大连沿海虾夷扇贝养殖群体遗传结构的研究

采用聚丙烯酰胺凝胶电泳技术,从5种同工酶和1种非酶蛋白中共检测到8个多态位点和25个等位基因,以此分析了大连沿海4个海区虾夷扇贝Patinopecten yessoensis养殖群体的遗传结构。结果表明,各养殖群体间基因频率分布差异大,相互间存在较大的遗传距离;基因型分布严重偏离Hardy—Weinberg平衡;群体内存在一定程度的近交。     

黄尾鲴6种同工酶的组织特异性研究

为了给黄尾鯝种质标准和种质鉴定提供生化遗传指标,以便合理保护和利用黄尾鯝种质资源。采用聚丙烯酰胺垂直凝胶电泳法对黄尾鲴的7种新鲜组织（肝脏、心脏、脑、肌肉、脾脏、头肾和鳃）中的苹果酸脱氢酶(MDH)、乳酸脱氢酶(LDH)、酯酶(EST)、苹果酸酶(ME)、6-磷酸葡萄糖脱氢酶(6-PGDH)、超氧化物岐化酶(SOD)共6种同工酶进行了分析,并对其同工酶位点及酶谱进行了分析。结果表明,黄尾鯝的6种同工酶在不同组织中的表达存在差异。酯酶、苹果酸酶、苹果酸脱氢酶及6-磷酸葡萄糖脱氢酶在肝脏中表达活性较强,乳酸脱氢酶在肝、脾以及头肾组织中表达活性强,超氧化物歧化酶在肝、脾脏组织中活性较强。     

Cu2+胁迫对家山黧豆幼苗POD活性及其同工酶的影响

[目的]研究Cu^2＋胁迫对家山黧豆幼苗过氧化物酶（POD）活性及其同工酶的影响,为提高家山黧豆的抗逆性和抗病性提供科学依据。[方法]通过不同浓度的Cu^2＋（50、100、150、200、250 mg/L）处理家山黧豆幼苗,考察不同浓度Cu^2＋胁迫对其POD活性及同工酶数量和种类的影响。[结果]在Cu^2＋胁迫下,各处理中家山黧豆幼苗根的POD活性均高于茎和叶,且各处理下的家山黧豆幼苗根、茎、叶中POD活性均高于对照（除250 mg/L）。不同浓度Cu^2＋胁迫下,家山黧豆幼苗根系同工酶的酶带数和活性变化较大,茎和叶片比较稳定。[结论]该研究为提高家山黧豆的抗逆、抗病性提供了科学依据。     

贵州3种小檗属植物种间的亲缘关系

为弄清贵州特有药用植物永思小檗(Berberis tsienii)和威宁小檗(B.weiningensis)以及广布种金花小檗(B.wilsonae)的种间与居群间的系统关系及遗传结构,采用聚丙烯酰胺凝胶电泳技术与PCR直接测序法,对小檗属3种植物7个居群的过氧化物酶(POD)同工酶和核糖体DNA的内转录间隔区(ITS...     

氮素形态对冬小麦旗叶GS及其同工酶活性和籽粒蛋白质含量的影响

为探明氮素形态对小麦品质形成的作用,以强筋小麦品种豫麦34为材料,通过盆栽试验,研究了酰氨态氮、铵态氮、硝态氮3种氮形态下,小麦花后旗叶谷氨酰胺合成酶（GS）和同工酶活性、籽粒蛋白质及蛋白组分含量的变化及其关系。结果表明,在小麦开花后,GS及其同工酶活性在不同时期受不同氮素形态的影响;GS同工酶在3种氮素形态处理下均呈现三条酶带,分别为GS1、GS2、GSx;铵态氮促进了灌浆前期GS的活性,并提高了GS2活性,酰氨态氮对GS1活性具有促进作用;GS活性受GS2活性的影响较大。不同氮形态对籽粒蛋白含量的影响表现为铵态氮提高了籽粒形成初期蛋白质的含量,酰氨态氮有利于后期蛋白质含量的提高。籽粒蛋白质组分对氮形态的反应不一致。同时,籽粒蛋白的合成与GS及GS同工酶活性相关。在生产上可以通过不同形态的氮源配合使用,调控小麦籽粒蛋白质的含量和各蛋白组分的形成。     

同工酶分析法鉴定百合杂种F1代

为提高育种的选择效率,及时、准确鉴别杂种F1代的真伪,采用聚丙烯酰胺凝胶电泳法,对百合11个杂交组合40个后代进行同工酶分析。结果如下：（1）鉴定的40个后代中,共有30个后代可以确定为真杂种。（2）11个杂交组合的酯酶、莽草酸脱氢酶、苹果酸脱氢酶、6-磷酸葡萄糖脱氢酶分析中,父本相较于母本存在特征性条带的杂交组合数分别为8、2、0、0。（3）组合2、3为正反交关系,并未发现父本或母本的特异性遗传。（4）同一品种不同时期,酯酶的酶谱上存在着一定差异,但其基带及特异性条带相对稳定,并未影响到杂种后代的最终判定结果。可见,同工酶技术是鉴定百合杂种的有效手段,酯酶及莽草酸脱氢酶在其中发挥着重要作用。     

Regulation of defense-related enzymes associated with bacterial spot resistance in Tomato

