杉木二代种子园自由授粉子代评选

对来自于贵州省黎平县国有东风林场杉木二代种子园的21个自由授粉家系进行了子代测定,结果表明:5~7年自由授粉子代的部分家系生长表现比1.5代种子园混系(ck1)差,多数家系生长量低于优良种源优树(ck2);5年、7年杉木二代种子园自由授粉子代生长性状差异显著,6年试验林的树高显著而胸径和材积差异不显著;7年的树高、胸径、材积家系遗传力分别为0.490、0.448、0.449,生长性状受中等程度的遗传控制;根据选择标准和综合考虑,评选出3个优良家系和2个劣势家系;3个优良家系7年平均单株材积为0.056 106 m3,现实增益比群体均值、1.5代种子园混系、优良种源单家系分别提高了27.1%、35.4%、14.4%,材积遗传增益分别提高13.0%、17.0%、6.9%;伐除2个劣势家系,种子园遗传增益将进一步提高。     

8个格木天然林种源苗期生长差异与早期选择

为研究格木不同天然种源家系苗的生长差异,选出相对速生的优良种源,本研究对8个格木天然林种源、110个家系1年生的苗高和地径等生长量指标进行测量,结合各家系的种子表型性状进行方差分析、多重比较、相关性分析和聚类分析。结果表明:不同种源的格木苗期生长量差异显著,具备种源选择的基础;不同种源的苗期生长量差异主要来源于种源内,具备从优良种源内选择优良家系的基础;苗期生长量与种子大小、种子厚和千粒重等性状呈极显著正相关关系,大粒、饱满种子可作为优良种源和家系选择的初选参考指标。初步选出浦北、北流种源作为格木优良种源。本研究为格木速生种源及家系的早期选择提供依据。     

黑荆树半同胞子代林幼林测定及优良家系初步选择

观测了黑荆树的3年生半同胞子代幼林的树高、胸径(地径)、冠幅等的年生长规律及生长量,并进行了变异分析、方差分析和相关分析,选出胸径作为优良家系初步选择的指标;采用加权系数法初步选出95个优良家系.     

贵州杉木第3代种子园建立及优良繁殖材料选择技术研究

采用多性状选择技术,选出30个优良家系进入杉木第3代种子园.与杉木第2代种子园相比,第3代种子园在树高、胸径和材积方面分别提高了10%、8%和15%以上.按生长量指标、回归系数和遗传稳定度的入选标准,评选出速生、抗逆性、材性好优良的家系58个,家系的增益幅度平均在20%以上.按杉木无性系生长量指标和重复率的入选标准.评选优良无性系26个,无性系的增益幅度在100%以上.     

不同亚美马褂木家系在鲁中地区生长性状分析

为评价亚美马褂木在中国北部地区生长适应性,选育出若干优良家系,推动亚美马褂木在中国北部地区的推广和应用,本实验以19个亚美马褂木家系和1个中国马褂木混合家系(对照)为材料,定植于山东中部地区,3 a后对其保存率和株高、米径等生长性状进行调查和分析。结果表明,与中国马褂木相比,亚美马褂木表现出明显的杂种优势。在抗寒能力方面,经2015和2016年2次寒潮,亚美马褂木各家系保存率最小为45.8%,最大为93.8%,平均保存率(81.6%)远高于中国马褂木(35.4%);亚美马褂木家系间株高、径粗等性状差异显著(p0.001);株高和米径家系间变异系数分别为5.59%~17.66%和9.78%~25.77%;根据生长量、家系内变异系数、保存率等综合指标,初步选出8、5、6、9四个生长快速,稳定性好,抗寒能力强的亚美马褂木家系,其株高分别达到6.20 m、6.14 m、5.95 m、5.89 m,米径分别达到8.2 cm、9.1 cm、8.5 cm、8.8 cm。     

离子注入桉树大田生长的变异与选择研究

对3地点30个以尾叶桉为主要亲本的桉树家系进行1.5,2.5,3.5a的性状分析与适应性分析,结果表明:生长性状在家系、地点和家系×地点交互效应上均存在极显著差异,试验可选择出生长优良的家系;不同地点生长量表现为:共和石湾凤安;3.5a时性状综合分析和评定表明:28,27,17号家系适应性广,具速生丰产性,可推广利用,13,8,6号是离子注入适应性广、丰产性强的家系,而2,18,30号家系丰产性和稳定性差,缺少利用价值;以3.5a单株材积为选择指标,3个地点突变株入选27株,突变率达到0.75%。     

