示激光复合诱变是遗传育种的一种有效方法。     

阿魏菇多糖高产菌的离子束和激光复合诱变育种

目的:诱变筛选阿魏菇多糖高产菌,探索食用菌的离子束和激光复合诱变育种方法。方法:尝试用阿魏菇菌丝单细胞为靶材,以离子束注入和激光辐照为复合诱变手段,采用营养缺陷型筛选办法定性初筛,摇瓶发酵定量复筛。结果:通过离子束注入诱变,获得了2株菌丝体多糖产量分别达到551.80mg/L和659.46mg/L、较1号出发菌株提高了46.5%和75.2%的多糖高产菌PFPH-1和PFPH-2;在此基础上,以激光辐照为复合诱变手段,获得了1株菌丝体多糖产量达到762.50 mg/L、较出发菌株PFPH-2提高了15.63%的多糖高产菌PFPH-3。结论:离子束和激光复合诱变育种方法在改良阿魏菇多糖高产性状方面诱变功效显著。     

虾青素高产菌株的选育

采用激光（Laser）、紫外线（UV）、亚硝基胍（NTG）及其复合诱变法夫酵母菌,再用高浓度葡萄糖培养基选育经复合诱变的法夫酵母菌。结果表明：与原始出发菌相比,菌株经诱变后其虾青素产量有显著提高,其中复合诱变的是青素产量可达7.26μm/ml。诱变高产菌株遗传稳定性好。     

产生鬼臼毒素菌株的诱变选育

目的:提高原始菌株鬼臼毒素的产量,以期组织工业化生产,从而扩大鬼臼类化合物的资源。方法:以交链孢霉Ty为研究对象,进行紫外线和He-Ne激光复合诱变,再对所获得高产菌株进行发酵条件的优化。结果:筛选到一株鬼臼毒素高产菌株Ty4-16-13,产量达4.213μg/L,比原始菌株提高96%。结论:诱变后的菌株经7次传代,产量较稳定,可用于工业化生产。     

提高展青霉(Penicillium patulum)产灰黄霉素效价的诱变育种研究

为进一步筛选高产灰黄霉素的工业生产菌株,分别对前期采用紫外线-氯化锂（UV-LiCl）、半导体激光（LD laser）及CO2激光（CO2laser）对展青霉FS80-1复合诱变获得三株高产菌株进行液体发酵和固体培养比较。结果表明,通过UV-LiCl复合诱变获得突变菌株GM120-43的液体发酵产灰黄霉素效价11 982μg/mL,比出发菌株提高37.52%,固体培养效价为89 496μg/g（干重）,比出发菌株提高80.04%。;半导体激光诱变获得突变株LD100-1的液体发酵效价9 440μg/mL,固体培养效价119 766μg/g干重,比出发菌株FS80-1提高了140%;两个突变株的生物学特性均发生不同程度的变化,突菌株GM120-43适合于液体发酵生产,突变株LD100-1适合于固体发酵培养。     

脱落酸高产菌的激光诱变筛选

对脱落酸产生菌分别进行了紫外诱变和紫外 -激光复合诱变筛选 ,结果表明紫外 -激光复合诱变正变率较高 ,正变幅度较大。从紫外 -激光复合诱变得到的突变株中筛选到一株遗传性状稳定的高产菌株 ,将其传代 5代 ,各子代发酵脱落酸的平均产量均在 2 .1mg·g-1 以上 ,比原始出发菌株产量提高了 32 %。     

数理统计在西索米星产生菌诱变育种中的应用

在西索米星产生菌橄榄星孢小单孢菌M－41诱变育种过程中,针对常规育种的随机特性,应用数理统计方法设计实验和整理分析实验数据。取得较好的效果,筛选到一株高产的优良菌株08－81。     

低能离子注入在CGTase高产菌株选育中的应用

应用能量30keV、剂量为5×1015N /cm2的离子注入对环糊精葡萄糖基转移酶产生菌进行诱变育种,得到液体发酵24h产酶高于出发株50%以上的菌株11株。5代传代试验表明诱变后得到的高产菌株产酶具有较好的传代稳定性。     

