文冠果幼苗对盐胁迫的生长策略响应和耐盐性阈值研究

为探讨盐胁迫对文冠果幼苗生长影响,对不同浓度配比(0%、0.2%、0.5%、0.8%) 盐分(NaCl:Na2SO4=9:1)胁迫处理下一年生文冠果幼苗的存活率、苗高、地径、生物量、根冠比、茎叶比进行测定。结果表明：随着盐浓度的增加,幼苗生长指标呈现逐渐下降趋势,生长明显受到抑制,在轻度盐胁迫(0.2%)处理下,地径、根系干重、根冠比高于对照;而中度(0.5%)和重度(0.8%)胁迫处理幼苗各生长指标均显著低于对照。对照、轻度和中度胁迫幼苗存活率为100%,重度胁迫幼苗存活率下降明显。试验表明在盐胁迫条件下,轻度胁迫对幼苗存活和抑制作用弱于中度和重度胁迫,当幼苗受轻度胁迫后通过增粗茎干,增加根系的生长发育,来维持幼苗的正常生长;将总生物量抑制率为50%的盐浓度定义为该幼苗的耐盐性阈值,文冠果幼苗的耐受阈值的盐浓度为0.8%。     

中国牛冷冻精液质量性状的评估与分析

为进一步提高牛冷冻精液的质量与探索技术关键,本研究对近年来国内各牛冷冻精液生产企业1720头份精液样品进行了质量分析,涉及品种有奶牛、肉牛类(包括乳肉兼用、黄牛、牦牛等)和奶水牛等。结果表明:剂量值(0.20±0.008)mL、活力(40.9±2.3)%、每剂量前进运动精子数(1224.3±291.7)万个、畸形率(12.6±3.8)%、细菌菌落数(38.9±192.7)个。年度间比较,活力呈不规则的起伏变化;2016年畸形率均值显著低于前2个年度,分别下降0.8%和1.3%,3个年度间均差异显著(P0.05),2014年细菌菌落数显著高于其他2个年度(P0.05);品种间比较,奶牛活力高于奶水牛0.5%、高于肉、兼用牛0.2%(P0.05),奶水牛与肉牛及兼用牛之间差异不显著(P0.05),奶水牛畸形率分别高于奶牛1.9%、高于肉用牛0.9%,均差异显著(P0.05),前进运动精子数,奶水牛最高,奶牛最低,品种间均差异显著(P0.05);生产企业间比较,活力、前进运动精子数、畸形率均分别存在不同差异。     

腈菌唑与甲基硫菌灵对苹果斑点落叶病菌、轮纹病菌和炭疽病菌的混配增效作用研究

采用菌丝生长速率法测定了腈菌唑、甲基硫菌灵及其5种不同配比对苹果斑点落叶病菌、轮纹病菌和炭疽病菌的毒力。结果表明,1:8和1:12两种配比对苹果轮纹病菌、炭疽病菌均有显著增效作用;以1:8配比最佳,对2病菌的增效系数分别是2.88、2.21。5种不同配比对苹果斑点落叶病菌增效系数均小于0.5,表现为拮抗作用。     

AFLP增效和减效位点预测杂交水稻产量性状模型构建

选用13个水稻不育系和19恢复系按NCⅡ设计配制2套半双列杂交组合,分别用每套组合F1产量性状对该套亲本AFLP多态性位点(总位点)进行筛选,获得阳性、增效和减效三类位点。分别用基于总位点、阳性、增效和减效4类位点的亲本遗传距离构建AFLP标记预测模型,对另一套组合产量性状进行预测。结果表明:(1)总位点中只有少数为阳性位点。与总位点相似,阳性位点用于产量性状预测时,预测值与实际值的相关系数(以下简称为预测系数)太低;(2)而单独利用增效或减效位点,以及同时利用该2类位点(构建二元模型),3类预测效果均大大提高,其中增效位点对结实率,增效或减效位点,及同时利用增效和减效位点对单株产量,4个预测系数在0.6以上,可以用于指导水稻育种;(3)利用2套组合均筛选到的共同增效和减效位点的预测也达到较高水平,其中4个预测系数在0.5以上,因其所使用的预测位点数大大减少,应用更为有利。     

药用兰科植物杜鹃兰的组织培养与快速繁殖

以带顶芽或不定芽的杜鹃兰假鳞茎切块为外植体进行试管培养,可在短时间内获得大量优质幼苗.经试验筛选出各培养阶段的最适培养基为:(1)原球茎诱导和增殖培养基:MS 6-BA 2.0mg/L(单位下同) 2,4-D0.5 杜鹃兰共生真菌提取物10.0 PVP500.0;(2)芽和根分化及试管苗生长培养基:1/2MS NAA0.5 IBA0.5 共生真菌提取物10.0 PVP500.0.上述2种培养基均加入3.0%蔗糖和0.8%琼脂,pH5.8.培养温度(25±1)℃,光照12h/d,光照度2000lx.     

