曲酸对甜菜种子萌发的影响

为了研究不同浓度曲酸（Kojic acid）对甜菜种子引发效果,为甜菜种子包衣剂物料筛选提供依据。以‘TD801’甜菜种子为试验材料,设置曲酸100、300、500 mg/L三种不同浓度和8、16、24 h三个时间梯度共9个处理（未引发干种子为对照）,对甜菜种子进行浸泡、回干发芽培养试验,测定其发芽势、发芽率、发芽指数、活力指数以及相对电导率。结果表明,9个处理在提高甜菜种子发芽势、发芽率、发芽指数、活力指数等方面,均有明显效果。经过处理的甜菜种子,其发芽势比对照提高5.67～10.67个百分点;发芽率比对照提高5.66～9.33个百分点;发芽指数比对照提高30.67%～64.45%;活力指数比对照提高33.13%～99.02%;相对电导率相比对照降低126.50～145.70个百分点。浓度为500 mg/L,时间为16 h对发芽势和发芽率效果最好;浓度为300 mg/L,时间为24 h对发芽指数和活力指数效果最好;浓度为100 mg/L,时间为16 h对相对电导率效果最好。总体而言,浓度为500 mg/L,时间为16 h曲酸溶液对甜菜种子引发效果最好。     

不同浓度NaCl对甜菜生长的影响

研究了营养液中不同盐度(2～280mmol/L)对甜菜生长状况的影响,结果表明,NaCl浓度低于10mmol/L,对甜菜的各生长指标没有明显影响;而NaCl浓度在50mmol/L左右比较适合甜菜生长;超过100mmol/L的高浓度NaCl对甜菜的生长有胁迫作用,浓度越高胁迫作用越强。营养液中盐浓度在280mmol/L以内对甜菜光合作用影响不显著。     

甜菜SSR-PCR反应体系的优化

为了建立适宜甜菜的SSR反应体系,笔者以甜菜不育系TB005A为试验材料,研究了甜菜SSR技术中PCR反应体系的主要成分对SSR扩增结果的影响。对SSR反应体系中的DNA模板浓度、引物浓度、Taq聚合酶浓度、dNTPs浓度以及退火温度进行了探索,确立了适合甜菜的SSR反应体系为;在20μL反应体系中,模板DNA为60ng,引物（50ng／μL）1．2μL,Taq DNA聚合酶1．0U,dNTPs（2、5mM／L）0．6μL。并利用该反应体系对30个甜菜不同品系进行SSR反应,用6％的变性聚丙烯酰胺凝胶电泳检测,不同品系间DNA谱带多态性丰富,证实该体系稳定可靠。     

甜菜SRAP-PCR反应体系的优化

为了建立适宜甜菜的SRAP反应体系,以40个不同类型的甜菜品系为试验材料,研究了PCR反应体系的主要成分对SRAP扩增结果的影响。对SRAP反应体系中的DNA模板浓度、Taq DNA聚合酶浓度、引物浓度以及dNTP浓度进行了探索,确立了适合甜菜的SRAP反应体系为:在20μL反应体系中,模板DNA为40ng,Taq DNA聚合酶1.0U,引物60ng,dNTP(2.5mmol/L)为1.6μL,扩增程序为94℃预变性3min,反应前5个循环在94℃1min,35℃1min,72℃1min的条件下运行;随后的35个循环复性温度提高到50℃,最后72℃延伸10min。并利用该反应体系对甜菜40个不同品系进行SRAP反应,用6%的变性聚丙烯酰胺凝胶电泳检测,不同品系间DNA谱带多态性丰富,证实该体系稳定可靠,可以用于甜菜的分子标记研究。     

氯化钠胁迫下甜菜不同品种(系)种子发芽率和幼苗生长的差异

研究了不同浓度的氯化钠胁迫下甜菜不同品种(系)种子发芽率和营养液培养幼苗生长的差异。以相对发芽率和幼苗干物质量来判断甜菜不同品种的相对耐盐能力,氯化钠胁迫适宜浓度为280mmol/L。甜菜不同品种(系)幼苗相对生长量和种子相对发芽率均存在较大差异,且两者相关性达到显著水平。用种子相对发芽率评价甜菜耐盐能力应统一种子繁育年份;通过营养液培养法用幼苗相对生长量评价甜菜耐盐能力准确可靠。采用上述方法,初步筛选出耐盐较强、中间型和盐敏感品种(系)各10余份。     

