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1.
Compensation capacity of wheat ears depending on temperature level during grain-filling period
In order to investigate the compensation capacity, effects of sterilization treatments on dry matter storage within spikelets and florets of wheat ears, growing in different temperatures during grain-filling period were tested. Alternatively proximal or distal florets from 6 spikelets in the central region were removed at different stages. — Grain weight/ear remained 40% smaller in the high compared with the low temperature level. With high temperature sterilization of proximal florets allowed more additional florets in distal positions to develop grains than with low temperature. Beyond of this in both levels single grain weights in the basal and the apical region of the ear increased. Compensation effects, especially by additional grains decreased as later the treatments were done. Relatively the grain weight loss by sterilization was compensated to a higher degree in high than in low temperatures. 相似文献
In order to investigate the compensation capacity, effects of sterilization treatments on dry matter storage within spikelets and florets of wheat ears, growing in different temperatures during grain-filling period were tested. Alternatively proximal or distal florets from 6 spikelets in the central region were removed at different stages. — Grain weight/ear remained 40% smaller in the high compared with the low temperature level. With high temperature sterilization of proximal florets allowed more additional florets in distal positions to develop grains than with low temperature. Beyond of this in both levels single grain weights in the basal and the apical region of the ear increased. Compensation effects, especially by additional grains decreased as later the treatments were done. Relatively the grain weight loss by sterilization was compensated to a higher degree in high than in low temperatures. 相似文献
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In this study, the correlation and path coefficients between ear characters and grain yield per plant were determined in triticale under Mediterranean climatic conditions.
Weight of grains per ear and number of ears per plant were the most important direct components of yield. Characters like ear length and the number of spikelets per ear were not found to be the important component characters of grain yield. It could be concluded that among ear characters in triticale, the number of ears per plant and the weight of grains per ear are the most important yield contributing characters and these characters should get due consideration in future triticale breeding programmes. 相似文献
Weight of grains per ear and number of ears per plant were the most important direct components of yield. Characters like ear length and the number of spikelets per ear were not found to be the important component characters of grain yield. It could be concluded that among ear characters in triticale, the number of ears per plant and the weight of grains per ear are the most important yield contributing characters and these characters should get due consideration in future triticale breeding programmes. 相似文献
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H. A. S. Agrama 《Plant Breeding》1996,115(5):343-346
The efficiency of a breeding programme depends mainly on the direction and magnitude of the association between yield and its components and also the relative importance of each factor involved in contributing to grain yield. The purpose of this research is to describe the application of causal path analysis to grain yield in maize (Zea mays L.) to take into account the sequential development of yield components. Causal-admissible path analysis was performed assuming unidirectional causal relationships among yield components of eight maize populations. Sequential path analysis of the five yield components studied revealed that ears per plant had the highest direct effect on grain yield. However, the indirect effects of component traits via number of grains per ear was maximum. It was concluded that the number of kernels per ear, prolificacy, and grain size serve as potential characters in breeding for superior lines for grain yield in maize. 相似文献
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The objective was to study the behaviour of 20 dwarf wheats in a field trial under irrigated situation and also to suggest parameters or group of parameters conducive to high yield. Considerable variability existed in respect of tillering and earing, LAI, net photosynthetic rate, total dry matter production rate (TDMPR), harvest index, number of grains per main and subsidiary ears and grain size (1000 grain weight). Number of grains per main and subsidiary ears, total grains per plant, rate of net photosynthesis, leaf area and harvest index as well as total dry matter production rates were found to be positively correlated with grain yield and as such contributed maximum towards grain yield.
