Breeding and molecular cytogenetic identification of wheat-Thinopyrum intermedium addition lines resistant to powdery mildew

Wheat-related species Th. intermedium was used to cross with common wheat Yannong 15. In the self progenies of the hybrid, two addition lines, Ⅱ-1-7-1 and Ⅱ-3-3-2, stable in cytology, were developed by cytology and powdery mildew resistance identification. Their chromosome number were 2n = 44 and formed 22 bivalents at PMC MI. In F1 of the two addition lines crossing with Yannong 15, there appeared about one univalent at PMC MI, respectively. Resistance identification in greenhouse and field using the No. 15 and mixed strains of E. gramnis f. sp. tritici showed that they were immune to powdery mildew. Chromosome number and resistance identification using the F2 single plants of the addition line crossing with Yannong 15 indicated that the resistant gene was located on the alien chromosomes. In situ hybridization using St and E genomic DNA as probe showed that the added chromosome in the two addition lines probably came from the E genome of Th. intermedium, which indicated that a pair of E genome chromosomes carried a new resistant gene to powdery mildew.     

抗白粉病硬簇麦-Am3杂种后代的形态学及细胞学鉴定

对硬簇麦与Am3的杂交后代进行白粉病抗性鉴定,从中选出9个抗白粉病的种质系。形态学鉴定结果表明,9个种质系的形态学特点明显不同于双亲,主要农艺性状表现较好。细胞学鉴定结果表明,9个种质系的根尖细胞染色体数目均为42,花粉母细胞减数分裂中期I基本形成21个二价体,偶尔有单价体或多价体出现,但频率较低,相对紊乱系数较小,说明9个种质系在细胞学上已基本稳定。     

Breeding of T. aestivum-Ag. intermedium translocation lines with T. timopheevii cytoplasm and characterization by GISH

A male-sterileT. aestivum-Ag. intermedium partial amphiploid with cytoplasm ofT. timopheevii as a female parent was crossed to common wheat. The hybrid was backcrossed to the male parent several times continually and setf-crossed at last. Two stable lines with common wheat phenotype, H96269-2 and H96278, have been obtained. The chromosome numbers of the two lines are all2n = 42 in somatic cetls. By inoculation test, the two lines show a high levet of resistance to yetlow rust. Through genomicin situ hybridization (GISH) withAg. intermedium total genomic DNA as a probe, it is demonstrated that the two stable lines are all small segmental translocation lines, and the translocated chromosome segments fromAg. intermedium are located on the short arm terminals of wheat chromosomes. Genetics analysis suggests that the yetlow rust resistance gene(s) are probably located on the translocated chromosome segments ofAg. intermedium.     

Tracing the location of powdery mildew resistance-related gene Stpk-V by FISH with a TAC clone in Triticum aestivum-Haynaldia villosa alien chromosome lines

Bacterial artificial chromosomes(BACs)or yeast artificial chromosomes(YACs)containing large inserts as probes for fluorescence in situ hybridization(FISH)have been used in the physical mapping of specific DNA sequences,especially for single-or low-copy sequences.Our earlier study identified Stpk-V,a powdery mildew resistance-related gene located on the 6VS chromosome arm of the wild grass Haynaldia villosa(tribe Triticeae),and obtained several Triticum aestivum–H.villosa alien chromosome lines carrying the Stpk-V gene.However,the precise physical location of the Stpk-V gene on chromosome 6VS is not known.In this study,we used TAC-FISH with TAC15 as the probe coupled with sequential genomic in situ hybridization(GISH)to determine the physical location of the Stpk-V gene in different T.aestivum–H.villosa 6V alien chromosome lines,including addition,substitution and translocation lines.The result indicated that the fraction length of the Stpk-V locus is 0.575±0.035 on the 6V chromosome short arm and this was confirmed by FISH using TAC15 as the probe for tracing the Stpk-V gene in other genetic stocks.The cytological mapping strategies used in this study will be of benefit for tracing the alien gene location in the course of introducing desirable traits from wild species.     

