共查询到20条相似文献，搜索用时 46 毫秒
1.
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
2.
The effect of defoliation on the vegetative, early reproductive and inflorescence stages of tiller development, changes in the dry‐matter yield of leaf, stem and inflorescence and the associated changes in forage quality was determined on plants of annual ryegrass (Lolium rigidum Gaud.) and Italian ryegrass (L. multiflorum Lam.). The field study comprised seventy‐two plots of 1 m × 2 m, sown with one annual ryegrass and seven Italian ryegrass cultivars with a range of heading dates from early to late; defoliation commenced 6 weeks after germination. During the vegetative stage of growth, plots were defoliated when the tillers had three fully expanded leaves (three‐leaf stage). During the early reproductive stage of growth, to simulate a cut for silage, plots were defoliated 6–7 weeks after 0·10 of the tillers displayed nodal development. The subsequent regrowth was defoliated every 3 weeks. Assessments of changes in tiller density, yield and quality were made in the growth cycle that followed three contrasting cutting treatments during the winter–spring period (from 10 July). In treatment 1, this growth cycle (following closing‐up before a subsequent conservation cut) commenced on 7 August following two defoliations each taken when the tillers were at the three‐leaf stage. In treatment 2, the growth cycle commenced on 16 October following: for early‐maturing cultivars, two cuts at the three‐leaf stage, a cut for silage and an additional regrowth cut; for medium‐maturing cultivars three cuts at the three‐leaf stage and a cut for silage; and late‐maturing cultivars, five cuts at the three‐leaf stage. In treatment 3, defoliation up to 16 October was as for treatment 2, but the growth cycle studied started on 27 November following two additional regrowth cuts for early‐ and medium‐maturing cultivars and cut for silage for the late‐maturing cultivars. Tiller development for all cultivars was classified into three stages; vegetative, early reproductive and inflorescence. In treatment 1, in vitro dry‐matter digestibility (IVDMD) and crude protein (CP) content were negatively associated with maturation of tillers. IVDMD ranged from 0·85 to 0·60 and CP ranged from 200 to less than 100 g kg–1 dry matter (DM) during the vegetative and inflorescence stages respectively. This large reduction in forage quality was due to an increase in the proportion of stem, inflorescence and dead material, combined with a reduction in the IVDMD and CP content of the stem. A high level of forage quality was retained for longer with later‐maturing cultivars, and/or when vegetative tillers were initiated from the defoliation of early reproductive tillers (treatments 2 and 3). However, 15 weeks after the closing‐up date in treatment 1, defoliation significantly reduced the density of inflorescences with means (±pooled s.e_m.) of 1560, 1178 and 299 ± 108 tillers m–2, and DM yield of inflorescence with means of 3·0, 0·6 and 0·1 ± 0·15 t ha–1 for treatments 1, 2 and 3 respectively. This study supports the recommendation that annual and Italian ryegrass cultivars should be classified according to maturity date based on the onset of inflorescence emergence, and that the judicious defoliation of early reproductive tillers can be used to promote the initiation of new vegetative tillers which in turn will retain forage quality for longer. 相似文献
3.
T. A. Williams M. T. Abberton W. J. Thornley D. R. Evans I. Rhodes 《Grass and Forage Science》1998,53(2):197-207
The components of actual and potential seed yield were examined in field experiments on a wide range of varieties of white clover (Trifolium repens L.). The factors affecting seed yield under conditions typical of management regimes used in the production of commercial seed crops were assessed in two experiments. In the first, carried out on spaced plants, considerable diferences are shown between six varieties across the range of leaf sizes in the distribution and profuseness of inflorescence production through the flowering season. In the second, carried out in plots, typical on-farm criteria were used to choose a single harvest date. Significant variation was found between varieties, including representatives of different leaf size categories, for seed yield components that include number of inflorescences m?2, number of florets per inflorescence and harvestable seed weight. Large-leaved varieties tended to produce more seeds per floret and higher seed weights per inflorescence, whereas small-leaved varieties gave the highest number of inflorescences ?2. However, the small-leaved variety AderDale, selected for strong peduncles, was exceptional, giving high values for all seed yield components. The impact of weather conditions on many seed yield components (e.g. total number of inflorescences) was demonstrated by the differences between the 2 years of the experiment. However, other characterstics, e.g. number of florets per inflorescence and number of seeds per floret, did not vary between years. Deviations from potential seed yield were assessed fromthe perspective of commerical seed production. The implications of these results for the production of white clover varieties with increased seed yields under UK conditions are discussed. 相似文献
4.