对金龟子幼虫有杀虫活性的苏云金杆菌HBF-1菌株发酵培养基优选

通过正交试验优选出对金龟子幼虫有杀虫活性的苏云金杆菌HBF-1菌株的发酵培养基组合为氮源B4.4%,淀粉1.2%,酵母粉0.5%,KH2PO4 0.04%,MgSO4 0.05%.用此配方进行摇瓶发酵,发酵液的平均菌数可达到44亿/mL,晶体产生量为2.1130 mgmL,发酵液稀释50倍对铜绿丽金龟幼虫进行生测,14 d平均死亡率达到78.3%.     

两种野生绣球花组培及快繁技术研究

以蜡莲绣球和莼兰绣球种子为外植体,探究不同培养基类型、不同激素浓度对其增殖及生根的影响。结果表明:蜡莲绣球最佳增殖培养基为MS+0.8 mg·L^-16-BA+0.05 mg·L^-1 NAA,增殖系数高达9,较适宜的生根培养基为1/2 MS+0.1 mg·L^-1 IBA+NAA 0.1 mg·L^-1或未加激素的1/2 MS,生根率为100%;莼兰绣球最佳增殖培养基为MS+0.8 mg·L^-16-BA+0.2 mg·L^-1 IBA,增殖系数高达9.67,较适宜的生根培养基为1/2 MS+0.2 mg·L^-1 IBA+NAA 0.5 mg·L^-1或未加激素的1/2 MS,生根率可达100%。     

赤桉优选株系离体培养和快繁技术优化的研究

对赤桉优选株系离体快繁技术进行了研究。结果表明:最适诱导培养基为MS BA0.5mg/L(以下单位同) NAA0.2 Vc3;增殖培养基为MS BA0.5 NAA0.1 IBA0.2;壮苗培养基为MS NAA0.1 IBA0.2;生根培养基为1/2MS NAA0.1 IBA0.5;太阳闪射光和壮苗培养有利于赤桉生根;最适pH为5.8—6.0;组培苗移栽基质以30%泥炭土 70%黄心土成苗最好。     

芦笋离体快速繁殖中嫩茎增殖培养对根分化的影响

本试验对芦笋组织培养中影响生根的培养基激素配比、嫩茎增殖培养中激素配比及嫩茎增殖次数等因素进行了研究。结果表明,嫩茎增殖培养基激素配比和嫩茎增殖次数等因素对后续的茎段生根有重要影响。芦笋组培再生完整植株优化培养过程为:芦笋外植体(茎段)在J2(MS NAA 0.2 mg/L BA 0.5 mg/L)培养中诱导出嫩茎后,再在嫩茎增殖培养基J3(MS NAA 0.2 mg/L BA 0.1 mg/L)或J9(MS NAA 0.05 mg/L BA 0.1 mg/L)增殖1次(嫩茎增殖次数对后续生根影响极大),然后取增殖1次后的茎段接种到生根培养基G4(MS IBA 0.5 mg/L BA 0.05 mg/L 2.0 mg/L PP333)中进行生根培养,最高生根率可达90%以上。芦笋组培苗移栽成活率主要受诱导出的根质量的影响。通过几个因素的优化,最终可使芦笋根诱导率达90%~100%,移植成活率达100%。     

药用植物红落藜组织培养研究

本试验以红落藜为试验材料,进行茎段组织培养及植株再生的研究。试验结果表明75%酒精5s+0.1%升汞8min既可进行彻底消毒,又保证具有较高的成活率;通过初代培养筛选出NAA为最适的生长激素,最适培养基为MS + 6-BA 1.5 mg?L-1 + NAA 0.2mg?L-1+琼脂0.8%+蔗糖2%+活性炭0.2%;通过继代培养筛选出最适培养基为MS + 6-BA 2.0 mg?L-1 + NAA 0.2mg?L-1+琼脂0.8%+蔗糖2%+活性炭0.2%;最适的生根培养基为1/2MS + IBA1.0 mg?L-1 + NAA 0.1mg?L-1+琼脂0.8% + 蔗糖2% + 活性炭0.2%,生根率为80%。当试管苗叶片数3～5片,苗高2cm～3cm,生根数3～4条时,移栽至蛭石和腐殖土(1∶2)混合的基质中,保湿遮阴,成活率可达90％以上。     

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.     

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.