陆地棉显性无腺体品系杂种优势及配合力研究

以７个显性无腺体陆地棉品系和４个常规品种（系）为材料，按ＮＣＩ设计，对２８个组合的杂种Ｆ１进行了分析。结果表明。杂种Ｆ１具有明显的优势，２８个组合所研究的１５个性状中全部具有中亲优势，６个性状具有高亲优势，４个性状具有竞争优势；配合力分析的１１个性状中，株高、衣分、纤维长度和麦克隆值主要受基因加性效应控制，而子棉产量、皮棉产量、单株铃数、铃重和子指等性状同时受基因加性和非加性效应作用，显无０７３是丰产的显性无腺体品系，而显无２６０是较好的优良品系，组合显无０７３Ｘ泗棉２号在重要性上表现较好。     

章丘大葱半成株采种单株产量与主要植物学性状的相关分析

章丘大葱采种植株的植物学性状与单株产量存在一定的相关性。通过对油薹初期与开花盛期的半成株采种植株的株高、花茎高、花球高、假茎长、假茎粗、花球横径、叶面积分别进行分析，发现单株采种产量与抽薹初期、开花盛期的叶面积均呈显著直线相关（r=0.582,0,358），花球高在开花盛期与产量呈直线相关（r=0.449），假茎粗则与产量在抽薹初期呈极显著正相关（r=0.557）。     

甘蓝型黄籽油菜产量性状的遗传分析

利用加性－显性－母体的遗传模型，分析了7个不同遗传来源甘蓝型黄籽油菜品系所配制的完全双列杂交资料。结果表明，产量性状主要受加性和显性效应共同控制，环境对产量性状有一定的影响而母体效应影响很小。基因效应分析发现y4单株粒重有极显著的加性效应，y3×y4单株粒重有极显著的显性效应。     

几个小麦品种（系）主要农艺性状配合力与遗传力分析

本文采用不完全双列杂交设计,对15个小麦品种(系)的8个主要农艺性状的配合力与遗传力进行了分析。结果表明,所有的8个性状(单株籽粒产量、单株生物产量、单株穗数、收获指数、株高、抽穗期、穗粒数、千粒重),其广义遗传力都较高,可在早代进行选择;株高与抽穗期的遗传主要受基因加性效应控制;其余性状(产量性状)的遗传除受基因加性效应控制外,非加性效应(显性效应和上位性效应)的影响更大。F1代的表现,同时受到双亲GCA的与SCA的影响。选择单株生物产量与单株穗数GCA较高、性状互补的亲本,才有可能选出单株籽粒产量高的强优势组合。从亲本的表现型不能推断其一般配合力效应的大小。本文同时对各材料的特点进行了分析。     

大麦若干经济性状的遗传特性分析

按Hayman方法对8×8完全双列杂交F_1的6个性状进行基因效应分析与模型检验,株高、穗长、实粒数符合加性-显性模型.株高、实粒数为部分显性,加性方差和显性方差均显著,基因的加性效应比显性效应更重要;穗长为超显性,显性基因效应比加性基因效应更重要.对杂交F_1、F_2进行配合力效应值分析表明,一般配合力方差和特殊配合力方差对所研究性状均重要,多数性状为加性基因效应占主导.亲本85G63、81-18、82-14为最佳配合者,其主要经济性状一般配合力好.杂交F_1各性状均有明显杂种优势,组合间和性状间的优势具有显著差异,以单株籽粒产量优势最强,其余依次为实粒数、穗长、株高、小穗粒数和千粒重.     

