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1.
Summary Twelve spring wheat cultivars were grown as isolated plants in the field and their pre-anthesis growth was interpreted in terms of plant growth analysis. Relative growth rate (RGR) decreased steadily with time due to a decline of leaf area per unit plant weight (LAR), which could be explained by the reduction of the portion of leaf weight in total plant weight (LWR). Growth per unit leaf area (NAR) and leaf area per unit leaf weight (SLA) changed only little with time.Differences between cultivars for NAR and LAR were of similar magnitude: both 8% when measured by the genetic coefficient of variation. Because both quantities were negatively correlated, the genetic variation of RGR was only 5%. Genetic variation for LWR and SLA were also of similar size, both about 4%. Estimates of genetic variances and covariances based on cultivar means appeared to be biased strongly when the error variation of the means was neglected.Special attention is paid to the methodology of plant growth analysis. 相似文献
2.
Breeding of cut and pot rose cultivars for efficient production under low-energy conditions in greenhouses will be facilitated
by understanding the inheritance of vigour. To get insight into the genetic variation of vigour-related traits, a diploid
rose population was employed for an evaluation study in greenhouses in The Netherlands and Denmark. For all the traits investigated
the population showed a continuous quantitative variation as well as a considerable transgression. For most of the traits,
the genetic variation found among the tested entries was highly significant and tended to be large in comparison to the effects
of genotype by environment interaction. The heritability based on means of the traits was high and ranged from 68 to 92%.
Strong simple correlations (r = 0.65 to 0.95) were found among the traits shoot length, leaf area, leaf dry weight, stem dry weight, total dry weight and
growth rate. The total dry weight and leaf area are suggested to be good parameters for early selection of rose genotypes
with vigorous growth under suboptimal growth conditions. 相似文献
3.
Summary Carnation cultivars vary considerably in the average weight of their cuttings. Cutting weight shows a high negative correlation with mean relative growth rate. This was initially attributed to differences in age of the cuttings when taken from the stock plants, age being defined as time elapsed since start of visible shoot growth. Shoots on a stock plant are removed as cuttings when they have reached an adequate size and number of leaf pairs. Cuttings from cultivars with a lower rate of growth are removed later, usually resulting in a higher dry weight. This could explain why a high cutting weight is associated with a low relative growth rate.The validity of this tentative explanation is tested in 13 carnation cultivars grown under controlled conditions in two trials, one with plants grown from pinched cuttings and one with plants grown from unpinched cuttings for early flowering (forcing). An analysis of the data for plant weight and leaf pair number at successive stages of development suggests that the primary cause of the negative correlation between cutting weight and mean relative growth rate is not genetic variation in age of the cuttings, but variation in the size of the fully developed axillary bud on the stock plant. Larger buds produce thicker shoots that grow more slowly. Their later harvesting as cuttings only enhances their initial weight advantage, and also the negative correlation with mean relative growth rate.When plants are pinched 20 days after planting, as is normal in a summer-grown crop, the newly developing shoots still show variation in age. This is attributed to variation in the developmental stage of the dormant axillary buds at the time of pinching, causing variation in the time interval between pinching and the start of visible shoot growth. 相似文献
4.
Plant traits associated with resistance to Thrips tabaci in cabbage (Brassica oleracea var capitata)
Roeland E. Voorrips Greet Steenhuis-Broers Marjolein Tiemens-Hulscher Edith T. Lammerts van Bueren 《Euphytica》2008,163(3):409-415
Thrips tabaci is a major problem in the cultivation of cabbage for storage, as this pest causes symptoms that necessitate the removal of
affected leaves from the product. Between cabbage varieties large differences in susceptibility occur. This study aimed to
identify plant traits associated with these differences, in field experiments with natural infestation in 2005 and 2006. One
factor affecting the amount of thrips damage was the timing of the development of the head. In an experiment with different
planting dates especially the early maturing, more susceptible varieties were shown to benefit from later planting. In comparisons
of multiple varieties in both years, regression studies showed that more advanced plant development in August and early September
increased thrips damage at the final harvest. However, no single plant trait explained more than 25% (2005, Brix) or 48% (2006,
compactness) of the variation in thrips damage. Optimal regression models, explaining up to 75% of the variation in thrips
damage included Brix and leaf surface wax late in the season, as well as an indicator of plant development earlier in the
season, and in 2005 also leaf thickness. The possible role of these plant traits in relation to thrips is discussed. 相似文献
5.