小麦F1和F2代抗白粉病性的配合力遗传力及相关分析

用８个抗白粉病性不同的春小麦品种进行不完全双列杂交，对亲本及杂交后代的抗白粉病性进行了遗传分析，结果Ｆ１和Ｆ２代抗白粉病性一般配合力和特殊配合力方差及ＭＳｇ．ｃ．ａ／ＭＳｓ．ｃ．ａ均达显著或极显著水平，抗白粉病性加性效应为主。     

Gene expression profiling related to powdery mildew resistance in wheat with the method of suppression subtractive hybridization

“Bainong 3217 × Mardler” BC₅F₄ wheat line at the initial stage of inoculation with powdery mildew pathogen (Erysiphe graminis DC) was used to construct a suppression subtractive hybridization (SSH) cDNA library. Totally 760 ESTs were obtained through sequencing. Similarity analysis of ESTs based on BLASTn and BLASTx with the sequences in GenBank, in combination with macroarray differential screening, revealed that 199 ESTs of 65 kinds were known to be functionally disease resistance related. Based on the gene expression profiling in the present study, it is postulated that salicylic acid (SA) and MAP-related signal transduction pathways were involved in powdery mildew resistance in wheat. System acquired resistance genes were predominant in terms of kinds and quantity. With the initiation of cell defense reaction, the genes conferring anti-oxidation substances were largely expressed and thus cell protection mechanism was activated. Much evidence revealed that phenylpropanes metabolic pathway was involved in phytoalexin synthesis in wheat powdery mildew resistance. Genes conferring some enzymes of structural modification of cell walls and proteinase inhibitors inhibiting pathogen growth were also detected. The genes controlling a few proteinases (mainly cysteine proteinase) had a considerable redundancy of expression.     

Analysis of F1 hybrid and BC1 monosomic alien addition line plants from Brassica oleracea × Sinapis alba by GISH

Sterile and semi-fertile F₁ plants were obtained by intergeneric sexual hybridization between paternal Brassica oleracea var. alboglabra (genome CC, 2n=18) and maternal Sinapis alba (genome SS, 2n=24), BC₁ plants were obtained by backcrossing between paternal B. oleracea and maternal semi-fertile F₁ plants. Genomic in situ hybridization (GISH) combined with dual-colour fluorescence in situ hybridization (dcFISH) showed that sterile F₁ plants contained 21 chromosomes consisting of one B. oleracea chromosome set and one S. alba chromosome set, belonging to expected hybrids, and semi-fertile F₁ plants contained 30 chromosomes consisting of two B. oleracea chromosome sets and one S. alba chromosome set. It is obvious that the semi-fertile F₁ plants belong to unexpected hybrids. 1―3 trivalents were detected at meiotic metaphase I of semi-fertile F₁ pollen mother cells (PMCs). Different separation ratios of S chromosomes were detected at anaphase I. A monosomic alien addition line (MAAL) was identified by GISH-dcFISH from BC₁ plants; it contained 19 chromosomes consisting of 18 C chromosomes and 1 S chromosome. At meiotic metaphase I, 9 divalents from B. oleracea and one univalent from S. alba could be detected. Sometimes, one putative C-S trivalent could also be detected. The achievement of B. oleracea-S. alba monosomic alien addition lines lays a foundation for gene introgression, location and cloning.     

白粉菌效应蛋白研究进展

在病原菌与植物的相互作用过程中,病原菌分泌大量效应蛋白帮助其侵染植物,因此效应蛋白一直是植物病理学研究的热点课题.该文基于大量白粉菌效应蛋白的研究成果,就近年来白粉菌效应蛋白的生物信息学预测分析结果、功能效应蛋白鉴定及其作用机理和无毒效应蛋白研究进展等方面进行综述,同时对未来值得重点关注的研究方向进行探讨,以期为白粉菌致病性的研究提供理论参考.     

C-banding pattern and nucleolar organizer regions of Cynoglossus semilaevis Günther, 1873

The C-banding pattern and nucleolar organizer regions of the metaphase chromosomes of Cynoglossus semilaevis are reported. The interstitial regions in all chromosomes including the pair of sex chromosomes had positive C-bands, and the 6th and 12th pairs of chromosomes were entirely stained in most cases. Some chromosomes such as the 1st, 2nd, 7th, 8th, 9th and 10th pairs showed C-bands at centromeric or distal ends. The C-banding heretochromatin occupies 30.03% of the total chromosome surface in C. semilaevis, which is similar to that of amphibians such as Mixophyes fasciolatus (30.2%) and M. schevilli (20.7%), but is rather lower than that of cephalochordate Branchiostoma belcheri (54.3%). Silver staining revealed a single pair of nucleolar organizer regions (NORs) located in the telomeric regions of Chromosome 2. The association of NORs with heterochromatin observed in vertebrates also occurs in C. semilaevis as the telomeric regions of Chromosome 2 are always stained positively with C-banding.     