Thus, in general, it may be concluded that there should be minimum reduction in grain numbers between the main ear and the subsidiary ears, for this seems to be the one of causes of reduction in grain yield. Besides, there ought to be high ratio between net photosynthetic rate and dark respiration because large amount of dry matter is otherwise lost through respiration and many not be available for grains. High harvest index and high biological yield are also desirable characters which may be combined to obtain higher yields in wheats. 相似文献
Thus, in general, it may be concluded that there should be minimum reduction in grain numbers between the main ear and the subsidiary ears, for this seems to be the one of causes of reduction in grain yield. Besides, there ought to be high ratio between net photosynthetic rate and dark respiration because large amount of dry matter is otherwise lost through respiration and many not be available for grains. High harvest index and high biological yield are also desirable characters which may be combined to obtain higher yields in wheats. 相似文献
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为选择铁茬条件下夏玉米的适播品种，试验采用单因素随机区组方法对20个玉米品种（品系）在小麦收获后铁茬播种条件下的产量、生物产量、经济系数和穗部性状等进行了研究。结果表明，燕202、浚单22、雅玉12、郑单958和矮225在中等肥力土壤下可以达到9000kg/hm2高产水平，穗数>60000穗/hm2、穗粒数420~515粒/穗、公顷粒数>2778万粒、千粒重>280g、生物产量>16300kg/hm2、经济系数>0.54、出米率88±1.34%。大穗型品种、特别是平展大穗型品种无高产优势。相关分析表明，产量与经济系数、收获穗数、公顷粒数、生物产量成极显著正相关。中小穗型品种穗粗、穗行数与产量显著正相关对产量影响较大；大穗型品种产量与穗粗为负相关，且产量与穗长、行粒数和出米率关系最为密切。 相似文献
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In field experiments carried out between 1989 and 1991, spring barley was sampled to observe changes in the grain viability and dormancy during grain filling. The weather during the grain filling periods of 1989 and 1990 was unusually warm and dry, and the crop in 1989 was affected by drought. Some grains were capable of germination shortly after anthesis, but were dormant. Dormancy declined with increasing maturity, but was prolonged by low temperatures and reduced by warm weather. Differences were found in the dormancy characteristics of the two cultivars tested. Apart from grains at the extremities of the ear, which were sometimes found to be small and with low viability and greater dormancy, though not significantly so, no consistent differences were found between the viability and dormancy of grains in different positions in the ear. 相似文献
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蔗糖和植物生长调节剂对离体培养穗籽粒建成的影响 总被引：8，自引：2，他引：6
利用麦穗离体培养技术，研究了不同蔗糖浓度和不同生长调节剂处理对籽粒形成和生长的影响，结果表明，开花后的早期阶段（籽料形成期）是决定穗粒重的关键时期，此期蔗糖供给和激素水平的变化对穗粒数和粒重均有显著调控作用，蔗糖与激素以及不同激素之间对籽粒生长的互作调控关系需要进一步研究。 相似文献
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新型超高油玉米种质的选育 总被引：37，自引：0，他引：37
分两批测定了3种类型共6 684粒微胚乳玉米（Zea mays L.）的粒重和含油率。发现1 944粒含油率高于20%,其中有32粒超过25%,最高为26.84%。计算了单粒重与含油率（df1 = 78）以及各果穗平均粒重与含油率（df2 = 14, df3 = 64）的相关系数,3个相关系数都未达显著水平。表明以籽粒或（和）以果穗为基础,选育既籽粒相对较重, 相似文献
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Maize ( Zea mays L.) plants were grown in the field and labelled with 14 CO2 at four leaf positions from silking up to maturity. The ear leaf was the most important source of labelled photosynthates to the ear, followed by the first leaf blade above and below the ear. The movement of labelled assimilates from the second leaf blade below the ear was predominantly downwards. The ear became an important sink soon after silking and continued in importance till harvest.
Initially assimilates were partitioned within the ear as husk < cob < grains but at harvest as grains < cob < husk. There was considerable remobilization of assimilates from the husk and stem. Removal of leaves drastically altered the pattern of distribution of labelled photosynthates and the direction of movement was determined by the position of the source leaf blade and the defoliation treatment. Darkening the leaf blades did not much alter the translocation of the labelled photosynthate and increased slightly its proportion to the grains. The removal of the ear severely altered the pattern of distribution of14 C, which was mostly deposited in the stem. 相似文献
Initially assimilates were partitioned within the ear as husk < cob < grains but at harvest as grains < cob < husk. There was considerable remobilization of assimilates from the husk and stem. Removal of leaves drastically altered the pattern of distribution of labelled photosynthates and the direction of movement was determined by the position of the source leaf blade and the defoliation treatment. Darkening the leaf blades did not much alter the translocation of the labelled photosynthate and increased slightly its proportion to the grains. The removal of the ear severely altered the pattern of distribution of
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The development of grains of different positions in the apical, middle and basal spikelets of wheat var. Kaly-ansona showed that beyond first two basal grains, the more distal a grain in a spikelet the lower its weight. The distal grains received less assimilates than the proximal grains as revealed from sugar concentration in the grains. The eflficiency of distal grains of kalyansona to synthesize reserves was, however, not inferior than the proximal grains in a spikelet. The depression in grain weight lowards extreme spikelet was lower compared to the depression in weight of individual grams towards a distal position in a spikelet. The study seems to suggest that in order to ensure better grain uniformity while maintaining a higher grain number per ear, the spikelet number per ear should be increased instead of increasing the grain number per spikelet. 相似文献
13.
