二角山羊草细胞质小麦雄性不育系的育性特异性分析

利用大量小麦亲本材料和优良品种(系)与具有粘果、易变、偏凸和二角山羊草细胞质的小麦雄性不育系杂交,并对其杂交F1过氧化物同工酶进行了分析,结果表明：(1)二角山羊草细胞质与小麦核内的遗传物质组成两个不同的核质互作不育系统,粘、易、偏型不育系育性基本表现一致,而二角型不育系除了与前三种不育系具有相同的1BL／1RS保持系以外,对某些小麦近缘植物的杂交后代材料还表现出育性特异性。(2)粘、易、偏和二角型同核异质不育系5-1及其与V9125杂交F1过氧化物同工酶分析表明,粘、易、偏和二角型不育系5-1过氧化物同工酶带型基本表现一致,粘、易、偏不育系5-1与V9125杂交F1过氧化物同工酶带型基本表现一致,而二角型不育系5-1杂交F1过氧化物同工酶则表现出酶带减少变弱。     

QTL analysis of fertility-restoration against cytoplasmic male sterility in wheat

The cytoplasm of Triticum timopheevi causes cytoplasmic male sterility (CMS) in common wheat (T. aestivum) cv. 'Chinese Spring' (CS), and that of Aegilops kotschyi causes CMS in spelt wheat (T. spelta) var. duhamelianum (Sp). CS has fertility-restoring (Rf) genes against the latter cytoplasm and Sp has the ones against the former. To know the genetic system concerning to CMS, we crossed 66 F8 recombinant inbred lines (RILs) derived from a cross between CS and Sp as males to the alloplasmic lines of CS and Sp having the cytoplasms of T. timopheevi and Ae. kotschyi, respectively. The fertilities of respective F1 plants derived from the crosses were examined for QTL analysis. The major QTLs detected in both systems were located on the short arm of chromosome 1B. One minor QTL on chromosome 2B was also commonly detected in both of the systems, while other minor QTLs against T timopheevi cytoplasm were distributed on the chromosomes 2A, 4B, and 6A.     

粘类非1BL/1RS小麦CMS基因定向选择及其育性特性的研究

对携有不同不育基因的4个粘类小麦雄性不育系进行了定向选择与鉴定,并对其育性特性进行研究,以选育更具应用价值的粘类非1BL/1RS小麦雄性不育系,推动三系杂交小麦的实际应用.结果表明:(1)根尖体细胞随体鉴定和A-PAGE技术分析筛选出的SP4、莫迦小麦为非1BL/1RS类型,其它供试不育系均属于1BL/1RS类型;(2)减数分裂及成熟花粉粒形态观察,粘类非1BL/1RS小麦雄性不育系其不育性是在整个配子发育过程中连续产生的,且在B型不育细胞质背景下,SP4和莫迦小麦的花粉细胞学形态与在K、Ven型2种不育细胞质背景下的不同,B型不育细胞质背景下SP4和莫迦不育系的花粉萌发率比K、Ven型不育细胞质背景下的花粉萌发率高;(3)以不同来源不育基因培育成的粘类K、Ven型非1BL/1RS不育系育性恢复性测定发现,SP4、莫迦小麦2种雄性不育系育性恢复性有一定差异,莫迦小麦不育类型育性恢复性高于SP4.     

APAGE技术在小麦细胞质雄性不育系选育中的应用研究

利用大量小麦亲本材料和优良品种(系)与具有粘果、易变、偏凸和二角山羊草细胞质的小麦雄性不育系杂交,筛选出一系列保持系。利用APAGE(酸性聚丙烯酰胺凝胶电泳)技术对其进行了醇溶蛋白电泳图谱分析,发现大部分保持系表现出1BL/lRS易位系的1RS醇溶蛋白标记位点GldlB3。利用细胞学镜鉴,发现含有GldlB3标记位点的保持系均只含有两个随体,而不含有GldlB3标记位点的保持系均含有4个随体,证明了GldlB3标记位点与两个随体数的一致性。粘、易、偏型不育系育性基本表现一致,而二角型不育系除了与前3种不育系具有相同的保持系以外,对某些小麦品种(系)还表现出育性特异性。同时还讨论了ANGE技术在快速筛选小麦细胞质雄性不育保持系中的作用,为非1BL/1RS不育系的选育提供了必要的手段。     

