水稻超丰早1号(高粱稻)的多芽蘖现象(简报)

ＢＡ能促进水稻超丰早１号（高粱稻）种子苗的发生,在０．５～２．５ ｍｇ·Ｌ－１浓度下,配以 ２,４Ｄ促使多分蘖,形成“多芽蘖”（芽蘖为胚芽腋芽或第１叶叶腋的叶芽）。黑暗中生长时,节间伸长,叶基部发生多芽蘖和次生腋芽,数目有３～７个不等。先照条件下,节间伸长不明显,虽有多芽蘖发生,但数略少,芽蘖由茎基部发生侧芽,也可由侧芽再分裂形成。     

半湿润地区氮磷钾配施对强筋小麦功能叶光合速率的影响

选用优质强筋小麦品种陕253为材料,研究了不同氮磷钾肥水平及组合对小麦生育后期主茎、主茎分蘖Ⅰ和主茎分蘖Ⅱ功能叶净光合速率的影响,结果表明:在不同的NPK肥配比处理中,功能叶净光合速率在蘖位、叶位间差异均极其显著,不同生育期间存在明显差异,具体表现为:孕穗期高于灌浆期,主茎>主茎分蘖Ⅰ>主茎分蘖Ⅱ,旗叶高于倒二叶.孕穗期以N225P120K120处理对茎蘖功能叶光合速率影响最为明显,分别比CK1和CK2增加20.41%和25.76%;灌浆期以N135P225K120处理对茎蘖旗叶净光合速率作用显著,分别比CK1和CK2增加43.48%和10.83%.研究发现,在一定磷钾肥基础上通过调节氮肥可以调节孕穗期茎蘖功能叶净叶光合速率,提高钾肥用量有利于提高灌浆期各茎蘖功能叶的净光合速率.     

水稻超丰早1号（高粱稻）的多芽檗现象（简报）

ＢＡ能促进水稻超丰早１号（高粱稻）种子苗的发生,在０．５￣２．５ｍｇ·Ｌ＾－１浓度下,配以２,４－Ｄ促使多分蘖,形成“多芽檗”（芽蘖为胚芽腋芽或第１叶叶腋的叶芽）。黑暗中生长时,节间伸长,叶基部发生多芽蘖和次生腋芽,数目有３￣７个不等。光照条件下,节间伸长不明显,虽有多芽檗发生,但数略少,芽蘖由茎基部发生侧芽,也可由侧芽再分裂形成。     

再生小麦

“再生小麦”是指小麦在拔节后至成熟前,植株主茎或大蘖受伤害后,当水分、养分、温度和湿度都较好时,茎节或分蘖节上已经休眠的蘖芽伸长长成较大的分蘖并抽穗结实。笔者1986年在温室内进行小麦盆栽试验,当小麦达籽粒半仁期时将主茎穗剪掉,不久即从地上第二节间基部长出新的分蘖,并迅速地拔节、抽穗、结实;同时还长出了次生根(气根,只是节间数比主茎少了1节(封面照片)。但是,这种于半仁期失去主穗后又长分蘖并能结实的现象在田间     

种植密度对两种穗型小麦品种分蘖期茎蘖生理特性的影响

选用分蘖成穗率不同的2种穗型冬小麦品种,通过3个密度水平大田试验研究了分蘖期主茎和不同蘖位分蘖间的干物质积累与光合特性的差异,以探讨2种穗型品种分蘖成穗的生理机制.结果显示:(1)在冬小麦分蘖期间,分蘖成穗率低的大穗型品种'兰考矮早八'高位分蘖干物质积累速率较慢,分蘖与主茎的差距较大;而分蘖成穗率高的多穗型品种'豫麦49-198'分蘖与主茎的干物质积累速率差距较小.(2)2品种分蘖与主茎干物重比值(蘖/茎)均随着种植密度增加而降低,成穗分蘖的蘖/茎值拔节期均大于0.5,而同期未成穗分蘖均低于0.5.(3)在分蘖期间,'兰考矮早八'分蘖的净光合速率随生育进程增长比主茎缓慢,且随密度增加分蘖与主茎的差距进一步加大;'豫麦49-198'分蘖与主茎的光合速率差异较小,且种植密度对其影响也较小.(4)拔节中前期种植密度对2品种的荧光参数影响较小,拔节后期2品种分蘖的初始荧光(F0)均显著大于主茎,而PSⅡ最大光化学效率(Fv/Fm)却显著低于主茎;随种植密度增加,2品种主茎与分蘖的F0和Fv/Fm差异增大,且这种趋势随蘖位上升表现得更加明显.研究表明,大穗型品种'兰考矮早八'拔节期主茎与分蘖间干物质积累和光合性能的差异过大是其分蘖成穗率低的主要原因.     

