低温胁迫转CBF3基因烟草生理生化响应

为研究低温胁迫对转基因烟草的影响,进行了转CBF3基因烟草幼苗及对照(未转基因烟草)在15℃和4℃低温胁迫8h试验,结果表明:可溶性糖、可溶性蛋白、游离脯氨酸、丙二醛(MDA)含量以及过氧化物酶(POD)和超氧化物歧化酶(SOD)活性均增加,在4℃低温下比15℃下的增加幅度大,转基因烟草的可溶性糖、可溶性蛋白、游离脯氨酸、MDA含量以及POD、SOD活性与对照存在极显著差异(P0.01)。说明转基因烟草幼苗获得了一定的抗寒能力。     

低温胁迫对枇杷生理特性及抗寒相关基因差异表达的影响

研究低温胁迫下2个枇杷幼果种胚生理指标变化及抗寒相关EjICE1基因的表达规律,为枇杷抗寒新材料的筛选及枇杷抗寒分子机理的解析提供理论依据。以洞庭枇杷（黄肉,DT）及洞庭枇杷突变型（白肉,DTM）挂果容器苗为材料,研究人工模拟低温对枇杷相对电导率(REC)、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性及EjICE1基因的表达规律的影响。结果表明,低温胁迫下2个枇杷幼果种胚相对电导率REC均呈“S”型曲线变化,Logistic方程显示,洞庭枇杷和突变型(DTM)半致死温度LT50分别为-4.759、-2.811℃,突变型（白肉,DTM）幼果的抗寒能力强于洞庭枇杷;2个枇杷的SOD、POD及CAT活性及洞庭枇杷(DT)的MDA含量均呈现出先升后降的变化趋势,但达到最大阈值的时间点不同,而突变型(DTM)MDA含量则呈现缓慢上升趋势,洞庭枇杷SOD在1℃达到最大阈值,丙二醛(MDA)含量、POD及CAT活性在-1℃达到最大阈值;突变型(DTM)SOD、POD及CAT活性在-3℃达到最大阈值,丙二醛(MDA)含量则在-5℃达到最大阈值。...     

套袋对鸭梨采后生理及贮藏品质的影响

以鸭梨为试材,研究了田间套袋对常温(25±2)℃下鸭梨果实呼吸速率和乙烯释放速率以及果实低温(0±0.5)℃贮藏品质的影响。结果表明,套袋并未推迟或提前常温下鸭梨果实的呼吸高峰和乙烯释放高峰,但套袋鸭梨的呼吸高峰低于未套袋鸭梨,而乙烯释放高峰无明显差别。采摘时,套袋鸭梨较未套袋鸭梨果实硬度大、可滴定酸含量高,VC含量低;随着贮藏时间的延长,套袋和未套袋鸭梨果实硬度均有所下降,但套袋鸭梨果实硬度下降更为迅速;可溶性固形物含量(SSC)在贮藏过程中整体上升,贮藏后期(210 d)套袋鸭梨果实SSC显著高于未套袋果实(P0.05),而之前两者无显著差异;套袋鸭梨果实TA含量较未套袋鸭梨下降更为迅速;贮藏初期套装鸭梨果实VC含量较低,但在贮藏后期这种差别已不明显;套袋鸭梨果心褐变指数较低,未套袋鸭梨果心总酚含量高且下降更为迅速,其PPO活性显著高于套袋鸭梨(P0.05),相关性分析表明鸭梨果心褐变指数与PPO活性呈极显著正相关(P0.01),说明套袋处理对抑制鸭梨贮藏期间果心褐变具有显著效果。     

枇杷EjICE1基因的克隆及其在低温胁迫下的表达分析

本研究以‘大五星’枇杷(Eriobotrya japonica Lindl.)为材料,采用RT-PCR与RACE法从枇杷中分离了EjICE1基因。该基因cDNA序列全长2 134 bp,具有一个1 623 bp长的开放阅读框,编码540个氨基酸,含MYC型bHLH结构域。同源性分析表明,枇杷ICE1蛋白与其他植物ICE1蛋白具有很高的相似性,与苹果(Malus domestica)相似性高达97%。进化树分析表明,枇杷与苹果聚在一起,与苹果进化关系最近。低温胁迫处理枇杷幼果,丙二醛含量呈上升趋势,游离脯氨酸含量呈先上升后下降趋势,表明枇杷幼果膜脂过氧化程度加剧,其抵御能力存在最大阈值。qRT-PCR分析发现,低温胁迫下EjICE1基因表达量明显增加,表明低温胁迫影响枇杷EjICE1基因表达,本研究为培育抗逆性强的优质品种提供了理论依据。     

