冬小麦春化过程中可溶性蛋白质组成的变化与形态发生的关系

冬小麦“农大139”经40天左右的春化处理才能迅速而整齐地抽穗,但经14—21天低温处理,已经具有在夏季抽穗的可能性,虽然抽穗推迟且极不整齐;再将春化时间延长,则抽穗百分比增加,且从播种到抽穗的时间缩短。这表明,春化过程中低温对发育的作用有两种效应:前期低温是诱发生理状态的转变,后期低温则只具有加速发育的作用,两个时期的转变是在春化的中期。蛋白质合成抑制剂乙基硫氨酸和对-氟苯丙氨酸能抑制冬小麦的春化,抑制时期也是在春化过程的中期。不同时间低温处理后冬小麦幼芽中可溶性蛋白质含量及组成发生了变化,春化过程中期(低温处理14天之后)不仅含量比对照增加了一倍,而且有新的蛋白质谱带出现。春麦中无类似现象,未经低温处理的春麦已含有冬麦中新出现的谱带。说明冬小麦春化过程的第14—21天左右是与春化过程有关的蛋白质合成的关键时期,该时期新合成的蛋白质与植株的发育状态之间存在着密切的相关关系。     

Zearalenone-Like Substance in Winter Plants and Its Relation to Vernalization

It was found that there is a zearalenone-like substance in the growing points of vernalized wheat seedlings and carrot plants. The content of this substance synchronously increased with the depth of vernalization. It was separated by thin layer chromatography. Its UV spectrum was similar to that of zearalenone. It is believed that this substance may be one of the important endogenous substances which control the vernalization of winter plants.     

Protoplast Culture and Plant Regeneration of Winter Wheat (Triticum aestivum L.)

Suspension cultures were established from embryogenic calli derived from cultured anthers of cv. Jinghua No.1 and mature embryos of cv. Youmangbai No. 7, respectively. After being isolated and cultured in WPMI, protoplasts began to form cell walls within 1 day post-isolation, followed by cell division observed between 2–3 days. A division frequency of 22.0% was estimated on the 7th day of culture, and 43.7% on the 14th day. During 10–15 days after the initiation of culture, a large number of cell aggregates emerged, with 0.5–0.8% of plating efficiency. Protoplast-derived calli grew up to lmm or more in diameter when cultured for 4 weeks, and eventually gave rise to green plants through embryogenesis and organogenesis after being transferred to differentiation media. Plant regeneration from protoplasts was already obtained from Jinghua No.l, and protoplast-derived calli from Youmangbai No.7; an experiment on organ differentiation for the latter is under way. A few factors affecting the protoplast cultures were also studied.     

Molecular Cloning of a Vernalization related cDNA Clone (Vrc) of Vrc79 in Winter Wheat (Triticum aestivum L.)

Vernalization is an essential factor in the flowering development of cold-required plants. There is a key stage of nucleic acid metabolism in the process of vernalization in winter wheat. To probe into the molecular determinants of vernalization, a cDNA library presumably enriching vernalization-related genes was prepared by specially expressed mRNAs from winter wheat ( Triticum aestivum L. cv. Jingdong No. 1) plumules at the key stage of 21 d vernalization being recovered as cDNAs after subtraction with mRNAs from nonvernalized and devernalized plumules. One vernalization-related cDNA clone (Vrc), Vrc79, which was only expressed at the key stage of 21 d vernalization, but not at other stages of nonvernalization, 4 d vernalization and devemalization, was isolated by differential screening of the library, and shown to be a vernalization-specific clone by Northern blot. Result of homology search suggested that Vrc79 was a novel gene identified in higher plant which was different from the cold-stress-induced genes and might play an important role in the floral induction in vernalization-requiring plants.     

冬小麦春化过程中低温诱导的与花芽分化相关的mRNA和蛋白质的合成

应用SDS电泳及高分辨双向电泳技术,分析了冬小麦经春化、脱春化及超期春化处理后茎类蛋白质组分的变化。发现52.5,38kD和16.2kD蛋白质与冬小麦开花诱导密切相关。mRNA体外翻译结果表明,春化作用中低温诱导与开花紧密相关的mRNA的出现有一定的顺序性。因此推测:春化诱导开花是低温导致某些特定基因表达的结果,而表达的调节主要发生在转录水平上。     

Inheritance of cell size in wheat (Triticum aestivum L.) and its relationship to the vernalization loci

