小麦籽粒产量及穗部相关性状的QTL定位

由小麦品种花培3号和豫麦57杂交获得DH群体168个株系,种植于3个环境中,利用305个SSR标记对籽粒产量和穗部相关性状(穗长、穗粒数、总小穗数、可育小穗数、小穗着生密度、千粒重和粒径)进行了QTL定位。利用基于混合线性模型的QTLNetwork 2.0软件,共检测到27个加性效应和13对上位效应位点,其中 8个加性效应位点具有环境互作效应。相关性高的性状间有一些共同的QTL位点,表现出一因多效或紧密连锁效应。5D染色体区段Xwmc215–Xgdm63,检测到控制籽粒产量、穗粒数、总小穗数、可育小穗数和小穗着生密度5个性状的QTL位点,各位点的遗传贡献率较大且遗传效应方向相同,增效等位基因均来源于豫麦57,适用于分子标记辅助育种和聚合育种。控制千粒重与穗粒数的QTL位于染色体不同区段,有利于实现穗粒数与粒重的遗传重组。     

Quantitative trait loci mapping for flag leaf traits in rice using a chromosome segment substitution line population

To study the genetic basis of rice flag leaf morphology, quantitative genetic analysis was conducted in a population of 37 chromosome segment substitution lines (CSSLs) of indica elite variety ‘Habataki’ in the background of japonica cultivar ‘Sasanishiki’ across three different environments. The CSSLs showed normal distribution with transgressive segregation, indicating that these four traits are controlled by polygenes. Moreover, analyses of variance showed that these traits were highly influenced by the growing environment, which are typical for polygenic quantitative traits. Seven quantitative trait loci (QTLs) on four chromosomes were detected in total: four for flag leaf width, one for flag leaf area and two for flag leaf angle. Two key QTLs, qFLW4 and qFLAG5 controlling flag leaf width and angle, respectively, were identified in all three environments. These QTLs could provide useful information for marker‐assisted selection in improving the performance of plant architecture with regard to leaf angle and area. Moreover, developed CSSLs with these QTLs information are also useful research materials to reveal the importance of leaf morphology in relation to grain yield.     

小麦旗叶和芒的遗传及其与产量性状的相关性研究

通过对20个小麦品种（系）的研究表明,旗叶、芒对产量形成影响较大。旗叶、芒具有一定的遗传变异度,旗叶性状遗传力中等,芒遗传力较高。旗叶长、旗叶宽、旗叶面积、穗平均芒长均与穗粒重呈显著正相关;旗叶开张角、披垂度与穗粒重呈显著负相关。旗叶长与开张角、披垂度正相关,旗叶宽与开张角、披垂度负相关。育种中可将旗叶宽作为良好的株型性状加以选择。     

CCC对风仙花生长与开花的影响

以凤仙花为试材，喷施CCC后使植株显著矮化，叶片变小，加厚，花期推迟，花序长度、花序节间长度缩短，叶绿素含量增加，呼吸强度提高，过氧化物酶活性增强。上述一系列变化，促使植株矮化、株型紧凑、生长茁壮，具有较高的观赏价值。     

不同矮秆基因对冬小麦农艺性状的影响

利用以冬麦品种ＭａｒｉｓＨｕｎｔｓｍａｎ为背景的含有不同矮杆基因Ｒｈｔ１,Ｒｈｔ２和Ｒｈｔ３及其不同结合形式的６个近等基因系,研究了不同矮秆基因对小麦农艺性状的作用,结果表明,Ｒｈｔ１半矮秆基因显著提高了单株穗数,粒数和粒重,地下部生物产量,经济系数和倒二叶面积,Ｒｈｔ２半矮秆基因显著提高了单株（或单穗）粒数和粒重,经济系数和倒二叶面积,显著降低了千粒重,Ｒｈｔ３矮秆基因对单株粒数,地上部生物产量     

一个化学诱变的小麦斑点叶突变体的生理和遗传分析

通过EMS诱变普通小麦品系H261获得一个稳定遗传的斑点叶突变体LF2010。在自然条件下, 该突变体在三叶期叶片基部开始出现黄色斑点, 随后逐步扩散到全片叶、叶鞘、颖壳和麦芒。斑点部位不存在细胞死亡, 斑点性状的表达受光照和温度诱导, 突变体的色素含量、光合速率随着斑点的出现而显著下降。突变体的株高、有效穗数、单株产量、穗长、结实率和旗叶长等农艺性状显著下降, 但是千粒重和旗叶宽却与野生型无差异。将突变体与正常绿色品系杂交, 对其F₁、F₂和BC₁代的遗传分析表明, LF2010的突变性状由1对隐性核基因控制。     