Twenty tomato (Solanum lycopersicon) cultivars were screened for resistance against bacterial spot disease incited byXanthomonas axonopodis pv.vesicatoria under field conditions with and without pathogen infection. Screening was done by artificially inoculating aX. axonopodis pv.vesicatoria suspension to 4-week-old tomato seedlings and observing them for typical symptoms of the disease. Seedlings were categorized into highly resistant, resistant, susceptible and highly susceptible cultivars on the basis of disease incidence. Tomato cultivars were screened for defense-related enzymes, total phenols and lignin contents. The temporal patterns of all these enzymes were estimated with a moderately susceptible tomato cultivar. Native PAGE analysis of both peroxidase (POX) and polyphenol oxidase (PPO) was carried out for the time course of enzyme activities and also by selecting three different tomato cultivars, following infection with the pathogen. Based on the inducible amounts of these enzymes upon pathogen infection, the tomato cultivars were correlated with the disease incidence under field conditions. A significant (P≤0.05) correlation was observed between the degree of host resistance and the enzyme levels. In highly resistant tomato cultivars the enzyme levels, total phenols and lignin contents were increased in comparison with highly susceptible tomato cultivars. Isoform analysis of POX and PPO enzymes indicated a clear difference between resistant and susceptible tomato cultivars in the number of isoforms and also in the intensity of each isoform in the presence of pathogen infection. The possible regulation of defense-related enzymes in imparting host resistance is discussed. http://www.phytoparasitica.org posting March 11, 2008.     

Mycorrhizal protection of chili plants challenged by <Emphasis Type="Italic">Phytophthora capsici</Emphasis>

Hydrogen peroxide (H₂O₂) has been implicated in many stress conditions. Control of H₂O₂ levels is complex and dissection of mechanisms generating and relieving H₂O₂ stress is difficult, particularly in intact plants. Here the role of the mycorrhizal inoculation in chili plants challenged with Phytophthora capsici was investigated to study the effect on hypersensitive response. In the treatment without mycorrhiza (treatment T3) and with mycorrhiza (considered treatment T4) visible disorders were detected two days after inoculation with P. capsici, but in the next days T3 plants rapidly developed 25% more necrotic lesions on the leaves than T4 plants. Leaf necrosis correlated with H₂O₂ accumulation and the greater damage observed in T3 plants coincided with larger accumulation of H₂O₂ after 12 h of inoculation accompanied with an increase in POX (peroxidase) and SOD (superoxide dismutase) activity. T4-infected and mycorrhizal plants exhibited an earlier accumulation of H₂O₂ starting 6 h after inoculation with lower levels compared to T3 plants. Correlated with observed damage, POX and SOD activity measured in T4 plants indirectly suggest a smaller accumulation of ROS (reactive oxygen species) leading to a decrease in the wounds observed and slightly diminishing the advance of the pathogen. According to these findings, we conclude that mycorrhizal colonization contributes significantly in maintaining the redox balance during oxidative stress, but the exact mechanism is still uncertain.     

豌豆蚜刺吸胁迫对不同苜蓿品种体内单宁含量及生理活性的影响

通过对甘农5号(G5)、甘农3号(G3)、金皇后(JH)和猎人河(Hu)4种不同抗蚜苜蓿(Medicago sativa L.)品种受豌豆蚜(Acyrthosiphon pisum)胁迫后其叶片内丙二醛(MDA)和单宁含量及防御性酶(超氧化物歧化酶(SOD)和过氧化物酶(POD))活性的动态变化研究,以期明确各项生理指标与抗虫性之间的关系。结果表明:在蚜虫刺吸诱导过程中,抗虫品种(G5)的MDA含量低于低抗品种(G3)和感虫品种(JH),抗虫品种和感虫品种的单宁含量高于低抗品种,感虫品种的SOD和POD活性低于抗虫品种和低抗品种,且所有品种的SOD和POD活性均表现先上升后下降的趋势,而MDA和单宁含量变化无规律。因此,MDA,SOD和POD活性的变化与苜蓿的抗蚜性密切相关,可作为苜蓿抗蚜性生理指标,而单宁与苜蓿抗蚜性的关系有待进一步研究。     

云南野生和逸生苜蓿资源POD和EST同工酶分析

为了摸清云南苜蓿(Medicago L.)资源的遗传多样性,采用聚丙烯酰胺凝胶不连续垂直板电泳系统,对30份云南野生和逸生苜蓿材料过氧化物酶(POD)和酯酶(EST)同工酶酶谱进行了分析。结果表明:供试材料的2种同工酶酶带数均为10条,多态位点百分数均达到100%。除二倍体材料外,其余材料均具有多条相同的共有谱带,有着丰富的多态性,但POD和EST酶谱存在明显差异;供试材料的POD和EST遗传距离均在0.00~1.00之间,其中1号、3号和4号二倍体苜蓿,与其他逸生材料遗传距离较大,亲缘关系较远;其余均为紫花苜蓿(M.sativa L.),POD和EST的遗传距离分别在0.00~0.56和0.00~0.33之间。采用类平均法(UPGMA)Nei氏距离进行聚类分析,表明30份供试材料亲缘关系的远近与地理分布呈一定的相关性。这将为云南苜蓿资源遗传关系的研究提供基础数据。