Previous results with red clover ( Trifolium pratense ) leaflets, leaf petioles and stems indicated that the epidermis continued to impose a barrier to water loss at low water contents. Further experiments with red clover leaf petioles and stems suggest that cuticular wax is the epidermal component concerned and that treatments which remove or merely modify this will also increase drying rate. However, when treatments to reduce epidermal resistance were applied to pseudostems and flowering stems of Italian ryegrass ( Lolium multiflorum ) the initial increase in drying rate produced was not sustained at low water contents. The pseudostems consisted of three layers of leaf material rolled one within the other and the true flowering stems were surrounded by one leaf sheath. Their pattern of response to treatments suggested that these affected only the outer sheath, which produced an initial acceleration in drying rate, but that this was not sustained after the outer sheath was dry because the lower untreated layers dried in a similar way to untreated controls.
The results suggest the possibility of devising practical treatments to increase drying rate at low water contents with crops containing a high proportion of leaf or stem not surrounded by leaf sheath. Devising such treatments for crops with a high proportion of grass pseudostem or flowering stem surrounded by leaf sheath will be considerably more difficult. 相似文献
The results suggest the possibility of devising practical treatments to increase drying rate at low water contents with crops containing a high proportion of leaf or stem not surrounded by leaf sheath. Devising such treatments for crops with a high proportion of grass pseudostem or flowering stem surrounded by leaf sheath will be considerably more difficult. 相似文献
5.
The effect of nutrient concentration on the reproductive development and seed yield of Poa annua was examined in a sand culture experiment. The nutrient concentration during the initial vegetative stage did not affect the time taken for double ridge formation by the main shoot but did influence the subsequent development of the inflorescence as did the post-initiation level of nutrients. At low nutrient levels flowering was inhibited in some individuals but at the higher concentrations inflorescence emergence was hastened, inflorescence size was increased and, in particular, the number of spikelets and hence the number of seeds per inflorescence was greatly increased. The mean weight of 100 seeds was unaffected by the nutrient concentration. The number of reproductive tillers per plant was increased by high nutrient supply but the proportion of dry weight allocated to root development was reduced. 相似文献
6.
Cornelia J. M. Almekinders 《Potato Research》1991,34(4):379-388
Summary Field experiments were carried out to evaluate the effect of stem density and pruning of lateral stems on flowering and true
seed production in potato (Solanum tuberosum L.). Increasing stem density reduced flowering, berry and seed production from every inflorescence in all cultivars. Increasing
density increased the proportion of primary flowers in the total number of flowers per plant and reduced the proportion of
flowers on lateral stems, but its effect on the quality of the seed production was small. Differences in total seed production
were principally determined by differences in flowering. There was an interaction between stem density and cultivars for the
number of flowers produced and on the yield of true seed per m2. Pruning lateral stems enhanced flowering of the main stem and decreased the total number of flowers per plant, but it did
not affect berry and seed production from main-stem inflorescences. 相似文献
7.
8.
O. R. Jewiss 《Grass and Forage Science》1972,27(2):65-82
Tillering is examined in relation to the morphology and habit of growth of the perennial herbage grasses; particular reference is made to the effects of cutting and grazing. The importance of tillering in establishment and regeneration or perennation of a grass sward is considered; greater importance is attached to the role of tillers in the regrowth of swards cut for conservation at the reproductive stage of growth. Amounts of regrowth are related to both the number and size of vegetative tillers present at the base of reproductive tillers at the time of cutting. The probable inhibition of the replacement tiller buds by the developing inflorescence is suggested as a reason for the poor growth of grass swards in the favourable environment of midsummer. The physiological mechanisms which control tillering during reproductive development are examined. Spring and winter wheat (Triticum aestivum), Lolium temulentum and Phalaris tuberosa are used as physiological tools to demonstrate that tillering is restricted during reproductive development, and that stem extension may be more important than changes at the stem apex in controlling this restriction of tillering at the base of the inflorescence-bearing stem. It appears from results of the application of a range of growth regulators that substances derived from the meri-stematic centres, in either the elongating stem or the terminal meristem, indirectly control the metabolic activity of the lateral buds from which new tillers are derived. The degree of apical dominance is shown to depend on the light intensity in which the plants are grown. Finally, the physiological results are used to suggest reasons for the commonly found apparent inability of heavily fertilized perennial ryegrass (Lolium perenne) swards to regrow after cutting at the inflorescence-emergence stage of growth. 相似文献
9.
