小麦茎尖超低温保存处理条件的优化研究

以普通小麦为材料,探讨保护液中不同DMSO浓度、蔗糖浓度及不同冷冻处理时间对超低温保存后小麦茎尖成活率的影响,以获得最优超低温保存方法。重点针对小麦在超低温保存时的各处理条件对小麦茎尖成活率的影响展开了试验。结果表明,当保护液中含16%浓度的DMSO和6%浓度的蔗糖,并将预处理后的小麦茎尖采用梯度降温法:0℃停留存放30 min、-7℃停留存放1 h、-20℃停留存放1 h、迅速转移放入-80℃冰箱停留存放1 h、迅速投入液氮中过夜的超低温保存条件达到最高成活率,从而确定了小麦茎尖超低温处理时保护液中的最佳浓度组合及低温处理的最佳时间。     

菊花茎尖外植体高效超低温保存技术建立的分析

菊花是全球最重要的鲜切花之一,建立高效的菊花茎尖超低温保存体系具有重要意义。本研究以菊花‘Sei Hillary’试管苗为材料,研究了茎尖大小、炼苗期光照条件、六种再生培养基配方、超低温保存方法、母株感染病害情况对超低温保存效率的影响,结果发现,上述参数均显著影响茎尖超低温保存效率,组织切片观察揭示了超低温保存方法影响再生效率的原因。本研究建立了一个高效的菊花茎尖超低温保存体系,主要技术步骤包括:健康试管苗在16 h的光周期下4℃炼苗6周、切取携带3～4片叶原基的茎尖(1.5 mm),利用小滴玻璃化法进行超低温保存,快速解冻后于添加0.05 mg/L GA3的1/2Knop培养基上再生培养。该体系可获得85.5%成活率和53.7%的再生率,为菊花种质资源提供了一种简单高效的长期保存方法。     

魔芋茎尖玻璃化冻存研究

研究了魔芋茎尖玻璃化冻存的主要技术环节，建立了较适宜的魔芋种质资源超低温保存体系：在实体显微镜下，从继代培养2周的不定芽上切取1～1.33mm大小的茎尖，经0.7mol/L蔗糖的MS-NH+4培养液室内预培养2d，玻璃化溶液PVS2室温下处理10～20min，直接投入液氮中保存。保存后，茎尖经40～77℃水浴快速化冻，1.2mol/L蔗糖的培养液     

合欢和青杄种子超低温保存研究

为了探讨超低温保存技术应用于园林树木种子的适应性,研究了合欢和青杄种子超低温保存.结果表明:(1)采用直接投入法,除了合欢部分种子进入液氮后炸裂外,2种种子液氮保存后都有萌发能力,但其发芽率、发芽势变化不同.在自然含水量下,液氮保存后合欢种子发芽率和发芽势较对照都显著提高;青杄种子发芽率明显降低,而发芽势则与对照没有显著差异.(2)不同树种用于液氮保存的适宜种子含水量不同.合欢种子在10％的自然含水量下保存于液氮中发芽率、发芽势和发芽指数最高;而青杄种子需经过干燥脱水,含水量在4％时,保存后种子萌发力较好.结果显示,常温保存下种子寿命有较大差异的园林树种都实现了超低温保存.因此,该技术在园林树木种子长期保存中有应用潜力.     

树莓试管苗茎尖包埋玻璃化法超低温保存

摘要：本试验对树莓茎尖包埋玻璃化法种质资源保存进行了研究,以期建立简单、高效的树莓种质资源超低温保存体系。试验以树莓试管苗茎尖为材料,探讨了不同因素对包埋玻璃化法超低温保存后成活率的影响。结果表明：长约1mm的树莓试管苗茎尖用海藻酸钙包埋后,采用分步预培养的方法,最后终止蔗糖浓度为0.9mol/L的MS培养基中进行预培养3d,再用含2M甘油和0.9M蔗糖的装载液处理90min, 在0℃下用PVS2处理180min后投入液氮中保存1h,在40℃下化冻3min,用含1M蔗糖的MS液体培养基洗涤20min,最后转到恢复培养基上,30d后在没有形成愈伤组织的情况下形成新的植株。以上的保存程序应用于6个树莓品种,成活率达87%。该结果为树莓种质资源的长期保存提供了理论依据。     