QTLs for uppermost internode and spike length in two wheat RIL populations and their affect upon plant height at an individual QTL level

Spike length (SL) is one of the most important components of spike morphology, and the uppermost internode represents an ideal organ to study the transportation system. We performed conditional and unconditional quantitative trait locus (QTL) mapping in two unrelated recombinant inbred line populations to precisely detect QTLs for uppermost internode length (UIL) and SL, and to dissect the genetic relationship between these two factors with plant height (PH). Both of the populations were derived from crosses with synthetic wheat. Ten repetitive QTLs for UIL and six environment-independent QTLs for SL were identified in this study, and twelve of these were completely independent of PH. Conditional QTL mapping analysis indicated that SL was more independent to PH than UIL was. The results indicated that the conditional QTL mapping method could evaluate PH component effects on PH, and thus accelerate the selection of suitable loci that improve commercial wheat morphology yet avoid changes to PH.     

利用“02428h”的eui基因选育长穗颈不育系

为研究隐性长穗颈水稻“02428h”的长穗颈基因eui在减轻不育系包颈度中的利用价值,以02428h为父本,培矮64S为母本和轮回亲本,经过连续3次回交将02428h的eui基因导入培矮64S,转育成了具有长穗颈基因的“P8hS”。与培矮64S相比,P8hS的株高增加35.6 cm,主要是穗颈节和倒2节间长度增加所致。eui基因的导入不仅可使培矮64S的穗包颈得到彻底改善,而且对培矮64S及其杂种的主要经济性状具有改进作用。     

Identification of coincident QTL for days to heading,spike length and spikelets per spike in <Emphasis Type="Italic">Lolium perenne</Emphasis> L.

Flowering time is a trait which has a major influence on the quality of forage. In addition, flowering and subsequent seed yields are important traits for seed production by grass breeders. In this study, we have identified quantitative trait loci (QTL) for flowering time and morphological traits of the flowering head in an F₁ mapping population in Lolium perenne L (perennial ryegrass), a number of which have not previously been identified in L. perenne mapping studies. QTL for days to heading (DTH) were mapped in both outdoor and glasshouse experiments, revealing three and five QTL for DTH which explained 53% and 42% of the total phenotypic variation observed, respectively. Two QTL for DTH were detected in both environments, although they had contrasting relative magnitudes in each environment. One QTL for spike length and three QTL for spikelets per spike were also identified explaining, a total of 32 and 33% of the phenotypic variance, respectively. Furthermore, the QTL for spike length and spikelets per spike generally coincided with QTL for days to heading, implying co-ordinate regulation by underlying genes. Of particular interest was a region harbouring overlapping QTL for days to heading, spike length and spikelets per spike on the top of linkage group 4, containing the major QTL for spike length identified in this population.     

Production and genetic characterization of the co-isogenic lines of a common wheat Triticum aestivum CV. S-615 for ten major genes

Summary Co-isogenic lines of a common wheat, Triticum aestivum, cv. S-615 with each of the following ten major genes were produced by repeated backcrosses; The gene C on 2D chromosome for the compactum character, s on 3D for the sphaerococcum character, Hd on 4B, B1 on 5A, and B2 on 6B for awn suppression, Hg on 1A for glume hairiness, Hp on 4A for peduncle hairiness, Ne1 on 5B and Ne2 on 2B for hybrid necrosis, and v1 on 3B for virescence. Seven of them showed the typical mendelian fashion of inheritance, while three others (C, s and v1) were transmitted at lower frequencies than their corresponding normal alleles.The effects of those major genes on 24 characters of cv. S-615 were investigated, which are summarized as follows: C: Increased node diameter, number of spikelets per ear and spike density, but decreased lengths of all ear rachis, awn, anther, empty and outer glumes, and grain, and grain index. s: Increased culm diameter and thickness, and spike density, reduced lengths of all 1st and 2nd internodes, culm, flag leaf, rachis, awn, anther, empty and outer glumes, and grain, and grain index, and accelerated heading. Hd: Increased number of spikelets per ear and anther length, while decreased length of awn, and empty and outer glumes. B1: Increased 1st internode, rachis, and anther lengths, and grain index, but decreased spike density, awn length and grain thickness. B2: Increased rachis length, number of spikelets per ear, empty and outer glume lengths and grain index, but reduced awn length and grain thickness. Hg: No effects. Hp: Increased number of spikelets per ear. Ne1: Accelerated heading, and increased empty glume length. Ne2: Increased node and culm diameters. v1: No effects.Two species-specific genes, C and s, affected a large number of characters expressed in various developmental stages. These genes were found to have pleiotropic effects, namely, they influenced, at least, two groups of interdependent characters. Three awn suppressors influenced a limited number of characters, but no evidence of their pleiotropic effects was obtained.Contribution from the Laboratory of Genetics, Faculty of Agriculture, Kyoto University, Japan, No. 422. The work was supported in part by a Grant-in-Aid (No. 148,004) from the Ministry of Education, Japan.     