Kihachi Ueno 《Euphytica》2002,126(1):107-113
A study was made of the effects of desiccation and a change in temperature on the germination of wheat grains harvested 20
days after anthesis. When the germination test was performed immediately after harvesting, germination percentages ranged
from 5.2% to 10.7%. Germination percentages increased to 48.2% to 90.3% after grain had been desiccated at 20 °C and then
hydrated at 10 °C. This increase occurred even if grains had been desiccated in an atmosphere of high relative humidity. The
germination percentage of non-desiccated grains depended on the germination temperature. When the pericarp and testa were
removed from embryos, the germination percentage of grains incubated at 20 °C and then at 10 °C was higher than that of grains
incubated at 10 °C. In general, a low germination temperature is believed to be effective in breaking dormancy of wheat grains.
However, a change in temperature stimulated germination to a greater extent than a constant low temperature. The germination
percentage of 5-day cycle alternating temperature was greater than that with 1-day, 2-day and 10-day cycles. Although the
germination of immature wheat grains was stimulated by both high and low germination temperatures, it is likely that cycles
shorter and, also, longer than a critical period induce limited germination. Loss of dormancy commonly occurs when development
of wheat grains proceeds at a high temperature, with imbibition at a low temperature. However, germination ability of non-desiccated
immature wheat grain was enhanced by a change in temperature during germination.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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杂交水稻甬优6号高产高效技术途径分析 总被引：1，自引：0，他引：1
为进一步发挥杂交水稻‘甬优6号’的增产增效潜力,论文利用相关、回归和通径分析方法分析了不同产量水平下单季杂交晚稻‘甬优6号’的产量结构,探讨了各产量因子间的内在联系和对产量贡献的大小。结果表明,各主要经济性状对产量的效应大小排序为：每穗实粒数>有效穗>结实率>粒重。研究提出单季杂交晚稻‘甬优6号’高产高效栽培的技术途径应是在确保高产所需有效穗数的基础上,主攻每穗实粒数,兼顾粒重。 相似文献
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为探讨小麦单株种子生产潜力及相关性状特征,以57个不同基因型F2代小麦超高产单株为材料,对超高产单株产量性状、相关性状间的相关、通经和回归关系进行了分析。结果表明：（1）超高产单株（≥80 g/单株）田间选择概率为0.00518%;（2）株穗数、穗粒数、千粒重、结实小穗数、穗粒重和容重与单株产量呈显著正相关,不孕小穗数呈显著负相关,株高、穗长和千粒重相关不显著;（3）株穗数对单株产量的直接贡献最大,决定单株产量的65.33%,穗粒数、穗粒重、千粒重、株粒数分别决定单株产量的19.92%、18.15%、13.72%和5.6%。≥80 g/株的单株田间选择概率为0.00518%。 相似文献
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High temperature is a major determinant of grain growth and yield formation in wheat. The present study was undertaken to investigate the effects of high temperature regimes on the activities of key regulatory enzymes involved in starch and protein accumulation in grains of two winter wheat (Triticum aestivum L.) cultivars Yangmai 9 and Xuzhou 26 with different protein contents. Four day/night temperature regimes of 34 °C/22 °C, 32 °C/24 °C, 26 °C/14 °C and 24 °C/16 °C were established after anthesis, resulting in two daily temperature levels of 28 °C and 20 °C and two diurnal temperature differences of 12 °C and 8 °C. The activities of glutamine synthase (GS) in flag leaves and glutamate pyruvic aminotransferase (GPT), sucrose synthase (SS), soluble starch synthase (SSS) and granule‐bound starch synthase (GBSS) in grains were measured during the periods of grain filling. High temperature reduced both content and yield of starch in grains, while enhanced protein content and reduced protein yield in grains. High temperature significantly enhanced the activities of SS and GBSS on 14 days after anthesis (DAA). High temperature affected SSS slightly in Yangmai 9, but reduced SSS activity markedly in Xuzhou 26 on 14 DAA. However, at the middle and late stages of grain filling, high temperature reduced the activities of SS, GBSS and SSS significantly in the two wheat cultivars. High temperature reduced GPT activity in grains in the two wheat cultivars, but reduced GS activity in flag leaves of Yangmai 9 and enhanced GS activity of Xuzhou 26 on 14 DAA. In addition, under the same high temperature level, SS activity was higher at 34 °C/22 °C, whereas the activities of SSS and GBSS were higher at 32 °C/24 °C. Also, diurnal temperature differences affected GPT and GS activities differently between the two cultivars. Under optimum temperature level, the activities of key enzymes for starch and protein synthesis were higher at 26 °C/14 °C. The activities of SS, SSS and GBSS significantly correlated with starch accumulation in grains, except for GBSS activity to starch content on 14 DAA. GPT activity was positively correlated with protein yield, and GS activity was negatively correlated with protein yield on 14 DAA, while the activities of both GPT and GS were negatively related to protein content in grains. 相似文献
