萌芽期玉米自交系耐苏打碱的等级评价

为研究苏打碱胁迫对不同玉米自交系种子萌发特性的影响,以实验室前期获得的玉米萌芽期苏打碱筛选浓度(170mmol/L)对120份玉米自交系进行碱胁迫下发芽试验,测定各自交系种子的发芽率、发芽势、发芽指数,并计算相对发芽率、相对发芽势、相对发芽指数,利用隶属函数法对玉米自交系耐碱性进行评价。结果表明,120份玉米自交系被分为高耐、耐、中等、敏感和高感5个等级,其中H旅28和春油30-1属于高耐自交系,JN 45、东156等4个自交系为耐碱性,龙98、叶单4等99个自交系对碱胁迫表现高敏感。该实验结果可为培育耐碱性玉米新品种提供种质资源。     

不同钠盐胁迫对苜蓿种子萌发的影响

研究了3种钠盐(中性盐NaCl及碱性盐NaHCO_3、Na_2CO_3)不同浓度处理对中苜一号紫花苜蓿的发芽率、发芽势、发芽指数、活力指数、胚芽长、胚根长以及根芽比的影响.结果表明:当NaCl浓度≤150 mmol/L、NaHCO_3≤20mmol/L、Na_2CO_3≤10mmol/L,苜蓿种子的发芽率、发芽势、发芽指数与对照无显著差异,仍可正常萌发.超过这一浓度,苜蓿种子发芽率、发芽势、发芽指数显著下降(P<0.05).当NaCl浓度≥300 mmol/L、NaHCO_3≥50 mmol/L、Na_2CO_3 ≥20 mmoL/L,苜蓿种子完全丧失活力.发芽期间,钠盐通过抑制胚根的生长(抑制作用胚根>胚芽),从而影响苜蓿种子芽的生长.根芽比随着浓度的增加呈下降的趋势.     

盐碱胁迫对白榆种子萌发和幼苗生长的影响

以常见的园林绿化树种白榆(Ulmus pumila L.)种子为材料,利用浓度分别为0,100,200mmol/L的中性盐NaCl和浓度分别为0,25,50mmol/L的碱性盐Na_2CO_3混合模拟出9种不同的盐碱胁迫处理,研究不同处理对白榆种子萌发率及幼苗生长的影响效应。结果表明:低盐(100mmol/L NaCl)处理对白榆种子萌发没有抑制效应,但高盐(200mmol/L NaCl)处理对白榆种子萌发有显著的抑制作用,表现为发芽率、发芽势、发芽指数、活力指数均显著降低;低碱(25mmol/L Na_2CO_3)处理对白榆种子萌发抑制作用不显著,但高碱(50mmol/L Na_2CO_3)处理抑制效果显著,且抑制效果显著强于高盐处理,白榆种子几乎不发芽。复合盐碱胁迫处理下,低盐低碱和高盐低碱复合胁迫对种子萌发率抑制效果不显著,但对幼苗生长抑制效果显著,表现为胚芽、胚根数量和长度减少;低盐高碱和高盐高碱混合胁迫对种子萌发率抑制效果显著,特别是高盐高碱混合胁迫下,种子几乎不发芽,发芽后的胚芽和胚根几乎不生长。     

碱胁迫对结缕草、高羊茅种子萌发及其胚生长的影响

用NaHCO3和Na2CO3两种碱性盐以9∶1的摩尔比配制浓度分别为30、60、90、120 mmol/L的混合盐溶液作为碱胁迫处理液,对结缕草和高羊茅种子进行碱胁迫发芽试验。结果表明,在碱胁迫下,结缕草和高羊茅种子的发芽率、发芽势、发芽指数以及胚芽长和胚根长均随着碱胁迫浓度的升高而呈降低趋势,碱浓度达到90 mmol/L和120 mmol/L时,相应的结缕草和高羊茅种子均未萌发;结缕草和高羊茅种子萌发耐碱性的临界值分别为30 mmol/L和60 mmol/L;高羊茅种子萌发的耐碱性强于结缕草。     

不同钠盐胁迫对松柳种子萌发及幼苗生长的影响

为了研究不同钠盐胁迫对松柳种子萌发及幼苗生长影响,采用0~400 mmol/L的NaCl、0~100 mmol/L的Na2CO3和0~100 mmol/L的NaHCO3溶液处理松柳(Lathyrus quinquenervius)种子,每种溶液设置6个浓度梯度,以此研究盐胁迫对种子萌发和幼苗生长的影响。研究结果表明:NaCl浓度在0~100 mmol/L时对种子发芽的各项指标影响不明显,在浓度大于200 mmol/L时,显著降低了种子发芽率、相对发芽率、发芽势和发芽指数,盐害率显著升高;Na2CO3溶液在所有浓度下均显著降低种子发芽指标,盐害率显著升高,仅在2 mmol/L时未影响种子发芽率;NaHCO3溶液在浓度为0~20 mmol/L时对种子发芽的各项指标无显著影响,而浓度>20 mmol/L后,对种子的发芽势、发芽指数、耐盐指数均产生显著抑制,浓度100 mmol/L时,盐害率显著升高。三种盐胁迫对苗高生长均表现为低浓度显著促进,高浓度显著抑制,NaCl和Na2CO3对胚根生长表现为低浓度无显著影响而高浓度显著抑制,NaHCO3对胚根生长以及三种盐对胚芽生长则始终呈抑制作用。     

PEG-6000胁迫对小麦种子材料萌发的影响

以6份小麦种子为材料,采用不同浓度PEG-6000溶液模拟干旱胁迫,通过种子萌发过程中相对发芽率、相对发芽指数、胚根长、胚芽长、相对抗旱指数、相对活力指数等指标对6份玉米材料种子抗旱能力进行测试.结果表明,小麦种子萌发期的相对发芽率、相对发芽指数、相对活力指数与干旱胁迫呈负相关;6份小麦种子材料萌发期的抗旱性表现为:荣...     

