Dependence of out-crossing indices on genotypic features in common wheat

The out-crossing indices (out-crossing rate, rate of plants on which out-crossing had occurred, and out-crossing intensity) in F₂ plants of soft winter wheat derived from the reciprocal crossing B-16 × Odesskaya Krasnokolosaya are analyzed using storage proteins as genetic markers. The out-crossing index is substantially dependent on the growing conditions. The out-crossing rate in a reciprocal population amounted to 0.35% (Odessa, 2000) and 5.11% (Kiev, 2004). The greatest out-crossing indices are observed in homozygotes for the presence of the rye 1BL/1RS translocation. The value of the out-crossing index in heterozygotes for the presence of this translocation is intermediate. Differences in the out-crossing index between plant populations derived from direct and reciprocal crossings are found. The multidirectionality of these differences with respect to out-crossing rate and the percentage of plants with out-crossing, on the one hand, and the out-crossing intensity, on the other hand, is noted.     

Conjugation of the 1BL/1RS translocation with qualitative and quantitative traits in the common wheat T.aestivum

The review considers the effect of the rye 1BL/1RS translocation in the common wheat genome on qualitative and quantitative traits: grain quality, resistance to diseases, productivity and adaptivity, parthenogenesis, regeneration in anther culture, frequency of chromosome aberrations and frequency of cross-pollination. Data on special features of transmission of the 1BL/1RS translocation through male and female gametes are presented.     

几类异质小麦雄性不育系育性恢复性的细胞遗传学研究

系统调查了4类异质(粘果、易变、偏凸、二角山羊草细胞质)1BL/lRS、非1BL/1RS小麦雄性不育系与其恢复系杂种F减数分裂中期Ⅰ出现单价体细胞频率,以及后期Ⅰ出现落后染色体和染色体桥细胞频率,并对中、后期染色体变异率与杂种F自交结实率进行了相关分析.结果表明(1)1BL/1RS型杂种在中期Ⅰ、后期Ⅰ染色体变异率要明显高于非1BL/1RS杂种;(2)4类异源细胞质在非1BL/1RS杂种中有着明显提高单价体细胞频率的作用;(3)在1BL/1RS杂种中,1B@1BL/1RS杂合核型染色体联会松弛,对单价体频率的影响远大于异源细胞质的影响;(4)1BL/1RS型杂种自交结实率与中期出现单价体细胞频率不直接相关,而与后期出现落后染色体和染色体桥细胞的频率呈高度负相关;(5)非1BL/1RS型杂种在减数分裂中、后期染色体行为相对稳定,易恢复且恢复度高,很有实际利用价值.     

Development of a wheat genotype combining the recessive crossability alleles kr1kr1kr2kr2 and the 1BL.1RS translocation, for the rapid enrichment of 1RS with new allelic variation

The main objective of the present work was to develop a wheat genotype containing both the recessive crossability alleles (kr1kr1kr2kr2), allowing high crossability between 6x wheat and diploid rye, and the 1BL.1RS wheat/rye translocation chromosome. This wheat genotype could be used as a recipient partner in wheat–rye crosses for the efficient introduction of new allelic variation into 1RS in translocation wheats. After crossing the wheat cultivars ‘Mv Magdaléna’ and ‘Mv Béres’, which carry the 1BL.1RS translocation involving the 1RS chromosome arm from ‘Petkus’, with the line ‘Mv9 kr1’, 117 F₂ plants were analysed for crossability, ten of which had higher than 50% seed set with rye and thus presumably carried the kr1kr1kr2kr2 alleles. Four of the ten plants contained the 1BL.1RS translocation in the disomic condition as detected by genomic in situ hybridization (GISH). The wheat × rye F₁ hybrids produced between these lines and the rye cultivar ‘Kriszta’ were analysed in meiosis using GISH. 1BL.1RS/1R chromosome pairing was detected in 62.4% of the pollen mother cells. The use of fluorescent in situ hybridization (FISH) with the repetitive DNA probes pSc119.2, Afa family and pTa71 allowed the 1R and 1BL.1RS chromosomes to be identified. The presence of the 1RS arm from ‘Kriszta’ besides that of ‘Petkus’ was demonstrated in the F₁ hybrids using the rye SSR markers RMS13 and SCM9. In four of the 22 BC₁ progenies analysed, only ‘Kriszta’-specific bands were observed with these markers, though the presence of the 1BL.1RS translocation was detected using GISH. It can be concluded that recombination occurred between the ‘Petkus’ and ‘Kriszta’ 1RS chromosome arms in the translocated chromosome in these plants.     