箭羽竹芋的离体培养和快速繁殖

1 植物名称 箭羽竹芋（Calathea lancifolia Boom）,又称披针叶竹芋。 2 材料类别地下分蘖芽。3培养条件芽诱导培养基：（1）MS＋6．BA5．0mg．L。（单位下同）＋NAA0．05：增殖与继代培养基：（2）MS＋6．BA3．0＋NAA0．05;生根培养基：     

水稻分蘖节位生产力比较

以籼型杂交稻(Oryza sativa) ‘汕优63’为供试材料, 在田间单株稀植条件下(100 cm × 50 cm)进行试验, 保留主茎1个节位、2个节位和4个节位, 其中节位处理分低节位、中节位和高节位, 每个植株通过人工去除特定节位分蘖, 都保留16个分蘖穗和相同的一次、二次和三次分蘖的构成。在此条件下研究了主茎和2-9节位一次、二次和三次分蘖的经济产量。试验结果如下: 1)主茎总叶数和穗重随分蘖节位减少和节位上移而增加。2)在相同分蘖节位条件下, 一次分蘖的平均穗重表现为高节位>中节位>低节位; 二次分蘖的平均穗重在1个节位时表现为中节位>高节位>低节位, 在2和4个节位时表现为高节位>中节位>低节位; 三次分蘖的平均穗重在1个节位时表现为中节位>高节位>低节位, 2个节位时表现为中节位>低节位>高节位, 在4个节位时表现为高节位>中节位>低节位。3)整个分蘖穗重的平均值在1个节位时和在2个节位时都表现为中节位>高节位>低节位, 在4个节位时表现为高节位>中节位>低节位。4)分蘖穗重平均值的不整齐度(占主穗的百分比)随着利用节位上升而增加, 但这种趋势随节位数的增加而变缓。上述结果表明, 低节位分蘖尽管出现的时间早, 有更多的叶片数, 但不一定比中、高节位分蘖有更高的经济产量。要正确比较低、中和高节位生产力, 必须在相同分蘖利用节位、相同的分蘖数和相同的分蘖构成前提下。     

野生扁穗牛鞭草无性系构件组成及生物量结构变异性

对60份野生扁穗牛鞭草的无性系种群构件数量、质量性状及生物量结构进行比较分析,结果说明：不同种群构件性状与数量呈现出变异性,叶长、叶宽、单蘖叶片数、无性系叶片数的变异系数分别为24．95％、20．00％、14．12％、43．56％;茎直径、节直径、节间长、单蘖节数、直立茎长度、匍匐茎长度、直立茎数、匍匐茎数的变异系数分别为21．11％、22．42％、20．10％、12．14％、46．73％、20．14％、72．76％、37．97％;根系深度、根系分布范围、分蘖面积的变异系数分别为19．81％、37．65％、33．68％;花序长、花序宽、花序厚、单蘖花序数、直立茎生殖蘖比例、匍匐茎生殖蘖比例的变异系数分别为13．33％、13．42％、14．80％、36.10％、118．96％、81．44％。不同种群构件生物量结构变异性丰富,叶生物量、茎生物量、根生物量、花序生物量变异系数分别为78．51％、91．66％、45．64％、192．24％;构件的数量差异高于性状差异,无性系种群差异主要体现在分蘖能力与空间拓展能力上。野生资源生态型变异性和对环境的适应性,为优异性状选择、品种选育、资源开发利用提供了丰富的物质基础。     

荸荠营养器官的发育与解剖学研究

荸荠同化茎起源于肉质主茎倒２或倒３叶的叶腋内。同化茎基部着生二鞘状叶,鞘状叶对早期同化茎穿出土面具保护作用。匍匐茎大多起源于同化茎基部鞘状叶的叶腋内。当植株开始抽生花茎时,地下匍匐茎顶端开始膨大。球茎的膨大是匍匐茎顶端５－６节的基本组织经细胞有丝分裂,增加细胞数目,然后由细胞体积的扩大来实现的。球茎具足够的营养物质供来年顶芽萌发的需要,故属水生植物冬芽的性质。     

