一种非光敏特早熟小麦品种光温特性之初探

以强冬性小麦品种京冬8号为对照,采用分期播种试验,分析了非光敏特早熟小麦新品种冬早5号的生长发育进程和光温特性,并探讨了播期对两种小麦品种生育期和产量的影响.结果表明,冬早5号小麦品种比对照品种京冬8号早熟3～4 d,标准播期增产43.4%.冬早5号小麦品种在低温、短光照条件下也能完成正常的穗分化进程,其每经历一个穗分化期Z所用的天文日照时数、有效积温和光温积明显少于京冬8号.该品种在穗分化阶段对光照不敏感,无需经过严格的春化阶段和光照阶段,品种类型介于冬性和春性之间,冬前适播期较广,适合秋播也可以春播,这在小麦育种领域是个突破.     

品种、种子大小和施肥对冬小麦生物学特性的影响

试验设不同年代冬小麦品种、粒重、播种方式和施肥等4个因子,品种选用白芒麦（20世纪60年代）、咸农39（20世纪70-80年代）、小偃6号（20世纪90年代后期）、远丰998（近期）等不同年代的4个冬小麦品种,粒重分为2种截然不同重量的大粒和小粒,播种方式设小粒单播、大粒单播以及大小粒等比例混播等3种播种方式,施肥设不施肥（CK）、施氮（N）、施磷（P）和同时施氮磷（NP）等4种方式,共48个处理。以土垫旱耕人为土为供试土样,进行盆栽试验,研究不同品种、种子大小和施肥对冬小麦生物学特性的影响。结果表明,不同品种间、大小粒播种间、不同施肥间植株株高均存在极显著差异（p〈0.01）,且这些因子间存在显著的交互作用（p〈0.05）。品种间,苗期和越冬前以近期品种远丰998植株最高,灌浆期以早期品种白芒麦植株最高。株高稳定后以早期品种高,反映了育种的演变趋势。大小粒播种间,苗期和越冬前大粒株高均显著高于小粒株高,但灌浆期大小粒播种间株高差异基本消失,说明大粒种子植株在苗期生长具有一定优势。不同施肥处理间株高差异在苗期与越冬前表现一致,单施P和NP配施植株较高;灌浆期以NP配施植株株高明显高于其它施肥处理。不同品种、大小粒播种方式和施肥显著影响冬小麦分蘖和单株叶面积。白芒麦、咸农39和小偃6号的分蘖数基本一致,变化在4.37个/株-4.74个/株之间,远丰998最少,仅为2.95个/株;NP配施和施P能够显著增加分蘖数,其分蘖数几乎是不施肥（CK）和单施N的2倍;各品种大粒种子植株分蘖数均多于小粒种子植株。远丰998绿叶面积最大（45.72cm^2/单茎）,白芒麦最低（仅为26.97cm^2/单茎）;NP配施单株绿叶面积明显大于其它施肥处理。除远丰998大粒种子植株绿叶面积（50.42cm^2/单茎）显著大于小粒种子（41.01cm^2/单茎）外,其余品种大、小粒种子植株绿叶面积相当。就施肥处理而言,施肥对近期品种小粒种子株高、分蘖数和叶面积的促进作用相对较大,而对远期品种小粒种子植株的影响相对较小。     

Accelerated evolution of the mitochondrial genome in an alloplasmic line of durum wheat

Background

Wheat is an excellent plant species for nuclear mitochondrial interaction studies due to availability of large collection of alloplasmic lines. These lines exhibit different vegetative and physiological properties than their parents. To investigate the level of sequence changes introduced into the mitochondrial genome under the alloplasmic condition, three mitochondrial genomes of the Triticum-Aegilops species were sequenced: 1) durum alloplasmic line with the Ae. longissima cytoplasm that carries the T. turgidum nucleus designated as (lo) durum, 2) the cytoplasmic donor line, and 3) the nuclear donor line.