Distribution of 1AL.1RS and 1BL.1RS wheat-rye translocations in Triticum aestivum using specific PCR

Chromosome arm 1RS of rye (Secale cereale) is a valuable resource for wheat (Triticum aestivum) improvement. 1AL.1RS and 1BL.1RS translocations play an important role in wheat breeding, since wheat carrying these chromosomal translocations has higher tolerance to biotic and abiotic stress. In this study, the presence of 1RS and the distribution of 1AL.1RS and 1BL.1RS wheat-rye translocations were examined in 66 Iranian cultivars and 70 regional foreign accessions of bread wheat, using three rye-specific primers (“RYER3/F3”, “O-SEC5′-A/O-SEC3′-R”, “PAWS5/S6”). Based on “RyeR3/F3”, the presence of 1RS was verified in 15 (23%) Iranian cultivars and in two (3%) foreign accessions. Further, “O-SEC5′-A/O-SEC3′-R” and “PAWS5/S6” were used to distinguish 1AL.1RS and 1BL.1RS translocations. According to results from these primers, 1BL.1RS was identified in 14 (21%) Iranian cultivars and two (3%) foreign accessions. The results confirm that “Sholeh” is the only cultivar (1.5%), among all cultivars and accessions, that carries 1AL.1RS. This study provides a useful tool in marker-assisted selection of materials containing 1RS, and in the creation of new Iranian common wheat cultivars with a larger genetic diversity in wheat breeding programs.     

Estimation of the contribution of the bioluminescent reaction rate and quantum yield to the enhancement of firefly bioluminescence in the presence of cationic liposomes.

Cationic liposomes containing phosphatidylcholine, cholesterol and distearyldimethylammonium chloride (DSDAC) enhanced maximum light emission (BL intensity) and total light emission from the firefly bioluminescence (BL) reaction. The increase in BL intensity was interpreted on the basis of the increase in both BL reaction rate and BL quantum yield (PhiBL) of the BL reaction. The increase in BL reaction rate was due to the increase in the localized concentration of BL reactants on the surface of cationic liposomes by electrostatic interaction. On the other hand, the increase in PhiBL was due to the change of light-emitting species in the presence of cationic liposomes. Each contribution of BL reaction rate and PhiBL to the enhancement of the BL intensity was estimated by measuring the BL reaction rate and PhiBL in the presence of cationic liposomes containing various amounts of DSDAC. The contribution of the BL reaction rate to the increase in the BL intensity was found to be two-fold greater than that of PhiBL.     

Paternal inheritance of egg traits in mice: a case of genomic imprinting

Eggs from reciprocal hybrids between the C57BL/6By and BALB/cBy strains were tested for their susceptibility to attack by hyaluronidase and pronase. There were significant reciprocal differences between the F1 females in the responses of their unfertilized eggs to both enzymes. The F1 hybrids from BALB mothers showed the increased susceptibility characteristic of C57BL whilst the F1 hybrids with C57BL mothers were more resistant to both enzymes, like BALB mice. Eggs from the four kinds of reciprocal F2 hybrid females also showed patroclinous patterns of susceptibility. A patroclinous difference was found between reciprocal crosses of the CXBD and CXBE recombinant inbred strains but not in crosses between recombinant inbred strains with similar phenotypes. Cross fostering did not alter the phenotypes of the C57BL and BALB females or those of their reciprocal F1 hybrids. The findings are interpreted in terms of differential genomic imprinting of paternally inherited information. The possible general usefulness of patroclinous differences between reciprocal F1 females in revealing differences in imprinting is noted.     