Compensative Effects of Chemical Regulation with Uniconazole on Physiological Damages Caused by Water Deficiency during the Grain Filling Stage of Wheat

Chemical regulation using plant growth regulators has proved to be potentially beneficial in water‐saving agriculture. This experiment was conducted with winter wheat (Triticum aestivum L. cv. ‘Jingdong 6’) to study the effect of chemical regulation on alleviation of water deficit stress during the grain filling stage. Uniconazole, a plant growth regulator, was foliar sprayed at 85 % (adequate irrigation) and 60 % (deficit irrigation) field capacity. Results showed that the distribution of ³H‐H₂O in roots and flag leaf, characteristics of vascular bundle in primary roots and internode below spike, roots activity, transpiration rate and stomatal conductance of flag leaf were negatively affected by deficit irrigation after flowering. Foliar spraying at the early jointing stage with 13.5 gha^?1 uniconazole was able to relieve and compensate for the harmful effects of deficit irrigation. Both the area of vascular bundle in primary roots and internode below the ear were increased by uniconazole, while root viability and their ability to absorb and transport water were increased. In the flag leaf, stomatal conductance was reduced to maintain the transpiration rate and water use efficiency (WUE) measured for a single wheat plant was higher. Uniconazole increased WUE by 25.0 % under adequate and 22 % under deficit irrigations. Under adequate irrigations, the ¹⁴C‐assimilates export rate from flag leaf in 12 h (E_12h) was increased by 65 % and 36 % in early and late filling stages, while under deficit irrigations, the E_12h of uniconazole‐treated plants exceeded that of control plants by 5 % and 34 % respectively. Physiological damages caused by water deficiency during the grain filling stage of wheat was alleviated by foliar spraying with uniconazole.     

钵苗机插密度对不同穗型水稻品种产量、株型和抗倒伏能力的影响

选用3种穗型水稻品种,设置3种钵苗机插密度,以毯苗机插为对照(CK),系统研究钵苗机插不同密度对水稻产量及其构成、穗部性状、冠层叶系配置、茎秆物理特性和抗倒伏的影响,旨在探明水稻钵苗机插配套不同穗型品种适宜栽插规格及其增产特点;同时,阐明钵苗机插不同密度下水稻株型特征和抗倒伏特性。结果表明:(1)3种钵苗机插密度处理下,大穗型品种产量随密度降低呈先增后降的变化趋势,但均显著高于CK;中、小穗型品种产量有随着密度降低而下降的趋势。不同穗型品种穗数随着密度降低而显著减少,每穗粒数显著增加,结实率和千粒重无明显变化规律。(2)钵苗机插下不同穗型水稻品种的穗长、着粒密度、单穗重、一次枝梗数、二次枝梗数、一次枝梗粒数和二次枝梗粒数均随密度降低而增加,且高于CK;一、二次枝梗数比值和一、二次枝梗粒数比值随密度降低而呈下降趋势。(3)钵苗机插下不同穗型水稻品种的上三叶的叶长、叶宽、叶基角、披垂度和比叶重随着密度降低而呈增加趋势;且上三叶的叶长、叶宽和比叶重高于CK。(4)随着密度降低,不同穗型品种钵苗机插水稻基部N1、N2、N3节间长度减少,茎秆粗度、茎壁厚度和节间干重增加,穗下节间长、秆长、株高、重心高增加,而相对重心高有减小趋势。(5)不同穗型品种钵苗机插水稻基部节间N1、N2、N3抗折力和弯曲力矩随着密度降低而增加,倒伏指数呈下降趋势,且低于CK。说明水稻钵苗机插配套大穗型品种宜适当降低密度,增加每穗粒数以获高产;中穗型品种需兼顾穗数和每穗粒数,提高群体颖花量而增产;小穗型品种依靠穗数而提高产量。水稻钵苗机插降低密度能改善穗部性状和增加上三叶的叶面积,但增大了叶基角和披垂度,同时利于缩短基部节间长度,增加基部节间粗度、茎壁厚度和充实度,从而提高抗折力,降低倒伏指数。     