NaCl和KCl胁迫对甜菜幼苗生长的影响

以甜菜品种HI0466为供试材料,通过水培试验,研究NaCl和KCl胁迫(0mmol/L(CK)、NaCl和KCl分别为100 mmol/L、200 mmol/L、280 mmol/L 7个处理)对甜菜幼苗生物量、叶面积及叶绿素含量的影响。结果表明:低浓度NaCl和KCl胁迫对甜菜幼苗生长、叶面积就产生一定的抑制作用,随着胁迫浓度的增加,对甜菜幼苗生长和叶片膨大抑制更加严重,并且高浓度KCl胁迫导致甜菜幼苗33.3%的致死率,对甜菜根系伤害和叶面积降低亦甚为严重。低浓度NaCl和KCl以及中浓度NaCl胁迫未影响甜菜幼苗叶片叶绿素的含量;中浓度KCl胁迫已经明显降低叶绿素含量;高浓度NaCl和KCl胁迫均显著降低甜菜幼苗叶片叶绿素含量,KCl胁迫甚为严重。因此,随着NaCl和KCl胁迫浓度的升高,甜菜幼苗生长抑制作用不断加重,中高浓度胁迫下KCl比NaCl盐害更重。     

水杨酸浸种对甜菜丛根病防御酶系的诱导作用

用不同浓度的水杨酸（salicylic Acid，sA）对甜菜抗（耐）、感丛根病品种进行浸种处理，研究了SA对丛根病地甜菜防御酶系活性的影响。结果表明，浸种处理的甜菜叶片中过氧化物酶（POD）、多酚氧化酶（PPO）、苯丙氨酸解氨酶（PAL）活性较对照均有所提高，病情指数下降，根产量、舍糖率和产糖量都有所增加．不同的SA处理浓度相比较，抗（耐）病品种适宜浓度为3mmol／L，感病品种适宜浓度为5mmol／L．     

GA3对不同磨光量甜菜种子萌发的影响

【目的】在甜菜种子加工过程中,通常需要磨光和浸种。为探究磨光量、GA₃浓度、浸种时间对甜菜种子萌发的影响。【方法】设置了5个磨光量、5个GA₃浓度、3个浸种时间,对甜菜种子进行引发试验。【结果】结果表明,100 mg/L GA₃浸种8 h,大(B)、中(M)种子的发芽势较其0 mg/L GA₃处理分别提高6.59%、10.04%,发芽率分别提高6.19%、9.56%;GA₃浓度为100 mg/L和200 mg/L时,B、M种子平均发芽时间较低,GA₃可加速种子萌发;100 mg/L GA₃浸种8 h,种子的发芽势、发芽率、发芽指数分别比其0 h处理提高10.48%、5.51%、88.12%,其发芽率显著高于16 h处理(P<0.05)。GA₃浓度和种子磨光、浸种时间和种子磨光量双因素方差分析表明,两因素交互显著影响种子主要萌发指标。【结论】100 mg/L GA₃浸种8 h,对较大粒径...     

钙营养对甜菜幼苗耐盐性的影响

为了研究钙营养对甜菜幼苗耐盐性的影响,以甜菜品种'KWS1176'为材料,通过水培,在不同浓度盐(3、280 mmol/L NaCl)处理下,施用不同浓度的钙营养(0.3、1.5、3.5、7.5 mmol/L),培养18 d后测定其对甜菜幼苗形态、生理生化等指标的影响.结果表明:(1)在3 mmol/L NaCl浓度下...     

不同盐离子胁迫对翅碱蓬幼苗的甜菜红素影响

[目的]通过对不同浓度的盐离子胁迫处理,检测翅碱蓬幼苗中甜菜红素的变化,对翅碱蓬的生理机制进行初步研究。[方法]通过对翅碱蓬幼苗使用不同浓度的盐离子胁迫处理,利用紫外-可见光分光光度计于538 nm测定吸光度,检测翅碱蓬幼苗中甜菜红素含量的变化。[结果]翅碱蓬幼苗在CaCl₂浓度为10 mmol/L时,甜菜红素含量达到最高(12.1 mg/(g·FW),但随着CaCl₂浓度进一步增加甜菜红素含量减少;翅碱蓬幼苗随着NaCl浓度的增加甜菜红素含量也逐步增加,当浓度达到300 mmol/L时,甜菜红素含量达到11.3 mg/(g·FW);Mg Cl₂、KCl随着不同浓度变化,甜菜红素都没有超过对照组。适量的CaCl₂、NaCl盐离子胁迫有利于甜菜红素含量的增长,而Mg Cl₂、KCl抑制翅碱蓬幼苗中甜菜红素的生成。[结论]可为研究翅碱蓬幼苗中甜菜红素生理合成机理提供参考。     

金龟子绿僵菌菌株培养基的改良

采用液体振荡与固体平板双培养的方法,对金龟子绿僵菌MA4,MAIml两菌株的培养基进行改良.研究结果表明:MA4,MAIml菌株的最适复合碳源均为玉米粉、最适氮源为蛋白胨、最适碳氮比为4:1(m:m,下同)、碳浓度分别为0.5,1.0mol/L,即改PPDA培养基为:MA4菌株以11.8g/L的玉米粉代替蔗糖,17.1g/L的酵母浸膏代替蛋白胨;而MAlml菌株的则以23.6g/L的玉米粉代替蔗糖,蛋白胨由10.0g/L更换为16.2g/L.     