商丘地区番茄白粉菌的鉴定

对中国商丘地区首次检出的番茄白粉菌进行了形态特征的观察、致病性检测及分子鉴定.结果显示,该病原菌经人工接种可导致番茄栽培品种致病,发病症状与自然状态一致,而对野生品种无作用;在显微镜下分生孢子单生呈椭圆状,孢子梗直立无分支;核糖体DNA转录间隔区(ITS)序列与来自Oidium neolycopersici的5条序列聚为1支,亲缘关系最近,而与来自Oidium lycopersici的3条ITS序列亲缘关系较远.以上结果表明,来自商丘的番茄白粉菌为O. neolycopersici.     

Chromosomal location of yellow rust resistance gene(s) inTriticum aestivum-Lophopyrum elongatum substitution lines

A set ofT. aestivum-L. elongatum substitution lines were studied on yellow rust resistance at seedling stage, inheritance of the resistance and esterase-5 (Est-5) analysis. The results demonstrated thatL. elongatum carried a new yellow rust resistance gene(s), which was dominant and located on chromosome 3E ofL. elongatum. The biochemical locus encoding Est-5 was also located on chromosome 3E, and was tentatively named Est-E5, which was co-segregant with theYr gene(s) in wheat background. In addition, the transmission frequencies of chromosome 3E in 3A/3E and 3D/3E hybrids selfing were significantly higher than that of chromosome 3E in 3B/3E hybrid, which was probably due to the difference on genetic relationships among A, B, D and E genomes.     

4个小麦品种的抗白粉病遗传分析

抗病品种郑315、CP87-26-12和91138-16-2-13-12,与感病品种豫麦49号杂交的F1代表现抗病,F2代抗、感单株的分离比例为31,表明这3个品种均携带1对显性抗病基因.N97189-2和豫麦18号的杂交F1代对白粉病表现高感,F2代抗、感单株的分离比例为13,由此推断N97189-2对白粉病的抗性由1对隐性基因控制.     

The inhibiting effect of 1·4 recombinant P chromosome of wheat-<Emphasis Type="Italic">Agropyron cristatum</Emphasis> addition line on the <Emphasis Type="Italic">Ph</Emphasis> gene

P chromosomes may carry a genetic system that inhibits the Ph gene in wheat. Abnormal chromosome synapsis in wheat-Agropyron cristatum addition line II-21-2 (additional 1·4 recombinant P chromosome) was observed in this study. The results of cytogenetics and Ph1 gene amplification showed that the Ph1 gene was normal and the average number of quadrivalents or hexavalents was determined to be 0.41 and 0.13, respectively, in pollen-mother cells of wheat-Agropyron cristatum addition line II-21-2. The analysis o...     

上海菠菜霜霉病菌生理小种鉴定及分子检测

明确我国不同区域菠菜(Spinacia oleracea L.)霜霉病菌(Peronospora effuse)生理小种的类别,是筛选和鉴定抗病菠菜种质资源和选育抗病新品种的基础.对采集于上海的2份菠菜霜霉病病原菌进行了鉴定,并根据内部转录间隔区(ITS)通用引物对其ITS序列进行克隆和分析.结果表明:上海地区的菠菜霜霉病菌为9号生理小种,属于Peronospora effusa.本研究明确了上海地区生理小种类别,为菠菜抗霜霉病育种提供参考.     

极大子群都同构的有限p-群

设群G是一个有限p-群.如果G的所有极大子群都同构,则称G为MI群.利用正则p-群以及MI群的性质,通过分类讨论的方法,给出了阶不大于p~6的MI群的结构.     

