Identification of primary trisomics and other aneuploids in foxtail millet

A complete set of nine primary trisomics (2n+ 1) for cv.‘Yugu No. 1’of foxtail millet, Setaria italica (L.) Beauv. (2n= 2x= 18), was identified cytologically from progenies derived from crosses between autotriploids(2n= 2x= 27) and their diploid counterparts. Five autotriploid plants were identified from 2100 seedlings derived from 4x-2x crosses; the reciprocal crosses (2x-4x) failed to produce autotriploids. Autotriploids grew vigorously and were morphologically very similar to diploids. Theprimary trisomics (2n= 2x= 19) constituted ?32.5% of the total progeny from the 3x-2x crosses, whereas 59.8% of the descendants were aneuploids with chromosome numbers ranging from 20 (double trisomics and tetrasomics) to 37 (2n= 4x+ 1; or autotetraploid with one additional chromosome). The nine primary trisomics identified were self-fertile; seven had characteristic morphology, whereas trisomics VIII and IX resembled the disomics. The seed set for trisomic V was the lowest (20%), and trisomic VIII the highest (74%). Other aneuploids with 20 or more somatic chromosomes were either self-sterile or partially fertile with various, but low, levels of seed set. Each of the primary trisomics showed its unique transmission rate when self-pollinated; trisomic IX had the highest (45.8%), whereas trisomic V had the lowest (19.6%) transmission rate.     

The use of wheat aneuploids for the chromosomal assignment of microsatellite loci

Summary The chromosomal assignment of 64 PCR-amplified microsatellite loci and 29 additional fragments amplified by the same primer pairs is described for bread wheat (Triticum aestivum). The distribution over the different chromosomes and chromosome arms appears to be random. The highest proportion of microsatellite loci is found on the B genome, followed by the A and D genome. About half of the primer pairs amplified unique fragments, while the other half amplified additional fragments. 25% of the primer pairs, mostly designed to clones of a PstI-library, amplify fragments on homoeologous chromosomes. In some cases, more than one fragment on a single chromosome or fragments on non-homoeologous chromosomes occurred. The use of an automated DNA sequencer accounts for the accurate resolution of multiple fragments and enables to differentiate between fragments, amplified by a single primer pair, with size differences as small as two base pairs.     

Stable classification and nomenclature in the Triticeae: desirability,limitations and prospects

Summary The two causes of destabilization of names in the tribe Triticeae are discussed in detail. These include changes in names due to changing classifications and changes in names due to application of nomenclatural rules. We favour the opinion that a classification should be based on maximum information and not on one single character like the genome as suggested in a recent classification of Dewey and that of Löve. The problem of changes in names is discussed using two examples-Triticum-Aegilops group and Agropyron-Elytrigia-Leymus group. The users of Triticeae grasses, should always authenticate the material they are using and specify the scheme or reference of classification they follow in naming their material, even though one would have the freedom to use a particular classification and thus the names given in this classification.The problem of instability in the names of Triticeae grasses due to nomenclatural rules are discussed using the examples of bread wheat (T. aestivum) and of Haynaldia villosa. A list of recommended names of World's flora for preservation as suggested by Brummitt recently has also been examined.     

Forage Chicory: A Plant Resource for Nutrient-Rich Sites

Grazing livestock create localized nutrient patches that increase soil ionic strength (IS) and influence plant productivity. The ability of plant root systems to control ion absorption and flux to xylem, and to sequester ions reaching leaf tissue in bound, nontoxic forms are means of minimizing IS. A greenhouse experiment was conducted to determine the growth and mineral acquisition responses of forage chicory (Cichorium intybus L. cv. Grasslands Puna) to increasing (0.9, 4, 8, and 12 dS m^?1) IS in the rhizosphere obtained by additions of NaCl/CaCl₂ (1 : 1 m ratio). Plants were harvested four times after planting (20, 27, 34 and 41 d) to identify responses as a function of time. Increased accumulation and localization of Na in roots in comparison to shoots suggested that chicory restricted Na transport to shoots, and that insoluble Na in tissues increased with increasing IS. Soluble cations in shoots were about 50 % of total cations, irrespective of rhizosphere IS and Na uptake. Differences in the cation:anion ratio could not be accounted for by organic acid concentrations in chicory, but substantial accumulation of nonstructural carbohydrates as fructans in roots could contribute to charge balance. Our results demonstrate that forage chicory has moderate tolerance to IS, suggesting that it might be a useful species for sites with potential for IS. Chicory growth would probably be sustained under IS conditions, and the resultant vigorous growth and accumulation of mineral nutrients in shoots would contribute to acceptable nutritive value for grazing livestock. Plants capable of growing in and acquiring nutrients from nutrient‐laden patches in the sward would help minimize erosion and nutrient transport, with positive benefits for water and soil quality.     

