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1.
《Field Crops Research》1998,58(3):167-175
Wheat (Triticum aestivum L.) is expanding into lower latitudes of the Nile Valley Region, where maximum air temperature can reach 38–40°C during the short growing season. Genotype and environment, particularly temperature, affect the rate of leaf appearance. Field experiments were conducted at the Gezira Research Station, Wad Medani, Sudan in 1992–94. The study aimed to determine the effect of high temperature (by manipulating sowing dates) on leaf and tiller appearance and growth of nine spring wheat cultivars. Linear response was found between rate of leaf appearance and thermal time and it was faster before double-ridge stage than after double ridge. Phyllochron ranged between 99°C d and 122°C d. Differences in phyllochron interval (PI) were pronounced among cultivars and early-maturing cultivars had faster leaf appearance compared with late-maturing ones. Mean final leaf number on the main stem ranged from 8.1 to 12.2 and it was highly correlated with thermal time from sowing to double ridge stage (r=0.71**). Genetic constitution of cultivars had larger effect on number of leaves per main-stem than temperature. Tillers were initiated at leaf stage 2.9 and cultivars differed in their tillering capacity and only 1.5–2.0 reproductive tillers per plant were produced. About 810°C d were needed to produce tillers 1 and 2 and about 1140°C d for tillers 3 and 4. Leaf senescence started at leaf stage 6.1 for cv. Wadi El Neil and 4.2 for Debeira. Cultivars sown late exhibited delayed senescence of their leaves. High temperature accelerated maturity and the cultivars suited for the irrigated tropical environment were found to be early-sown late-maturing types. 相似文献
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基因型和氮肥对冬小麦叶片形态建成和分蘖的影响 总被引：1，自引：0，他引：1
于１９９８～１９９９ 年在浙江大学华家池校区实验农场进行了田间试验,研究基因型和环境对小麦叶片形态建成和分蘖的影响。试验由３ 个基因型（浙麦１ 号,ＺＡＵ９７－２,扬麦５ 号）和３ 种氮肥水平（０,１２０,２４０ ｋｇ／ｈｍ ２）的９ 种组合处理组成。主茎各叶片长度,除第１、９ 和１０ 外,基因型之间差异显著,叶片宽度随叶位高度而增加,各叶片面积的变化与叶长基本一致,第１ 至５ 叶依次增加,第６ 叶明显减小,第７ 叶又逐渐递增;单株分蘖数和分蘖消长动态因基因型而异。氮对叶片形态有明显影响,但除旗叶外,Ｎ１２０ 和Ｎ２４０ 两种氮水平之间叶长无显著差异。氮对分蘖的发生影响较小,但能显著促进其后的生长。基因型和氮肥对叶片形态和分蘖的影响存在着一定的互作效应。 相似文献
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Because an outgrowth of auxiliary bud in plant is regulated by light quality detected by phytochrome, branching differences in various environment or cultivars in soybean would be the results of the responses to light environment. Therefore, we analyzed differences in the number of branches of two determinate soybean cultivars, ‘Hatsusayaka’ and ‘Sachiyutaka’, between low and high planting densities in relation to light quality within the canopy. We compared changes in the ratio of red to far red (R:FR) irradiance at the ground level over time and with canopy height with those in the fraction of intercepted photosynthetically active radiation (FIPAR) and leaf area index (LAI). Regardless of time or distance from the top of the canopy, the changes in R:FR were sigmoidal, and were symmetrical with those of FIPAR and LAI. The effects of density and cultivar on FIPAR, LAI, and R:FR could be modeled with a logistic function. The number of branches was greater at low density than at high density, and in Hatsusayaka than in Sachiyutaka. However, there were no notable differences in the dynamics of R:FR between planting densities or between cultivars. Close relationships between parameters of the dynamics of the changes in R:FR and of those in FIPAR and LAI suggest that FIPAR and LAI are major factors that regulate R:FR, regardless of time or canopy depth. We found no evidence of a causal relationship between the dynamics of R:FR within the canopy over time or with canopy depth and number of branches of either cultivar. 相似文献
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播期对四川小麦分蘖发生、消亡及成穗特性的影响 总被引：1，自引：0，他引：1