Xiujuan Wang Amélie MathieuPaul-Henry Cournède Jean-Michel AllirandAlexandra Jullien Philippe de ReffyeBao Gui Zhang 《Field Crops Research》2011,122(1):60-69
The number of pods per plant and the number of seeds per pod are the most variable yield components in winter oilseed rape (WOSR). Both the number of ovules per pod and the potential for the ovule to develop into a mature seed may depend on pod position in the plant architecture and time of appearance. The complex developmental pattern of WOSR makes it difficult to analyse. The objectives of this study were to investigate the variability of the following yield components (a) ovules/pod, (b) seeds/pod, and (c) pods/axis in relation to two explanatory variables. These two variables include (1) flower and inflorescence position and (2) time of pod appearance, linked to the effect of assimilate availability.Field experiments were conducted with the variety Mendel. Different trophic states were created by clipping the main stem or ramifications. The number and position of flowers that bloomed within the inflorescence were recorded based on observations every two to three days throughout the flowering season.On the control plants, for the main stem we observed that the number of ovules per pod decreased for a few ranks and then tended to increase and again to decrease at the end. On ramification R1 and R4, the number of ovules increased at first, and then remained constant with the pod rank. Furthermore, the number of ovules per pod remained constant along the inflorescence on the other ramifications and increased with ramifications from top to bottom. The number of seeds per pod did not vary with the pod rank at the basal positions on inflorescences and decreased afterwards along the inflorescence. The clipping of the main stem or ramifications increased the number of ovules per pod, seeds per pod and pods per axis. The number of ovules and seeds per pod did not vary with the time of pod appearance for the pods located at normalised rank 0.01-0.1. However, the number of ovules and seeds per pod can be impacted by the time of pod appearance on the plant scale. Thus, our results indicate that the amount of available assimilates was the primary determinant of pod and seed production during the flowering period. The distribution of resources was significantly affected by both the positions of pods within an inflorescence and the position of inflorescences within a plant. 相似文献
10.
Perennial ryegrass tillers were collected from intensively used set-stocked and zero-grazed leys and from an old permanent pasture, grown on and compared at 30 cm spacing. All swards except the permanent pasture had been sown with cv. S23 and were of known age, ranging from 6 months to 11 years from sowing. Each genotype was scored for date of inflorescence emergence, and subsequently in vitro dry matter digestibility (DMD), D-value of green leaf and the ratio of leaf dry weight: stem dry weight were determined. Both DMD and D-value declined significantly in green leaf samples of populations from the older zero-grazed swards but no significant changes were detected in populations from set-stocked swards. In set-stocked populations there was a shift towards later flowering. In zero-grazed populations there was a consistent increase in the amount of leaf relative to stem with the age of the sward from which the plants were sampled. The survivor plants were more prostrate and leafier and it is suggested that under zero grazing, where cutting was to a uniform height, plants of this form were less severely defoliated and thus at a selective advantage. 相似文献
11.
LEWIS JONES 《Grass and Forage Science》1979,34(2):139-144
The drying of Italian ryegrass (RvP) tillers under controlled conditions at three stages of growth is described. The rate of water loss was dependent on tiller morphology as well as on water content. Leaf laminae dried faster than stems and also aided the loss of water from stems. Drying time was shortest for vegetative tillers despite their high water content, and longest for reproductive tillers shortly before ear emergence. The practical implications in relation to haymaking are discussed. 相似文献
12.