植物叶绿素含量不同提取方法的比较研究

为探索不同提取液提取爬山虎叶绿素的效果,分别采用80%丙酮溶液、96%乙醇溶液、90%乙醇丙酮混合溶液、95%乙醇丙酮混合溶液四种提取溶液来提取五叶爬山虎叶片叶绿素。结果表明：叶绿素溶液吸收峰的峰值和不同提取液对植物叶绿素的提取能力随提取液的不同而不同,由大到小排序的顺序为95%丙酮乙醇溶液>90%丙酮乙醇溶液>80%丙酮>96%乙醇,相比于研磨法,用试剂浸泡法的叶绿素提取效率更高,这可为准确提取与检测植物叶绿素的提供一定参考作用。     

油菜种子中亚麻酸研究现状及改良思路

提高油菜种子（油）中亚麻酸含量对缓解目前亚麻酸资源日益紧缺的压力、提高国民健康水平均具有重要意义。本文从形成过程、含量差异、影响因素、杂种优势、遗传方式和控制基因等方面对油菜种子中亚麻酸研究现状进行了综述;在剖析油菜高亚麻酸育种的意义、可行性、难点的基础上,提出开展高亚麻酸种质资源创新利用,创建高亚麻酸育种体系,建立高效保优栽培技术体系,开展油菜籽加工技术和抗氧化研究,构建标准体系等5个方面促进油菜高亚麻酸产业发展的建议。     

一个含LoxP-FRT重组酶位点及易于操作的植物表达双元载体pYBA100

在农杆菌(Agrobacterium tumefaciens)介导的植物遗传转化中,常常需要用到植物表达双元载体。为便于基因工程操作并能在获得转基因植物后方便将标记基因删除,我们构建了植物表达双元载体pYBA100,以满足用于生产安全转基因植物的需要。本研究通过融合PCR方法,尽可能去除所有非必需的序列,将pYBA载体最小化。pYBA载体在大肠杆菌中为多拷贝,骨架为3.69kb。我们构建的含NptⅡ植物筛选标记基因的载体pYBA100仅为5.37kb,多克隆位点为22个,方便基因工程操作。载体pYBA100的T-DNA植物筛选基因表达框两侧预留有LoxP-FRT融合位点,方便在获得转基因植物后通过Cre或FLP重组酶将植物筛选标记基因删除。pYBA100载体能于大肠杆菌和农杆菌中自我复制,并成功转化了拟南芥,符合农杆菌介导的植物转基因要求。离体删除实验结果证明,载体pYBA100能经Cre重组酶删除植物标记基因表达框。     

云南小麦品种(系)株高和粒重相关功能基因的KASP标记检测

利用矮秆基因Rht-B1、Rht-D1和千粒重功能基因TaCwi-A1、TaGW2-6A、TaSus2-2B的KASP标记,对云南省育成的42份小麦品种(系)进行单倍型检测,旨在筛选出含有目标基因的优异小麦种质,为云南省小麦产量相关性状的遗传改良提供材料和方法。结果表明,供试材料的株高基因组成分为5种类型,分别为Rht-B1a/Rht-D1a(40.48%)、Rht-B1a/Rht-D1b(23.81%)、Rht-B1a+197bp/Rht-D1a(4.76%)、Rht-B1b/Rht-D1a(28.57%)、Rht-B1b/Rht-D1b(2.38%)。供试材料中TaCwi-A1基因TaCwi-A1a高粒重单倍型的分布频率为42.86%,TaGW2-6A基因Hap-6A-A高粒重单倍型的分布频率为38.10%,TaSus2-2B基因Hap-H高粒重单倍型的分布频率为71.43%。5份品种(系)为3个千粒重基因的TaCwi-A1a/Hap-6A-A/Hap-H高粒重单倍型组合,频率为11.90%。研究表明,云南小麦品种(系)产量相关性状具有较好的遗传改良潜力。     

Methods for Plant Differential Expressed Gene Cloning and Progress

The research of plant genome has been transferred from the structural genomics focusing on determining the complete sequences of the genome to the functional genomics focusing on elucidating the biological function of genes. Now cloning differential expressed genes is of prime interest in molecular biology. In the past ten years, some methods used for studying changes of gene expression in plants have been developed. The authors review the developments of techniques and studies for the plants related gene cloning in RNA level and expound their principles, technical routes, improved methods, advantages and defects. Moreover, their applications and prospects in plants related studies are discussed.     