Results

The mitochondrial genome of the T. turgidum was 451,678 bp in length with high structural and nucleotide identity to the previously characterized T. aestivum genome. The assembled mitochondrial genome of the (lo) durum and the Ae. longissima were 431,959 bp and 399,005 bp in size, respectively. The high sequence coverage for all three genomes allowed analysis of heteroplasmy within each genome. The mitochondrial genome structure in the alloplasmic line was genetically distant from both maternal and paternal genomes. The alloplasmic durum and the Ae. longissima carry the same versions of atp6, nad6, rps19-p, cob and cox2 exon 2 which are different from the T. turgidum parent. Evidence of paternal leakage was also observed by analyzing nad9 and orf359 among all three lines. Nucleotide search identified a number of open reading frames, of which 27 were specific to the (lo) durum line.

Conclusions

Several heteroplasmic regions were observed within genes and intergenic regions of the mitochondrial genomes of all three lines. The number of rearrangements and nucleotide changes in the mitochondrial genome of the alloplasmic line that have occurred in less than half a century was significant considering the high sequence conservation between the T. turgidum and the T. aestivum that diverged from each other 10,000 years ago. We showed that the changes in genes were not limited to paternal leakage but were sufficiently significant to suggest that other mechanisms, such as recombination and mutation, were responsible. The newly formed ORFs, differences in gene sequences and copy numbers, heteroplasmy, and substoichiometric changes show the potential of the alloplasmic condition to accelerate evolution towards forming new mitochondrial genomes.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-67) contains supplementary material, which is available to authorized users.     

The effect of Furolan on the physiological and biochemical characteristics of ripening winter wheat grain

The effects of the preparation Furolan, (2-furyl-2)-1,3-dioxolane, on the degree of mRNA polyadenylation and the pattern of protein synthesis in the ripening grain of several soft winter wheat (Triticum aestivum L.) cultivars were studied. It was demonstrated that Furolan stabilized mRNA in a cultivar-specific manner, thereby accelerating to various degrees the biochemical processes taking place in the ripening grain. Of the wheat cultivars studied, Krasnodarskaya 99 was the most responsive cultivar with respect to a set of changes in nucleic-protein metabolism; the cultivar Deya was next followed by the cultivar Bat'ko. The cultivar Kroshka did not respond to the treatment with Furolan. The cultivar specificity of this preparation allows its practical application to be optimized.     

小麦品种蛋白质品质性状稳定性研究

用陕西省关中小麦品种区域试验所选用的12个小麦品种（品系）在12个试点的数据资料。分析了品种,环境及品种与环境互作（CEI）对籽粒硬度,蛋白质含量,沉淀值及湿面筋含量的影响。结果表明：基因型效应对所有品质参数均有显著影响,基因型与环境互作对沉淀值影响较大,而对籽粒硬度,蛋白质含量与湿面筋含量影响较小,环境效应对湿面筋含量和好粒硬度影响较大,而对蛋白质含量与沉淀值影响较小,蛋白质品质参数的回归系数（b值）表明,基因型对不同环境的反应存在着显著差异。对于籽粒硬度,蛋白质含量与湿面筋含量回归偏差显著的品种很少,这表明线性回归模式占了基因型变异的绝大部分,一些品种的沉淀值显著偏离了回归,上述结果表明,要改善小麦品种的蛋白质品质,也应重视环境对小麦蛋白质品质的影响。     

The effect of Furolan on the physiological and biochemical characteristics of ripening winter wheat grain

The effects of the preparation Furolan, (2-furyl-2)-1,3-dioxolane, on the degree of mRNA polyadenylation and the pattern of protein synthesis in the ripening grain of several soft winter wheat (Triticum aestivum L.) cultivars were studied. It was demonstrated that Furolan stabilized mRNA in a cultivar-specific manner, thereby accelerating to various degrees the biochemical processes taking place in the ripening grain. Of the wheat cultivars studied, Krasnodarskaya 99 was the most responsive cultivar with respect to a set of changes in nucleic-protein metabolism; the cultivar Deya was next followed by the cultivar Bat’ko. The cultivar Kroshka did not respond to the treatment with Furolan. The cultivar specificity of this preparation allows its practical application to be optimized.     