沟叶结缕草遗传转化体系的建立

为构建有效的沟叶结缕草遗传转化体系,以沟叶结缕草愈伤组织为受体材料,通过农杆菌介导法将笔者单位克隆的耐盐相关基因ZmPDI基因转入野生型植株中,研究共培养时间、侵染液浓度、侵染时间和抗生素浓度等因子对转化效率的影响。结果表明：最佳遗传转化体系为菌株OD₆₀₀值为0.4,侵染30 min,共培养3 d后进行选择培养。特美汀在选择培养阶段最适抑菌浓度为250 mg/L,潮霉素愈伤组织筛选的最适选择压力为40 mg/L,苗筛的最适浓度为15 mg/L。通过GUS活性的组织化学分析和PCR鉴定,显示目的基因已成功转入沟叶结缕草基因组中。     

A Reexamination of the Effectiveness of Ribavirin on Eradication of Viruses in Potato Plantlets in vitro Using ELISA and Quantitative RT-PCR

The potato plantlets singly infected by PVA, PLRV, PVS, PVX and PVY and mix-infected by PVM, PVS and PVY were cultured on MS medium with different concentration of ribavirin. The effects of ribavirin on growth of the plantlets and efficiency of virus elimination were investigated. Results showed that the plant height and fresh weight obviously decreased with increase of ribavirin concentration from 0 mg/L to 150 mg/L, and most of the plantlets could not survive when the concentration reached 200 mg/L. According to the ELISA tests, ribavirin was more efficient for eradicating PVA, PVM, PVS and PVX than PVY and PLRV, and healthy plantlets could be obtained with high frequency (up to 100 %) by culturing with 75?~?150 mg/L ribavirin after 2?~?3 subcultures. Whereas, only 33?~?66 % PVY and PLRV infected plantlets were found to be virus-free after 3 subcultures with 75?~?150 mg/L ribavirin. The results of quantitative RT-PCR (qPCR) indicated that ribavirin could obviously reduce virus content in the plantlets. Except PLRV was detected positive after 3 subcultures with ribavirin, the healthy seedlings were obtained from infected stocks at the first or end of propagation and no viruses could be detected at the post-eradication stage. No apparent difference of genetic variation resulted from ribavirin treatment was found by SSR analysis between the control and the treated plantlets. All of these results above proved that ribavirin treatment in vitro was an effective method to eliminate viruses in the propagation of potato.     

A survey of ryegrass swards for the presence of fungal pathogens in relation to management

Surveys of perennial and Italian ryegrass swards (Lolium perenne L. and L. multiflorum Lam.) at regular intervals in 1977 and 1978 in Berkshire, Wales and Devon confirmed that leaf infection by Drechslera spp. was the most frequently occurring foliar fungal disease. Rhynchosporium spp. and Puccinia coronata Corda were also recorded but in contrast to Drechslera spp., which caused damage throughout the year, attacks by these two fungi were only sporadic.
The incidence of Drechslera was greater in 1977 than in 1978 and was greater in Berkshire where most fields were infected in both years than in Wales and Devon. Both perennial and Italian ryegrasses were infected. The number of leaves damaged increased with leaf age. Damage was greater on fields managed for conservation than those which were grazed. Infection increased from February onwards and was greatest in autumn. It is concluded that Drechslera might be controlled by removing infected herbage in autumn by cutting.
Rhynchosporium spp. were prevalent only in Berkshire and more Italian ryegrass fields ( ca , 50%) were infected than perennial ryegrass fields ( ca , 10%). Infection was confined to the period March to May. This pathogen caused more leaf area damage than Drechslera .
Puccinia coronata occurred only once in Devon and Wales. In Berkshire incidence was confined to 1978 and was common from September to November, when 60–70% of both Italian and perennial ryegrass fields were infected. Some difference between perennial ryegrass cultivars was observed.     

Plant-to-plant transmission of the bacterial ring rot pathogenClavibacter michiganensis subsp.sepedonicus

Summary Plant-to-plant transmission of the bacterial ring rot (BRR) pathogen,Clavibacter michiganensis subsp.sepedonicus (Spieck. et Kott.) Skapt. et Burkh. of potato (Solanum tuberosum L.), was studied in field trials over a three year period. Healthy and infected seed tubers were planted 35 cm apart. In one treatment, a subsurface barrier was placed between the healthy and infected seed tubers separating the root systems of neighbouring plants. In this treatment, none of 216 plants grown from healthy seed tubers was infected at harvest, as determined by indirect immunofluorescence antibody staining (IFAS) with monoclonal antibodies. In the other treatment, no subsurface barrier was used. In this treatment, two of 368 plants (0.5%) grown from healthy seed tubers were infected at harvest. It is concluded that plant-to-plant transmission may occur but at very low frequency, and is unlikely to play a significant role compared with the potential of transmission by shared potato handling equipment.     