套袋对桃果皮生理生化指标的影响

摘 要：【研究目的】晚熟桃套袋是生产上常用技术,本研究通过对套袋后桃果实果皮生理生化指标的测定,为桃桃袋研究提供参考。【方法】以晚熟桃品种‘晚西菲’为试验材料,在幼果期对桃果实进行套袋处理,成熟期采收时测定桃果实果皮的可溶性糖、电导率、SOD、POD等生理生化指标。【结果】套袋处理后果皮的电导率、脯氨酸及可溶性糖含量有所降低;可溶性蛋白、丙二醛含量、超氧化物歧化酶（SOD）、过氧化物酶(POD)活性均有所增高。【结论】套袋环境对于晚西非桃果实发育是有利环境。     

套袋对苹果果实表皮组织抗氧化特性的影响

树冠不同方位果实由于所处的微域环境不同,抗氧化特性有很大差异.生长季晴天,无论套袋与否,均以树冠西南面果实氧化胁迫程度最重.其中,O2-含量相当于树冠其他方位1.23～1.37倍; MDA含量相当于树冠其他方位1.32～1.75倍; SOD活性相当于树冠其他方位1.40～1.69倍.一般情况下,套袋后致使果实经受的环境胁迫程度加大,因而果皮组织中O2-和MDA含量以及SOD活性都高于不套袋处理.由于套袋果实长期经受高温、弱光微域环境的驯化,除袋后果实对外界环境条件的剧烈变化较为敏感.表现为果皮组织O2-含量增加,SOD活性明显提高,表明果实中迅速启动了环境胁迫下的应急反应.     

套袋对苹果果实表皮组织抗氧化特性的影响

树冠不同方位果实由于所处的微域环境不同,抗氧化特性有很大差异。生长季晴天,无论套袋与否,均以树冠西南面果实氧化胁迫程度最重。其中,O2^-含量相当于树冠其他方位1．23～1．37倍;MDA含量相当于树冠其他方位1．32～1．75倍;SOD活性相当于树冠其他方位1．40～1．69倍。一般情况下,套袋后致使果实经受的环境胁迫程度加大,因而果皮组织中O2^-和MDA含量以及SOD活性都高于不套袋处理。由于套袋果实长期经受高温、弱光微域环境的驯化,除袋后果实对外界环境条件的剧烈变化较为敏感。表现为果皮组织O2^-含量增加,SOD活性明显提高,表明果实中迅速启动了环境胁迫下的应急反应。     

套袋对苹果果实表皮组织抗氧化特性的影响

树冠不同方位果实由于所处的微域环境不同,抗氧化特性有很大差异。生长季晴天,无论套袋与否,均以树冠西南面果实氧化胁迫程度最重。其中,O2^-·含量相当于树冠其他方位1.23-1.37倍;MDA含量相当于树冠其他方位1.32-1.75倍;SOD活性相当于树冠其他方位1.40-1.69倍。一般情况下,套袋后致使果实经受的环境胁迫程度加大,因而果皮组织中O2^-·和MDA含量以及SOD活性都高于不套袋处理。由于套袋果实长期经受高温、弱光微域环境的驯化,除袋后果实对外界环境条件的剧烈变化较为敏感。表现为果皮组织O2^-·含量增加,SOD活性明显提高,表明果实中迅速启动了环境胁迫下的应急反应。     

夜间低温对栽培和野生番茄果实抗逆性的影响

以低温敏感性栽培番茄Money Maker和耐低温性野生番茄LA1777为试材,研究了夜间15,9,6℃及其恢复处理对番茄果实中抗逆生理指标的影响。结果表明,夜间低温胁迫后,LA1777和Money Maker中可溶性糖和脯氨酸含量急剧增加,过氧化物酶(POD)活性上升,特别是前者;LA1777中超氧化物歧化酶(SOD)活性低于对照,过氧化氢酶(CAT)活性高于对照,而Money Maker中变化与之相反;Money Maker中丙二醛(MDA)含量增加,显著高于对照,而LA1777差异不显著。说明2种番茄通过提高脯氨酸含量来调节渗透势响应低温,耐低温性番茄通过提高POD和CAT的活性来提高抗低温能力,而低温敏感性番茄通过提高SOD的活性来适应低温;耐低温的番茄受伤害程度较低。     

低温胁迫对偃麦草与高羊茅抗性生理生化指标的影响

通过偃麦草与高羊茅在20~5℃范围内不同降温处理试验,测定叶片相对电导率、丙二醛含量、超氧化物歧化酶活性和游离脯氨酸含量4个生理指标在1~9d内的动态变化。结果表明,地上部分在低温处理过程中丙二醛积累量偃麦草略高于高羊茅,相对电导率、超氧化物岐化酶活性和脯氨酸积累量的变化,均显示偃麦草对零上低温的抵御能力远高于高羊茅。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.