冬小麦（Triticum aestivum）分蘖冗余生态学意义以及减少冗余对水分利用效率的影响

通过盆栽试验,以旱作冬小麦（Triticum aestivum）为材料,分别在拔节和抽穗期对分蘖进行人工干扰,来模拟不可预测的自然干扰,对冬小麦分蘖冗余的生态学意义以及减少这些冗余对水分利用效率影响进行研究。设置3个处理：从拔节期开始剪去所有小的分蘖,仅保留主茎和一个大的分蘖（A）;在拔节期剪去主茎和两个大的分蘖,保留所有小的分蘖（B）;在孕穗期剪去主茎和有效分蘖,保留无效分蘖（C）。没有被干扰的植物作为对照（CK）。通过花期测定叶片的叶绿素含量、叶绿素荧光参数、气孔导度和蒸腾速率等生理指标来评价植物的生理与生化活性。结果显示,在拔节期和抽穗期去除主茎和大蘖后,无效分蘖的生理活性被激活,开始执行有效分蘖的功能。到花期时,这些无效分蘖已经在生理活性上满足了补充和替代有效茎的要求。虽然株高和穗的整齐度、穗数和产量显著下降,但并没有防碍小麦的繁衍子代,因此,正是这些由早期“无效分蘖”补充而来的有效茎,避免了小麦绝种的风险。 而在拔节期去除无效分蘖后,对小麦产量没有显著影响,但提高了水分利用效率,和对照相比水分利用效率提高了10%。因此,可以认为小麦在分蘖上存在着对水分利用不利的生长冗余,减少这些冗余有望节约用水、提高作物的水分利用效率。     

Tillering in grain sorghum over a wide range of population densities: identification of a common hierarchy for tiller emergence,leaf area development and fertility

Most studies of tiller development have not related the physiological and morphological features of each culm to its subsequent fertility. This introduces problems when trying to account for the effects of tillering on yield in crop models. The objective of this study was to detect the most likely early determinants of tiller fertility in sorghum by identifying hierarchies for emergence, fertility and grain number of tillers over a wide range of assimilate availabilities. Emergence, phenology, leaf area development and dry weight partitioning were quantified weekly for individual tillers and main culms of tillering and uniculm plants grown at one of four densities, from two to 16 plants m(-2). For a given plant in any given density, the same tiller hierarchy applied for emergence of tillers, fertility of the emerged tillers and their subsequent grain number. These results were observed over a range of tiller fertility rates (from 7 to 91%), fertile tiller number per plant at maturity (from 0.2 to 4.7), and tiller contribution to grain yield (from 5 to 78 %). Tiller emergence was most probably related to assimilate supply and light quality. Development, fertility and contribution to yield of a specific tiller were highly dependent on growing conditions at the time of tiller emergence, particularly via early leaf area development of the tiller, which affected its subsequent leaf area accumulation. Assimilate availability in the main culm at the time of tiller emergence was the most likely early determinant of subsequent tiller fertility in this study.     

Tillering in grain sorghum over a wiide range of population densities: modelling dynamics of tiller fertility

The prediction of tillering is poor or absent in existing sorghum crop models even though fertile tillers contribute significantly to grain yield. The objective of this study was to identify general quantitative relationships underpinning tiller dynamics of sorghum for a broad range of assimilate availabilities. Emergence, phenology, leaf area development and fertility of individual main culms and tillers were quantified weekly in plants grown at one of four plant densities ranging from two to 16 plants m(-2). On any given day, a tiller was considered potentially fertile (a posteriori) if its number of leaves continued to increase thereafter. The dynamics of potentially fertile tiller number per plant varied greatly with plant density, but could generally be described by three determinants, stable across plant densities: tiller emergence rate aligned with leaf ligule appearance rate; cessation of tiller emergence occurred at a stable leaf area index; and rate of decrease in potentially fertile tillers was linearly related to the ratio of realized to potential leaf area growth. Realized leaf area growth is the measured increase in leaf area, whereas potential leaf area growth is the estimated increase in leaf area if all potentially fertile tillers were to continue to develop. Procedures to predict this ratio, by estimating realized leaf area per plant from intercepted radiation and potential leaf area per plant from the number and type of developing axes, are presented. While it is suitable for modelling tiller dynamics in grain sorghum, this general framework needs to be validated by testing it in different environments and for other cultivars.     