小麦重要产量性状的主基因+多基因混合遗传分析

以单株产量等为代表的重要性状是选育小麦高产良种的主攻目标性状,分析小麦重要产量性状的数量遗传特性,为深入研究其遗传机制提供依据。本研究选用品冬34为母本(P_1)和BARRAN为父本(P_2)配置杂交组合,在2年4个环境下应用主基因+多基因混合遗传模型方法对该组合单世代(P_1、P_2、RIL_(7:8)、RIL_(8:9))单株产量、千粒重、株高、穗下节间长、旗叶上节间长和分蘖数进行遗传及相关分析。结果表明,除千粒重和分蘖数外,其余性状间均显著或极显著相关,穗下节间长与旗叶上节间长平均相关系数达0.91 (P≤0.001)。最优遗传模型对于单株产量是4对加性上位性主基因+多基因遗传模型,其主基因加性效应值分别为3.78、2.89、–6.18和0.15,多基因遗传率为86.23%;对于千粒重是2对互补作用主基因+加性效应多基因混合遗传模型,多基因加性效应值是22.37,主基因遗传率为66.96%,多基因遗传率为28.25%;对于株高是2对累积作用主基因+加性作用多基因混合遗传模型,控制株高的第1对主基因加性效应值是5.15,加性×加性上位性互作效应值为–9.66,多基因加性效应值为–9.31,主基因遗传率为58.57%,多基因遗传率为39.71%;对于穗下节间长和旗叶上节间长均是加性-上位性多基因遗传模型,其主基因遗传率分别为97.65%和99.14%;对于分蘖数是加性-上位性多基因混合遗传模型,主基因遗传率为78.89%,多基因遗传率为19.87%。这些性状在多个环境下主要受主基因+多基因混合遗传控制。在选育优良品系的过程中,要兼顾适应生态环境条件的重要表现,进一步为筛选与目标性状紧密连锁标记及推进分子标记辅助选择提供理论依据。     

干旱胁迫下马铃薯块茎形成期部分农艺性状的遗传分析

以旱作敏感型品种大西洋和耐旱型品种陇薯6号为亲本构建的F₁分离群体为材料,采用主基因+多基因混合遗传模型分析方法对其单株结薯数、单株块茎重、株高、茎粗等4个性状进行遗传模型分析。结果表明,4个性状的最适遗传模型均为2 MG-AD,受2对主基因+加性-显性多基因控制,4个性状的主基因的遗传率在16.02%～96.11%之间。     

小麦几个数量性状不同生长时期的基因效应分析

依据Ｌｏｇｉｓｔｉｃ生长拟合曲线，把小麦株高，单株叶数和千粒粒重等性状建成划分为个生长时期。采用世代平均值分析法，对不同生长时期净增量进行了基因效应分析，结果表明，各性状不同生长时期基因作用的方向和程度具有明显差异，遗传模型也有所不同，并且各个时期的基因效应相互独立。上位性效应对于株高和单株叶数的遗传具有重要作用，而粒重的遗传基本符合加性－生三参模型。     

特用玉米主要性状的配合力及相关分析

以 PST等 7个特用玉米自交系为亲本 ,按 griffing( )配成 2 1个杂交组合 ,分析单株粒重等 10个性状的一般配合力和特殊配合力 ,主要农艺性状和产量之间的关系。结果表明 :行粒数主要受加性基因控制 ,其余大部分性状的加性和非加性基因效应同时存在。在一般配合力效应上 ,同一性状不同亲本的效应值不同 ,各性状值的效应最高出现于不同亲本。在单株产量上 ,一般配合力效应值大小为 PHT>PYT>PHBT;特殊配合力效应较大的组合有 :PYT× PHT>PYT× PHBT>PHT× PHBT等 ,这些具有较高 SCA和 TCA的组合一般都符合本地种质与热带种质、本地种质与温带种质和热带种质与温带种质的杂交组配模式。相关分析表明 ,行粒数与产量关系最为密切 ,其次为株高、穗长。对于这些性状而言 ,一般配合力高的亲本容易产生特殊配合力高的组合 ,但也不排除一般配合力都不高的双亲获得较高的特殊配合力的可能性 ,根据配合力互补原理 ,可望从 7个亲本间选配出高产优质的组合。     

转基因抗虫棉产量性状的遗传效应及其杂种优势分析

采用加性-显性与环境互作的遗传模型,分析了9个亲本和36个F1的皮棉产量、单株铃数、铃重和衣分的两年资料,估算了转基因抗虫棉各项遗传方差和成对性状间各项遗传效应的相关性.结果表明,转基因抗虫棉的产量性状受加性和显性效应共同控制,皮棉产量、铃重和衣分都以基因的显性效应为主,而单株铃数是以加性效应为主,单株铃数和衣分还具有基因与环境互作效应.遗传相关分析表明,转基因抗虫棉的皮棉产量与单株铃数的基因型和表现型相关系数都比较大而且比较接近;皮棉产量与单株铃数、铃重和衣分的加性相关系数都达到极显著水平,而且皮棉产量与单株铃数、衣分的数值比较大.利用亲本和F1的资料预测了F2基因型值和杂种优势,结果表明,转基因抗虫棉F2的皮棉产量、单株铃数、铃重和衣分的群体平均优势分别为4.0%、5.1%、-1.3%和3.2%,群体超亲优势分别为-7.3%、-6.0%、-4.2%和-0.5%.     

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.