基因型与环境对小麦品种粉质参数的影响

用陕西省关中小麦品种区域试验所选用的20个小麦品种(品系)在12个试点1996～1997、1997～1998两年度的数据资料,分析了品种、环境及品种×环境互作(GEI)对粉质参数的影响。结果表明:品种与环境对所有粉质参数指标均有显著影响,但由品种决定的粉质参数的变异程度远大于环境引起的变异。基因型×环境互作效应对形成时间、稳定时间、软化度与评价值影响较大,而对吸水率影响较小。品种稳定性分析的回归系数(b值)表明基因型对不同环境的反应存在着显著差异。对每一粉质参数指标大部分品种都具有平均稳定性,只有1至2个品种稳定性显著较好或较差。     

The adaptability of wheat alloplasmic lines during hybridization

The adaptability of alloplasmic wheat lines and their hybrids with a wheat-allogenic amphiploid and wheat was studied. The influence of the nuclear genome and the interaction of nuclear and cytoplasm genomes on the adaptability of wheat and its hybrids has been established. For an assessment of adaptability, it is necessary to use a complex of attributes (morphological, cytogenetic, and resistance to abiotic and biotic factors of the environment).     

Breeding technology of alloplasmic wheat

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Grain aphid infestations of winter wheat variety trials, 1984

Aphid infestations of wheat yield trials near Cambridge were assessed by shoot sampling and by breeder's scores. Both resistant and extremely susceptible cultivars were identified. Results from the two methods of assessing infestation were well correlated, indicating that the simpler scores could be used effectively for making selections.     

Unusual inheritance of the mitochondrial genome organization in the progeny of reciprocal crosses between alloplasmic hexaploid wheat regenerants

The transmission of a structurally-hypervariable fraction of the mitochondrial genome has been studied in 42 F₁ progenies obtained from reciprocal crosses between self-pollinated alloplasmic wheat plants regenerated after long-term somatic embryogenesis. This fraction of the genome is maternally and stoichiometrically inherited. In contrast, some additional restriction fragments specific to regenerated plants display a more complex mode of sexual transmission: one of the additional fragments was stoichiometrically and systematically inherited whereas two others were detected only in certain F₁ hybrids. Assuming that the detection, by Southern analysis, of such a fragment in regenerated plants is due to the amplification of a pre-existing substoichiometric molecule generated by the activation of a rare recombination event, our results suggest that the probability of detecting a novel fragment in the F₁ hybrids could be determined by the length of the repeated sequence at which recombination occurs.     

The effect of humic acid on transamination in winter wheat plants

A very low, for the most part unmeasurable glutamic-aspartio transminase activity and a very high glutamic-alanine transaminase activity was found in the overground parts and roots of young wheat plants. The roots had a higher glutamic-alanine transaminase activity than the overground parts in the first and second leaf stage. Plants cultivated in Knop’s nutrient solution (variant with humate and without) showed a higher glutamic-alanine transaminase activity than poorly growing plants, cultivated in distilled water (with humate and without). In plants cultivated in nutrient solutions, transaminase activity increased with the age of the wheat plants. As in the previous experiments, the effect of humate was only significant, in the roots of plants cultivated in distilled water with humate, where transamination activity was greater than in the control without humate. The roots of this variant with a stimulatory growth effect showed a large accumulation of free sugars in the previous experiments. The connection between these effects of humate on the roots of young winter wheat plants is discussed.     