The inheritance of morphological and agronomic characters in spring wheat

Summary Inheritance of yield and its component (number of ears per plant, number of spikelets per ear, number of kernels per ear, 1000-kernel weight), together with the inheritance of morphological characters (flag leaf length, flag leaf breadth, peduncle length, extrusion length and leaf sheath length) and anthesis date was studied in a 5-parent diallel cross of spring wheat varieties. The diallel analysis of gene actions indicated that a large part of the total genetic variation observed for all the characters studied was in the form of additive genetic effects. The degree of dominance was also determined for each character. Number of ears per plant showed most overdominance, followed by leaf sheath length. Full or nearly full dominance was found for anthesis date, flag leaf length and yield per plant. Other characters showed partial dominance. Correlation coefficients showed that yield per plant, as well as being correlated with the yield components, was also assiciated with flag leaf breadth and leaf sheath length. There was no evidence of genetic barriers to the combining of ideal characters among the varieties of different origin.     

利用90k芯片技术进行小麦穗部性状QTL定位

小麦穗部性状与产量密切相关,挖掘穗部性状基因及其关联分子标记具有重要意义。本研究以周8425B?小偃81衍生的RIL群体(F8)为材料,利用90k芯片标记构建的高密度遗传图谱对3个环境下的穗长、小穗数、不育小穗数、穗粒数、千粒重进行QTL定位。共检测到19条染色体上的71个QTL,变异解释率(PVE)范围为2.10%~45.25%,其中37个位点为主效QTL(PVE10%)。QSl.nafu-6A.2(穗长)、QSl.nafu-7A(穗长)、QSsn.nafu-2A.1(不育小穗数)、QSsn.nafu-2D(不育小穗数)和QGns.nafu-2B(穗粒数)在多个环境中被检测到,且LOD10,PVE20%。位于同一个基因簇中的QSl.nafu-6A.2(穗长)、QGns.nafu-6A(穗粒数)和QTgw.nafu-6A(千粒重)在多个环境中被检测到,且与已报道的相关位点位置相同或相近,在分子标记辅助育种中具有较大参考价值。     

长江中下游双季稻高产株型特征初步研究

以19个早稻和16个晚稻品种,通过方差分析对不同产量水平水稻的主要株型特征进行研究。结果表明,高产类型双季稻具有库容量大、产量潜力高、物质生产能力和氮素吸收能力强的特点。高产类型早稻生育期110~115 d,株高95~105 cm,上部节间较长,倒2、倒3叶片较长,叶片披垂角相对较大,穗长较长,1次枝梗和2次枝梗数目多,每穗粒数100~130粒,千粒重27~29 g,单穗干重2.5 g以上。高产类型晚稻生育期120~125 d,株高100~110 cm,上部节间长,茎秆粗壮,叶片长度适中,叶片披垂角相对较小,穗长较长,枝梗数目特别是2次枝梗数目多,着粒密度大,每穗粒数120~150粒,千粒重25~27 g,单穗干重3 g左右。     

燕大1817/北农6号重组自交系群体穗部性状的QTL定位

小麦穗部性状与单株产量密切相关。本研究以小麦骨干亲本燕大1817与优良品系北农6号衍生的269个重组自交系为材料,通过在北京和河北石家庄的2年田间试验数据,利用本实验室已构建的高密度SNP和SSR遗传连锁图谱进行穗长、穗粒数和穗粒重QTL定位。采用完备复合区间作图法共检测到29个穗部性状加性效应QTL,其中10个穗长QTL分布于1B、2D、3A、3B、4A、5A、5B、6A和7D染色体上,解释的表型变异率为2.96%~9.63%,QSl.cau-4A.2在所有5个环境中均能被检测到,解释的表型变异为5.89%~9.62%,另有7个QTL能在2个或2个以上环境中被检测到;8个穗粒数相关QTL分布于1A、3A、3D、4A和5B染色体上,解释的表型变异为4.06%~11.17%,为单个环境QTL。11个与穗粒重相关QTL分布于1A、1B、2A、2D、3A、4D、5A、5B和6B染色体上,解释的表型变异为2.79%~16.12%,其中QGws.cau-1B、QGws.cau-3A和QGws.cau-6B.2在2个或者2个以上环境中能被检测到。另外,鉴定出6个分布于1A、2D、3A、4A和5B染色体上的QTL富集区段。     

Heat Stress Effects are Stronger on Spikelets Than on Flag Leaves in Rice Due to Differences in Dissipation Capacity