粘型小麦雄性不育系减数分裂特征及育性恢复研究

调查了粘型1B／1R和非1B／1R小麦雄性不育系,保持系及其F2的花粉母细胞减数分裂中期Ⅰ染色体联会情况、后期Ⅰ出现落后染色体的细胞频率以及末期Ⅱ含有微核的四分体的频率,结果表明：（1）粘果山羊细胞质对1B／1R型不育系减数分裂染色体配对水平具有特异性降低作用;（2）粘型1B／1R不育系减数分裂中期Ⅰ出现单价体细胞频率与后期Ⅰ出现落后染色体细胞的频率呈正相关,也与含微核的四分体频率呈正相关,而对应保持系则没有相关性;（3）粘果山羊草细胞质对非1B／1R不育系减数分裂过程影响不大,5个1B／1R不育系减数分裂过程中,3个时期染色体行为变异率的差异是特定的1B／1R核型与粘果山羊草细胞质互作的结果;（4）粘型1B／1R不育系杂交R2单株减数分裂3个时期染色体行为变异率与其恢复度成反比,这类不育系减数分裂中染色体行为不同步是其恢复不高且变异较大的一重要原因。     

几类异质易恢复小麦雄性不育系杂种籽粒品质研究初报

利用具有粘果出羊草（Ae.kotschyi),易变山羊草（Ae.variabilis),偏凸山羊草（Ae.ventricosa)和二角山羊草（Ae.bicornis)异源细胞质小麦雄性不育系（以下简称粘,易,偏和二角型）组配成不同组合的杂种小麦,研究这4种不育系对杂种小麦籽粒品质的影响。结果表明,由它们所配制的杂种小麦在蛋白质含量,湿面筋含量,沉淀值等性状上均高于具有普通小麦细胞质的相同核型杂种小麦,尤其粘,易型某些组合在湿面筋含量,沉淀值两性状上差异达到显著水平。因此,利用这4种不育系很有希望培育出优势,高产的杂种小麦。     

两类二角山羊草细胞质小麦雄性不育系的细胞学研究

对具有二角山羊草(Aegilops bicornis)细胞质的同质异核1BL／1RS型小麦雄性不育系ms(Ae．bicornis)-5-1和非1BL／1RS不育系ms(Ae．bicornis)一V9125进行了花药发育细胞学分析。幼穗染色体制片显示,1BL／1RS不育系ms(Ae．bicornis)-5—1减数分裂正常,非1BL／1RS不育系ms(Ae．bicornis)-V9125减数分裂期染色体排列不整齐,出现不正常的四分体和含微核的小孢子。花药发育的细胞学观察表明,1BL／1RS不育系ms(Ae．bicornis)-5—1表现为染败,花药各壁层的发育是正常的;BC3代的非1BL／1RS不育系ms(Ae．bicornis)-V9125表现为园败,且发生了药室合并现象,从细胞学角度证明了二角型小麦不育系存在两个核质互作不育系统。     

RAPD markers linked to the nuclear gene from Triticum timopheevii that confers compatibility with Aegilops squarrosa cytoplasm on alloplasmic durum wheat.

Alien cytoplasms cause a wide range of phenotypic alterations in the nucleus-cytoplasm (NC) hybrids in the Triticeae. Nuclear genomes of timopheevii wheat (Triticum timopheevii and Triticum araraticum) are fully compatible with the cytoplasm of Aegilops squarrosa, while those of a majority of emmer or durum wheat cultivars and more than half the wild emmer wheats are incompatible, and a maternal 1D chromosome is required to restore seed viability and male fertility in the NC hybrids. A euploid NC hybrid of Triticum durum cv. Langdon with Ae. squarrosa cytoplasm produced by introgressing the NC compatibility (Ncc) gene from T. timopheevii was used to identify random amplified polymorphic DNA (RAPD) markers linked to it. After a survey of 200 random decamer primers, four markers were selected, all of which were completely linked in 64 individuals of a SB8 mapping population. One marker was derived from a single locus, while three others were from interspersed repetitive sequences. Also, the hybrid chromosomes and those of the parental T. durum had identical C-banding patterns. RAPD-PCR analysis of 65 accessions from wild and cultivated tetraploid wheat species showed the exclusive presence of the markers in timopheevii wheat. In conclusion, the chromosomal region flanking Ncc of T. timopheevii is highly conserved in the genome of this group of tetraploid wheats.     

