液质联用法分离鉴定甜叶菊叶片中的甜菊糖苷

为了进一步完善甜叶菊叶片中不同甜菊糖苷的测定方法,采用液质联用技术对多种甜菊糖苷标准品和‘鑫丰3号’甜叶菊叶片粗提物进行分析测定。最终共确定12种甜菊糖苷的出峰时间和顺序,其中甜茶苷、甜菊糖双苷和莱鲍迪苷E的出峰时间和顺序为首次确定。基于莱鲍迪苷A的测定标准曲线和多种甜菊糖苷的高效液相检测图谱结果确定‘鑫丰3号’叶片中的甜菊糖苷组成。‘鑫丰3号’叶片中共含有甜菊苷,莱鲍迪苷A、B、C、D、E和莱鲍迪苷F,甜茶苷,甜菊糖双苷9种甜菊糖苷,其中莱鲍迪苷D和E为痕量存在。本研究不仅为后续甜菊糖苷的测定提供了最全面的紫外检测图谱依据,同时也为新类型甜菊糖苷的发现和鉴定提供了方法参考。     

一个潜在催化莱鲍迪D苷合成的新型糖基转移酶

尿苷二磷酸糖基转移酶(uridine diphosphate glycosyltransferases,UGTs)催化糖基转移反应,与植物次生代谢密切相关。本研究根据甜叶菊(Stevia rebaudiana)转录组数据库,克隆到一个催化莱鲍迪D苷(rebaudioside D,RD)合成的新型糖基转移酶候选基因,对其开展生物信息学分析。结果表明,该基因开放阅读框长1380 bp,编码459个氨基酸,等电点(pI)预测为5.54,理论分子量约49.66 kD,系统发育分析表明该基因与向日葵中的UGT89A2同源,故将其命名为SrUGT89A2。构建pET28a-SrUGT89A2原核表达载体,并在大肠杆菌(BL21(DE3))中诱导表达得到重组蛋白,HPLC检测表明粗酶液能催化甜叶菊提取液形成一个新的色谱峰,该峰保留时间与莱鲍迪D苷一致。经进一步纯化UGT89A2蛋白,添加不同甜菊糖苷标准品为催化底物,但未鉴定出该蛋白催化的具体糖苷。该潜在催化甜菊糖RD苷合成的新型糖基转移酶基因SrUGT89A2的发现,为RD苷的生物合成和甜菊糖苷的生物途径研究提供新的理论依据。     

甜叶菊甜菊醇糖苷生物合成关键酶基因表达量与莱宝迪苷A含量的相关关系

莱宝迪苷A(rebaudioside,RA)是甜叶菊甜菊醇糖苷中的主要甜味成分,其含量受到生物合成中多个酶基因的影响。本研究以6个甜叶菊品种为材料,利用实时荧光定量RT-PCR测定RA生物合成途径中UGT85C2、UGT91D2m和UGT76G1三个关键酶基因的表达量,并与其RA含量进行相关性分析。结果显示UGT76G1基因相对表达量与RA含量有极显著相关关系(p=0.008),而UGT85C2和UGT91D2m基因表达量与RA含量无相关关系,说明UGT76G1基因的表达对RA合成有着较为重要的影响。研究结果可为利用基因工程手段人为调控甜菊醇糖苷的生物合成,提高RA的含量提供理论依据。     

高效液相色谱-蒸发光检测法测定木薯生氰糖苷的含量

为研究所收集木薯品种叶片中生氰糖苷含量的高低,笔者将所有品种茎杆按木薯正常种植方式扦插于试验地中,在收获季节前采集顶端倒数第2叶,通过HPLC测定各品种叶片中生氰糖苷的含量。结果表明,与国外所用木薯品种‘Mcol22’相比,在笔者所测试的木薯品种中,包括热区大面积推广的‘华南5号’(SC5)和‘华南8号’(SC8)中,大部分生氰糖苷含量都不高,其中‘Q10’生氰糖苷最低,每克鲜重只有11.3μmol,大约是最高含量‘Ecu81’的1/4。研究结果为筛选低生氰糖苷含量的木薯资源提供了一个参考。     

胶孢炭疽病菌对不同核桃品种的致病性测定

为确定胶孢炭疽病菌对核桃不同品种致病性的差异,给炭疽病的综合防治提供一定的理论依据,采用室内接种测定胶孢炭疽病菌(Gloeosporium fructigenum Berk)对12个品种的果实和14个品种的叶片的致病力。结果表明：（1）放置菌碟的方法接种较喷雾和直接挑菌丝发病早,扩展快,试验结果可靠,故选用放置菌碟的方法接种;（2）胶孢炭疽病菌对‘中林1号’、‘扎343’、‘晋丰’3个品种果实的致病性最强,病斑直径>10 mm,其次是‘中林5号’、‘辽核1号’、‘香玲’、‘鲁光’、‘京861’、‘金薄香1号’和‘辽核4号’,对‘丰辉’和‘绿波’的致病性最弱。（3）与果实相比,叶片发病早,接种后3天开始发病,其中‘丰辉’、‘辽核4号’和‘绿波’3个品种的叶片病斑最大,直径达20 mm左右,抗病性最好的是‘京861’、‘辽核1号’和‘辽核3号’3个品种,病斑直径在10 mm左右。     

