氮离子注入井冈霉素产生菌诱变高产菌株的研究

探索了氮离子注入技术在井冈霉素产生菌高产菌株诱变中的应用。向井冈霉素产生菌注入能量10 keV、剂量15×1013个/cm2氮离子实施诱变,再生培养后单菌落接斜面上摇床进行效价测定,筛选高产菌株。结果获得诱变菌株9275#,其有效A组分含量较出发菌株提高33.52%,且具有高的遗传稳定性。     

Mutations of K-ras oncogene in primary colorectal tumors,related liver metastases and portal vein blood of patients with colorectal cancer

AIM: To evaluate the concordance of K-ras oncogene mutations in primary colorectal tumors, liver metastases and portal vein blood of the patients with colorectal cancer, and to find out the relationship between mutated K-ras oncogene and liver metastases in colorectal cancer.METHODS: Fifty-nine patients with colorectal cancer were screened for the mutations of K-ras oncogene in the tissue samples of primary tumors, portal vein blood and liver metastases (only 15 cases of the 59 patients) by real-time fluorescence quantitative PCR and DNA sequencing. The results were also analyzed with the clinical data of the patients.RESULTS: Point mutations of K-ras were found in the primary tumors in 20 (33.9%) of the 59 patients with colorectal cancer, and 18 (30.5%) of the 59 patients in their portal vein blood. K-ras mutations in 8 (53.3%) of 15 liver metastases were also detected. No significant difference among the rates of K-ras mutation in primary tumor tissues, portal vein blood and related liver metastases was observed (P>0.05). Eighteen cases with mutated K-ras gene in portal vein blood showed the mutations in primary tumor tissues. The patients without mutated K-ras gene in primary tumor tissue also showed negative mutation of K-ras in the portal vein blood. The mutated K-ras gene in both liver metastase and portal vein blood were detected in 8 of the 15 cases with liver metastases, and no mutated K-ras gene was detected in the others with liver metastases. The main types of K-ras mutations found in primary tumors, liver metastases (5 simultaneous, 2 metachronous) and portal vein blood were GGT to GAT and GGT to GTT at codon 12. A K-ras mutation at codon 13 (GGC to GAC) was found in one case with metachronous liver metastases. The rate of concordance of K-ras status between primary tumors and portal vein blood was 96.6%. Detection of K-ras mutations in liver metastases was accordant with that in portal vein blood, but the type of K-ras mutation was partially discordant.CONCLUSION: The K-ras mutations in primary tumors, liver metastases and portal vein blood of patients with colorectal cancer are concordant, and mutated K-ras detected in both cancer tissue and portal vein blood may indicate liver micrometastases from colorectal cancer.     

利用EMS化学诱变改造玉米自交系的研究

选用生产上的玉米骨干自交系,使用不同浓度的甲基磺酸乙酯(EMS)处理其成熟花粉.处理后代采用系谱法种植;在后代群体选择早熟、晚熟和各种有利用价值的株型变异;通过M1、M2代两代田间选择和M3代田间鉴定, 从多个自交系中选出了已稳定的早熟、晚熟突变体和一个有利用价值的株型突变体;并得出浓度为0.667×10-3的EMS-石蜡油有利于早熟突变的发生,而大于10-3的EMS-石蜡油有利于晚熟突变的发生.由于所得自交系为原自交系的等基因突变体,因此该技术在育种实践和理论上具有重要意义。     

新疆阿勒泰地区区域旱涝变化特征分析

利用1961-2008年阿勒泰地区7个气象站的降水量资料计算其区域旱涝指数（W,简称W指数）,主要采用线性趋势法、Mann-Kendall法（简称M-K法）分析其变化特征;选取5个典型干旱、湿润年的NCEP/NCAR资料,对比分析其500hPa环流形势的异同;选取前一年500hPa部分环流特征量与当年W指数进行相关分析。结果表明：年和各季的W指数均具有明显的年际和年代际波动,均有旱涝交替、连旱或连涝的特征。M-K突变检测分析结果表明,年、季W指数突变主要发生在20世纪60年代中后期和80年代中期。分析典型干旱与湿润年500hPa距平场表明,干旱年东欧至西西伯利亚为较强的正距平,新疆受暖脊控制,湿润年则相反。若前一年极涡面积偏小,强度偏弱,而西太副高强度偏强,面积偏大,并盛行纬向环流,次年W指数则容易偏大,即易出现涝年。科学准确认识该地区旱涝规律,把握未来旱涝趋势变化,及时进行农业结构调整,合理安排农业生产,是防御旱涝夺丰收的有效措施。     