Chromosomal location of fertility restoring genes for ‘wild abortive’ cytoplasmic male sterility using primary trisomics in rice

Summary Identification and location of fertility restoring genes facilitates their deployment in a hybrid breeding program involving cytoplasmic male sterility (CMS) system. The study aimed to locate fertility restorer genes of CMSWA system on specific chromosomes of rice using primary trisomics of IR36 (restorer), CMS (IR58025A) and maintainer (IR58025B) lines. Primary trisomic series (Triplo 1 to 12) was crossed as maternal parent with the maintainer line IR58025B. The selected trisomic and disomic F₁ plants were testcrossed as male parents with the CMS line IR58025A. Plants in testcross families derived from disomic F₁ plants (Group I crosses) were all diploid; however, in the testcross families derived from trisomic F₁ plants (Group II crosses), some trisomic plants were observed. Diploid plants in all testcross families were analyzed for pollen fertility using 1% IKI stain. All testeross families from Group I crosses segregated in the ratio of 2 fertile: 1 partially fertile+partially sterile: 1 sterile plants indicating that fertility restoration was controlled by two independent dominant genes: one of the genes was stronger than the other. Testcross families from Group II crosses segregated in 2 fertile: 1 partially fertile+ partially sterile: 1 sterile plants in crosses involving Triplo 1, 4, 5, 6, 8, 9, 11 and 12, but families involving triplo 7 and triplo 10 showed significantly higher X² values, indicating that the two fertility restorer genes were located on chromosome 7 and 10. Stronger restorer gene (Rf-WA-1) was located on chromosome 7 and weaker restorer gene (Rf-WA-2) was located on chromosome 10. These findings should facilitate tagging of these genes with molecular markers with the ultimate aim to practice marker-aided selection for fertility restoration ability.     

竞争性等位基因特异性PCR分型技术在植物抗病遗传育种中的应用

单核苷酸多态性(single nucleotide polymorphism,SNP)广泛分布在植物基因组中,位点丰富,易于实现高通量分析.竞争性等位基因特异性PCR(kompetitive allele specific PCR,KASP)是一种对特定位点处的SNP以及插入和缺失(insertion-deletion...     

Development of near-isogenic lines of wheat carrying different null Wx alleles and their starch properties

The granule-bound starch synthase (GBSS I) encoded by the Wxgenes, is involved in amylose synthesis. For analyses of mechanisms of amylose synthesis and associated starch properties in hexaploid wheat, eight possible genotypes having different combinations of the three null alleles at the Wx loci with a common genetic background are a prerequisite. A near-isogenic population of doubled haploid (DH) lines was produced from Chinese Spring × waxy Chinese Spring F₁ plants using the wheat × maize method. The Wx protein phenotypes of the DH progeny were examined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and found that the null alleles at each of the three Wx loci segregated in a Mendelian fashion. A field trial demonstrated no differences between the eight types for ear emergence time, plant height and grain yield traits. Amylose content in the endosperm starch was highest in the wild type while lowest in the waxy type having no Wx proteins. Comparison between single null types and double null types indicated that the amylose synthesis capacity of Wx-A1a allele is the lowest. Pasting properties of starch are the highest in the waxy type, followed by the double null types. Consequently, both peak viscosity and breakdown were negatively correlated with amylose content. The chain-length distribution analysis of amylopectin structure revealed no clear difference among the eight types,suggesting that the reduced GBSS I activity due to introgression of the null Wx alleles does not affect either the chain length or the degree of branching of amylopectin. This revised version was published online in July 2006 with corrections to the Cover Date.     

Gene dosage effect of the wheat Wx alleles and their interaction on amylose synthesis in the endosperm

To find out gene dose effect of each of the three homoeologous Wx genes and their interaction on the production of granule-bound starch synthase (GBSS I) and amylose biosynthesis in the endosperm, Chinese Spring and its near-isogenic waxy types were crossed reciprocally and, obtained a plant population with varying doses of each Wx gene. The amount of GBSSI was increased linearly with increasing gene dose of either of Wxloci. In each of the three Wx loci, the change in amylose content was linear up to 3 doses, with a more potent capacity ofWx-B1a at any dose. Higher level of amylose production was observed in the reciprocal F₁ grains than the expected effect of dose/s of each gene or additive effect of different allelic combination by artificially blend starches which have amylose produced by equivalent number ofWx alleles to that of relevant F₁ cross. When Wx-B1a and Wx-A1a were combined, increase in amylase content was not in proportion to increase in gene dosage. The enhanced amylase synthesis was shown by 2-gene and 3-geneinteraction, indicating that not only type of the three Wx genes and its dose but the interaction among them have significant roles in determining the amylose content. This revised version was published online in July 2006 with corrections to the Cover Date.     