峨眉拟单性木兰的开花生物学特性与繁育系统

为阐明峨眉拟单性木兰(Parakmeria omeiensis)在自然条件结实率低的原因和确定最佳人工授粉时期,该文通过观察峨眉拟单性木兰的开花动态,采用杂交指数估算、花粉胚珠比、花粉活力及柱头活性检测、人工授粉试验等方法对其繁育系统进行了研究。结果表明:(1)植物园保育的峨眉拟单性木兰花期在4月底到5月中下旬,持续17～23 d,雄株始花期比雌株早3～4 d,但两者花期可遇。(2)两性花经检测雄蕊败育,实为功能上的雌性,部分雄株个体的雄花上残留1～2个心皮,其性别分化是通过雌、雄蕊选择性败育形成的,为隐性雌雄异株(cryptic dioecy)。(3)雄花、两性花开放经历佛焰苞开裂、花被片开裂、展开、闭合、二次开放、凋落6个阶段,历时4 d。(4)雄花初次展开时花粉活力最高,达92.8%,开花2 d后活力显著下降;两性花柱头在花被片展开期可授性最强,盛开后柱头部分可授。(5)杂交指数为5,P/O比为2.14×10~4。(6)套袋试验表明,峨眉拟单性木兰不能进行自花传粉,人工异花授粉的结实率和出种数显著高于自然授粉,且不存在无融合生殖。这说明峨眉拟单性木兰繁育系统为专性异交,传粉过程需要传粉媒介,自然条件下结实率低,主要是受传粉昆虫和柱头可授期短的限制。     

Inheritance of hydronephrosis in the inbred mouse strain DDD

The mode of inheritance of hydronephrosis was investigated by crossing inbred DDD mice having a high incidence of hydronephrosis and C57BL/6 mice having normal kidneys. In the males, incidences of hydronephrosis in F1 animals were intermediate between the two parental strains at a rate of 32.6% in (DDD x C57BL/6)F1 and 23.4% in reciprocal F1. The same tendency was observed in F2 male animals. In BCF1 males, the number of affected mice was higher in (C57BL/6 x DDD) F1 x DDD (72.4%) than in (DDD x C57BL/6)F1 x C57BL/6 (11.1%). A few affected mice were found among the females of hybrids F1, F2 and BCF1. These results suggested that hydronephrosis in the DDD strain of mice was controlled by polygenes, and that male hormones may have some effect on the occurrence of hydronephrosis.     

Genetics of Glucocorticoid Receptor Levels in Recombinant Inbred Lines of Mice

Hepatic glucocorticoid receptor binding activity was measured in A/J, C57BL/6J, their F1 reciprocal crosses and their F1 recombinant inbred (RI) lines. The glucocorticoid binding capacity was measured in Hepes buffer and Hepes buffer plus dithiothreitol (DTT). The A/J parental strain showed higher levels, and a greater increase of glucocorticoid binding in the presence of DTT, than did the C57BL/6J strain. The response of binding in the presence of DTT to that without DTT was expressed as a ratio. The levels and distribution of these measurements among the RI lines and F1 reciprocal crosses suggested that there was a maternal effect on glucocorticoid receptor binding capacity. The data on RI lines suggested epistatic interactions, but could fit a two-gene model. beta 2-Microglobulin, beta-glucuronidase and H-2 (located on chromosomes 2, 5, and 17, respectively) were chosen to analyze any association to glucocorticoid receptor binding, because they have been considered to be related to glucocorticoid-induced cleft palate or glucocorticoid receptors. No significant associations were found.     

The molecular genetic characterization of the 'Bobwhite' bread wheat family using AFLPs and the effect of the T1BL.1RS translocation