卷丹不同继代试管苗茎尖超低温保存效果及组织细胞学研究

为了研究组培茎尖的继代次数对其超低温保存后存活的影响,以卷丹试管苗不同继代次数的茎尖为材料,采用玻璃化法进行了超低温保存效果比较研究。结果表明,1~4代试管苗茎尖冻后存活率分别为55.8%、93.3%、67.0%和64.1%。同时,即初代培养后继代培养2个月的第2代试管苗茎尖超低温保存后存活率显著高于其他继代培养子组培苗。对各代试管苗茎尖进行石蜡连续纵切片显微观察,结果表明2代试管苗顶端分生组织细胞形态不同于其他继代代数,其显著特征是细胞体积小、细胞核大且细胞质浓密,这可能是其茎尖超低温保存显著高于其他3代的原因。     

肉豆蔻种子超低温保存技术及生理生化活性研究

［目的］研究旨在探索肉豆蔻种子超低温保存方法,并检测超低温保存对肉豆蔻种子生理生化指标的影响。［方法］ 以肉豆蔻新鲜种子为材料,分别用玻璃化法、缓慢冷冻法和直接冷冻法进行超低温保存,并测定超低温保存后生活力,对生活力最高的一组超低温保存方法保存的肉豆蔻种子进行生理生化活性测定。［结果］试验结果显示,肉豆蔻种子含水量在24.44%时,用玻璃化冷冻法和缓慢冷冻法进行超低温保存生活力分别为50.00%和46.05%,且随着含水量的增加而减少。用直接冷冻法进行超低温保存时,肉豆蔻种子生活力随着含水量的增加先增加后减少,其中含水量为27.15%时,生活力最高为62.68%。直接冷冻法超低温保存前后肉豆蔻种子浸出液电导率、超氧化物歧化酶活性和过氧化氢酶活性差异不显著,丙二醛含量降低,过氧化物酶活性和α-淀粉酶活性增高。［结论］试验表明,用液氮进行超低温保存肉豆蔻的种子是可行的。     

枇杷花粉干冻法超低温保存研究

采用花粉干冻法对枇杷花粉超低温保存进行了研究。将枇杷盛花期的花粉干燥后直接液氮超低温保存,取出后观察其萌发率。结果表明：花粉的含水量是决定枇杷花粉超低温保存成败的关键因素。脱水至30％左右的含水量能够保证超低温保存花粉的生活力;解冻温度及方式对超低温保存后花粉的生活力没有明显的影响。     

杏种子与种胚的超低温保存研究

含水量为６．９％带有内果皮的种子，以－５Ｃｍｉｎ＾－１速率降至－８０℃，放入ＬＮ２，在室温缓慢解冻，成活率可达９１．５％。去掉内果皮含水量为７．１％的种仁，以上述方式保存，成活率也可达到８８．２％。含水量是超低温保存杏种子最重要的因素。研究表明：冰冻保护剂ＤＮＳＯ对杏种子的超低温保存影响不大。含水量为４．８％￣８．１％去掉子叶的种胚超低温保存后ＴＴＣ染色成活率为８２．８％，并能在ＭＳ培养基上发育为     

番木瓜种质的超低温保存与植株再生初探

以番木瓜成年植株茎尖、侧芽为试材，探讨番木瓜种质超低温保存的最适条件。结果表明：用添加3％DMSO的培养基培养3d后，保留2个叶芽长2mm左右的茎尖，在38℃下以60％PVS2溶液处理50min，再用纯PVS2于-4~0℃处理30min，迅速投入液氮中保存24h后，在40℃水浴中解冻后洗涤数次，接种到再生培养基上，存活率51．5％，植株再生率50．1％。     

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...     

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.     

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...     

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.