粘类小麦细胞质雄性不育系的RAPD分析

利用250条10-聚寡核苷酸随机引物对具粘果山羊草(Aegilops kotschyi)、易变山羊草(Ae.variabilis)、偏凸山羊草(Ae.ventricosa)和二角山羊草(Ae．bicornis)细胞质不育系及其保持系5-1的总DNA进行了RAPD多态性分析,其中31条引物对4种不育系及其保持系总DNA均无扩增,217条引物扩增条带完全相同。有2条随机引物在2种不育系之间有特异的扩增片段,其中引物S22在偏凸山羊草细胞质雄性不育系基因组DNA中扩增出分子量约为1600bp的特异带,引物S202在粘果山羊草细胞质雄性不育系基因组DNA中扩增出约1300bp特异带。线粒体基因组DNA的RAPD分析表明,4种不育系及其保持系mtDNA存在明显的差异。证明了S22—1600为偏凸山羊草细胞质不育系及其mtDNA基因组DNA的RAPD特异片段．S202—1300可能为粘果山羊草细胞质不育系及其ctDNA基因组DNA的RAPD特异片段。     

二角型非1B/1R 小麦CMS不育恢复体系的建立

通过对具有二角山羊草细胞质的1B/1R型小麦雄性不育系m s(A e.bicorn is)-5-1回交置换,获得了新型二角山羊草细胞质小麦雄性不育系m s(A e.bicor)-V 9125和m s(A e.bicor)-M 853.利用染色体制片、分子标记、原位杂交和酸性聚丙烯酰胺凝胶电泳对其保持系V 9125和M 853进行分子细胞遗传学检测,并对其育性恢复性机理进行了初步研究.结果表明:(1)V 9125和M 853均为非1B/1R易位系.V 9125为小麦-簇毛麦易位系,m s(A e.bicor)-V 9125是二角山羊草细胞质与普通小麦核背景中簇毛麦外源染色体互作产生的一类新的核质互作不育系.(2)M 853为小麦-滨麦易位系,m s(A e.bicor)-M 853是二角山羊草细胞质与普通小麦核背景中滨麦外源染色体互作产生的一类新的核质互作不育系.(3)利用一些普通小麦品种(系)与这两个不育系杂交,m s(A e.bicor)-V 9125和m s(A e.bicor)-M 853仅与T 6-3杂交育性得到恢复,且恢复度较高,变异小,而与其它大部分普通小麦杂交F1表现雄性不育,且扬花期花药不外露.而m s(A e.bicor)-5-1与包括T 6-3在内的普通小麦品种(系)杂交F1育性得到不同程度的恢复.从而得出结论,二角山羊草细胞质与小麦细胞核的互作存在两个不同的不育-恢复系统.     

普通小麦1BL—1RS K,V型雄性不育体系育性恢复的研究

对１ＢＬ－１ＲＳ Ｋ,Ｖ型雄性不育系及其保持素与中国春及其第一部分同源群染色体全部６个缺－四体杂种Ｆ１的育性恢复进行了研究。结果表明：Ｋ型杂种的育笥恢复主要受１ＢＳ上Ｒｆｖ１基因的控制;而Ｖ杂种则受Ｒｆｖ１的１Ｄ染色上育性恢复基因的共同控制;在保持１Ｄ正常剂量的情况下,使恢复系中载有Ｒｆｖ１的１Ｂ染色体（片段）加倍,如１Ａ缺体－１Ｂ四体能使Ｋ,Ｖ型杂种1Ｆ的育性完全恢复。     

Natural or induced nucleocytoplasmic heterogeneity in Triticum longissimum.

