成团泛菌低分子脂多糖的急性毒性、刺激性、致敏性及遗传毒性评估

本研究对成团泛菌低分子脂多糖（Pantoea agglomerans lipopolysaccharide,LPSp）的安全性进行初步评估。本研究采用一次限量法,用昆明种小鼠进行LPSp急性经口毒性试验,了解LPSp的急性毒性;采用新西兰兔分别进行LPSp急性和多次皮肤刺激性试验以及急性眼刺激性试验,了解LPSp的皮肤和粘膜刺激性;采用豚鼠进行LPSp皮肤变态反应试验,了解LPSp的致敏性;应用平板掺入法进行鼠伤寒沙门氏菌/回复突变试验和小鼠骨髓细胞微核试验考察LPSp的遗传危害。急性毒性试验结果显示,LPSp对小鼠经口一次灌胃的LD50大于5000mg/kg体重,属实际无毒级别;LPSp急性和多次皮肤刺激性试验以及急性眼刺激性试验结果显示,皮肤刺激和眼刺激积分均为0分,LPSp对皮肤无刺激性、对眼睛无急性刺激性;在皮肤变态反应试验中,LPSp在各观察时间点的皮肤变态反应积分均为0分,其致敏率均为0%,说明LPSp对豚鼠无致敏性;LPSp的鼠伤寒沙门氏菌/回复突变试验结果呈阴性（P〉0.05）;LPSp的小鼠骨髓细胞微核试验结果亦呈阴性,LPSp各剂量组的微核发生率与阴性对照组未见统计学差异（P〉0.05）,而与阳性对照组有明显差异（P〈0.01）。本研究结果表明,在本实验剂量范围内,LPSp对小鼠经口毒性极低,属实际无毒级别,对家兔皮肤和眼睛无明显刺激性,对豚鼠无致敏性,对所试菌株和小鼠体细胞无诱变性和致突变性。     

ADAMTS17 mutation associated with primary lens luxation is widespread among breeds

Primary lens luxation (PLL) is a well-recognized, painful and potentially blinding inherited ocular condition in dogs. We screened PLL-affected dogs of 30 different breeds, to identify those which carried a previously described c.1473+1 G>A mutation in ADAMTS17 that is associated with PLL in Miniature Bull terriers, Lancashire Heelers, and Jack Russell terriers. This ADAMTS17 mutation was identified in PLL-affected dogs from 14 additional breeds. PLL-affected dogs from some breeds (most notably the Shar pei and the Brittany spaniel) did not carry the G1473+1A ADAMTS17 mutation, indicating they must suffer from a genetically distinct form of the condition. We also estimated the frequency of this ADAMTS17 mutation in some of the breeds. Our findings indicate the mutation segregates in a large number of different breeds of dog, many of which are terriers or breeds with terrier co-ancestry, but some of which have more diverse origins. Our results also indicate that the mutation is present at high frequency within most of the breeds in which it segregates. In the miniature bull terrier breed estimates of mutation frequency ranged from 0.27 to 0.39, corresponding to 7.3-15.2% PLL-affected dogs in this breed. We also identified an increased risk of PLL associated with heterozygosity at ADAMTS17, suggesting that carriers carry a low risk of developing PLL.     

高辣椒素含量航天辣椒桂航一号的选育

桂航一号是红椒一号经过太空诱变处理后,单株选育3代、混合选育2代育成的高辣椒素含量辣椒新品种。该品种中晚熟,从定植至采收红椒约90d。株高90cm左右,植株开展度85cmx85cm左右。第一花着生13—14节。果实羊角形,纵径15～16cm,横径1．3cm,肉厚0．19cm,2—3心室。果肩平或斜,果顶锐尖,果面光滑,果皮薄,果形较直,青果深绿色,生物学成熟果鲜红色,平均单果质量12～13g,最大单果质量15g。果实每100g鲜质量维生素C含量87．9mg,辣椒素含量104mg／kg,干物质含量8．56％。其中辣椒素含量比红椒一号（5．55mg／kg）提高了近20倍,解决了红椒一号作为辣椒酱原料辣度不够的缺点。667m2产量3942．1奴,较红椒一号增产15．8％,达极显著水平。植株外被茸毛,较耐炭疽病、疫病、病毒病,抗高温,耐湿能力强,适于嗜辣地区作鲜食、加工盐渍、酱制或干制栽培。     

和田市1961-2009年太阳总辐射的变化特征

应用和田市国家基准气象站1961-2009年逐月太阳总辐射资料,采用线性倾向估计、Morlet连续小波、滑动t检验法分析了49a来和田市太阳总辐射的趋势变化、周期及突变特征,结果表明：年太阳总辐射呈显著的减少趋势,减少率达96.8MJ/m2.10a,夏、秋、冬三季亦呈显著减少变化趋势;60年代平均辐射最多且明显偏多、8...     