Regulation of tillering in sorghum: genotypic effects

MethodsFive sorghum hybrids, derived from inbred lines with a common genetic background and with similar phenology and plant height but contrasting tillering, were grown in five experiments. The experiments covered a wide range in radiation and temperature conditions, so that number of tillers produced varied significantly. Data on leaf area, tiller number, and biomass accumulation and partitioning were collected at regular intervals. To quantify internal plant competition for carbohydrates, a carbohydrate supply–demand index (S/D_index) was developed and related to variation in tillering.ConclusionsThe results support the hypothesis that genotypic differences in tillering were associated with differences in plant carbon S/D balance, associated with differences in leaf size and in the threshold at which tillers grow out. The results provide avenues for phenotyping of mapping populations to identify genomic regions regulating tillering. Incorporating the results in crop growth simulation models could provide insight into the complex genotype-by-management-by-environment interactions associated with drought adaptation.     

Insights on the role of tillering in salt tolerance of spring wheat from detillering

Tillering is reduced by salinity, with the primary and secondary tillers being more affected than is the mainstem. To understand the importance of tillering in the salt tolerance of wheat plants, two contrasting genotypes of spring wheat (Triticum aestivum L.) were grown in a greenhouse under saline or non-saline conditions and were subjected to five progressive levels of detillering. Regardless of the genotype and salinity, shoot dry weight, seed yield and seed number per plant were all significantly decreased in the treatments where only one or two tillers per plant remained compared with the untouched treatment (more than three tillers), whereas these same variables per tiller tended to be increased on a per tiller (mainstem or substem tiller) basis. The increased seed yield per tiller observed with tiller reduction may be attributed to the enhanced seed number within the spikelet. Under saline conditions, the reductions in shoot dry weight, seed yield and seed number per plant for the salt-tolerant genotype Kharchia were of a greater magnitude in the treatments where only one or two tillers per plant were present compared with the untouched treatment, whereas the magnitude of this reduction in the salt-sensitive genotype Sakha 61 was decreased.     

Modulation of leaf elongation, tiller appearance and tiller senescence in spring barley by far-red light

Supplemental far-red (FR) illumination of light-grown grass seedlings inhibits tiller production while enhancing leaf elongation. Although much is known about FR enhancement of internode elongation in dicots, relatively little research has been conducted to determine the effects of FR on monocot development. In growth chamber experiments, fibre optics were used to direct supplemental FR to elongating leaf blades, main stem bases and mature leaf blades of light-grown barley (Hordeum vulgare L.) seedlings. Our objective was to identify specific sites of perception for FR enhancement of leaf elongation and inhibition of tiller production, and to assess potential FR effects on tiller senescence. Far-red illumination of elongating leaves or of the main stem base reduced the total number of tillers per plant, primarily by reducing secondary and tertiary tiller production, and enhanced leaf elongation. However, leaf elongation was less sensitive to stem base treatments than to illumination of the elongating blade. Increased leaf length resulted from increased leaf elongation rate, while the duration of leaf elongation was unaffected. Exposure of mature leaf blades to FR had no effect on tillering or leaf elongation. None of the FR treatments led to tiller senescence. Localization of FR perception in vertically oriented tissues such as elongating blades and stem bases permits early detection of reflected light from neighbouring plants, allowing rapid response to impending competition.     

Leaf and Tiller Production of Prairie Grass (Bromus willdenowii Kunth) and Two Ryegrass (Lolium) Species