Reduced cell size is an important adaptive feature in plant response to environmental stresses. The objectives of the present study were to determine the inheritance and location of genes controlling cell size and to establish the relationship between cell size, low-temperature (LT) tolerance, and growth habit as determined by the Vrn loci in wheat. Guard cell length was measured in F₁, F₂, andF₂-derived F₃ populations from parents ranging widely in cell size and in the Chinese Spring/ Cheyenne (CS/CNN) chromosome substitution series. The cell size of F₁ hybrids was similar to the parental midpoint and the F₂ frequency distribution was symmetrical about the mean indicating that cell size was determined by additive gene action with little or no dominance. It appears that there are several genes involved since none of the F₂ progeny had a cell size as large or as small as the parental mean range. The cell size of the homozygous spring and winter lines from F₂-derived F₃ populations fell into two distinct groups that were related to plant growth habit. Large cell size was associated with the spring-habit alleles (Vrn-A1) and small cell size was associated with the winter-habit alleles (vrn-A1) on chromosome 5A. Analyses of the CS/CNN chromosome substitution series showed that CNN chromosomes 5A and 5B both reduced cell size without changing the growth habit, indicating that growth habit per se does not determine cell size. The group-5 chromosomes therefore appear to carry homoeologous alleles with major effects on cell size in wheat. This places cell-size control and many other low-temperature (LT) tolerance associated characters in close proximity to the vrn region of the group-5 chromosomes. Received: 17 August 2000 / Accepted: 20 November 2000     

Whole Genome Association Mapping of Plant Height in Winter Wheat (Triticum aestivum L.)

The genetic architecture of plant height was investigated in a set of 358 recent European winter wheat varieties plus 14 spring wheat varieties based on field data in eight environments. Genotyping of diagnostic markers revealed the Rht-D1b mutant allele in 58% of the investigated varieties, while the Rht-B1b mutant was only present in 7% of the varieties. Rht-D1 was significantly associated with plant height by using a mixed linear model and employing a kinship matrix to correct for population stratification. Further genotyping data included 732 microsatellite markers, resulting in 770 loci, of which 635 markers were placed on the ITMI map plus a set of 7769 mapped SNP markers genotyped with the 90 k iSELECT chip. When Bonferroni correction was applied, a total of 153 significant marker-trait associations (MTAs) were observed for plant height and the SSR markers (−log₁₀ (P-value) ≥4.82) and 280 (−log₁₀ (P-value) ≥5.89) for the SNPs. Linear regression between the most effective markers and the BLUEs for plant height indicated additive effects for the MTAs of different chromosomal regions. Analysis of syntenic regions in the rice genome revealed closely linked rice genes related to gibberellin acid (GA) metabolism and perception, i.e. GA20 and GA2 oxidases orthologous to wheat chromosomes 1A, 2A, 3A, 3B, 5B, 5D and 7B, ent-kaurenoic acid oxidase orthologous to wheat chromosome 7A, ent-kaurene synthase on wheat chromosome 2B, as well as GA-receptors like DELLA genes orthologous to wheat chromosomes 4B, 4D and 7A and genes of the GID family orthologous to chromosomes 2B and 5B. The data indicated that besides the widely used GA-insensitive dwarfing genes Rht-B1 and Rht-D1 there is a wide spectrum of loci available that could be used for modulating plant height in variety development.     

小麦品种的耐肥性与光合作用

本试验以耐肥性不同的三个冬小麦品种为试材,研究了品种的耐肥性与光合作用的关系。结果表明,旗叶的光合速率顺序为: 泰山一号(中度耐肥)>济南13(高度耐肥)>昌乐5号(不耐肥)。光合速率的绝对值虽因不同年度间环境条件的不伺而有所变动,但品种间的差别则保持相对稳定。增施氮肥,能使昌乐5号的光合速率明显降低,而泰山—和济南13的光合速率则因增施氮肥受到显著的促进。     

干旱胁迫下小麦叶片脯氨酸和蛋白质含量变化与染色体的关系

以中国春-Synthetic 6x小麦染色体代换系及其亲本为材料,研究干旱胁迫条件下染色体对不同生育时期叶片脯氨酸和蛋白质含量的调控效应。结果表明,在干旱胁迫条件下,1D和5D代换系叶片的脯氨酸含量变化在孕穗期、开花期、灌浆期始终显著或极显著高于中国春;而4A、4B、2D和6D代换系的可溶性蛋白质含量变化始终显著或极显著低于中国春。表明,Synthetic 6x的5D和1D染色体上可能有干旱胁迫下促进脯氨酸积累的基因存在,Synthetic 6x的4A、4B、2D和6D染色体上可能有干旱胁迫下抑制蛋白质含量下降的基因存在,小麦叶片游离脯氨酸的积累与可溶性蛋白质含量的下降无显著相关性。     