为探讨四川小麦分蘖发生、消亡与成穗规律,了解穗数形成的制约因子,在四川两个典型小麦生态区(川西平原区和川中丘陵区),以主推品种川麦104(春性)和半冬性品种川农30为材料,通过定点调查茎蘖动态,以及定株调查分蘖发生、消亡时间和叶位,研究过早播(10月16日)、早播(10月23日)、适播(10月30日)、晚播(11月6日)下小麦的分蘖成穗特性。结果表明,四川小麦分蘖发生一般持续50d左右,分蘖发生数量少且低位分蘖缺位多。平原区(温江点)小麦第1叶位分蘖发生率为61%~80%,丘陵区(仁寿点)为13%~60%;第2叶位分蘖发生率在两生态点分别为63%~98%和45%~83%;第3、第4叶位以及二级分蘖很少发生。川麦104单株分蘖数(1.4~2.4个)显著低于川农30(1.6~2.9个)。四川小麦分蘖消亡持续时间长,从拔节一直持续到开花,分蘖消亡率高达50%以上,花后也还有8.0%~19.4%的分蘖消亡,其中川麦104分蘖消亡各期(拔节-孕穗、孕穗-抽穗、抽穗-开花)比较均衡,川农30分蘖消亡集中在孕穗-抽穗阶段(占总消亡率的43.9%)。四川小麦分蘖成穗率低,平原区和丘陵区分别为27.7%~48.8%和9.0%~19.4%,其中平原区第1、2叶位分蘖成穗率分别为65.0%和50.2%,丘陵区分别34.8%和24.4%。10月23日左右是利于丘陵区小麦分蘖成穗、高产的适宜播期,平原区还可提前到10月16日左右。 相似文献
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Phenological development affects canopy structure, radiation interception, and dry matter production; most crop simulation models therefore incorporate leaf emergence rate as a basic parameter. A recent study examined leaf emergence rate as a function of temperature and daylength among wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) cultivars. Leaf emergence rate and phyllochron were modeled as functions of temperature alone, daylength alone, and the interaction between temperature and daylength. The resulting equations contained an unwieldy number of constants. Here we simplify by reducing the constants by > 70%, and show leaf emergence rate as a single response surface with temperature and daylength. In addition, we incorporate the effect of photosynthetic photon flux into the model. Generic fits for wheat and barley show cultivar differences less than +/- 5% for wheat and less than +/- 10% for barley. Barley is more sensitive to daylength changes than wheat for common environmental values of daylength, which may be related to the difference in sensitivity to daylength between spring and winter cultivars. Differences in leaf emergence rate between cultivars can be incorporated into the model by means of a single, nondimensional factor for each cultivar. 相似文献
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《Field Crops Research》2001,72(1):51-66
Pearl millet (Pennisteum americanum L.) is an essential crop in farming systems of the dry areas of the semi-arid tropics and its tillering habit is an important adaptive feature. This is the first paper in a series aiming at developing and validating a pearl millet simulation model that recognises tillers as functional entities, analogous to intercrops. The objective of this paper is to quantify the effects of total leaf number per axis (TLN), cultivar, plant density and axis number on parameters that are used to simulate potential leaf area per plant. Four cultivars with different phenology and tillering habit were grown under well-watered and well-fertilised conditions at two locations in India, covering a range of daylengths and plant densities. For selected plants, the area of fully expanded leaves was measured non-destructively. A bell-shaped function adequately described the relationship between individual leaf area and leaf position on an axis. Its shape was determined by the position (X0) and area (Y0) of the largest leaf and by the breadth and skewness of the leaf area profile curve. TLN affected all four parameters, although the association with Y0 was weak. Cultivar only affected Y0, suggesting that parameterising new cultivars is straightforward. The observed density effect confirmed that competition for light between axes started during stem elongation. The results highlighted the consistent differences between leaf area profiles of main shoots and tillers. For a high-tillering crop like pearl millet, modelling leaf area dynamics through individual leaves is justified, as this approach can potentially deal with cultivar and environmental effects on tillering. 相似文献
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I. Bahmani C. Varlet-Grancher L. Hazard C. Matthew M. Betin A. Langlais G. Lemaire & E. R. Thom 《Grass and Forage Science》2000,55(4):367-371