菊花辐射诱变育种研究进展

综述了辐射诱变的方法及变异机理,探讨了当今菊花产业中辐射诱变的发展方向,提出了以辐射诱变、组培和分子标记相结合的复合育种的思路。     

产碱性蛋白酶菌株ZK202的鉴定及其诱变

[目的]为产碱性蛋白酶菌株在生产中的应用提供依据。[方法]从河南省兰考县盐碱地土壤中分离1株产碱性蛋白酶的菌株ZK202,通过形态观察、生理生化试验和16SrDNA序列分析对其进行鉴定。经紫外照射和DES处理后,测定诱变菌株的酶活力。[结果]菌株ZK202的形态符合芽孢杆菌属的特征,其16SrDNA序列与短小芽孢杆菌的同源性在99%以上。该菌株为短小芽孢杆菌一个新亚种,命名为Bacillus pumilus ZK202,属中等嗜盐菌。ZK202在氯化钠浓度0～12.5%条件下均能生长,以浓度5.0%时最佳。ZK202在碱性环境中生长良好,当培养基pH值在11.0以上时仍能生长,也属嗜碱性菌。经复合诱变后,菌株Zkud202-4发酵液的酶活力达321U/ml,比出发菌株高3.9倍。[结论]Zkud202-4具有稳定的产酶性能,可作为产碱性蛋白酶的突变菌株。     

脂蛋白脂肪酶基因的研究进展

脂蛋白脂酶是脂质代谢的关键酶,主要催化乳糜微粒和极低密度脂蛋白中的甘油三酯水解。产生供组织利用的脂肪酸和单酰甘油。笔者综述了LPL基因的结构、功能、表达调控以及基因突变的研究进展。     

诱变与组织培养相结合在植物育种中的应用

诱变育种是利用理化因素诱发变异,再通过选择育成新品种的方法,是选育新品种的有效技术。植物组织培养是指对具分生能力的组织进行离体培养,为现代植物育种创造新的变异体,脱毒原种、繁殖体提供了可能和条件。诱变与组织培养相结合可以将二者的优点综合到一起,扬长避短,加速植物育种进程。报道了诱变结合组织培养在国内外植物遗传育种研究中的应用与进展,从抗病虫育种、抗旱育种、抗盐育种、多倍体育种及基因工程等各个方面作了综述。     

Comparison of the nucleotide and amino acid sequences of parental and attenuated isolates of Zucchini yellow mosaic virus

To identify possible sites of viral attenuation, the complete nucleotide sequences of two isolates of Zucchini yellow mosaic virus (ZYMV) were determined; a severe isolate Z5-1 and an attenuated isolate from Z5-1 (designated ZYMV-2002). The viral genome of both isolates consisted of 9593 nucleotides in size and contained an open reading frame encoding a single polyprotein of 3080 amino acids. Comparison of the nucleotide sequences for Z5-1 and ZYMV-2002 revealed 14 nucleotide mutations, resulting in seven amino acid substitutions with four in the HC-Pro region, two in the CI region, and one in the NIb region. These results provide a genetic basis for future manipulation of the ZYMV reverse genetics system. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under the accession numbers AB188115 and AB188116     

三叶木通体细胞秋水仙素诱变苗期表型变异研究

采用正交设计，对三叶木通体细胞秋水仙素诱变，子叶平展期和苗期表现出非常明显的两种表型变异，且成苗率低。影响三叶木通大子叶表型变异出现频率的因素主要有３个：秋水仙素浓度（Ａ）、处理时间（Ｂ）和诱变材料（ｃ），且Ａ＞Ｂ＞Ｃ。影响矮缩茎表型变异出现频率的主要因素是诱变材料（Ｃ）。成苗率主要受诱变材料和诱变时间的影响。以４００～８００ｐｐｍ浓度秋水仙素诱变根尖，成活率和大子叶、矮缩茎表型变异出现频牵均较理想