离子束诱变木聚糖酶产生菌(Aspergillus niger A3)筛选方法的比较研究

木聚糖酶产生菌株的初筛方法主要分为平板法和液体发酵法。它们都有一定的优点和不足。找出适宜于离子束诱变育种的初筛方法,是必要而且是必须的。本文就木聚糖酶产生菌的几种初筛方法做了比较研究,以便找出适宜于离子束诱变高产木聚糖酶菌株育种的初筛方法。     

原生质体诱变选育乳糖酶高产菌株

采用紫外线诱变和^60Co-γ射线协同诱变的方法,对出发菌株Uco-3的原生质体进行诱变处理,通过正突变率与诱变剂量的相互关系,确定最佳诱变剂量。采用4min的紫外线照射和剂量为500Gy的γ射线对黑曲霉Uco-3的原生质体进行诱变,软得一株产高温乳糖酶的高产突变株,突变株产乳糖酶能力显著提高,产酶活力达44．37U／mL,是出发菌株Uco-3的2．73倍。     

提高辐射诱变育种效果及辐射遗传效应的研究──Ⅰ提高水稻辐射诱变效率的研究

６０Ｃｏ—γ辐射与杂交相结合,６０Ｃｏ—γ射线处理分别与Ａｒ＋、ＣＯ２、远红外激光处理相结合以及在总照射量一定的条件下,根据不同的育种目标选择适宜的照射量率,均有提高水稻诱变效果的作用。     

不同诱变因素对小麦性状的影响

以粉质、中杆、无芒小麦辐３６为材料，分别用Ｎ２激光、氮离子注入和＾６０Ｃｏγ射线三种诱变因素处理，对第二代植株高度有影响，经前二者处理的对株高有提高趋势，氮离子注入的，二代出现高杆植株占７２．６％，１焦耳Ｎ２激光处理的在二代中有４５．５％是高杆。＾６０Ｃｏγ射线处理的Ｍ２株高明显变矮，７９ｃｍ以下的单株占总株数中４６．３％；在芒性变异上出现顶芒和长芒类型，处理间诱变效果顺序为γ射线〉１焦耳Ｎ２激光     

微波对阿维拉霉素产生菌诱变效应的研究

阿维拉霉素产生菌SV微波诱变效应的研究发现：菌株SV对微波敏感（微波处理60s,SV菌株存活率低于10％）,菌落形态变化大。微波诱变处理最佳作用方式为培养皿不加盖、快速冰上冷却,最佳处理时间为50s（其正突变率25．3％）。通过微波诱变处理、阿维拉霉素推理筛选,最终获得一株稳定性良好,阿维拉霉素产量达到21．5mg／L,较出发菌株提高119．4％的突变株SV-15。     

氮离子注入棉花花粉诱发农艺性状变异的研究

Ｎ＋注入陆地棉和海岛棉的成熟花粉用于自交和远缘杂交,结果表明：离子注入花粉,在Ｍ１代就可表出现较高频率的有益突变,在Ｍ１相对成苗率和花粉育性为５０％时,花粉辐照Ｍ２突变率是种子辐照的１．６倍,用Ｎ＋离子注入陆地棉和海岛棉花粉进行正反远缘杂交,Ｆ２Ｍ２农艺性状表现出偏母遗传且后代遗传稳定加快,并观察到父本某些性状的转移。离子注入花粉适宜的剂量范围为２×１０１５—１０×１０１５Ｎ＋／ｃｍ２。     

Studies on the Mutagenic Effect of the Chromosome by 5 MeV Electron

In this experiment, electron and y-ray-radiation were used to irradiate dry seeds of Vicia faba. Experimental results show that electron just as affective as γ-ray has significant mutagenic effect on cells. In the range of the dose, the frequency of chromosomal aberrations on the root tip cells, there are singnificantly dose-effect. But the relationship between the dose and frequency of aberrations is close to straight line and redplication. An analysis from the type of chromosomal aberrations by electron also leads to different results, in which there are more bridges and rings by electron than by γ-ray. Therefore, electron possibly have stronger two hit aberrations, and the frequency of aberration increased in proporti on with the square of dose.     

