利用高油分的花粉直感效应鉴别玉米单倍体

通过对农大高诱1号衍生材料的诱导率和含油量的分析,筛选出了一个诱导率与含油量均较高的高诱株系.该系油分具有显著的花粉直感效应,父本效应值为0.38,以其为父本与普通玉米杂交,杂交当代籽粒含油量显著高于自交籽粒和单倍体籽粒,花粉直感的增油率在30%以上.利用这一区别所发展的单倍体油分筛选法准确率超过90%,明显高于标记     

高油玉米花粉对普通玉米籽粒性状和含油量的影响

为研究高油玉米花粉对普通玉米籽粒性状及含油量的影响,通过3个普通玉米品种与3个高油玉米品种混种,利用高油玉米花粉为普通玉米授粉,试验结果表明：通过花粉直感效应,普通玉米在接受高油玉米花粉后籽粒产量提高或变化不大,胚的重量显著增加。普通玉米和高油玉米杂交与相应的普通玉米自交相比,籽粒中胚的比重大大增加。籽粒中含油量的增加很大程度上是由于胚在籽粒中比重的增加引起的。     

高油玉米及其栽培要点

高油玉米是一种籽粒含油量比普通玉米高50%以上的高附加值玉米类型,其突出特点是籽粒含油量高.普通玉米的含油量通常为4%～5%,而高油玉米的籽粒含油量却高达8%以上,使玉米从单纯的粮食或饲料作物变成了油粮或油饲兼用作物,大大提高了种植玉米的经济效益.     

浅谈高油玉米发展现状及在新疆利用途径

高油玉米是 2 0世纪人工创造的玉米新类型。它指籽粒含油量达到 6%以上的玉米 (普通玉米籽粒含油量一般为 3%～ 5 % ) ,高油玉米不仅大大提高了玉米籽粒的总能量水平 ,而且也全面改善了它的多种营养成分 ,因而具有普通玉米难以比拟的优越性。 2 0世纪 80年代以来 ,高油玉米的发     

高油玉米杂交种品质及其花粉直感效应的稳定性分析

为探讨环境对高油玉米品质的影响,以100个高油玉米杂交种和200个高油花粉直感的当代组合为材料,对品质性状的稳定性进行了分析。结果表明,高油玉米杂交种组合在不同年份和不同地点间的含油量差异平均为1.00%,最小为0.17%,最大相差可达1.91%,不同组合间油分变化有一定差异,即不同品种在油分性状表现的稳定性上存在差异。年份和地点效应对蛋白质含量影响的程度接近,不同年份和地点间的最大差异在1.00%左右;年份间的淀粉差异在0.4%左右,地点间的差异在1.7%左右,而单个组合在不同年份和不同地点间籽粒淀粉含量的最大差异则达到5.81%。普通玉米籽粒高油花粉直感后,在地点和年份间油分变化最大的组合其油分变化达到1.88%,最小的组合为0.37%,总体平均为1.00%;单个组合的蛋白质含量在不同年份和不同地点间的最大差异达到3.37%,最小为0.61%,总体平均为1.78%;单个组合的淀粉含量在不同年份和地点间最大相差6.21%,变化最小的组合相差0.71%,所有组合平均为2.95%。     

高油玉米的利用价值和发展对策

1高油玉米代表了玉米发展的大方向普通玉米含油量为4%～5%,而高油玉米为7%～10%。高油玉米是人工创制的一种高附加值玉米(VEC)新类型,是现代科技对玉米育种的重大贡献,也是杂交种问世以来,玉米遗传育种的最重要发展。它把玉米的高产与优质结合起来,在籽粒品质方面,不仅大大提高了含油量和总能量水平,也相应地提高了籽粒的蛋白质含量。而在蛋白质的组成中,高油玉米的10种限制氨基酸,如赖氨酸、色氨酸、苏氨酸、蛋氨酸等均高于普通玉米。除此之外,高油玉米籽粒中的Va和Ve也是高的,因而是一种全方位综合优质玉米籽粒。我国从70年代引进美国高…     

高油玉米自交系的培育与改良

一、高油玉米自交系培育的历史与状况卑在40年代,美国伊利诺埃大学的C.M.伍德俄士(WoodWorth)和R.W.尤根海麦(Jugen-heimer)把普通玉米自交系与伊利诺埃高油(IHO)系进行杂交,接着进行几次回交和自交,结合对大胚面籽粒的选择,把一批普通玉米自交系,如WF₉、L₃₁₇和B₃₇等转换成了高油系。这些系原来的含油量为2~5%,新转育的高油系达4~10%。     

糯玉米优质高产栽培技术

糯玉米原产于我国 ,其籽粒香甜 ,营养丰富 ,适口性好。随着人们生活水平的提高和对食品多样化的要求 ,糯玉米越来越受到人们的青睐。种植糯玉米生产周期短 ,经济效益高 ,是农民朋友致富的捷径。本文作者在致力于培育和开发糯玉米新品种的同时 ,也积累了一些种植糯玉米的经验。现加以归纳总结 ,供广大种植糯玉米的农民朋友参考。1　隔离种植糯玉米的糯质是受隐性基因 (WX)所控制 ,开花吐丝期如果有外来普通玉米花粉侵入 ,受了普通玉米花粉的籽粒就会因花粉直感失去应有的糯质 ,变成普通玉米 ,从而失去糯玉米应有的品质。这也是隔离种植的主…     

谈谈高油玉米

1 高油玉米的特点 与普通玉米相比，高油玉米有以下特点： 1．1 高油玉米的子粒含油量高。普通玉米的含油量为4％～5％，我国正在推广的高油玉米含油量都在7％～9％之间。而目前正在试验示范的一些高油玉米杂交种，如高油115、高油298，含油量更高达10％左右。我国玉米……     

高赖氨酸玉米籽粒形成过程的生物化学研究

对不同遗传背景的高赖氨酸玉米杂交种 o_2C103×o_2330、o_2二南_(24)×o_2金02及普通玉米京杂6号在授粉后不同时期籽粒的干物质积累、籽粒容重、出粉率、玉米粉细度、蛋白质、赖氨酸及亮氨酸等形成的动态进行初步研究,并测定了花粉、胚及胚乳中的氨基酸含量。三年结果表明:不同遗传背景的高赖氨酸玉米在授粉后不同时期籽粒的     

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.