Post-flowering tillering responses of 'Ellett' and 'Grasslands Ruanui' perennial ryegrass ( Lolium perenne L.) cultivars after inflorescence production were studied at INRA, Lusignan in France, at near ambient light (absence of light competition, control treatment) and under shading (low-light intensity and low red–far red ratio). A dense sward containing inflorescence bearing plants of both perennial ryegrass cultivars at ambient light was cut to a height of 50 mm above ground level after which the light treatments were imposed. Forty-five days later, data were collected on the number of tillers per plant, the number of new tillers per original tiller and the dry weight of vegetative and reproductive tillers. Regardless of light treatment, cv. 'Ellett' had fewer tillers per plant, higher weight per tiller and a higher proportion of reproductive tillers than did cv. 'Grasslands Ruanui'. Number of tillers per plant and number of new tillers per tiller were consistently reduced under shade compared with the control treatment for both cultivars. When shaded, weight of reproductive tillers of cvs 'Ellett' and 'Grasslands Ruanui' were 40% and 43%, respectively, less than the control, whereas vegetative tiller weight did not change. In addition, differences between cultivars in the tillering strategy after flowering seem to be unaffected by the light environment. Thus, field observations regarding tillering of cvs 'Ellett' and 'Grasslands Ruanui' were consistent with current results suggesting different grazing managements are needed after flowering to optimize the replacement of tillers for both cultivars. 相似文献
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《Plant Production Science》2013,16(4):254-257
SummaryThe rate of leaf development in wheat is related to time and temperature in units of degree-days (DD) leaf?1 (phyllochron). Experiments were conducted in controlled environment chambers to study the effect of day to night variation in temperature on leaf development in two wheat cultivars, Penawawa and Stephens. Plants were grown at constant 20°C, and in eight day/night temperature ranges as wide as 8/32°C to 32/8°C, all with a mean temperature of 20°C. The leaf number on the main stems was counted (in Haun units) every other day, from the emergence of the 2nd leaf until the emergence of the 5th leaf. Leaf phyllochron values were derived from the inverse of the slopes of the linear regression of leaf number on DD. Phyllochron values ranged from 99 to 153 DD leaf?1. The phyllochron values were greater when higher temperatures were imposed at night under extreme day to night temperature treatment. 相似文献
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长江中下游麦区小麦迟播的不利影响及育种对策 总被引：5，自引：0，他引：5
近年来长江中下游稻麦轮作区水稻成熟期不断推迟,致使小麦播期大幅度推迟,这已成为该麦区小麦高产稳产的主要障碍。迟播不仅导致小麦生育期缩短,积温、光照时数减少,营养生长不足,难以形成高产群体基础,还导致赤霉病和白粉病严重发生,增加了灌浆期遭遇高温危害的风险及收获前遇阴雨发生穗发芽的概率。为了减少小麦迟播的不利影响,除了栽培措施应对外,根本措施是培育适合迟播的小麦品种。在育种时应重点加强迟播条件下出苗快、生根快、分蘖早、越冬期仍能保持较大生长量和分蘖发生量等性状的选择;提高抗性,特别是赤霉病抗性、耐渍性和抗穗发芽性;注重选择灌浆速率高、耐高温逼熟的品种,利用灌浆速率的提高补偿灌浆时间缩短的不利效应,培育迟播高产品种。 相似文献
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为给小麦大面积高产栽培提供依据，1997～1999年在河南省偃师市高产麦田研究了多穗型和大穗型小麦品种产量形成特点及超高产关键栽培技术。结果表明．多穗型和大穗型冬小麦品种在群体动态变化、小穗和小花发育、籽粒灌浆过程等方面有较大差异。针对多穗型品种在高产奈件下分蘖成稳率高、穗粗重较低的特点，采取在拔节期追氮的措施能有效减少小花、子房退化，达到穗粒数增加、粒重提高的效果；大穗型品种分化小穗、小花数多，穗粒数高，在拔节期以后分蘖发育明显慢于主茎，致使分蘖成穗率低，群体穗数不足，产量低于多穗型品种，适当增加播量可有效增加穗数，提高小麦产量。 相似文献
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《Plant Production Science》2013,16(2):257-266
AbstractUsing a Chinese large-panicle-type high-yielding indica rice cultivar, Yangdao 4 (YD), pot experiments were carried out to determine the effects of the removal of the lower nodal primary tillers on the growth and yield-related characteristics in comparison with a Japanese cultivar, Hinohikari (HH), with almost the same growth duration. The plants with all tillers remaining (Cont), those with tillers from the 5th and higher nodes (T5) and those with tillers from the 8th and higher nodes (T8) were prepared by removing the other tillers and grown in early, normal and late cropping seasons, sowing in late April, May and June, respectively. The lowest nodal primary