Alien cytoplasms produce a variety of phenotypes in durum wheat (Triticum turgidum) and common wheat (Triticum aestivum) cultivars, which indicate the prevalence of cytoplasmic variability in the subtribe Triticinae. Intraspecific cytoplasmic differences have been demonstrated between the subspecies of Triticum speltoides, Triticum dichasians, and Triticum comosum. In this study, durum wheat lines with cytoplasm from two accessions, B and C, of Triticum longissimum were compared, and meiotic chromosome pairing between the group 4 homoeologues from the same two accessions was examined in common wheat. First, monosomic addition or monosomic substitution lines of common wheat with cytoplasm and one chromosome (designated B) from accession B were crossed with those having cytoplasm and a chromosome designated C-1 or C-2 from accession C. In each substitution line, an alien chromosome substituted for a group 4 homoeologue. Each alien chromosome had a "selfish" (Sf) gene, which remained fixed in the wheat nucleus. The F1s had greatly reduced meiotic pairing between chromosomes B and C-1 and B and C-2, which indicated greatly reduced homology between the group 4 homoeologues from the two accessions. Second, by using Triticum timopheevii as a bridging species, chromosome B in a common wheat line was eliminated and an euploid durum line with cytoplasm from accession B was obtained. This line was fertile. In contrast, a similarly produced durum line with cytoplasm from accession C was male sterile and retained a species cytoplasm specific (scs) nuclear gene from T. timopheevii. In conclusion, nuclear and cytoplasmic heterogeneity pre-existed between accessions B and C and they represent varieties or incipient subspecies in T. longissimum. Alternatively, the Sf genes produced chromosomal heterogeneity and mutated cytoplasmic genes from one or both accessions. Key words : meiotic drive, selfish gene (Sf), gametocidal gene (Gc), Triticum, Aegilops.     

Basic studies on hybrid wheat breeding

Summary The nuclei of 12 common wheats (genome constitution AABBDD) were placed into the cytoplasms of Aegilops kotschyi and Ae. variabilis (both C^uC^uS^vS^v) by repeated backcrosses. Using these nucleus-cytoplasm hybrids, male sterility-fertility restoration relationship was investigated. Male sterility was expressed by these cytoplasms only in Slm, Splt and Mch. The other nine common wheat nuclei gave normal fertility against these cytoplasms. These cytoplasms were compared with the Triticum timopheevi cytoplasm that is now widely used in the hybrid wheat breeding program in order to investigate their effects on important agronomic traits of the 12 common wheats: The kotschyi and variabilis cytoplasms were as good as the timopheevi cytoplasm in this respect.The F₁ hybrid between (kotschyi)- or (variabilis)-Splt and CS showed normal fertility. Segregation of the fertiles and steriles in their F₂ generations followed the simple Mendelian fashion, i.e., 3 fertile1 sterile. Thus, the fertility restoration in this case is mainly controlled by a single dominant gene which will be designated as Rfv1. To determine its location, ditelo-lBS and -lBL of CS were crossed as male parents to male sterile (kotschyi)- and (variabilis)-Splt. The F₁ hybrids between the male sterile Spit's and CS ditelo-lBS became male fertile, while those between the male sterile Spit's and CS ditelo-lBL became completely male sterile. Thus, the location of the gene Rfv1 has been determined to be on the short arm of chromosome lB of CS. Furthermore, a close relationship between the fertility-restoring genes and the nucleolus organizer region was pointed out.Finally, the schemes of breeding the male sterile lines of a cultivar with these cytoplasms, and its maintainer line were formulated. The following two points were considered as the advantages of the present male sterility-fertility restoration system over that using the timopheevi cytoplasm in breeding hybrid wheat: (1) easier fertility restoration in F₁ hybrids, and (2) no need of breeding the restorer line.This work was supported by a Grand-in-Aid from the Ministry of Education, No. 386002. Contribution from the Laboratory of Genetics, Faculty of Agriculture, Kyoto University, Japan, No. 420.     