盐旱交互胁迫对多花黑麦草(Lolium multilorum)种子萌发及胚生长的影响

为了揭示多花黑麦草(Lolium multilorum)对岩溶地区钙盐、干旱环境的适应机制,本研究采用不同浓度(0,5%,10%,15%,20%)聚乙二醇(PEG-6000)的干旱胁迫和不同浓度(0,5 mmol/L,10 mmol/L,25 mmol/L,50 mmol/L,100 mmol/L)CaCl2的钙盐胁迫,探讨干旱、钙盐及盐旱交互胁迫对多花黑麦草种子萌发及胚生长的影响。结果表明:随单一胁迫及交互胁迫浓度的增加,发芽势、发芽率、发芽指数呈先增后减的趋势,活力指数则不断下降。PEG浓度为10%时对多花黑麦草发芽率和发芽指数有促进作用;CaCl2浓度为5 mmol/L时对多花黑麦草的发芽势、发芽率和发芽指数有促进作用;5%PEG+10 mmol/L CaCl2交互胁迫下的发芽势、发芽率、发芽指数均较对照有所提高(p<0.05)。干旱胁迫下的胚芽长随胁迫浓度的增加呈先增后减的趋势,交互胁迫下胚根长及胚芽长均随胁迫浓度的增加而降低,15%PEG+100 mmol/L CaCl2、20%PEG+(5~100 mmol/L)CaCl2交互胁迫下种子不能萌发。本研究发现,岩溶区域低浓度的单一盐、旱胁迫和交互胁迫均对多花黑麦草种子的萌发有促进作用,干旱程度是影响该区域种子萌发和胚生长的限制性因子。本研究对多花黑麦草在岩溶地区的推广、种植有重要的指导意义。     

NaCl胁迫对红秀一号籽瓜种子萌发的影响

以红秀一号籽瓜种子为材料,研究了不同浓度NaCl胁迫对该籽瓜种子发芽率、发芽势、发芽指数、活力指数、相对盐害率、胚根长、地上鲜重、胚根鲜重、地上干重、胚根干重及侧根数的影响。结果表明:浓度为40 mmol/L时,籽瓜的各项测定指标比对照高,即低浓度NaCl胁迫对籽瓜种子萌发具有促进作用;而随着NaCl胁迫浓度增大,种子萌发的抑制作用明显增强,浓度80~240 mmol/L时,籽瓜各项生长指标都低于对照,即高浓度NaCl胁迫对籽瓜种子萌发具有抑制作用。     

钠盐胁迫对中华羊茅种子萌发的影响

以中华羊茅种子为材料,研究钠盐(NaHCO_3、NaCl+NaHCO_3)胁迫对中华羊茅种子萌发的影响,探讨中华羊茅种子的耐盐碱能力。结果表明,随着钠盐溶液浓度的升高,中华羊茅种子的发芽率、发芽势、发芽指数和活力指数均呈先上升后下降的趋势;耐盐指数在低浓度下表现为促进,高浓度下抑制;胚根长、胚芽长均受到抑制,呈下降趋势;相同钠盐浓度条件下,NaHCO_3溶液对种子的萌发抑制作用更强。以种子发芽率作为钠盐胁迫适宜浓度指标的筛选并进行线性回归,确定中华羊茅种子对NaHCO_3溶液和NaCl+NaHCO_3混合溶液胁迫的半致死浓度分别为57.09 mmol·L~(-1)和90.64 mmol·L~(-1)。     

不同浓度PEG-6000对苦荞种子萌发的影响及抗旱性评价

选取4个苦荞材料,以不同浓度(0%、5%、15%、25%)的PEG-6000溶液胁迫萌发,研究不同浓度PEG-6000对苦荞种子萌发影响,以期筛选出苦荞抗旱性鉴定指标并对不同苦荞材料的抗旱性进行综合评价。结果显示,5%PEG-6000胁迫促进了云南花苦和晋荞2号的种子萌发,提高了黔苦4号的幼苗活力指数、胚芽含水量、胚根干物重和储藏物质转运率。15%PEG-6000胁迫抑制了苦荞的种子萌发,降低了苦荞的胚芽长、幼苗活力指数和储藏物质转运率,提高了苦荞的根茎比、黔苦4号的胚根长和胚根干物重。25%PEG-6000胁迫下4个材料均未发芽,复水后川荞1号多倍体恢复发芽率仅为16.7%。通过灰色关联分析筛选出萌发指数、发芽率、储存物质转运率作为抗旱鉴定的初级指标,发芽势、胚芽干物重、胚芽含水量、胚根含水量作为抗旱鉴定的次级指标。通过隶属函数对苦荞材料抗旱性进行评价,发现不同苦荞材料在5%PEG-6000、15%PEG-6000胁迫下种子的抗旱性不同。     

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.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

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...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

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.     

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...     

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).     

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...     

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.     

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.