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为选育成熟期籽粒低含水量玉米杂交组合,以15个玉米自交系组配的54个杂交玉米组合为材料,对杂交组合的苞叶层数,苞叶、穗柄、籽粒、穗轴含水量及穗长、穗粗等9个产量相关性状进行相关和通经分析。结果表明:籽粒含水量与苞叶层数、苞叶含水量、穗轴含水量极显著正相关,与穗长和行粒数显著正相关,与出籽率和容重显著负相关。通径分析结果显示,籽粒含水量与苞叶层数、苞叶含水量、穗轴含水量、穗长、行粒数的直接通径系数为正值,与出籽率和容重的直接通径系数为负值,直接通径系数大小依次为:苞叶含水量>穗轴含水量>穗长>苞叶层数>行粒数>容重>出籽率。在育种策略上应选择苞叶层数较少,苞叶、穗轴含水量较低,出籽率、容重较高的材料加以改良,组配籽粒低含水量宜机收的玉米品种。 相似文献
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T. Sivakumar Virendranath & G. C. Srivastava 《Journal of Agronomy and Crop Science》2001,186(1):43-46
Grain yield and yield components (grains per ear, grain weight, 1000-grain weight, ear weight, ear seed ratio and dry matter partitioning between ear and seed) were examined in a wheat genotype (PBW-343) with well-filled grains and a Triticale genotype (DT-46) with poorly filled grains (showing grain shrivelling) grown in pots. Six days after anthesis (DAA), benzyladenine (BA) @2 µg ear−1 and abscisic acid (ABA) @4 µg ear−1 were injected at the base of the mother shoot ear in both species. It was observed that, in both wheat and Triticale , BA increased the grain weight, grain number and partitioning of dry matter between ear and seed, whereas ABA decreased the grain weight, grain number and dry matter partitioning between ear and seed. However, these decreases were slower in Triticale than in wheat. BA treatment increased the grain dry matter accumulation, which in turn resulted in better filling of grains and increased the grain weight in both wheat and Triticale . The average grain weight of Triticale was lower than that of wheat. Thus, it appears that variation in grain weight between wheat and Triticale might be due to different availabilities of growth-promoting phytohormones such as cytokinins and assimilates. 相似文献
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Tocopherols are one of the most important bioactive compounds in vegetable oils. It is known that these antioxidants present a dilution like relationship with oil weight per grain but the mechanism underlying this relationship are unknown. The aim of this work was to analyze the dynamics of tocopherol accumulation in sunflower grains, its relationship with oil accumulation and its effects on final oil quality in genotypes with different fatty acid composition. Three field experiments were conducted with genotypes with different potential fatty acid composition (a traditional, a high oleic and a high stearic−high oleic) and treatments with different source (intercepted solar radiation) or sink (grains) during grain filling to obtain varied grain filling conditions and grains with different oil concentration and oil unsaturation. Intercepted solar radiation modified oil per grain but did not affect tocopherol per grain. The rate of accumulation explained 79% and 74% of the oil and tocopherol per grain variation, respectively. When intercepted solar radiation increased, the duration of the period of oil and tocopherols accumulation increased, being the first the most responsive. These differences in the duration of accumulation periods are reflected in a larger relative increase in oil than tocopherols per grain and thus a dilution of the latter in the oil. These differences in the dynamics of oil and tocopherol accumulation are common to genotypes with different level of unsaturation. These results help to understand the mechanism associated with the dilution curve of oil tocopherol concentration reported in the literature. 相似文献