Rice is most sensitive to heat stress at the flowering stage, with different degrees of heat damage in spikelets and leaves. To investigate the heat damage in spikelets and flag leaves, two rice genotypes, N22 (heat‐tolerant) and GT937 (heat‐sensitive), were subjected to a heat‐stress treatment (40 °C for 15 days). The results showed that more damaging was found in spikelets than in flag leaves and the heat stress significantly decreased the seed‐setting rate by 12.41 % in N22 and by 65.02 % in GT937. However, the difference in the net photosynthetic rate of the flag leaf between heat‐stressed and control was not significant. Moreover, the difference of temperatures in spikelets and flag leaves was attributed to the differences in heat dissipating. Under heat stress, the transpiration rate was significantly higher in flag leaves than in spikelets, and the temperature in flag leaves were at least 4 °C cooler than in spikelets. Although the spikelet temperatures did not differ significantly between the two genotypes under heat stress, spikelets of GT937 were more severely damaged than those of N22, which might result from the differences in the antioxidant capacities between genotypes. Results showed that little difference of superoxide dismutase, peroxidase and catalase activities of spikelets was found in N22, while significant reduction was found in GT937 under heat stress, compared with control. These results suggest that organ temperature is controlled mainly by transpirational cooling, and that heat stress is an indirect result of oxidative stress, rather than a direct result of heat damage.     

Associations between 23 Quantitative Traits and 10 Genetic Markers in a Barley Cross

Associations of 23 quantitative traits and 10 genetic marker characters were examined in 63 chromosome-doubled lines (DH-lines) derived from the F₁- generation of a cross between an old and a modern spring barley variety. One fourth of the marker × trait combinations showed significant associations. More than two thirds of these associations were to earliness (heading date). Earliness was found to be controlled by two loci: the previously known eak locus and a new locus designated Ea. It is concluded that the associations of quantitative traits with the earliness loci were caused by pleiotropy. Associations were found between two absolutely linked C-bands on chromosome 3 and QTLs (quantitative trait loci) for lodging, straw diameter, and length of top internode of the straw. The three loci on chromosome 5, eak and the two linked powdery mildew loci, Mla9 and Mlk, were associated with a possible QTL for magnesium concentration in grain. Association to the C-band on chromosome 6 suggests QTLs for TGW (thousand grain weight), straw diameter and magnesium concentration in grain. Locus Estl on chromosome 3 was not associated with any of the quantitative traits.     

水稻品种魔王谷粒形、剑叶性状和株高QTL定位

以粳稻魔王谷和籼稻CO39配组衍生的280个重组自交系为材料, 2015年和2016年对其粒形、剑叶形态、株高性状进行了相关性分析和QTL检测。剑叶长分别与粒厚和株高存在极显著负相关和正相关, 剑叶宽与粒宽存在极显著正相关。检测到17个粒形QTL, 分布于第1、第2、第3、第4、第5、第6、第7、第9和第10染色体上, 贡献率为3.51%~48.65%; 其中, 第3染色体RM6080-RM6283区间对粒长和千粒重兼具显著作用, 第5染色体RM8211-RM3381区间同时影响粒宽和粒厚。检测到12个控制剑叶形态性状的QTL, 分布于第1、第3、第4、第6、第7和第9染色体上, 贡献率为4.26%~38.40%; 有5个多效QTL区间, 其中, 第4染色体RM252-SFP4_6区间同时控制剑叶长、剑叶宽、剑叶面积和粒长, 第9染色体RM257-RM3909区间同时影响剑叶面积和粒长。只检测到一个控制株高的QTL, 位于第1染色体的RM6333-RM5536区间, 是一个主效QTL, 贡献率为28.76%。这些结果为进一步开展粒形、剑叶形态、株高基因的精细定位、克隆和分子辅助育种奠定了基础。     

水稻中胚轴伸长特性的遗传分析

以长中胚轴/短中胚轴杂交组合的两个亲本、F₁、B₁、B₂和F₂为试验材料，在小型人工气候箱黑暗条件下培养幼苗，对水稻中胚轴伸长特性的遗传规律进行了研究。结果表明，中胚轴伸长特性受两对隐性基因控制。F₂群体中长、短中胚轴植株在节间长度、穗长、株高和剑叶长等性状上均存在较明显的差异，而中胚轴伸长特性与节间粗、剑叶宽、单株穗数、每穗总粒数、结实率、千粒重和单株产量等性状关系不明显。还对水稻中胚轴伸长特性的遗传改良以及长中胚轴材料在直播稻育种上的利用进行了探讨。