利用卡那霉素浸种法鉴定抗虫棉

卡那霉素浸种是一种简单、方便的转基因抗虫棉间接鉴定技术.本实验以不同浓度卡那霉素溶液、采用不同浸泡时间处理棉花种子,研究转基因抗虫棉与非转基因棉花在发芽率、根系生长、子叶颜色等生理指标方面的变化.结果表明,卡那霉素浓度为4000mg/kg时将棉花种子浸泡48h可有效筛选出转基因抗虫棉.     

转基因抗虫棉种子室内筛选

为了对转基因抗虫棉后代进行简单、快速、准确地鉴定和筛选,利用Bt-CryI Ab/Ac试纸条法、硫酸卡那霉素浸种法对转基因和非转基因棉花种子进行鉴定和筛选。结果表明：3种不同品牌的转基因试纸条检测结果完全一致,均能快速、准确地检测出转基因和非转基因棉花种子。利用5000mg/L的硫酸卡那霉素将棉花种子浸泡48h并持续培养10d,通过观察棉花种子的发芽率及侧根生长情况也可有效筛选出转基因抗虫棉,但此种方法较试纸条法检测周期长,而且存在试验误差,影响试验准确率。因此,转基因试纸条法是一种更为快速、简单、准确的鉴定和筛选转基因抗虫棉植株的方法。     

棉花氮素和SPAD值叶位分布规律研究

 在盆栽和大田氮肥试验的基础上,研究棉花氮素和叶绿素含量（SPAD值）随叶位的空间分布特征,并对不同叶位叶片的含氮率、SPAD值之间及其与总叶片含氮率和植株含氮率之间的相关性进行了分析。结果表明棉花不同叶位叶片含氮率、叶绿素含量、SPAD值均存在差异,增加施氮量能提高叶片含氮率、叶绿素含量和SPAD值,同时减小叶位间的差异;SPAD值对氮素的敏感性为倒4叶最高,倒2叶最低,而倒1、倒3叶的敏感性排序因品种不同而不同;蕾期、初花期和盛花期均以倒4叶与总叶片及植株含氮率相关系数最高;且适宜氮素水平下,初花期倒4叶SPAD值的变异系数最小。以某一特定叶片的SPAD值或以叶色差的大小来诊断棉花氮素营养状况时,倒4叶是较为理想的指示叶。     

基于高光谱的棉花叶片磷含量估测模型

研究不同施磷条件下棉花叶片叶绿素含量的变化规律,旨在建立基于高光谱的叶片磷含量估测模型,实现棉花叶片磷含量快速监测。在盆栽试验条件下,设置不同的磷肥量,测定棉花功能叶叶绿素含量与磷含量,并利用植被指数和叶绿素含量的相关性构建磷含量的光谱变量,从而实现利用高光谱对棉花叶片磷含量的定量监测。结果表明：(1)棉花播种后100天左右,叶片磷含量与叶绿素呈现显著关系(决定系数R²=0.96)。(2)利用多个植被指数(X)和叶绿素含量(I)的相关性构建倒一叶、倒二叶、倒三叶、倒四叶的磷含量光谱变量,其中各叶片相关性最优的模型：倒一叶(L₁)为I₁=2.6131X_RENDVI-0.4275,X_RENDV为红边归一化植被指数,R²=0.71,RMSE=0.2;倒二叶(L₂)为I₅=0.0142X_TVI+0.3274,X_TVI为三角植被指数,R²=0.76,RMSE...     

含NPTⅡ标记基因的转基因抗虫棉室内快速鉴定方法

通过试验研究,提出了3种室内快速筛选和鉴定含NPTⅡ标记基因的转基因抗虫棉的方法.一是待检测棉子去种皮,在含卡那霉素培养基培养,根据幼苗子叶颜色和棉苗状态来辨别是否是转基因材料,卡那霉素最适浓度为0.75 g·L-1;二是去皮种子培养在无卡那霉素的萌苗培养基上,在棉苗子叶上涂抹卡那霉素溶液进行鉴定,最适浓度为4.0 g·L-1;三是在待测棉苗子叶上打孔、滴加一定浓度的卡那霉素,根据打孔并滴加卡那霉素部位的叶片颜色变化,鉴别并统计转基因植株,其最适浓度为2.0 g·L-1.3种方法均可在卡那霉素处理后4～7 d内快速鉴定出转基因植株.同时,对转基因阳性植株进行PCR鉴定,结果表明3种卡那霉素方法鉴定的准确率均在90%以上.     