陆地棉品种百棉1号主要株型性状的遗传研究

对陆地棉品种百棉1号主要株型性状进行了主基因-多基因混合遗传分析。结果表明,株高、果枝长度、株高/果枝长度、主茎节间长度、果枝节间长度、总果节数、总果枝数、有效果枝数和果枝夹角的最适模型分别为D-4、C-0、D-4、D-2、E-0、D-2、B-1、B-1和C-0,除果枝长度和果枝夹角外,其它性状均检测到主基因。总果枝数、有效果枝数和果枝节间长度为主基因遗传或以主基因遗传为主,对其可采用单交重组或简单回交转育转移增效主基因;株高、株高/果枝长度、主茎节间长度、果枝长度和果枝夹角为多基因遗传或以多基因遗传为主,对其可采用聚合回交或轮回选择累积增效多基因;总果节数以主基因和多基因遗传并重,对其可根据主基因、多基因相对效应大小分别考虑。     

Inheritance of zeins: The catalogue of zein alleles of three multigenic loci and its potential for maize breeding

Inheritance of zein components in maize has been studied by a highresolution system of acidic continuous polyacrylamide gel electrophoresis. This method revealed extraordinarily high polymorphism of zeins. Previously, three multigenic loci, Zep1, Zep2 and Zep3, encoding most zein polypeptides were identified. Four other loci control the synthesis of some minor components. Single F₂ grains from 16 hybrid combinations involving 19 inbred lines were analysed. Correspondingly, 12 and 14 alleles of the Zep1 and the Zep2 loci were identified for 19 inbreds. Six alleles of the Zep3 locus were identified in five crosses. All 32 alleles of three multigenic loci were included in the catalogue of zein alleles. Genetic nomenclature for the alleles designation is proposed. Such nomenclature is in good agreement with ‘a standard for maize genetics nomenclature. The catalogue may serve for practical use and as basis for more detailed genetic studies of zeins. Practical application of the catalogue in maize breeding is discussed.     

植物抗寒剂研究进展

旨在为植物抗寒剂的研发及应用提供科学依据。笔者首先简要介绍了植物抗寒剂的定义、特点,并通过概括植物细胞内游离脯氨酸、可溶性糖含量以及保护酶活性等生理指标对植物抗寒性的影响,分析了植物抗寒剂的作用机理。其次依据时间顺序总结了国内外植物抗寒机理的研究进展及抗寒剂的研发历程,详细阐述了植物抗寒剂的国内外研究现状。最后简要分析了目前植物抗寒剂研发存在的问题以及未来的发展趋势,对今后抗寒剂研究的方向和思路做出了比较可靠的趋向预测。     

超甜玉米果糖含量的遗传模型分析

以8个超甜玉米自交系为亲本,按照Griffing Ⅱ双列杂交方法配制组合,利用Hayman法分析了超甜玉米果糖含量的杂种优势及遗传模型。结果表明：（1）果糖性状表现出较高的超低亲优势和超中亲优势及一定的超高亲优势;（2）果糖性状的遗传受加性基因和非加性基因的共同控制,符合“加性-显性-上位性”模型,平均显性度为1.15,表现为超显性;狭义遗传力为10.92%,广义遗传力为94.15%;（3）控制甜玉米果糖含量性状遗传的基因最少有4对基因。因此,超甜玉米高含糖量亲本选育和新组合配制实践中,应在利用基因显性效应的基础上,协调加性效应及上位性效应,制定高效快捷的育种方案以提高超甜玉米的商品质量和食用品质。     

沙生经济植物沙米出苗土壤水分阈值研究

出苗是植物成苗的最重要阶段,明确沙米出苗的土壤水分阈值,对促进野生沙米种群发展和推进沙米人工种植具有重要意义.本文通过设置温度、播种时间、土壤含水率梯度盆栽控制试验,研究沙米不同条件下的出苗率变化,以确定沙米在风沙土出苗的适宜土壤水分含量.结果 表明:(1)室内3个不同温度梯度、供试风沙土播前掺水(或播后喷水)的沙米出...