以具有亲缘关系的橡胶树(Hevea brasiliensis Muell. Arg.)热研88-13、热试47、热试62为研究对象，对不同品系橡胶树开花侧枝上的花序和花序上的一级花序、雌花、一级雌花、二级雌花的数量和位置分布进行了调查和统计分析。结果表明：不同品系橡胶树间开花侧枝上花序、一级花序、雌花、一级雌花、二级雌花的数量和位置分布差异显著，不同品系橡胶树间花序上雌花、一级雌花和二级雌花的数量和位置分布差异显著；橡胶树开花侧枝上的花序数、雌花数、一级雌花数、二级雌花数之间相关性显著，花序上的雌花数，一级雌花数和二级雌花数之间相关性显著。可以将开花侧枝上的花序数和/或花序上的雌花数作为品种识别的指标之一，将花序上的一级花序数、一级雌花数和二级雌花数作为品种识别的辅助指标。 相似文献
13.
《Plant Production Science》2013,16(3):275-280
AbstractIncrease in seedling vigor is necessary to improve the yield of early-maturing spring wheat with a limited growth period. The importance of coleoptile tillers in increasing seedling vigor has been suggested. However, most previous studies on the development of coleoptile tillers have been made with only a limited number of varieties and under controlled environmental conditions. In this study, we examined difference in the development of coleoptile tillers among early-maturing varieties of wheat under field conditions. We observed large differences among varieties in the percentage of plants with coleoptile tillers, ranging from 5.6% in Haruyutaka to 60.1% in Bandouwase. The percentage of plants with coleoptile tillers was closely correlated with the number of leaves developed on the main stem. The dry weight of the plants with coleoptile tillers was heavier than that without coleoptile tillers (by 34.8% in Fukuwase komugi). However, in some varieties, the dry weight of the plants with coleoptile tillers was similar to that of plants without coleoptile tillers. The increase in dry weight per plant seemed to be achieved by the production of either a few heavy tillers or many light tillers. 相似文献
14.
Under terminal drought conditions, cereal varieties with limited tillering have been suggested to be advantageous, because they have fewer nonproductive tillers, thereby limiting water consumption prior to anthesis. In this study, four field trials were conducted over two growing seasons in southern Spain, under rainfed and irrigated conditions. Twenty-five genotypes were studied to evaluate the contribution of the main stem (MS) and tillers to grain yield and its components. Significant differences were found among genotypes for these contributions under non-stressed environments, but these differences were not significant under water-stress conditions. The contribution of the MS to plant grain yield was higher than that of tillers (68% vs. 32%) and was stable between years in irrigated trials. However, in the rainfed trials, MS contributed differently depending on year-to-year climate variations. Thus, under favorable weather conditions the contribution of MS to grain yield was higher than in the unfavorable year (85% vs. 59%). In irrigated environments, MS and tiller grain yield depended on the number of grains per spike, spikelets per spike, and thousand kernel weight (TKW). Under water-limited conditions, MS yield depended on the number of grains per spike and grains per spikelet, whereas the number of spikelets and TKW had less influence on MS grain yield. Furthermore, under water-stress conditions, high tillering genotypes showed yield levels similar to the genotypes with restricted tillering. Additionally, there was no significant evidence of a positive or negative effect of maximum tiller number on grain yield under rainfed conditions. 相似文献
15.
16.
The effect of light intensity after onset of anthesis on dry matter distribution, water soluble carbohydrate (WSC) concentration and seed filling in Lolium perenne was investigated in a pot experiment. Spaced plants of five clones were brought to flowering and exposed to four light intensities (24%, 57%, 100%, 115% of natural light) from 7 days after onset of anthesis onwards. The two oldest flowering tillers (i.e. the main and the first tiller) were separated from the rest of the plant and dissected after a seed-filling period of 450°Cd (temperature sum counting from 7 days after onset of anthesis). Their stem dry weight and WSC concentration were reduced at the lowest light intensity. WSC amount was more reduced in the first, younger, tiller. Seed yield per ear of the main tiller was reduced by 14% because seed set and average seed weight were lower at the 24% light intensity. Seed yield and seed number per ear of the first tiller were lowered by 21% and 17%, respectively, at the 24% light intensity, but average seed weight was not. The relative contribution of the seeds to total tiller weight was about 20% and was similar for both tillers and all light intensities. WSC concentration and WSC amount in the stem + rachis were reduced only at 24% light in the main tiller and at 24% and 57% light in the first tiller. It is inferred that seed yield was not limited by assimilate availability, but by the ability of the seeds to utilize fully the abundantly available reserves in the stem. The tiller can support seed yield under a wide range of tight intensities. 相似文献
17.