澳洲坚果人工杂交子代苗木生长量变异分析

为了认识澳洲坚果植株生长量性状的传递遗传规律,以澳洲坚果10个无性系品种为材料,正反交设计,共90个杂交组合,获得90个全同胞家系苗木。并对种子横径、苗木株高、地径及冠幅进行变异分析。结果表明,10个母本间种子横径达显著差异(P<0.05),同一母本所对应9个父本的组合间种子横径达显著(P<0.05)或极显著(P<0.01)差异,说明种子的大小不仅仅决定于母本,而且也受父本的影响。对苗木株高、地径和冠幅的分析表明,全同胞家系间差异显著(P<0.05),母本半同胞家系间差异显著(P<0.05),而父本半同胞家系间差异不显著。苗木生长量受父母本的基因共同决定,但母本影响的变异分量相对较大,父本影响的变异分量相对较小。     

滇西地区西南桦种源家系早期选择

以收集自云南、广西和贵州的30个种源250个家系为材料,在滇西地区进行西南桦种源家系联合选择试验.结果表明:在1.5、2.5年和3.5年时西南桦树高、胸径在种源间和家系间均存在显著差异(p＜0.05),而且各生长性状在种源内的变异大于种源间,胸径的变异大于树高;各年龄西南桦树高生长均与种源所在经度呈极显著负相关(p＜0.01),呈现出明显的地理变异规律;综合各年龄阶段的生长表现,应用聚类分析初步筛选出30号(滇昌宁)、31号(滇龙陵)、3号(滇墨江)、4号(滇景洪)和19号(桂德保)等5个优良种源,并依据3.5年生时的生长表现筛选出30个优良家系.研究结果为滇西地区西南桦人工林的持续健康发展提供了优良种质.     

杉木二代种子园无性系单交子代遗传变异及优良家系选择研究

对3年和4年杉木2代种子园优良无性系单交子代测定林进行了调查和分析,结果表明:参试家系(组合)间生长性状差异显著,生长性状受到中等强度遗传控制,主要生长性状的家系遗传力为0.54～0.64,生长表现与立地交互作用明显.单交子代林总体生长表现优异,3年测定林参试家系平均树高3.63 m、胸径4.71 cm、材积0.004 167 m3；4年平均树高4.82m、胸径7.40 cm、材积0.012 86 m3.以胸径和树高生长表现对该子代林进行联合选择,所有单交子代均优于2代种子园混系,3年测定林初选出5个速生最优家系,材积遗传增益为67.9％；4年测定林初选出6个速生最优家系(组合),材积遗传增益为59.0％.筛选的优良家系是高世代种子园营建、优良无性系选育和造林应用的优良繁殖材料.     

40月生赤桉家系抗风性评价及选择

为了选择优良赤桉抗风家系,对114个40月生赤桉家系进行生长性状树高、胸径、冠幅、单株材积、树皮厚度和无损木材性状Pilodyn值进行测定和遗传分析。结果表明:树高、胸径、单株材积、冠幅、风害等级、Pilodyn值、树皮厚度、保存率等8个研究性状中除胸径间差异为显著差异(p0.05)外其余性状间差异性极显著(p0.01)。不同赤桉林木单株存在着较大的差异,表型变异系数超过15%,风害等级变异系数达到77.84%,赤桉家系间性状各性状中家系遗传力均高于单株遗传力,其中树高、胸径、冠幅、单株材积、Pilodyn值和风害等级均受高等强度的遗传控制(遗传力大于0.40)。风害等级遗传、环境、理论表型变异系数最大、单株材积次之。风害等级与树高遗传相关、环境相关、理论表型相关关系中均呈极显著负相关,与材积遗传、环境相关性极显著,与胸径、Pilodyn值遗传相关呈极显著相关性(rp=-0.341,rp=-0.476)。对各性状不同权重系数进行综合评定选择的15个优良家系,再进一步从生长(遗传增益10%)及抗风性能(遗传增益-10%)方面选择出3个优良家系为20026、20027、2002。遗传增益分析表明选择的家系生长性状均高于参试家系平均值,而提高了家系的抗风性。     

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.