The responses of virus-free and virus-infected lily ‘Enchantment’ to the retardants ancymidol,chlormequat chloride,mepiquat chloride and BTS 44 584, a ternary sulphonium carbamate

The new growth retardants mepiquat chloride (a quaternary ammonium compound of the piperidinium type, coded BAS 083 00W) and a ternary sulphonium carbamate (coded BTS 44 584) were compared with ancymidol (A-Rest or Reducymol) and chlormequat chloride (Cycocel) for their ability to dwarf virus-free and virus-infected (ordinary) Mid-Century Hybrid lily cultivar ‘Enchantment’. Single compost drenches were given 3 weeks after transferring plants to the glasshouse.Compared with the virus-infected control plants, virus-free controls were 62% taller and 33% greater in leaf spread; floret number was approximately doubled and floret diameter was increased by 12%, but flowering was delayed by 6.5 days. The length of the lower stem bearing dead leaves was 15% of the total in virus-infected controls and 3% of the total in virus-free controls.Ancymidol, chlormequat chloride and mepiquat chloride were all effective growth retardants, and were without adverse side-effects. On a concentration basis, mepiquat chloride was 2–2.5 times as active as chlormequat chloride in reducing stem extension, but ancymidol was several orders of magnitude more active than both those compounds. With BTS 44 584, the maximum reduction in stem length obtained was 16% compared to controls. The decreases in stem extension were more pronounced, in both percentage and absolute terms, in the virus-free bulbs. Nevertheless, for a given retardant treatment, plants of the virus-free stock remained taller than those of the virus-infected stock. As a result, 2–3 times the amount of an active retardant was required by virus-free than by virus-infected plants in order to produce similar stem lengths at flowering. Effects of the retardants on the time of flowering, flower number, floret diameter and leaf spread were small, but increasing concentrations of all chemicals progressively increased the proportion of the stem bearing dead leaves.The effects of ancymidol, chlormequat chloride and mepiquat chloride persisted in the year after treatment.     

不同栽培方式下‘巧玲’芍药花蕾败育研究

 芍药生长发育的各个时期都存在花蕾败育现象,降低了成花率。以芍药品种‘巧玲’为材料,研究温室促成盆栽、室外盆栽和大田地栽方式下的花蕾败育情况,结果表明：不同栽培方式下芍药花蕾败育率明显不同,与各生长发育阶段蕾径大小相关。蕾径2 ~ 4 mm败育蕾发生率呈现温室促成栽培（67.9% ~ 86.6%）> 室外盆栽（44.9%）> 大田地栽（16.3%）的规律,此类败育蕾是由萌芽初期芽分化速度晚于同期正常芽的芽体发育而引起,蕾径达2 mm的败育蕾的雄蕊、雌蕊原基分化已完成;蕾径4 ~ 8 mm的败育蕾发生率呈现室外盆栽（29.6%）> 温室促成栽培（9.2% ~ 25.6%）> 大田地栽（11.8%）的规律,蕾径达5 mm的败育蕾处于胚珠原基分化阶段;蕾径8 ~ 17 mm的败育蕾在温室促成栽培条件下发生率为0 ~ 4.8%,但在室外盆栽及大田地栽环境中均没有发生,蕾径达10 mm的败育蕾其胚珠的珠心和珠柄已形成;蕾径17 ~ 27 mm的败育蕾在室外盆栽环境中发生率最高,为19.9%,其次为大田地栽,为9.2%,温室促成栽培最低,为0 ~ 1.4%,蕾径达18 mm的败育蕾可见胚珠的珠心、珠被、珠孔。3种栽培方式下败蕾率最高均出现在茎伸长期,即主要发生在2 ~ 4 mm大的花蕾,温室促成栽培中控制该阶段花蕾败育是降低败蕾率的关键,可以通过肥水管理,适当延长低温处理时间及保持后期栽培温度稳定来减少其发生,提高成花率。     

Study of some factors affecting the growth and development of myoga (Zingiber mioga Roscoe)

In order to optimise production of the edible flower buds produced by myoga (Zingiber mioga Roscoe) a greater understanding of the growth and development of the plant and factors influencing flower initiation and development are required. The vegetative growth phase in myoga was characterised by a distinct period of pseudostem development from the planted rhizome piece followed by an extended period of rhizome growth from both the base of pseudostems and the planted rhizome piece. The transition from pseudostem formation to the initiation of rhizome growth occurred at the same time as the dry weight of the planted rhizome piece ceased to decline. Flower bud initiation and development occurred over an extended period, beginning soon after the commencement of new rhizome growth and ending prior to foliage senescence. Flower buds were observed at the terminal meristem of first, second, third and fourth order rhizomes. Increasing temperatures stimulated both increased vegetative growth and flower bud initiation and development. Low flower bud yields recorded under conditions of low temperature were the result of reduced rate of floral initiation and not abortion of flower buds. Increased shading of plants grown under glasshouse conditions resulted in reduced flower bud yield and similarly the response resulted from decreased initiation rather than abortion.     

An evaluation of new growth retardants on Mid-Century Hybrid lilies

The new growth retardants piproctanyl bromide (Alden or Stemtrol), dikegulac-sodium (Atrinal), PP 528 (a phenyl tetrazole compound) and 2,3-dihydro-5,6-diphenyl-1,4-oxathiin (coded UBI-P293) were compared with the established compounds chlormequat chloride (Cycocel), ancymidol (A-Rest or Reducymol) and chlorphonium chloride (Phosfon), for their ability to dwarf Mid-Century Hybrid lily cultivars ‘Enchantment’ and ‘Joan Evans’. Single compost drenches were given 2–3 weeks after transferring plants to the glasshouse.Piproctanyl bromide at high concentrations (2000 mg a.i. per plant) produced some dwarfing, as did chlorphonium chloride (at 250 mg a.i. per plant). Chlormequat chloride produced a similar response at 1250 mg a.i. per plant, but on a concentration basis ancymidol was by far the most active compound (only 0.25–0.50 mg a.i. per plant was required). Plant and flower quality was generally good with these 3 chemicals.Dikegulac-sodium reduced stem length but prevented the development of flower buds and the plants senesced. PP 528 also restricted stem extension but plant quality was unsatisfactory; increasing concentrations led to smaller florets, weaker stems and drooping leaves. UBI-P293 produced as great a reduction in stem length as did ancymidol, and 100 mg a.i. per plant was as active as 500 mg. However, as the concentration was raised there was a decrease in floret size and number.     