A detailed morphological study of three prairie grass cultivars(Bromus willdenowii Kunth) was conducted under ‘vegetative’and ‘reproductive’ growth conditions (short andlong photoperiods) and at different temperatures. Perennialryegrass (Lolium perenne L.) and Westerwolds ryegrass (Loliummuhiflorum Lam.) were compared during vegetative growth. Prairie grass had higher leaf appearance rates (leaves per tillerper day) and lower site filling (tillers per tiller per leafappearance interval) than the ryegrass species. Tillering rates(tillers per tiller per day) were also lower, except under vegetativeconditions at 4C. Low tiller number in prairie grass was notdue to lack of tiller sites but a result of poor filling ofthese sites. Lower site filling occurred because of increaseddelays in appearance of the youngest axillary tiller and lackof axillary tillers emerging from basal tiller buds. In prairiegrass, no tillers came from coleoptile buds while only occasionallydid prophyll buds develop tillers. Low tiller number in prairiegrass was compensated for by greater tiller weight. Prairiegrass had more live leaves per tiller, greater area per leafand a high leaf area per plant. Considerable variation between cultivars was found in prairiegrass. The cultivar ‘Bellegarde’ had high leaf appearance,large leaves and rapid reproductive development, but had lowlevels of site filling, tillering rate, final tiller numberand herbage quality during reproductive growth. ‘Primabel’tended to have the opposite levels for these parameters, while‘Grasslands Matua’ was intermediate and possiblyprovided the best balance of all plant parameters. prairie grass, Bromus willdenowii Kunth, perennial ryegrass, Lolium perenne L., Westerwolds ryegrass, Lolium multiflorum Lam., temperature, photoperiod, leaf appearance, leaf area, tillering, site filling, tillering sites, yield     

A comparative analysis of the temperature response of leaf elongation in Bromus stamineus and Lolium perenne plants in the field: intrinsic and size-mediated effects

BACKGROUND AND AIMS: Growth of grass species in temperate-humid regions is restricted by low temperatures. This study analyses the origin (intrinsic or size-mediated) and mechanisms (activity of individual meristems vs. number of active meristems) of differences between Bromus stamineus and Lolium perenne in the response of leaf elongation to moderately low temperatures. METHODS: Field experiments were conducted at Balcarce, Argentina over 2 years (2003 and 2004) using four cultivars, two of B. stamineus and two of L. perenne. Leaf elongation rate (LER) per tiller and of each growing leaf, number of growing leaves and total leaf length per tiller were measured on 15-20 tillers per cultivar, for 12 (2003) or 10 weeks (2004) during autumn and winter. KEY RESULTS: LER was faster in B. stamineus than in L. perenne. In part, this was related to size-mediated effects, as total leaf length per tiller correlated with LER and B. stamineus tillers were 71% larger than L. perenne tillers. However, accounting for size effects revealed intrinsic differences between species in their temperature response. These were based on the number of leaf meristems simultaneously active and not on the (maximum) rate at which individual leaves elongated. Species differences were greater at higher temperatures, being barely notable below 5 degrees C (air temperature). CONCLUSIONS: Bromus stamineus can sustain a higher LER per tiller than L. perenne at air temperatures > 6 degrees C. In the field, this effect would be compounded with time as higher elongation rates lead to greater tiller sizes.     

Morphological Analysis of Leaf and Tiller Number Dynamics of Wheat (Triticum aestivumL.): Responses to Temperature and Light Intensity

In recent literature on Gramineae species, leaf and tiller numberdynamics have been studied by analysing site filling and thephyllochron of the mainstem. However, site filling is influencedby three components: (1) the phyllochron of the mainstem anddaughter tillers; (2) specific site usage (i.e. fraction ofbuds that ultimately develop into a visible tiller at a specificsite); and (3) HS-delay (i.e. difference in Haun Stage (HS)between the parent tiller and daughter tiller above the pointwhere the daughter tiller appears). These three morphologicalcomponents affecting site filling were studied under differentenvironmental conditions in a growth chamber experiment withspring and winter wheat (Triticum aestivumL.). Treatments weretemperature (daily average 10.5, 15.5 or 20.5 °C) and lightintensity (111, 191 or 286 µmol m^-2s^-1). Effects of temperatureand light intensity on phyllochron were well described by equationsalready reported in the literature. Specific site usage washigher at cooler temperatures and greater light intensitiesand was related to tiller position. It is proposed that theseeffects on specific site usage reflect differences in availabilityof local assimilate for tiller appearance. HS-delay of a tillerwas shorter if the expected tiller appearance was later andwas only slightly affected by light intensity or temperature.This new concept, combining HS-delay and specific site usage,can be useful in constructing more general models of the effectsof environmental factors on the dynamics of leaf number andleaf area ofGramineaespecies.Copyright 1998 Annals of BotanyCompany Triticum aestivum; wheat; phyllochron; temperature; light intensity; leaf number; tillering; site filling; site usage.