tillers in each group emerged earlier and the number of days from sowing to flag leaf expansion and to full heading stage was reduced in the late cropping season, especially in HH. The maximum number of stems and number of panicles were larger in HH than in YD, and tended to be higher in the order of Cont > T5 > T8 plants. The average panicle weight per stem was higher in YD than in HH and higher in the order T8 > T5 > Cont. Panicle weight per hill was higher in YD than in HH in each cropping season and higher in early cropping season in both cultivars. Panicle weight decreased with delayed tiller emergence in YD, but not in HH. Panicle weight was more closely related to straw weight in YD than in HH. Therefore, the promotion of vegetative growth by early sowing and development of lower nodal tillers is more effective for attaining a high yield in YD than in HH. 相似文献
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Long days partially depress tiller growth of spring cereals. In this study we characterised and quantified growing conditions and cultivar-induced variation in tiller traits and contribution of tillers to grain yield. Experiments were done at two locations in southern Finland, incorporating two nitrogen fertiliser application rates (80 and 120 kg N ha−1) and 12 two-row barley (Hordeum vulgare L.), 10 six-row barley, ten oat (Avena sativa L.) and 11 wheat (Triticum aestivum L.) cultivars. Spring cereal species differed significantly in their tillering: two-row barley was superior compared with other spring cereals, with the highest number and growth capacity of tillers and head-bearing tillers. Grain yield produced by tillers was, however, always modest compared with that of main shoots, ranging from 13% and 15% in oat and wheat to 20% in six-row barley and 64% in two-row barley. Cultivar and growing condition-induced differences were marked in tiller traits, but tillers were never able to out-yield the main shoot. This is likely to be emphasised by standard use of high seeding rates. Tillers are dominated by the main shoot under long day conditions at high latitudes, and tiller yield potential remains clearly underutilised even under conditions favouring growth. 相似文献
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稀植条件下杂交稻分蘖成穗规律和穗粒结构研究 总被引：16，自引：0，他引：16
研究了19.5,13.5和7.5穴/m2 3个种植密度下杂交稻组合中优6号和两优培九不同时期的分蘖成穗规律和穗粒结构.结果表明,稀植促进分蘖发生,并导致最高分蘖期和有效分蘖期延迟,13.5和7.5穴/m2比19.5穴/m2的最高分蘖期分别推迟7和14 d;随种植密度下降,中后期发生的分蘖在茎蘖数中的比例提高,相应成穗率也提高;早期分蘖所成的穗与后期分蘖所成穗的每穗粒数差异较大,结实率差异较小,两者的产量差异主要由穗粒数差异引起;随种植密度下降,分蘖力较弱的组合产量显著下降,而分蘖力较强的组合产量没有差异. 相似文献
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Al-Zyoud FA 《Pakistan journal of biological sciences: PJBS》2012,15(4):177-185
Due to the importance of wheat and barley production in Jordan, prevention of the cereal leafminer, Syringopais temperatella Led. (Lepidoptera: Scythrididae) is of vital importance. The insect is a severe pest and plays an important role in limiting the production of these crops. The use of insecticides is neither economic nor sustainable, so that there is an urgent need to initiate a viable alternative to chemical control. Therefore, this study aimed at investigating the effect of crop rotation on S. temperatella and its preference to different wheat and barley cultivars. The field history experiment was conducted using five different crop rotations. For the preference experiments in the laboratory, two major experimental groups were conducted. The first was set up to measure the consumed leaf area and the second one to record the number of larval attaches. Each group consisted of four different subgroups; 6 wheat cultivars, 6 barley cultivars, two and one cultivar of each crop. The results indicated that the infestation percentage and number of larvae were significantly the lowest in the crop rotation, wheat/chickpea/wheat while the highest were recorded for barley/barley/barley. The preference results showed that wheat cultivar, Horani Nawawi is significantly the most