L. H. M. Broers 《Euphytica》1989,44(3):187-195
Summary Latency period (LP), infection frequency (IF) and urediosorus size (US) of leaf rust were determined on primary leaves and young flag leaves of 18 spring wheat cultivars. A large growth stage effect and a large cultivar effect on all three components were observed. Partial resistance as measured by the three components was generally better expressed in the adult plant stage than in the seedling stage. Associated variation of the components was observed: long LP, low IF and small US tended to go together. The association was not complete, cultivars with clear deviations of this association for one of the components were found suggesting the existence of at least partly different genetic factors controlling the respective components. LP measured on flag leaves gave the most reliable results and, therefore, could best be used as a selection criterion in breeding programs for partial resistance. 相似文献
6.
芝麻黄化突变体YL1的叶片解剖学及光合特性 总被引：1，自引：0，他引：1
表型性状标记在作物遗传育种中具有重要的应用价值。在芝麻地方种质"庙前芝麻"中发现了能够稳定遗传的黄化突变体YL1,对该突变体的叶片解剖特征、光合特性及农艺性状的比较分析表明,突变体YL1黄化心叶和平展叶在各个发育时期的叶绿体结构均与同时期野生型存在明显差异,下表皮气孔保卫细胞数是正常叶的2倍左右。YL1的叶绿素a、总叶绿素、类胡萝卜素含量均只有同时期正常含量的30%~40%,叶绿素b含量只有正常叶的20%;光合速率在初花期及以前均显著低于同期正常叶,但到终花期与正常叶相当;YL1的生育期和初花期显著推迟,株高和单株蒴果数明显降低,每蒴粒数和千粒重略微降低。显微观察表明,YL1的叶绿体形态结构发育不规则,基粒和基粒片层数目明显少于野生型,使得叶绿素含量过低,属于叶绿体发育异常导致的叶绿素缺少型突变体。 相似文献
7.
小麦叶锈病（leaf rust）是对小麦危害最严重的真菌病害之一,原菌群体中新致病菌类型的不断出现导致部分抗叶锈病基因的抗性功能逐步丧失,不断发掘和研究利用新抗源基因、培育种植抗病品种是控制该病害最有效的方法。周麦22在田间成株期对叶锈病表现出良好的抗性,为解析周麦22成株期抗叶锈病的遗传基础,将周麦22与铭贤169杂交构建遗传群体,获得255个F2:3家系群体,经2个年度的大田成株期抗叶锈病鉴定,并利用复合区间作图法对该群体的抗叶锈病QTL进行定位分析。结果显示,该群体成株期检测到2个抗叶锈病QTL位点,分别位于1BL和2BS染色体上,命名为QLr.hebau-1BL和QLr.hebau-2BS,分别解释9.62%~11.88%和16.89%~20.99%的表型变异,该位点对叶锈病抗性表现稳定,均来自抗病品种周麦22。初步的遗传定位结果显示,QLr.hebau-2BS可能为已知抗叶锈病基因LrZH22,而QLr.hebau-1BL是新的抗病QTL。 相似文献
8.
Summary The reaction of eight triticales and of the respective wheat and rye parental lines to infection by the leaf rust fungi of wheat and rye were studied in the seedling stage. The histological observations indicated that wheat and triticale showed a typical nonhost reaction to the leaf rust of rye: sporelings of this fungus were arrested after the formation of primary infection hyphae and before the formation of extensively branched mycelium, mostly without necrosis of plant cells. The rye inbred lines were all susceptible to the rye leaf rust. The reaction of wheat and triticales to the wheat leaf rust was susceptible or resistant. The reaction of resistant lines could be early or late and complete or incomplete, but was associated with substantial necrosis of plant cells, and therefore entirely different from the nonhost reaction to rye leaf rust. In their reaction to wheat leaf rust the rye lines were similar to the resistant wheat and triticale lines. They did not show an important degree of nonhypersensitive early abortion as would be expected in a nonhost species. It appeared that genes for hypersensitive resistance in triticale may be contributed by either the wheat or the rye parental line.A screening of sixty wheat, rye and triticale lines confirmed the nonhost status of wheat and triticale to rye leaf rust and the hypersensitive or moderately susceptible reaction of rye to wheat leaf rust. 相似文献
9.