The effect of parental divergence on F2 heterosis in winter wheat crosses

Summary In winter wheat (Triticum aestivum L.), the development of a methodology to estimate genetic divergence between parental lines, when combined with knowledge of parental performance, could be beneficial in the prediction of bulk progeny performance. The objective of this study was to relate F₂ heterosis for grain yield and its components in 116 crosses to two independent estimates of genetic divergence among 28 parental genotypes of diverse origins. Genetic divergence between parents was estimated from (a) pedigree relationships (coefficients of kinship) determined without experimentation, and (b) quantitative traits measured in two years of field experimentation in Kansas and North Carolina, USA. These distances, designated (1 -r) and G, respectively, provided ample differentiation among the parents. The 116 F₂ bulks were evaluated at four locations in Kansas and North Carolina in one year. Significant rank correlations of 0.46 (P = 0.01) and 0.44 (P = 0.01) were observed between G and grain yield and kernel number heterosis, respectively. Although (1 -r) was poorly associated with grain yield heterosis, G and midparent performance combined to account for 50% of the variation in F₂ yields among crosses when (1 -r) was above the median value, whereas they accounted for only 9% of the variation among crosses when (1-r) was below the median. Midparent and (1 -r) had equal effects on F₂ grain yield (R ²= 0.40) when G was greater than the median value. A breeding strategy is proposed whereby parents are first selected on the basis of performance per se and, subsequently, crosses are made between genetically divergent parents that have both large quantitative (G) and pedigree divergence (1 -r).Paper No. 12162 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7643, and Contribution No. 89-396-J of the Kansas Agricultural Experiment Station, Manhattan, KS 66506     

Dependence of cross-pollination indices on genotype characteristics of winter common wheat

Out-crossing indices (the out-rcrossing rate, the frequency of plants with cross-pollination and outcrossing intensity) in F2 plants of winter common wheat from the reciprocal cross B-16 x Odesskaya Krasnokolosaya were analysed using storage proteins as genetic markers. Outcrossing indices greatly differed depending on growth conditions. The out-crossing rate was 0,35 % (Odessa, 2000) and 5,11% (Kyiv, 2004). The highest out-crossing indices were detected in homozygotes for the presence of the rye 1BL/1RS translocation. The out-crossing indices in heterozygotes for the presence of the 1BL/1RS translocation were intermediate. Differences in the out-crossing indices were detected between populations of F2 plants derived from direct and reciprocal crossing. Different directions of these differences were noted for the out-rcrossing rate and the frequency of plants with cross-pollination, on the one hand, and out-crossing intensity, on the other hand.     

行距对晚播冬小麦群体的调节效应

为了明确行距对晚播冬小麦群体的调节效应,在2011—2013年度,以"济麦22"为试验材料,在晚播条件下设置3个行距处理(12、20、30 cm),比较了不同行距类型群体生育后期的冠层结构和冠层下部环境的差异、群体内植株个体性状及变异程度、产量和产量构成因素的变化。结果表明:行距缩小至12 cm,群体生育后期的叶面积指数显著提高,中上部冠层的光能截获显著增加、冠层下部的漏光损失显著减小;与20 cm和30 cm行距相比,12 cm行距群体内部的最高温度分别降低0.9和2.5℃,相对湿度增加0.3%和0.9%;行距缩小后,群体内单株性状的变异程度缩小,穗长和小穗数显著增加,单株穗粒重变异系数缩小,群体产量的稳定性提高,产量增加7.8%~24.5%。研究认为,窄行距(12 cm)播种有利于提高华北平原干旱缺水地区晚播冬小麦的群体产量。     