Seed Storage Protein Profiles of Seven Indian Wheat (Triticum aestivum L.) Varieties

Seed storage protein profiles, Including triticin, gliadin and glutenin, of seven Indian wheat varieties were Investigated using sodium dodecyl sulfate-polyacrylamide gel eletrophoresis (50S-PAGE). A strategy was developed for half-seed analysis of the three seed storage protein classes. The results are presented In the form of a key for Identification of these varieties based on their seed protein composition. A minimum of 10 seeds of each variety were analysed to check for possible intravarietal heterogeneity, and all the varieties except HUW-12 were homogeneous. The HUW-12 was a mixture of two ‘biotypes’ with respect to the low molecular weight (LMW) glutenin subunits coded by the Glu-A3 locus. The varieties were also analysed for the presence of rye chromatin using a rye-specific repetitive DNA probe (pAW-161), and two of the recently released varieties HUW-206 and HUW-318 were found to possess rye chromatin. Based on the DNA dot-blot results, presence of rye secalins and the absence of chromosome 1 B-speclflc gliadlns It was concluded that these two varieties possess 1BL-1RS wheat-rye translocation. Both of these varieties also have high molecular weight (HMW) glutenin subunits 5 + 10 which may be necessary for compensating the loss of dough strength associated with the wheat-rye translocations.     

小麦蛋白质和淀粉含量与籽粒发育过程中内源激素含量的关系

研究粒重差异较小、蛋白质和淀粉含量差异大的小麦品种‘川麦107’和‘川麦36’籽粒发育过程中激素含量变化与籽粒蛋白质和淀粉积累之间关系的结果表明,‘川麦36’蛋白质含量一直高于‘川麦107’的,而其淀粉含量一直低于‘川麦107’;‘川麦36’籽粒中ZR初始含量和IAA峰值高些,开花后5~20d籽粒中ZR含量与蛋白质含量呈显著正相关,IAA峰值与此期的蛋白质积累速率跃变相对应。两品种籽粒中GA峰值与蛋白质含量的低谷相对应,开花后5~30d的籽粒中GA含量与淀粉含量呈极显著正相关,而‘川麦107’籽粒中GA含量较高。     

九个春化作用特性不同的小麦品种中VRN1基因的组成和特性分析

采用序列特异性PCR扩增技术,分析9个春化特性不同品种小麦春化基因VRN1在A、B和D基因组中等位基因的显隐性组成特性的结果表明:小麦品种'辽春15'中春化基因VRN1的A、B和D等位基因均为显性;小麦品种'新春2号'只在A基因组中为显性;小麦品种'豫麦18'的D基因组中为显性;'郑麦9023'和'新冬18'两个品种的B基因组中为显性;'周麦18'、'豫麦49-198'、'京841'和'肥麦'4个品种的A、B和D等位基因均为隐性.     

Floret Initiation and Development in Spring Wheat (Triticum aestivum L.)

The number and developmental stages of florets were determinedin each spikelet of the spike in the main shoots of spring wheat.Samples were taken frequently from plants grown in a phytotronand in a nitrogen application field-test. Ten stages of development,from floret initiation until anthesis, were recognized and described. Inter-spikelet variation in the total number of initiated floretswas rather small. However, the number of florets at advancedstages of development, as well as the number of grains, washighest in the central spikelets in which florets initiatedfirst. Floret initiation did not proceed beyond spike emergence,whereafter the distal florets and the spikelet apex degenerated.Grain-set was restricted to florets which had developed at leastto the stage of visible anther lobes at spike emergence. Thenumber of these florets was increased significantly by nitrogenapplication. Wheat, Triticum aestivum L., spikelet, floret, grain set, nitrogen     

Colchicine-induced Paracrystals in Root Cells of Wheat (Triticum aestivum L.)