Summary Grain amaranth populations from their centers of origin in the New World had shown a pattern of allozyme variation that suggested most landraces to be highly homozygous mixtures of genotypes. To compare this pattern of variation with the variation for morphological traits, 15 selfed families from each of six populations were grown in a replicated field experiment. Four pigmentation traits known to be smiply inherited were scored along 18 other morphological traits. Populations varied for the amount of polymorphism for marker loci, and exhibited little heterozygosity. Analysis of variance for the quantitative traits showed significant interpopulation differences for each of the observed characters. Populations differed for the number of metric traits showing significant between-family differences for just one of the metric traits whereas another had between-family differences for all ten. These results suggested high levels of homozygosity within these landraces; thus, variation for quantitative traits conformed well with the allozyme variation patterns.Stepwise multiple regression of all characters on yield as the dependent variable was used to compare the relative contributions of specific characters to yield within individual populations. Plant height, days to flowering, and leaf length were included in the regression equations for 6, 5, and 5, of the populations, respectively. Days to floweing was negatively correlated with yield, while plant height and leaf length were positively correlated. These correlations suggest the potential for developing early flowering, high yielding cultivars having short stature, selected by breaking its correlation with yield. Several breeding strategies based on these findings on genetic resources are discussed briefly. 相似文献
10.
Summary Up to 100 single plant derived lines of 18 Ethiopian barley landraces were evaluated for infection type in the seedling and adult plant stage, and for latent period in the adult plant stage only. A low infection type indicates the presence of race-specific resistance genes of the hypersensitive type, while the latent period is the major component of the polygenic, partial resistance.In the seedling stage 1721 of these single plant derived landrace lines were assessed for infection type against two barley leaf rust races. In the adult plant stage 1227 from these 1721 lines were evaluated for infection type against one race. In the seedling stage 2 (against race 1-2-1) and 29 against race A) out of the 1721 lines showed an infection type lower than 6–7 on the 0 to 9 scale. In the adult plant stage none of the 1227 lines had an infection type lower than 6–7 against race 1-2-1.The variation between and within the landraces for latent period in the adult plant stage was large. Some landraces such as landrace 212845 showed a highly significant and longer mean latent period than most other landraces. Virtually all plants in all landraces carry at least some partial resistance.The near-absence of race-specific, major, resistance genes and the high frequency of moderate levels of partial resistance indicates that the durability of leaf rust resistance in Ethiopian barley landraces is due to the latter type of resistance, and that the multiline principle does not operate. 相似文献
11.
重庆市农业科学院近年引进或选育的来自不同地区的甜玉米种质材料,部分种质资源遗传背景较为模糊,对进一步通过杂交方式选育优良品种造成一定障碍。本研究以重庆市农业科学院近年选育或引进的93份来自不同地区的甜玉米种质材料为研究对象,对吐丝期、成熟期、株高、穗位高、总叶片数、穗长、穗粗、轴粗、秃尖长、穗行数、行粒数、单穗粒重、百粒重共13个性状进行统计分析,单因素方差分析表明,各性状均达到了显著水平,说明13个性状均存在真实的差异,变异系数差别最大的是秃尖长,为27.5%,变异系数最小的是生育期和成熟期,为2.4%。对其农艺性状进行相关性分析表明,产量性状与植株性状相关性较高,单穗粒重与吐丝期、株高、穗位高、总叶片数、穗长、行粒数呈显著正相关。通过聚类分析,93份材料可以划分为4个类群,结果较符合已知亲缘关系。93份材料遗传变异丰富,为甜玉米自交系创制、性状改良提供了部分可利用的资源,可为后续甜玉米杂种优势利用及新组合测配提供参考。 相似文献
12.
Black spot disease, incited by the fungus Diplocarpon rosae Wolf, is the most important disease of roses (Rosa hybrida L.) in the outdoor landscape. Though partial resistance exists in cultivated germplasm, the genetic basis of this trait has
not yet been elucidated. Six diploid and six tetraploid rose cultivars were crossed in two factorial combining ability arrays.
Whole plant and detached leaf inoculation methods were used to assess partial resistance under two different disease pressures
using a characterized single-spore isolate. Parents from both arrays had significant general combining ability effects across
multiple inoculation methods and environments. Specific combining ability was not significant for either array. Parent per
se performance was highly correlated with progeny performance on a family mean basis. High positive correlations among whole
plant and detached leaf inoculation methods indicate that detached leaf assays can substitute for whole plant assays. Based
on these results, a breeding strategy including parental selection and early, among-family selection is proposed. To our knowledge,
this is the first investigation of combining ability for disease resistance in rose. 相似文献
13.