preferred while Horani 27 is the least cultivar. In case of barley, Mutah was the most preferred cultivar and the least preference was recorded for Athroh. Also, wheat was significantly less preferred than barley. The wheat cultivars, Sham, Em-Qees and Acsad 65 had the highest number of attaches and Deer Alla the least. In contrast, the barley cultivar, Acsad 176 had the highest and Athroh and Rum 1 had the least attaches. Barley cultivars had higher attaches than wheat ones. There was a positive relation between the infestation percent and number of larvae, as well as the consumed area and number of attaches in all of the four subgroups. In conclusion, the crop rotation, wheat/chickpea/wheat should be followed and there is a preference variation among the tested wheat and barley cultivars. 相似文献
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施氮量对强筋小麦产量、氮素利用率和品质的影响 总被引：11，自引：0，他引：11
为探明协同提高强筋小麦产量、氮素利用率和品质的施氮量,以强筋小麦品种济麦20（中穗型）和洲元9369（大穗型）为材料, 研究了180、240和300 kg·hm-2三个氮肥水平（分别用N180、N240和N300表示）对强筋小麦产量、氮素利用率、品质及其相关指标的影响。结果表明,相同施氮量下,洲元9369的产量、氮素利用率、面团形成时间、面团稳定时间、面包体积和面包评分均高于济麦20。当施氮量由N180增至N240时,2个品种的产量无显著变化,但沉降值、面团形成时间、面团稳定时间、面包体积和面包评分均显著提高;施氮量增至N300后,2个品种的产量和品质又都显著下降,籽粒总蛋白含量、谷蛋白含量、SDS-不可溶性谷蛋白含量、醇溶蛋白含量和谷蛋白聚合指数均明显降低,而SDS-可溶性谷蛋白含量和谷醇比却表现为上升趋势。经相关分析,SDS-不可溶性谷蛋白含量、谷蛋白聚合指数与面团形成时间、面团稳定时间、面包体积和面包评分均呈显著正相关。以上结果表明,谷蛋白聚合程度降低是过量施氮条件下强筋小麦品质下降的主要原因。综合考虑小麦产量、氮素利用率和籽粒品质,240 kg·hm-2为本研究条件下的最佳施氮量。 相似文献
18.
大穗型小麦兰考906分蘖发育的生理特征及其调控 总被引：7，自引：1，他引：7
通过对大穗型小麦兰考 90 6研究表明 ,密度和酚类物质处理对麦苗的物质代谢和分蘖生长有明显的调节效应。密度增大导致 IAA氧化酶 (IAAO)、硝酸还原酶 (NR)及蔗糖磷酸合成酶 (SPS)活性降低 ,IAA含量和可溶糖 /氨基酸 (WSC/ AA)比值提高 ,单株分蘖减少。间苯二酚 (RES)处理促进体内的 IAAO活性 ,导致 IAA含量和WSC/ AA比值下降 ,单株分蘖增多 ,而临苯二酚 (CT)的效应相反。适当增加密度和采用 RES处理 ,可增加大穗型品种兰考 90 6的单位面积穗数 ,提高产量。 相似文献
19.
Carbon dioxide (CO2), along with light, water and nutrients, represents an essential resource needed for plant growth and reproduction. Projected and recent increases in atmospheric carbon dioxide may allow breeders and agronomists to begin intra-specific selection for yield traits associated with CO2 sensitivity. However, selection for maximum yield, particularly for cereals, is continuous, and it is possible that modern cereal cultivars are, in fact, the most CO2 sensitive. To test CO2 responsiveness, we examined two contrasting spring wheat cultivars, Marquis and Oxen, over a 3-year period under field conditions at two different planting densities. Marquis was introduced into North America in 1903, and is taller, with greater tiller plasticity (i.e. greater variation in tiller production), smaller seed and lower harvest index relative to modern wheat cultivars. Oxen, a modern cultivar released in 1996, produces fewer tillers, and has larger seed with a higher harvest index relative to Marquis. As would be expected, under ambient CO2 conditions, Oxen produced more seed than Marquis for all 3 years. However, at a CO2 concentration 250 μmol mol−1 above ambient (a concentration anticipated in the next 50–100 years), no differences were observed in seed yield between the two cultivars, and vegetative above ground biomass (e.g. tillers), was significantly higher for Marquis relative to Oxen in 2006 and 2007. Significant CO2 by cultivar interaction was observed as a result of greater tiller production and an increased percentage of tillers bearing panicles for the Marquis relative to the Oxen cultivar at elevated carbon dioxide. This greater increase in tiller bearing panicles also resulted in a significant increase in harvest index for the Marquis cultivar as CO2 increased. While preliminary, these results intimate that newer cultivars are not intrinsically more CO2 responsive; rather, that yield sensitivity may be dependent on the availability of reproductive sinks to assimilate additional carbon. Overall, understanding and characterizing vegetative vs. reproductive sink capacity between cultivars may offer new opportunities for breeders to exploit and adapt varieties of wheat to projected increases in atmospheric carbon dioxide concentration. 相似文献