Bobwhite is a generic name that refers to all sister lines derived from the cross CM 33203 with the pedigree Aurora//Kalyan/Bluebird/3/Woodpecker made by the CIMMYT bread wheat program in the early 1970s. Individual sister lines can be distinguished by their unique selection history. One of the parents, Aurora, contains the T1BL.1RS translocation from rye, and approximately 85% of the sister lines have inherited the translocation. The sister lines demonstrate great variability for agronomic traits such as maturity, height, grain color, reaction to leaf rust, stem rust, yellow rust, septoria leaf blotch and powdery mildew. Certain groups of sister lines derived from particular F(1) plants can be distinguished by their phenotype. One hundred and one Bobwhite sister lines were fingerprinted using four AFLP enzyme/primer combinations. Following multivariate analysis, two main and very distinct clusters were found, which reflected the presence or absence of the T1BL.1RS translocation. Within these clusters, lines clustered together, for the most part, with other sister lines sharing a common selection history. Removal of the AFLP markers that were correlated with the presence or absence of the translocation caused lines to cluster based on pedigree alone. Therefore, the presence of translocations in wheat could bias genetic diversity studies using unmapped markers such as AFLPs that are located on the translocated segment(s), with the result that the resulting clusters will not reflect the true degree of relatedness.     

Identification of new T1BL.1RS translocation lines derived from wheat (Triticum aestivum L. cultivar “Xiaoyan No. 6”) and rye hybridization

Two new T1BL.1RS translocation lines, 48112 and 89121, derived from cross between common wheat (Triticum aestivum L.) cultivar “Xiaoyan No. 6” and rye (Secale cereale L.) cultivar “German White”, were developed and identified by using of molecular markers and cytogenetical methods, GISH and FISH. PCR results of primers NOR-R1 specific for rye and Glu-B3 for 1BS detected the presence of 1RS chromatin and absence of 1BS, and primer for gene 1Bx14 in 1BL indicated the existence of chromosome arm 1BL in the two lines. GISH and FISH methods confirmed the replacement of chromosome arm 1BS with 1RS. Further stripe rust resistant test and quality analysis demonstrated that the new 1BL.1RS translocation lines were higher resistant to mixed races of P. striiformis Westend and observed considerable better quality than other popularized T1BL.1RS cultivars in China. The two lines have been used in wheat breeding for high-yield potential and rust resistance.     

The segregation characteristics at the alleles of the gliadin-coding Gli-B1 locus in hybrid soft winter wheat

Segregation at the Gli-B1 locus was studied in F2 seeds of common wheat from crosses between near-isogenic lines with respect to this locus. Segregations differed from the expected ratio in hybrids involving the lines with the allele Gli-B1l (Gli-B1-3), which is a marker for the 1BL/1RS translocation, as well as in the hybrid between the lines with the alleles Gli-B1b (1) and Gli-B1e (4). Reduced transmission of the chromosome with the 1BL/1RS translocation through pollen was observed in the hybrids involving the line with this translocation. In the cross GLI-B1-1 x GLI-B1-4, the significantly lower frequency of female gametes with the allele Gli-B1e (4) was detected. This is due to linkage of the Gli-B1 locus to a factor responsible for segregation distortion in female gametes. We proposed to designate this locus Sd3. The line with the gliadin block Gli-B1e differs in alleles at the Sd3 locus from the lines with the blocks Gli-B1b and Gli-B1o.     

Nuclear gametophytic genes from chromosome arm 1RS improve regeneration of wheat microspore-derived embryos.

The effect of the 1RS chromosome arm from rye on plant regeneration from microspore-derived embryos was studied using anther culture technology with genotypes carrying the 1BL-1RS translocated chromosomes, the normal wheat chromosome 1BL-1BS, and ditelosomic lines DT 1BS and DT 1BL. A significant difference was observed in microspore-derived green plants between chromosome structure concerned with 1RS and 1BS arms. An analysis of the inheritance of the 1B-1R translocation was performed on the basis of the frequency of male gametes 1BL-1RS in the microspore-derived green plants and that of the 1B-1R translocation inherited through the pollen or the egg cell from structurally heterozygous hybrids 1BL-1BS/1BL-1RS. Both the normal 1B and the translocated 1BL-1RS chromosomes were sexually transmitted through the pollen grains with the same frequency. The 1BL-1RS chromosome is only transmitted through 45% of the egg cells. On the contrary, two-thirds of the microspore-derived green plants regenerated from the anther culture experiments possess the translocated chromosome. The involvement of the rye chromosome arm 1RS from 'Aurora' on regeneration capacity of the microspore-derived embryos has been proposed through the effect of a "gametophytic gene."     