红叶山茶(Camellia japonica)叶片色素含量与叶色参数的相关性分析

以3个红叶山茶品种‘红叶黑魔法’、‘黑魔法’和‘黑蛋石’为试验材料,分别测定叶片不同发育阶段叶绿素、类胡萝卜素、总花青苷含量及叶色参数L~*、a~*、b~*值,并通过相关性分析探讨叶色参数与叶片色素含量变化之间的关系。结果表明,首先,3个不同发育阶段叶片中叶绿素a、叶绿素b和类胡萝卜素含量呈上升趋势,不同品种同一发育阶段的色素含量相近。‘红叶黑魔法’和‘黑蛋石’叶片总花青苷含量在新叶展开10 d左右达到最大值,此后极显著下降,而‘黑魔法’叶片的花青苷含量则变化不大。其次,从色素比值来看,在新叶展开10 d时,花青苷的所占比值最大,‘红叶黑魔法’和‘黑蛋石’的花青苷比值分别达到87.88%和79.08%,极显著地高于叶绿素所占比值。到50 d时,花青苷比值下降至31.74%和23.68%,且3个品种花青苷含量相近,而叶绿素和类胡萝卜素比例则显著增加,这一结果较好地解释了这3个品种叶片的呈色变化,说明花青苷含量及其各种色素含量的比例变化是导致红叶山茶叶色变化的主要原因。最后,3个品种的a*值均与花青苷含量呈显著正相关,而与叶绿素a、叶绿素b、类胡萝卜素呈负相关,a~*值可作为描述红叶山茶品种叶色变化的代表性参数。     

瓠瓜类型砧木品种根系DNA提取方法比较及指纹图谱构建

为利用瓠瓜砧木根系提取DNA进行品种真实性分子检测,本研究比较了CTAB法(方法 1)、SDS简易法(方法 2)、SDS法(方法 3)、TPS法(方法 4)、快速制备法(方法 5)和简易快速制备法(方法 6)提取瓠瓜类型砧木根系基因组DNA的效果。研究结果表明,SDS简易法(方法 2)提取瓠瓜根系总DNA质量好,蛋白污染小,PCR扩增条带清晰稳定,满足瓠瓜根系DNA分子检测的要求。利用该法提取的‘甬砧1号’、‘甬砧3号’、‘甬砧4号’、‘甬砧5号’、‘神通力’和‘京欣砧1号’的根系DNA可重复上述6份瓠瓜材料幼叶DNA的指纹图谱结果(01001,10010,10101,01010,00110和00000)。新增加‘华欣948’、‘5756’、‘1715’和‘56YZ2’等4份瓠瓜砧木材料,通过根系DNA构建的指纹图谱分别是00110、01011、11000和01000。10份瓠瓜类型砧木品种根系DNA指纹图谱出现概率为1/13 500,图谱出现概率低,表明可以利用根系取代叶片提取DNA,用于构建指纹图谱进行品种鉴定与保护。     

不同基因型甜叶菊产量和甜菊糖苷含量研究

为了充分了解甜叶菊的生态适应性,为甘肃甜叶菊生产基地建设提供理论支持,从江苏、河北、安徽等地引进7个甜叶菊进行栽培比较试验,通过对参试基因型的生长特性、产量和甜叶菊糖苷含量分析结果表明：甜叶菊具有较强的适应性,在西北地区可以广泛种植;引进的ZS-4的干叶产量和茎杆产量都最高,达4801.50kg/hm2和5647.33 kg/hm2;ZS-3的莱苞迪苷A和总苷含量都高,分别为7.69％、12.39％,达极显著水平。综合分析得出,ZS-3甜叶菊糖苷产量最高,可以作为优势种在河西推广栽培,ZS-4也具有一定的推广价值。     

2种花色的薰衣草花色苷成分分析

为明确2种不同花色薰衣草间花色苷成分及含量差异性，探索薰衣草花色与花色苷的相关性。以‘新薰二号’（蓝花）和‘YXA-05’（白花）2种薰衣草花器官为研究材料，利用超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF/MS)联用技术测定2种薰衣草花器官中花色苷的成分及含量。结果表明，‘新薰二号’和‘YXA-05’2种薰衣草花冠中总花色苷含量分别为42.24μg/g和35.96μg/g，均含有6类花色苷，分别为矢车菊素、芍药花素、飞燕草素、矮牵牛素、锦葵素和天竺葵素。其中‘新薰二号’含有39种花色苷‘，YXA-05’含有37种花色素苷‘，新薰二号’含有6种‘YXA-05’中不存在的花色苷，而‘YXA-05’含有4种‘新薰二号’中不存在的花色苷。可见，2种薰衣草中花色苷的种类丰富，且成分及含量存在差异，薰衣草花冠的颜色与其花色素苷的成分和含量有关。     

高酸海棠苗木抗寒性生理指标的分析

为了研究高酸海棠栽种适宜区域,用高酸海棠新品种‘冰心1 号’、‘红勋1 号’与现有品种‘新苹1号’进行抗寒性比较,以枝条作为试验材料进行低温处理,并根据外渗电导法、脯氨酸及丙二醛(MDA)含量的变化,研究了各样品的抗寒性能。通过试验测定结果可判定3 个样本的相对电导率大小依次为‘新苹1 号’＞‘红勋1 号’＞‘冰心1 号’,脯氨酸含量由高到低的顺序依次为‘冰心1 号’＞‘红勋1 号’＞‘新苹1 号’,MDA含量大小的总体趋势依次为‘红勋1 号’＞‘新苹1 号’＞‘冰心1 号’。总体而言,‘冰心1号’的抗寒性最强,3 个品种的抗寒顺序依次为‘冰心1 号’＞‘红勋1 号’＞‘新苹1 号’。其中‘冰心1 号’与‘红勋1号’都具有较强的耐寒能力,适宜栽种于新疆天山以北及其他寒冷区域。     

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.     

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.     

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...     

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.     

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.