Summary Faster canopy development in temperate cereals can result in more efficient utilization of wate, light and nutrients if these are in limited supply. It can also result in more competitive plants and less use of herbicides. The possible importance of the coleoptile tiller for increasing early vigour in wheat (Triticum aestivum L.) was determined for twelve F4 lines in two experiments. Each F4 line was chosen for variation in the presence and absence of a coleoptile tiller in plants in the previous generation; each F4 line was traced to a single F2 plant from a multiple convergent cross of sixteen parents. Eight plants of each of the F4 lines were grown in a single row in both experiments. Just after the coleoptile tiller appeared, plants within each line were classified into one of two groups; one group contained plants with large coleoptile tillers whereas the other group had either small coleoptile tillers or none at all. Leaf expansion rates were determined non-destructively at regular intervals, and plants were harvested to determine leaf and tiller characteristics when there were about five mainstem leaves. There was substantial variation in the leaf area of the coleoptile tiller both between groups and among lines. In both experiments plants with a large coleoptile tiller had 24–30% more leaf area and dry weight than plants selected with a small or absent coleoptile tiller up to the final harvest. Leaf expansion rates (increase in leaf area per day) were 25 to 35% greater in the large coleoptile tiller selections from the time tillers first appeared to the time of harvest, whereas the relative leaf expansion rate (increase in leaf area per unit of leaf area present per day) of the large selections was significantly greater than the small selections only at the time of appearance of the coleoptile tiller and just after. There was no evidence that the early appearance of a coleoptile tiller was associated with the largest seedlings or that it inhibited the growth of later tillers. It is concluded that selection for the appearance of a large coleoptile tiller should improve the early vigour of temperate cereals.Abbreviations DAS
days after sowing
- LA
leaf area
- LAR
leaf area ratio
- LER
leaf expansion rate
- RLER
relative leaf expansion rate
- SLA
specific leaf area
- VPD
vapor pressure deficit
- +COL
large coleoptile tiller group
- –COL
small or absent coleoptile tiller group 相似文献
14.
Summary Growth room experiments were conducted to study associations of grain protein content with properties of seedling leaf sections of oats (Avena sativa L.) using (1) 10 cultivars differing genetically in grain % protein, and (2) 10 populations of a single high protien cultivar (Hinoat) differing phenotypically in grain % protein. These populations, which were derived from a nitrogen fertilizer experiment, had grain protein concentrations which varied over the whole range displayed by the high and low protein cultivars when the latter were tested in a conventional field trial.Seedling leaf % protein was closely associated with grain % protein in both (1) and (2). Chlorophyll content per unit leaf area and leaf dry weight per unit leaf area were significantly higher in the high than in the low protein cultivars, and were significantly higher in all the Hinoat populations than in the low protein cultivars.Excised seedling leaf sections were placed on filter paper moistened with 1 ppm kinetin solution and kept in the dark at 25°C. After 96 h chlorophyll content per unit leaf area was again significantly higher in the high protein cultivars and in all the Hinoat populations than in the low protein cultivars, and the consequent differences in leaf colour were then readily visible. Absolute amounts of chlorophyll lost per unit leaf area were similar in all cultivars and populations, but the low protein cultivars showed a greater proportional loss (as % of initial content). A colour scale was used to visually rate the senesced leaf sections. The visual rating allowed the rapid separation of the high and low protein cultivars, and there was no significant variation in the ratings of the Hinoat populations.It is suggested that this procedure may be useful in the early selection phases of protein breeding programs for screening large populations rapidly at the seedling stage to detect genetic differences in potential grain protein content.Contribution No. 438 from Ottawa Research Station. 相似文献
15.
不同氮素水平下双季稻株型与冠层内光截获特征研究 总被引：1，自引：0，他引：1
本文旨在阐明双季稻株型与冠层内光合有效辐射截获的时空分布特征。选用4个不同株型早、晚稻品种,设置4个不同施氮水平,系统观测其植株形态和冠层内光合有效辐射截获率(IPAR)的时空分布状况。结果表明,施氮水平对早、晚稻株高、穗长、叶长和叶基角均有显著影响,均表现为随施氮水平的增加而增大;早、晚稻孕穗期的分层叶面积指数(LAI)和向上累积LAI大于抽穗后12 d,分层LAI呈冠层中部大于上部和下部的分布特征,最大分层LAI出现在0.58相对高度处;冠层上中部分层LAI和向上累积LAI随施氮水平的增加而增大;向上累积LAI随相对高度呈S型曲线分布,可用Logistic方程定量描述(R~2 0.99);早、晚稻孕穗期的冠层IPAR大于抽穗后12 d,且随施氮水平的增加而增大,其日变化表现为正午较小,早晚较大;株型紧凑的早、晚稻品种,冠层IPAR低;冠层IPAR与向下累积LAI之间的关系可用方程IPAR=a (1-e~(-b×LAI))定量描述(R~2 0.88);冠层内IPAR的三维空间分布表现为冠层上中部水平面上IPAR较低,光斑变化大,冠层下部水平面上IPAR较高,光斑变化较平缓,同一冠层高度水平面上的IPAR呈不均匀分布。研究结果可为双季稻高产栽培及理想株型的优化设计提供支撑。 相似文献
16.