Rapid detection of 1B, 1BL/1RS heterozygotes in the development of homozygous 1BL/1RS translocation stocks of Triticum turgidum (2n = 4x = 28).

A biochemical marker was utilized to facilitate detection of chromosome 1B, 1BL/1RS translocation heterozygote plants in segregating backcross progenies during the development of 1BL/1RS homozygous lines in several Triticum turgidum L. cultivars (2n = 4x = 28; AABB). Isoelectric focussing of glucose phosphate isomerase (GPI) on either pH 3.5-9.5 or 5.5-8.5 polyacrylamide gels facilitated the detection of 1B, 1BL/1RS translocation heterozygotes from the homozygous 1B or 1BL/1RS derivatives during each backcross of the heterozygote to the respective recurrent parent. The biochemical diagnostic procedure complements the more time consuming and cumbersome chromosome banding technique. This GPI diagnostic in durum 1BL/1RS development is also swifter than a similar stocks development in T. aestivum where both GPI and acid PAGE are essential.     

Changes of reliability and efficiency of micronucleus bioassay in Vicia faba after exposure to metal contamination for several generations

Mitotic root micronucleus (MCN) frequency in Vicia faba as a bioassay, is primarily based on the extent of the sentinel Vicia response in terms of cytogenetic damage quantitatively or qualitatively to indicate the presence of mutagenic contaminants. This paper describes an investigation designed to assess changes in MCN frequencies of Vicia faba from three generation plants obtained, respectively from a reference site (RS) and a metal-contaminated experimental field (EF) in the bioassay of mutagenic Cd(2+) and NaN(3). The background value, dose-response to Cd(2+) and to NaN(3) in three generation (F(1), F(2) and F(3)) plants of the EF and the initial (F(0)) plants were determined in terms of MCN frequencies. With more generations of growing Vicia plants in the EF, a higher background value of MCN frequency, a lower slope value in the regression equation, a smaller ratio of MCN frequency between the control and treatment in the same generation and larger perturbation values were observed. This denotes that the decreased reliability and efficiency are represented in Vicia plants from the EF if the plants are used as sentinels in the bioassay of mutagenic Cd(2+) and NaN(3). It was concluded that the Vicia MCN bioassay should be used as an endpoint biomarker acceptable in biomonitoring environmental mutagens when the sentinel plants were collected from clean areas. Because no place is absolutely without pollutants, it is suggested that several seed stock centers should be established for providing sentinel Vicia if Vicia MCN bioassay is used as a biomarker to identify the global environmental status.     

Centromere structure and function analysis in wheat–rye translocation lines

1RS.1BL translocations are centric translocations formed by misdivision and have been used extensively in wheat breeding. However, the role that the centromere plays in the formation of 1RS.1BL translocations is still unclear. Fluorescence in situ hybridization (FISH) was applied to detect the fine structures of the centromeres in 130 1RS.1BL translocation cultivars. Immuno‐FISH, chromatin immunoprecipitation (ChIP)‐qPCR and RT‐PCR were used to investigate the functions of the hybrid centromeres in 1RS.1BL translocations. New 1R translocations with different centromere structures were created by misdivision and pollen irradiation to elucidate the role that the centromere plays in the formation of 1RS.1BL translocations. We found that all of the 1RS.1BL translocations detected contained hybrid centromeres and that wheat‐derived CENH3 bound to both the wheat and rye centromeres in the 1RS.1BL translocation chromosomes. Moreover, a rye centromere‐specific retrotransposon was actively transcribed in 1RS.1BL translocations. The frequencies of new 1RS hybrid centromere translocations and group‐1 chromosome translocations were higher during 1R misdivision. Our study demonstrates the hybrid nature of the centromere in 1RS.1BL translocations. New 1R translocations with different centromere structures were created to help understand the fusion centromere used for wheat breeding and for use as breeding material for the improvement of wheat.     