Temperature characteristics and adaptive potential of wheat ribosomes

The translational efficiency of wheat ribosomes was studied as a function of an in vivo temperature pretreatment of wheat seedlings (Triticum aestivum L.). Ribosomes were isolated from heat-pretreated (36°C) and reference (4°C, 20°C) wheat seedlings. The efficiency of the ribosomes in translating polyuridylic acid was assayed. Ribosomes from heat-pretreated seedlings exhibit a threefold enhanced incorporation rate of phenylalanine as compared to ribosomes from wheat seedlings adapted to 20 or 4°C. This difference develops within 24 hours after onset of the heat treatment of seedlings following a 3 hour lag phase. The temperature induced changes can be traced back to the cytoplasmic ribosomes, since cycloheximide inhibits translation almost completely. Thermal inactivation of ribosomes occurs at 45°C, irrespective of the temperature pretreatment of the wheat seedlings. Specific differences in the yield of ribosomes, in the polyribosomal profiles, and in the apparent Arrhenius' activation energy of protein synthesis were observed depending on the age and the temperature pretreatments. The results presented here are considered an important molecular correlation to phenotypical temperature adaptation of in vivo protein synthesis in wheat (M Weidner, C Mathée, FK Schmitz 1982 Plant Physiol 69: 1281-1288).     

The effect of nitrogen and growth regulators on stem and root characteristics associated with lodging in two cultivars of winter wheat

The effects of nitrogen and plant growth regulators (stem shorteners)on root and shoot characteristics associated with lodging resistancewere investigated in two winter wheat (Triticum aestivum L.)cultivars of contrasting lodging resistance: the susceptibleGalahad and the resistant Hereward. The morphology and mechanicalstrength of the stems and anchorage systems grown at two levelsof nitrogen and with or without growth regulators were measuredand related to the incidence of lodging recorded in a fieldtrial. In both cultivars high levels of nitrogen increased theheight of the stem, thereby increasing the ‘self-weight’moment transmitted into the ground and weakened both the stemsand the anchorage coronal roots. As a result, the anchoragestrength was also reduced, plants failing in the root systemin simulated lodging tests. Growth regulators, in contrast,had little effect on the bending strength of the shoots androot systems, but reduced plant height so that the over turningmoments generated by the weight of the shoot were less. Therewere also differences between cultivars: Galahad plants hadweaker anchorage due to the smaller number and lower strengthof the coronal roots. The morphological and mechanical measureswere used to calculate a safety factor against both stem androot lodging. Five factors were found to influence the safetyfactors, these were: cultivar type, the type of lodging, therate of nitrogen and growth regulator application, and time,being lowest in Galahad plants at high levels of nitrogen andwithout growth regulators and at grain filling when the earswere heaviest. This was consistent with the observed patternof lodging: root lodging occurred at grain filling and onlyin Galahad which had been treated with high nitrogen rates,most strongly in plants without growth regulators. Key words: Lodging, safety factors, anchorage, ‘self-weight’ moment     

The effect of minimum cultivation on the incidence of take-all down the root profile of winter wheat

The effects of direct drilling, shallow cultivation and ploughing on the infection of winter wheat roots by the take-all fungus (Gaeumannomyces graminis var. tritici) were studied on three field sites over a number of years. All three soil types were categorised by Cannell, Davies, Mackney & Pidgeon (1978) as suitable for sequential direct drilling. The results show that a smaller proportion of roots was infected at depth in the direct-drilled plots in May/June. However by July these differences had all but disappeared and an estimate of infection in the top 7 cm of the roots (approximately equivalent to traditional hand sampling for take-all) gave a reliable comparison of the total take-all on plants grown under these different cultivation systems.     

氮素营养对小麦根冠协调生长的调控

在植物生长箱通过溶液培养方式,对不同氮素条件下不同抗旱性的小麦品种西农1043和小偃6号的幼苗根苗生长特性进行了研究,结果表明在不同氮素浓度下,氮肥用量的提高对地上部干重和叶片气体交换参数表现为增效效应,当用量增至一定程度时,地上部干重和叶片气体交换参数均呈下降趋势,只是各自的适宜用量存在差异。培养介质氮素浓度低时,有利于小麦根系干重累积,培养介质氮素浓度高时,不利于根系干重累积。西农1043和小偃6号根长分布基本相似,水分利用效率随着根冠比的增大而降低。小麦根冠比的增加并不利于叶片水分利用效率的提高,而叶片光合作用最优的根冠比为0．5左右。