Tubulin conformations other than microtubules in the meristematiccells of wheat roots grown in the presence of 2 mM colchicinesolution were investigated by immunofluorescence and electronmicroscopy. In the affected cells microtubules disappeared andwere replaced by tubulin fluorescent strands that occurred inthe cortical cytoplasm. With increasing time of exposure tocolchicine the tubulin strands became better organized and occurredalso in the subcortical cytoplasm and finally they were restrictedto the area around the nucleus. In prophase and preprophasecells thick strands occupied the cortical cytoplasmic zone wherein normal cells a preprophase microtubule band (PMB) was expectedto be assembled. In the colchicine-treated cells electron microscopy revealedan accumulation of paracrystalline aggregates, which initiallyoccurred along the cell wall and later deeper in the cytoplasm,in the perinuclear regions and the cytoplasmic invaginationsof the nucleus. In transverse planes the paracrystalline strandsappear to consist of hexagonal subunits in a 'honeycomb' arrangement,while in longitudinal and oblique sections they exhibit variableimages. Since their distribution coincides with that of thetubulin strands visualized by immunofluorescence, they are consideredto be the same structure. Therefore, the paracrystals consistof, or at least contain, tubulin. They are most likely to bepolymers of tubulin-colchicine complexes.Copyright 1995, 1999Academic Press Wheat roots, colchicine, immunofluorescence, electron microscopy, tubulin paracrystals, Triticum aestivum L     

用C—带技术识别小麦21对染色体及染色体结构变异

用C-带技术分析了普通小麦中国春、84001-1-33和扬麦3号的根尖染色体,结果如下:(1)除1A外,普通小麦的所有染色体均可显示出稳定的区分性带型;(2)以中国春小麦为标准建立了C-带核型;(3)对照中国春的C-带核型,发现84001-1-33的5B,7B染色体发生了相互易位,形成了重组染色体——5BS/7BS和7BL/5BL;(4)扬麦3号的1B,4B染色体与中国春明显不同,从带型上看有可能扬麦3号的1B和4B的长臂之间发生了相互交换,交换的区段包括1B,4B长臂的大部分。     

A Study of Floret Development in Wheat (Triticum aestivum L.)

Plants of wheat (Triticum aestlvum L.) cv. Aotea were grownat high or low nitrogen levels and in a natural photoperiodor continuous light. Starting 17–21 days from the double-ridgestage, eight plants from each treatment were sampled every 3days until anthesis, and the two basal, the sixth, and the terminalspikelets were sectioned longitudinally. A developmental scorewas assigned to each floret and rates of development calculated.Continuous light hastened development but reduced the numberof spikelets per ear, while high nitrogen delayed developmentbut increased spikelet numbers. The number of florets initiatedin each spikelet varied within narrow limits, but grain settingdepended strongly on spikelet position and on treatment. Althoughflorets were initiated in acropetal succession, the rate ofdevelopment tended to increase up to floret 4 but then declinedmarkedly. As a result grain setting was confined to basal floretpositions, although the two basal spikelets developed so slowlythat they contributed relatively little to grain yield. Distalflorets degenerated almost simultaneously at or before ear emergence,but those in intermediate positions continued to develop untilafter fertilization in the lower florets. It is argued thatthe spikelet is an integrated system in which correlative mechanismsplay a part throughout the development of the florets.     

Quantitative-genetic analysis of reciprocal crosses between a winter and a spring cultivar of common wheat (Triticum aestivum L.)

The winter wheat cultivar Sakhalin (parent A) and the spring wheat cultivar Khush-hal (parent B), assumed to be both nuclear-genetically and plasmotypically different, were reciprocally crossed and the F₁ generation of the reciprocals backcrossed to either parent. The populations (AxB)F₁, (AxB)F₂, [(AxB)F₁xA]F₁ and [(AxB)F₁xB]F₁, and their reciprocals (BxA)F₁, (BxA)F₂, [(BxA)F₁xA]F₁ and [(BxA)F₁xB]F₁, assumed to have the plasmotypes of the parents A and B respectively, were spring sown in the same field from unvernalized (experiment #1) and vernalized (experiment #2) seeds. The results of the analyses of variance of the data recorded in the two experiments are fairly similar. In both the experiments the plasmotypically A populations have produced more heads and higher grain yields per plant than their plasmotypically B reciprocals. The components of the family means and of half the differences between the reciprocals within the families show that vernalization has not affected the efficiency of the nuclear genes of parent A but has reduced the efficiency of the nuclear genes of parent B in both the homozygous and the heterozygous states. This in turn has affected the components of family mean squares and those of the family x reciprocals interaction mean squares in the analysis of variance tables.