棉花叶片不同位点SPAD值与植株氮营养相关性研究

为了确定最能代表棉花氮素营养水平的叶片SPAD值测定位点,采用水培试验方法,设7个供氮水平,分3次测定棉花6片主叶（倒1叶至倒6叶）17个不同位点的SPAD值,对棉花不同叶位及同一叶片不同测定位点SPAD值与棉株氮素营养水平的相关关系进行研究。结果表明,倒4叶SPAD值与棉株地上部氮含量的相关性最好,相关系数为0.6524,达到了显著水平,可认定倒4叶为棉花的功能叶。而棉花倒4叶17个测定位点中,叶片上缘位置SPAD值与地上部氮含量的相关性较靠近叶柄的部位更好,其中S3位点即叶尖位置的相关系数最高,为0.4597,达极显著水平。可以初步确定棉花倒4叶叶尖位置为测定SPAD值以判断棉花氮素营养水平的最佳位点。     

3种筛选NPT-Ⅱ标记转基因油菜方法研究

利用卡那霉素溶液叶片涂抹法、种子浸泡法以及卡那霉素MS培养基筛选法三种方法对含有NPT-Ⅱ标记基因的转基因油菜种子（T0）进行筛选。结果表明,三种筛选方法的最佳卡那霉素选择压为200mg/L;涂抹叶片法4-5d可以明显识别植株对卡那霉素抗性与否,此法筛选到的4株植株PCR检测全部呈阳性,可靠性达100%;浸泡种子法2-3d可以明显识别植株对卡那霉素抗性与否,此法筛选到的5株植株PCR检测全部呈阳性,可靠性100%;MS培养基筛选法一般10d可以明显植株识别对卡那霉素抗性与否,此法筛选到20株植株,移栽后存活5株,PCR检测3株呈阳性,2株是假阳性植株,可靠性为60%。因此可以认为卡那霉素涂抹叶片和浸泡种子两种方法是转基因油菜进行大规模、快速的筛选及后代的遗传分析的理想方法。     

高品质转野生荠菜凝集素基因棉花的获得

利用花粉管通道转基因技术,将DE35S启动子驱动的野生荠菜凝集素(WSA)基因导入10个高品质棉花品种(系)。所使用的转基因表达载体还含有选择标记基因NPTⅡ(卡那霉素抗性基因)和Ω序列,以利于转基因植株的筛选以及WSA基因的高效表达。对转化当代3197棵棉苗的检测结果表明,4.88%植株具有卡那霉素抗性(Kan )。根据野生荠菜凝集素基因序列设计一对特异性引物,对156个Kan 植株进行PCR检测,筛选出45个转WSA基因棉花工程植株。45个株系纤维品质测定结果表明,获得了9个高品质转WSA基因棉花株系。并对植物基因工程研究中以NPTⅡ作为标记基因的局限性以及一些转WSA基因棉花株系纤维强度变劣的原因进行了探讨。     

卡那霉素浸种筛选转基因棉花的初步研究

转基因技术已经被广泛应用于作物的抗虫、抗病及高品质等的改良育种 ,而且转基因植株的鉴定方法也有多种 ,其中带有NPTⅡ标记基因的转基因后代材料的大田筛选 ,主要是在苗期 ,利用卡那霉素溶液 (Kanamycin)点涂植株幼叶 ,以幼叶的变黄与否来确定。为防止漏点漏涂 ,出现假阳性植株 ,须在花铃期以前对材料点涂 2～ 3次 ,因此从大量的转基因材料中筛选转基因植株 ,工作量相当大。本研究的目的是试图筛选出适当的卡那霉素浓度 ,通过浸种以快速地鉴定出转基因植株。1　材料和方法1.1　供试材料转基因抗虫棉新棉 33B、非抗虫棉豫棉 11号和转基因…     

通过转CaM基因提高了棉花抗寒性

为了获得耐低温棉花新材料,通过花粉管通道法获得了转CaM基因棉花,经过分子检测得到了3个转基因株系。同时对得到的转基因株系的T4代(C1、C2、C3)和棉花受体(CK)在低温处理后的相关生理生化指标进行了初步测定。发现在低温(4℃)处理24 h后,C1、C2、C3叶片中的丙二醛(MDA)含量明显低于对照,超氧化物歧化酶(SOD)、过氧化物酶(POD)的活力、可溶性糖的含量明显高于对照,而常温下(23℃)测定值没有明显的差异。表明转CaM基因棉花在低温时能够通过减轻叶片膜脂过氧化程度,提高抗氧化酶活力等反应来缓解低温对棉花叶片的损伤。本研究筛选出了3个具有一定抗寒能力的转基因株系,为下一步选育抗寒新品种奠定了基础,也为其他棉花抗寒转基因技术提供了理论依据。     

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...     

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.     

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.     

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.