苏云金芽胞杆菌Cry1Ba3 蛋白定点突变对杀小菜蛾活性的影响

Cry1Ba3是由本实验室发掘的对小菜蛾有高毒力的杀虫晶体蛋白。为了寻找对杀虫活性有重要影响的氨基酸,为杀虫机理研究和改造杀虫蛋白提供理论依据,本研究利用Ple Bio Informatique Lyonnais数据库对Cry1Ba3的二级结构进行模拟;采用BioEdit软件分析Cry1Ba3的疏水区;将Cry1Ba3与Cry1Aa1、Cry2Aa1、Cry3Aa1以及Cry4Ba1进行多序列比对,从而确定了20个氨基酸突变位点。利用半重叠引物PCR的方法对Cry1Ba3进行定点突变,将突变体在大肠杆菌BL21中进行诱导表达。通过浸叶法对各个突变蛋白杀小菜蛾的生物活性进行测定。获得的20个Cry1Ba3突变体均能在大肠杆菌BL21中表达,并以包涵体形式存在。杀虫活性测定结果表明M6(R192L)、M10(W303A)、M19(H485G)对小菜蛾的活性明显降低,二级结构预测表明活性降低的突变蛋白的构象均发生明显变化,其余17种突变蛋白的活性和二级结构都没有明显变化。说明第192位的精氨酸、第303位的色氨酸和第485位的组氨酸对Cry1Ba3的杀小菜蛾活性有重要影响,上述3个位点氨基酸突变引起的蛋白活性减低可能与毒素的空间结构变化有关。     

Low pesticide rates may hasten the evolution of resistance by increasing mutation frequencies

At very low pesticide rates, a certain low proportion of pests may receive a sublethal dose, are highly stressed by the pesticide and yet survive. Stress is a general enhancer of mutation rates. Thus, the survivors are likely to have more than normal mutations, which might include mutations leading to pesticide resistance, both for multifactorial (polygenic, gene amplification, sequential allelic mutations) and for major gene resistance. Management strategies should consider how to eliminate the subpopulation of pests with the high mutation rates, but the best strategy is probably to avoid too low application rates of pesticides from the outset.     

辐射诱变培育玉米自交系辐746及其应用

内容用60Coγ射线105Gy剂量照射杂交组合铁13×C103 F1干种子,用系谱法选育出配合力高、抗病性强、早熟质佳的玉米自交系辐746。用辐746作亲本育成龙辐玉1号、龙辐玉2号、龙高1号、龙单16等玉米杂交种,辐746玉米自交系在黑龙江省玉米育种中具有一定的应用价值。     

籼稻直立穗突变体的培育、鉴定及其突变性状的遗传分析

采用60Coγ射线辐射诱变技术,首次育成了1个籼稻直立穗突变体。该突变体穗型直立,与亲本品种9311的弯曲穗型显著不同。与9311相比,该突变体的株高显著下降,穗粒数减少、穗子缩短、剑叶变短、谷粒变宽变短,但千粒重没有发生变化。遗传分析表明,直立穗突变性状受1对隐性单基因控制。利用该突变体与培矮64S组配的杂种与原杂交稻品种之间的主要农艺性状和产量构成因素差异不显著。     

离子注入在生命科学中的应用研究

本文概述了近十几年来离子注入技术在机理研究、生物品种改良及介导外源基因转移等方面的研究进展     

水稻长穗颈光温敏核不育系培矮64eS(1)的选育

用直接诱变获得eui基因突变的技术路线 ,成功地将目前生产上应用面积最大的光温敏核不育系培矮 64S改造为长穗颈培矮 64eS( 1 )。培矮 64eS( 1 )从遗传上解除了包穗 ,提高了培矮 64eS( 1 )的异交潜势 ,保持原培矮 64S的优良特性 ,可望达到建立不用或少用赤霉素的两系稻种子生产技术体系。利用其组配的杂种具增产趋势。