白粉菌对抗、感白粉病小麦品种叶片组织侵染情况的研究

采用透明染色法对白粉菌15号生理小种侵染的小麦叶片进行处理,观察不同时间段白粉菌对京411,Brock及其杂交后代近等基因系（NIL）叶片的侵染情况。结果表明：Brock,NIL抗病耐受性均强于京411,此结果可为今后抗病基因的克隆、植物抗性信号转导机制等研究提供细胞学上的依据。     

凤仙白粉病的病原菌鉴定

凤仙白粉病菌使凤仙花科植物叶片出现白色病斑.对河南商丘地区的凤仙白粉病菌进行了致病性分析、形态学及分子生物学鉴定.该病原菌分生孢子椭圆形或桶形,大小为22～28μm×16～21 μm.分生孢子梗直立,圆柱形,简单不分枝,包含1个足细胞,1～3个远基细胞,3～6个排列成链的桶形分生孢子,大小为112～180 μm×9～1...     

A transgenic wheat with a stilbene synthase gene resistant to powdery mildew obtained by biolistic method

Stilbene, a kind of phytoalexin, plays an important role in resistance to fungal and bacterial infection in plants. It strongly inhibits the growth of fungi and sprout of spore. Stilbene synthase gene (Vst1) obtained from grapevine has been transferred into common spring wheat Jinghong 5 by using the biolistic transformation method. Five transgenic plants (T₀) were obtained from the bombarded 2014 immature embryos. One immune plantlet and 3 plantlets with mid-resistance to powdery mildew were identified from the transgenic plants of T₃ generation which came from 2 T₀ transgenic plants.     

P15——a new tumor suppressor gene

In addition to the tumor suppressor genes such as Rb and p53, it has been found that some molecules of the same class named CKI (cyclin-dependent kinase inhibitor) also play an important role in the inhibition of tumorigenesis and the tumor progression. In the KIP and INK4 families of CKIs, p15 shares extensive homology with p16. Findings in many tumors and their cell lines show that the inactivation of p15 (deletion, mutation, rearrangement, etc.) is very frequent, and inactive p15 is involved in the progress of some tumors. These studies provide evidence that the p15 is a new tumor suppressor gene. Furthermore, the research on the molecular mechanism of p15 in regulation of cell proliferation shows that p15 can inhibit the growth of some kinds of tumor cells, and p15 is the mediator of TGF-β-induced cell arrest. Investigations on p15 in cell differentiation suggest that increased p15 is related to the change of malignant phenotype. These results supply clues for further interpretation about the molecular mechnism of cell cycle control and cell tumorigenesis. And they may provide theoretical and experimental basis for application of p15 to clinical therapy of tumors.     

Development of Triticum aestivum-Leymus racemosus ditelosomic substitution line 7Lr#1S（7A） with resistance to wheat scab and its meiotic behavior analysis

Leymus racemosus is highly resistant to wheat scab （Fusarum head bright）. The transfer of scab resistant gene from L. racemosus to Triticum aestivum is of great significance for broadening the base of wheat resistance. In the present study, the pollen of T. aestivum-L, racemosus monosomic addition line with scab resistance was treated by irradiation with 1200 R ^60Co-γ-rays prior to pollinating to emasculated wheat cv. Mianyang 85-45. Nine plants with a telocentric chromosome 7Lr#1S were observed in M1, and one ditelosomic substitution line 7Lr#1S was selected from selfcrossing progenies and confirmed by chromosome C-banding and GISH. Furthermore, a co-dominant EST-SSR marker CINAU 31 was employed to identify this substitution line. A pair of chromosome 7A of common wheat were found to be replaced by a pair of telocentric chromosome 7Lr#1S, and further investigation showed that chromosome configuration of the substitution line at MI of PMCs after GISH was 17.50Ⅱ^w ＋ 2.19Ⅱ^w ＋ 0.42Ⅱ^7Lr#1S ＋ 1.08 Ⅰ^7Lr#1S ＋ 0.69 Ⅰ^w. Two telocentric chromosomes paired as a bivalent in 59.7% of PMCs. Abnormal chromosome behaviors of telocentric chromosomes were observed in part of PMCs at anaphase I and telophase I, including the moving of two telocentric chromosomes to the same pole, lagging and earlier separation of their sister chromatid. All these abnormal behaviors can be grouped into three distinct types of tetrads according to different numbers of 7Lr#1S in their daughter cells and various micronucleus in some tetrads. However, due to the high transmission frequency of the female and male gametes with a 7Lr#1S, 84% of the selfcrossing progeny plants had ditelosomic substitution. The substitution line showed high resistance to wheat scab in a successive two-year test both in the greenhouse and field; hence, the line will be particularly valuable for alien gene mapping, small fragment translocation induction and telosomic cytological behavior analysis.