Determinations of the in vitro digestibilities of leaf-blade, leaf-sheath and stem fractions of the grasses cocksfoot, perennial ryegrass, timothy and tall fescue and of the leaves and stems of lucerne and sainfoin have shown that all parts of the plant have a high digestibility at early stages of growth. With increasing maturity, however, the digestibility of the stem falls off at a much faster rate than that of the leaf; in grasses, leaf-sheath digestibility declines at an intermediate rate. The decline of digestibility is associated with a reduction in the content of water-soluble and protein constituents in the plant, and with a reduction in the digestibility of fibre. This may provide a biochemical basis for the selection of forage plants of high digestibility in plant-breeding studies. 相似文献
18.
The dates of their first appearance and the dates of flowering were recorded monthly over three years from time of sowing for all tillers produced by S215 meadow fescue plants growing in simulated sward conditions in large concrete pots outdoors. The results are expressed and discussed in terms of the percentage contribution of inflorescences by tillers in relation to their chronological and ontogenetic age. The latter appeared the more important. The major contribution of inflorescences was made by primary tillers in the first harvest year, by secondary and tertiary tillers in the second year and by tertiary and quaternary tillers in the third year. The chronological age at which tillers could flower ranged from 3 to 33 mouths. 相似文献
19.
播期和播量对滴灌冬小麦群体性状及产量的影响 总被引：4，自引：0，他引：4
为了给滴灌冬小麦种植选择适宜的播期和播量组合, 以两个冬小麦品种新冬22号和新冬27号为材料,设置2个播期（9月27日和10月7日）和3个播量（150、225和300 kg·hm-2）,通过大田裂区试验研究了播期和播量对滴灌冬小麦的群体性状、产量以及产量构成的影响。结果表明,冬前总茎数、返青后总茎数、成熟期收获穗数和主茎穗比重均随播量的增大而增加,且不同播量间差异显著;播期推迟,出苗数、冬前总茎数和返青后总茎数均降低。各处理均在孕穗期叶面积指数达到最大,且孕穗后10月7日播种的冬小麦叶面积指数下降比较慢。适当晚播有利于花后同化物和花前贮藏同化物在花后向籽粒的转运。播期和播量对滴灌冬小麦产量及其构成影响显著性,在10月7日播种、播种量为225 kg·hm-2处理下产量达到最高。 相似文献
20.
为研究木薯花序与叶片中 sRNA 表达特性,探索 microRNA 对其开花过程的调控。本研究以木薯品种“华南 八号”花序和幼叶为材料,利用 RNA-seq 技术进行 sRNA 测序分析;并筛选开花相关 microRNAs 进行表达特性分析。 从花序和幼叶测序结果中分别获得 12 092 109 条和 11 499 655 条 sRNA 序列。花序中筛选出 139 条已知 microRNAs 和 253 条新预测 microRNA,分别预测得到 992 和 3 736 条靶基因;幼叶中筛选出 134 条已知 microRNA 和 191 条新预测 microRNAs,分别预测得到 979 和 2 603 条靶基因。最终筛选出 8 种与开花调控相关和 3 种花色调控相关的 microRNAs。 表达分析显示,miRNAs 在两样品间呈现出较大的整体性差异,并且在功能与代谢通路上也不尽相同;开花相关 microRNAs 中表达差异较大的为 miR156、miR172 和 miR169,其中 miR156 表达量在花序中高于幼叶,而 miR172 表 达量在花序中低于幼叶,推测其功能为抑制后续的开花过程,避免过度开花。本研究分析了木薯花序与幼叶中 sRNA 的整体特性,通过表达差异分析初步明确了 microRNAs 对木薯开花的调控,为进一步深入探索奠定了基础。 相似文献