Relationship between leaf injury and colonization of cabbage by Sclerotinia sclerotiorum

Mechanical and insect feeding injuries of cabbage provided sites for ingress by Sclerotinia sclerotiorum. In field studies, injuries sustained by hitting cabbage heads with a blunt object penetrated several leaf layers and were readily infected by S. sclerotiorum. Incidence of Sclerotinia rot ranged from 15 to 36% infected plants in the hitting treatment. Disease incidence was low (0–5%) when wounds were created by allowing lepidopterous larvae (the imported cabbageworm, Pieris rapae L., the diamondback moth, Plutella xylostella L., and the cabbage looper, Trichoplusia ni Hubner) to feed on cabbage leaves. The incidence of colonization of lepidopterous larvae feeding sites by S. sclerotiorum was greater in greenhouse studies (5–60% infected feeding sites) than in field studies. In greenhouse studies, disease incidence was significantly greater in plants receiving hitting injuries than tearing injuries. There was little evidence of inoculation day or injury day effects. Colonization frequency of tissue injured mechanically was similar whether wounds were inoculated immediately or 4 days later. Plants that were incubated in a dry environment developed fewer infections than plants held in a moist environment. Inoculated plants that were not injured did not develop disease.     

Nodulation and root growth of forage legumes sown into tall fescue swards

Establishing forage legumes into endophyte‐infected tall fescue (Festuca arundinacae Schreb.) pastures is problematic, especially in well‐established stands. A oversowing field experiment determined if this problem was because of poor nodulation. Four renovation techniques, clipped sward (treatment A), herbicided + rye seeding in the previous autumn (treatment B), herbicided in the autumn and spring (treatment C) and herbicided to suppress the sward (treatment D), were investigated to determine their effect on nodulation and root growth of lucerne (Medicago sativa L.), red clover (Trifolium pratense L.) and white clover (T. repens L.) at 16, 22 and 29 d after sowing the legumes. A pot experiment was also conducted under optimal growth conditions and using the same soil to determine the nodulation and root growth potentials of these legume species. At adequate rhizobial populations (>6 × 10⁴ cfu g^?1 soil), substantial nodulation of all species occurred by 29 d after sowing in treatments C and D, whereas nodulation of clovers was usually reduced in treatment A. Total root lengths for all sampling dates, species and treatments were severely restricted, especially under treatment A. A general correspondence of nodulation with root growth was observed for all species, with high correlations (r ≥ 0·85) between these variables for all legume species and treatments, suggesting that soil moisture, and possibly competition for light, were the limiting factors. These results demonstrate that weak stands of forage legumes, typically found when sown into tall fescue swards, are probably not because of inadequate nodulation. Rather, inhibition of root growth by detrimental physical/chemical conditions or allocation of limited photosynthate to shoots instead of roots is suggested.     

The effect of metribuzin interaction with potato viruses X and Y on potato foliage,yield and grade

Foliar treatment of potato (Solanum tuberosum L.) with metribuzin at 0.57–1.0 lb/A caused a necrotic reaction in leaflets of plants infected with potato virus Y (PVY), but not in plants infected with potato virus X (PVX) or potato leafroll virus. Necrosis symptoms resulting from metribuzin-PVY interaction were distinct from symptoms of either PVY infection or of metribuzin injury. This reaction was similar in the Russet Burbank, Lemhi Russet, and Pioneer cultivars. Russet Burbank infected with PVY and PVX, alone or in combination, was treated with metribuzin to study herbicidevirus interaction effects on yield. Secondary PVY infection alone caused a 57% yield reduction, and when combined with PVX caused a 71% yield reduction. Although leaflet necrosis was induced by the metribuzin-PVY combination, there was no significant yield interaction. Results suggest that post-emergence application of metribuzin can be used as an aid for detecting and removing potato virus Y infected plants from potato seed fields     

地被银桦试管苗增殖培养研究

地被银桦是杂交品种，无性繁殖对保持地被银桦的品种特性至关重要。本研究以组织培养为繁殖方法，从激素的浓度、种类、大量元素及糖等方面对地被银桦的增殖培养进行了系统的研究。结果表明，6-BA的浓度对增殖苗的高度有显著影响，6-BA和IBA对试管苗的玻璃化比例均有显著影响，NH4NO3和KH2PO4的浓度也显著影响增殖苗的高度。最适增殖培养基配方为：改良MS培养基(NH4NO3 412.5 mg/L ，KH2PO4 85 mg/L)＋6-BA 0.3 mg/L＋IBA 0.1 mg/L＋糖35 g/L。