光周期敏感细胞质雄性不育小麦的研究

选用我们创建的Ｄ＾２型细胞质与普通小麦品种,经多年回交核置换获得的１５种异质系在,不同发育期置于武汉不同光长条件下,并春播于哈尔滨自然长日条件下,抽穗时套袋自产,进行碘染花分观察,成熟后考察自交结实率等。     

Male sterility systems in wheat and opportunities for hybrid wheat development

The common wheat (Triticum aestivum L.) is a poly(hexa)ploid, derived from an amphi-diploidization process involving the donor species—Triticum urartu, Aegilops speltoides, Triticum turgidum, and Aegilops tauschii. The genetic diversity of the autogamous wheat is narrow, which is a major reason for lesser rate of yield gain in wheat, in contrast to rice and maize. It is desirable to encourage hybrid breeding, i.e., combining different lines into genetically divergent heterotic pools. Thus, hybrid plants are a unique combination of desired alleles produced by crossing between genetically different parental lines. Hybrid seed production in a crop requires male-sterile female parents along with a reliable outcrossing system. The male-sterile female parent prevents pollen shedding and self-fertilization, maintaining the purity of hybrid seeds. An outcrossing system enhances hybrid seed production. This article emphasizes the biological relevance of crossbreeding and self-pollination in wheat, and reviews different male sterility systems which could be utilized for the development of hybrid wheat. Several biotechnological approaches and their practical utility in generating cross-compatible male-sterile female parent lines have been discussed.     

三例小麦细胞质雄性不育系线粒体DNA的扩增片段长度多态性分析

细胞质雄性不育是小麦杂种优势利用的重要途径,为了鉴定3例小麦雄性不育系的细胞质类型,对其线粒体DNA(mtDNA)进行扩增片段长度多态性(Amplified fragment length polymorphism,AFLP)分析。文中利用差速离心法和不连续蔗糖密度梯度超速离心法提取纯化小麦线粒体。结果表明:通过该提取方法获得的mtDNA,其质量和纯度能够满足PCR反应和遗传学分析。在64对选扩引物中,筛选到了4对特异性引物,其中引物E1/M7在ms(Kots)-90-110不育系扩增出3条特异条带;引物E4/M2在ms(Ven)-90-110不育系扩增出2条特异条带;引物E7/M6在ms(S)-90-110不育系中扩增出2条特异条带;引物E6/M4在ms(Kots)-90-110不育系中扩增出2条特异条带。这些特异引物可以用来作为鉴定具有粘果山羊草Aegilops kotschyi、偏凸山羊草Ae.ventricosa、斯卑尔脱小麦Triticum spelta 3类不育细胞质型小麦雄性不育系的细胞质分子标记,为研究小麦细胞质雄性不育机理奠定了分子基础。     

Cytoplasmic effects on DNA methylation between male sterile lines and the maintainer in wheat (Triticum aestivum L.)

Male sterile cytoplasm plays an important role in hybrid wheat, and three-line system including male sterile (A line), its maintainer (B line) and restoring (R line) has played a major role in wheat hybrid production. It is well known that DNA methylation plays an important role in gene expression regulation during biological development in wheat. However, no reports are available on DNA methylation affected by different male sterile cytoplasms in hybrid wheat. We employed a methylation-sensitive amplified polymorphism technique to characterize nuclear DNA methylation in three male sterile cytoplasms. A and B lines share the same nucleus, but have different cytoplasms which is male sterile for the A and fertile for the B. The results revealed a relationship of DNA methylation at these sites specifically with male sterile cytoplasms, as well as male sterility, since the only difference between the A lines and B line was the cytoplasm. The DNA methylation was markedly affected by male sterile cytoplasms. K-type cytoplasm affected the methylation to a much greater degree than T-type and S-type cytoplasms, as indicated by the ratio of methylated sites, ratio of fully methylated sites, and polymorphism between A lines and B line for these cytoplasms. The genetic distance between the cytoplasm and nucleus for the K-type is much greater than for the T- and S-types because the former is between Aegilops genus and Triticum genus and the latter is within Triticum genus between Triticum spelta and Triticum timopheevii species. Thus, this difference in genetic distance may be responsible for the variation in methylation that we observed.     

Genotypic variation in tetraploid wheat affecting homoeologous pairing in hybrids with Aegilops peregrina.