Summary In this study genetic variation for resistance to the greenhouse whitefly (Trialeurodes vaporariorum) of four genotypes of tomato (L. esculentum) and two subspecies of L. hirsutum was investigated. Resistance was quantified by the whitefly life history components adult survival, oviposition rate, pre-adult survival and developmental period, measured on plants inoculated with whiteflies in clip-on cages.The largest differences between species were found when life history components were measured on adult plants of about four months old. On L. hirsutum f. glabratum whiteflies had the lowest adult survival, oviposition rate and pre-adult survival. On L. hirsutum these components were intermediate whereas on all L. esculentum genotypes they were highest. The variation between plants was low compared to the variation within plants. These results indicate that single plant tests can be used to determine accurately genetic variation between individual plants in a segregating population. 相似文献
17.
Summary Immature inflorescences of smooth bromegrass were cultured on MS agar media supplemented with varying combinations of 2,4-D and kinetin. Callus was initiated from segments of young inflorescences on each medium. All of the calli were subcultured monthly for 5–6 times and transferred onto hormone-free MS medium for plant regeneration. Addition of kinetin to the basal medium stimulated shoot initiation in the callus cultures. Plantlets were regenerated only from calli grown on media containing 2 and 6 mg I-1 2,4-D with a supplement of 0.2 mg I-1 kinetin. No albino plantlets were produced. Morphological characteristics and dry matter yield of ten somaclones and the parental plant (SBG7) were studied in the greenhouse in a randomized complete block experiment with five replications. There was significant variation (P>0.01) among genotypes for all morphological characteristics studied. Although all somaclone heights and leaf widths were lower than those of the parental plant, the somaclone F9A, F10A, and F10B had larger tiller numbers, and leaf/stem ratio by dry weight than the parental plant. Only somaclone F9B gave higher specific leaf area and leaf area ratio than the parental plant. Almost all somaclones had the same leaf length, total dry weight, and specific leaf weight as the parental plant. The variation found in somaclones should permit selection for desirable agronomic traits. 相似文献
18.
Summary Anthers of the diploid (2n=77) and the colchi-tetraploid (2n=154) Pelargonium roseum were cultured in vitro. In both ploidy level anthers containing uninucleate or binucleate microspores were incubated on a modified White's medium. Calli formed were then subcultured on Murashige and Skoog's medium for organoid differentiation. Plants developed from organoids were transferred to filter paper bridges and after that transplanted into pots. Plants derived from anthers of the tetraploid had diploid chromosome number. Wide variation of their essential oil components suggested their genetic heterogeneity. Further, high correlations between different seasons in the rate of essential oil components showed that the wide variation was due to genetic differences. Therefore, these plants probably originated from pollen grains. On the other hand, plants derived from anthers of the diploid had diploid chromosome number. Small variation and low correlations between different seasons in essential oil components indicated their genetic homogeneity. Their origin was ascribable to the somatic tissues of the mother plant. It is concluded that in plant species in which usual sexual reproduction is difficult, anther culture of chromosome-doubled plants will give a useful method for obtaining genetic variation. 相似文献
19.
Summary Genotypic differences for growth stage dependent expression of partial resistance to barley powdery mildew have been identified on the basis of two components of resistance in the glasshouse and the pattern of epidemic development in the field.Differences for infection frequency and proportion of sporulating colonies were highly significant between the 16 genotypes investigated at four stages of plant development in the glasshouse. Both resistance components were significantly correlated mutually (r=0.73 to 0.86) and with the infection level on leaves developed at comparable growth stages in the field (r=0.52 to 0.73). The infection level of seedlings in the glasshouse was significantly correlated with the infection level of the leaves of the first until the third node in the field (r=0.70 to 0.73). Adult plant resistance was predominantly expressed at the uppermost leaf. A clear genotype × growth stage interaction was apparent for infection level; some genotypes showed partial resistance predominantly at the seedling stage and others predominantly at the adult plant stage.Abbreviations IF
Infection Frequency, number of colonies per cm2 leaf area, glasshouse experiment
- IL
Infection Level, number of colonies per cm2 leaf area, field experiment
- PSC
Proportion Sporulating Colonies from total number of colonies, glasshouse experiment 相似文献
20.
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. 相似文献