Mutagenic and membranal effect of a phytotoxic molecule isolated from olive leaves parasitized by the fungusCycloconium oleaginum Cast

A phytotoxic substance (C₂₃H₄₄O₃) which is named Substance A, was purified from olive leaves infected withCycloconium oleaginum Cast. The mutagenic effect of this substance was detected using TA 100 and TA 102 strains ofSalmonella in the Ames test usingBacillus subtilis strains M45 rec^–, H17 rec⁺ in the rec assay. Another substance manifesting the mutagenic effect was found in the extract from theCycloconium oleaginum culture. This substance was not detected in the extract from contaminated olive leaves. Substance A increased electrolytes leakage from tissue of olive leaves, thus manifesting its phytotoxicity.     

He—Ne激光对家蚕诱变效应的研究

采用一定剂量的ＨｅＮｅ激光辐照家蚕蛹,在子代与对照相比较,出现熟性、茧形、斑纹等多种变异,利用ＰＡＧＥ,进行血液蛋白质电泳分析结果,也产生谱带数目及活性的变化,首次证明ＨｅＮｅ激光对家蚕具有一定的诱变效应。     

激光诱变效应及育种研究

在激光与常规育种的试验中,我们采用不同波长和不同剂量的激光处理各种不同的植物种子,研究生长发育状况有关的生物效应,并已改进少数基因控制的个别性状。     

DNA sequence analysis of spontaneous histidine mutations in a polA1 strain of Escherichia coli K12 suggests a specific role of the GTGG sequence

Summary Spontaneously arising histidine mutations in an Escherichia coli K12 strain deficient for DNA polymerase I were analysed at the DNA sequence level. We screened approximately 150000 colonies and isolated 106 histidine auxotrophs. Of these, 98 were unstable hisC mutations; 12 representative mutants analysed were shown to have arisen by the excision of a single quadruplet repeat in the sequence 5-GCTGGCTGGCTGGCTG-3. Of the eight mutations at other sites, three hisA deletions and one hisD deletion occurred as a consequence of misalignment of tandemly repeated pentamers (hisD) or decamers (hisA). A single hisA point mutation was found to be a missense mutation. Two extended deletions, covering the his operon were not analysed. We could not identify the hisC deletion by sequencing. We conclude that polA1 is a strong imitator that induces mutations mostly of the minus frameshift and deletion type by a Streisinger-type of mispairing in repetitive DNA sequences. Finally, the possible role of a 5-GTGG-3 sequence and its inverted or direct complements, which are found in the vicinity of all the deletions and frameshifts, is discussed.     

Cytogenetic,cytotoxic and GC–MS studies on concrete and absolute oils from Taif rose,Saudi Arabia

Taif rose (Rosa damascena trigintipetala Dieck) is a sort of damask rose, which is considered as one of the most important economic products of Taif. In this study, the authors investigated the possible cytotoxic, genotoxic, antimutagenic and anticancer effect of concrete and absolute rose oils. The results showed that both concrete and absolute rose oils were cytotoxically and genotoxically safe at a dose of 10 μg/ml when tested on cultures of normal human blood lymphocytes. Also, the results showed significant antimutagenic activity at p < 0.001 for absolute rose oil at the same dose level when tested on cultures of normal human blood lymphocytes supplemented with 300 ng/ml mitomycin C (MMC). On the other hand, concrete and absolute oils exerted a cytotoxic activity against two kinds of human cancer cell lines: HepG2 and MCF7. Concrete oil showed cytotoxic activity against HepG2 and MCF7 with a half maximal inhibitory concentration (IC₅₀) of 16.28 and 18.09 μg/ml, respectively, whereas absolute rose oil showed its cytotoxic activity against HepG2 and MCF7 with an IC₅₀ of 24.94 and 19.69, respectively. From this study, it is concluded that concrete and absolute rose oils are cytotoxically and genotoxically safe at a dose of 10 μg/ml when tested on cultures of normal human blood lymphocytes. In addition, absolute oil has an antimutagenic activity at the same dose. Further investigations are needed to study the activity of higher doses of both oils in vitro and in vivo in experimental animals in order to evaluate the capability of using these oils as therapeutic for treatment of some kinds of cancers.