The Ph1 gene has long been considered the main factor responsible for the diploid-like meiotic behavior of polyploid wheat. This dominant gene, located on the long arm of chromosome 5B (5BL), suppresses pairing of homoeologous chromosomes in polyploid wheat and in their hybrids with related species. Here we report on the discovery of genotypic variation among tetraploid wheats in the control of homoeologous pairing. Compared with the level of homoeologous pairing in hybrids between Aegilops peregrina and the bread wheat cultivar Chinese Spring (CS), significantly higher levels of homoeologous pairing were obtained in hybrids between Ae. peregrina and CS substitution lines in which chromosome 5B of CS was replaced by either 5B of Triticum turgidum ssp. dicoccoides line 09 (TTD09) or 5G of Triticum timopheevii ssp. timopheevii line 01 (TIMO1). Similarly, a higher level of homoeologous pairing was found in the hybrid between Ae. peregrina and a substitution line of CS in which chromosome arm 5BL of line TTD140 substituted for 5BL of CS. It appears that the observed effect on the level of pairing is exerted by chromosome arm 5BL of T turgidum ssp. dicoccoides, most probably by an allele of Ph1. Searching for variation in the control of homoeologous pairing among lines of wild tetraploid wheat, either T turgidum ssp. dicoccoides or T timopheevii ssp. armeniacum, showed that hybrids between Ae. peregrina and lines of these two wild wheats exhibited three different levels of homoeologous pairing: low, low intermediate, and high intermediate. The low-intermediate and high-intermediate genotypes may possess weak alleles of Ph1. The three different T turgidum ssp. dicoccoides pairing genotypes were collected from different geographical regions in Israel, indicating that this trait may have an adaptive value. The availability of allelic variation at the Ph1 locus may facilitate the mapping, tagging, and eventually the isolation of this important gene.     

Homoeoallelic gene Ncc-tmp of Triticum timopheevii conferring compatibility with the cytoplasm of Aegilops squarrosa in the tetraploid wheat nuclear background.

A nuclear gene, Ncc-tmp1A, of Triticum timopheevii is required for the nucleus-cytoplasm (NC) compatibility in tetraploid NC hybrids with the cytoplasm of Aegilops squarrosa. A euploid NC hybrid of T. durum was previously produced by introgressing the gene from chromosome 1A of T. timopheevii. To examine the possible presence of a functional homoeoallele in the G genome of T. timopheevii, segregation of seed viability was studied as a marker phenotype in BC1s involving the two types of NC hybrids, (Ae. squarrosa)-T. timopheevii and (Ae. squarrosa)-T. turgidum. The result of these test crosses suggested that the G genome possesses a functional homoeoallele Ncc-tmp1G. Segregation of two RAPD (random amplified polymorphic DNA) markers that were closely linked to Ncc-tmp1A was further studied among the viable BC1s obtained from a test cross of (Ae. squarrosa)-T. timopheevii x T. turgidum. Some viable BC1 segregants without the markers were obtained, suggesting a limited degree of transmission of chromosome 1G carrying Ncc-tmp1G. However, a similar RAPD analysis of BC1s obtained after backcrosses of reciprocal F1s of T. timopheevii/T. turgidum with T. turgidum showed random marker segregation. Thus, it was concluded that Ncc-tmp1A is not required for compatibility with its own cytoplasm. Southern blot analysis of the euploid NC hybrid using RFLP (restriction fragment length polymorphism) markers on the homologous group 1 chromosomes showed that Ncc-tmp1A locates in the centromeric region.     

几类异质1BL／1RS小麦雄性不育系诱导孤雌生殖性的研究

系统调查了4种异质（即偏凸,粘果,易变和二角山羊草细胞质）1BL/1RS小麦雄性不育系与其一系列异质同核系,同质异核系,异质异核系杂交,回交世代诱导孤雌生殖性的遗传变异规律,染色体分裂行为和对外表现特点,结果表明：1、异源细胞质与小麦1BL/1RS核型专一互作,有着消弱同源染色体配对,提高中期单价体细胞率的作用;2、特定细胞质背景下,专一核型内细胞单价体频率高低与诱导孤雌生殖性的频率直接相关;3、1BL/1RS易位染色体中易位片所存在系列差异以及1BL/1RS易位染色体外基因型背景不同,诱导孤雌生殖性的频率明显不同;4、提高或抑制不同杂交,回交世代间孤雌生殖频率,不育系母本或不同基因型父本有着同等重要的作用。选择最佳父母本组合杂交可明显提高或降低后代群体中的孤雌生殖性频率。