栽培黄瓜与野黄瓜正反杂交的几种同工酶分析

运用天冬氨酸转氨酶(AAT)、苹果酸脱氢酶(MDH)以及酯酶(EST)3种同工酶对栽培黄瓜"长春密刺"Cucumis sativus cv. Changchunmici (2n=14)与野黄瓜C. hystrix (2n=24)的正反交种间杂种F1 (正交: 野黄瓜×栽培黄瓜"长春密刺", 反交: 栽培黄瓜"长春密刺"×野黄瓜)及其双亲进行鉴定和比较研究。结果表明: 正反交种间杂种F1主要表现为双亲酶带的互补, 同时还形成4个杂合带(Aat-1-94、Aat-2-104、Mdh-3-102和Est-5-102)。上述3种酶均能准确地鉴定种间杂种的真实性。研究还发现正反交杂种F1的AAT和MDH的酶谱分别在酶带数目和强弱上表现出一定的差异, 进一步证实了野黄瓜与栽培黄瓜杂交存在正反交差异。     

Identification and Characterization of Phosphorus Use Efficiency in a Doubled Haploid Population of Chinese Spring ~ Lovrin No.lO

It is reported that chromosome 1 R of rye (Secale cereale L) convey phosphorus use efficientgene (s), and 1RS/1BL translocation genotype Lovrin No. 10 is P use efficient. So we hypothesized whetherP efficient gene(s) locate on 1RS, and the high P efficiency of Lovrin No.10 is from 1RS? To test thishypothesis, we investigated the P use efficiency (PUE) of a doubled haploid (DH) population with 61 linesderived from anther culture of F1 hybrid between Lovrin No.10 and phosphorus uptake inefficient genotypeChinese Spring to see whether PUE differs between DH line with and without 1RS/1BL translocation.Acidic polyacrylamide-gel electrophoresis (A-PAGE) of gliadin and genomic DNA in situ hybridization (GISH)were employed to discriminate 1RS/1BL translocation DH lines from the normal 1B DH lines. Among the61 DH lines investigated, A-PAGE analysis showed that 34 lines contained the 1RS/1BL translocationchromosome, which was characterized by the presence of a 1RS-specific Sec- 1 marker bands. Furtherverification with GISH proved that 33 in the 34 lines contained a pair of homozygous 1RS/1BL transloca-tion chromosomes, only one line was a 1RS/1BL monosomic line. A field experiment was carried out on Pdeficient soil to investigate grain yield, biomass, numbers of spikes per plant (SPP), P uptake efficiency(PUpE), and P utilization efficiency (PUtE) of the DH lines and their parents under -P (nil P applied) and P(60 kg P/hm2 applied) at maturity. Results showed soil P deficiency decreased the values of the first fourtraits in Lovrin No.10, but were more severe for Chinese Spring. Lovrin No.10 had higher values of all theabove tested traits at both -P and P than Chinese Spring did, but had similar PUtE with Chinese Spring.These five traits segregated, and differed greatly among DH lines under both -P and P conditions.Although the variations among DH lines exceeded the difference between the two parents, the averagevalues of the DH lines were between the two parents. The average of the above five traits, and P deficiencytolerance (PDT) (measured by relative grain yield of -P/ P) were not different between the DH lines withand without 1RS/1BL translocation. This indicated that there was no association between 1RS and PUEand PDT in Lovrin No.10, and 1RS may not have P efficient gene(s). Therefore, in the offspring of LovrinNo.10, it is possible to combine high PUE and PDT with good quality without the negative effect of 1RS onflour quality.     

Effect of the 1B/1R translocation on anther culture ability in wheat (Triticum aestivum L.)

Using two varieties, their reciprocal hybrids, F₈ lines and doubled haploids, results confirmed that three genetic components are involved in wheat anther culture ability, viz embryo induction frequency, regeneration ability and the frequency of albinism. In these experiments, no significant maternal effects were noticed. For embryo yields, transgressive lines were obtained from hybrids between distant genotypes. Regeneration of green plants depended upon two independent traits: regeneration ability and the frequency of albinos. F₈ lines and two doubled haploids equaled the 50% regeneration rate of the hybrids, but they only regenerated green plants. Based upon cytological examination and gliadin patterns, it is suggested that genes favoring regeneration ability could be linked to the 1BL-1RS translocated chromosome from Aurora.Abbreviations DH doubled haploids - MS Murashige and Skoog - MPG multicellular pollen grains