The effect of day length,source of light and growth regulators on growth and flowering of Clerodendrum thomsonae Balf

The formation of flower buds in Clerodendrum seems not to be affected by day length, but the development of the buds is delayed in long days. When long days were established by means of low-intensity illumination with incandescent lamps, few flowers developed and the stems elongated considerably even at a day length of 16 hours. When fluorescent lamps were used for day-length extension, short shoots with many flowers were obtained even in 24-hour days. Flower development was also delayed by gibberellic acid (GA₃), but promoted by chlormequat both in short and long days. Shoot elongation was retarded by chlormequat and promoted by GA₃.Plants obtained from commercial greenhouses varied considerably with respect to growth and flowering. By selection a clone was obtained which flowered richly on short shoots. Shoot elongation stopped when flowering began. A ‘negative’ selection gave rise to a clone which flowered sparsely and in which shoot elongation was not influenced by flowering.     

Abortion of reproductive organs in sweet pepper (Capsicum annuum L.): a review

Summary

Levels of abortion of reproductive organs (i.e., buds, flowers, and young fruits) in sweet pepper plants (Capsicum annuum L.) are high, and cyclical fluctuations occur in fruit set. Stages susceptible to abortion are very young buds (< 2.5 mm), buds close to anthesis, and flowers and fruits up to 14 d after anthesis. An overview of factors and processes involved in flower and fruit abortion in sweet peppers is presented. More light, higher CO₂ concentrations, and lower planting density, increase the availability of assimilates per plant, and decrease fruit abortion. The cyclical pattern in fruit set is caused by changes in demand for assimilates. High flower abortion occurs when fast growing fruit (at approx. 3 weeks after anthesis) are present, due to competition for assimilates. Fruit set increases when fast growing fruit are almost mature and have a low assimilate demand. Prior to abortion, auxin export from the reproductive organ diminishes, ethylene production increases, and lower levels of activity of sucrose-cleaving enzymes are found. Severe water stress and low nutrient supply also increase abortion levels. Low night- and high day-time temperatures hamper pollen development, causing low seed set, which can result in fruit abortion. Two theories have been used to explain abortion: unbalanced demand for and supply of assimilates, and hormonal dominance of developing fruit over young fruit. Attempts to prevent abortion or to diminish the cyclical pattern of fruit set have not yet been successful, but new suggestions are presented.     

Temperature effects on flower formation in saffron (Crocus sativus L.)

The temperature conditions for shoot growth and flower formation were characterised for saffron (Crocus sativus L.). Leaf withering occurred during late winter or spring depending on location, and coincided with a rise in temperature. No growth was detectable in the buds during the first 30 days after leaf withering, neither in underground corms nor in lifted corms incubated in the laboratory under controlled conditions. Flower initiation occurred during the first growth stages of the buds. The optimal temperature for flower formation was in the range from 23 to 27 °C, 23 °C temperature being marginally better. To ensure the formation of a maximum number of flowers, the incubation at these temperatures should exceed 50 days, although incubation longer than 150 days resulted in flower abortion. Flower emergence required the transfer of the corms from the conditions of flower formation to a markedly lower temperature (17 °C). Incubation of the corms after lifting at a higher temperature (30 °C), reduced flower initiation and caused the abortion of some of the initiated flowers. No flowers formed in corms incubated at 9 °C. A variable proportion (20–100%) of the corms forced directly at 17 °C without a previous incubation at 23–27 °C formed a single flower. The wide differences in the timing of the phenological stages in different locations we found in this study seemed related to the ambient temperature. Leaf withering was followed shortly by flower initiation, which occurred during late spring or early summer as the rising temperature reached 20 °C. A long hot summer delayed flower emergence which occurred in late autumn as the temperature fell to the range of 15–17 °C.     

Flowering influences adventitious root formation in chrysanthemum cuttings

Root formation in chrysanthemum (Dendranthemum grandiflora (Ramat.) Kitamura) cuttings was reduced as flowers developed on stock plants. This effect was shown for all ten cultivars evaluated in this study. Not all cultivars were affected equally by the presence of flower buds on cuttings. There was no relationship (r² = 0.06) between root formation in vegetative cuttings and the ability for a cultivar to root from flowering cuttings. IBA (1 mM) could partially overcome the negative effect of flowering on root formation, but cuttings taken after the flower buds had fully opened failed to root even after auxin treatment. Removing buds from cuttings or continually removing flower buds during stock plant growth reduced rooting compared to cuttings with flower buds intact. Furthermore, cuttings taken from the top three nodes of the stock plant containing flower buds rooted comparably to cuttings taken from the lower stem section that contained only vegetative buds. The negative influence of flowering on root formation appears to be due to the photoperiodic induction of the flowering stimulus rather than a direct competition for resources between flowers and developing roots.     

早美丽李雌雄蕊败育过程的解剖学观察

为探明近年来早美丽李芽萌发阶段发生的花芽严重败育脱落的原因,采用石蜡切片方法,以皇家宝石为对照,观察花器后继发育过程中雌雄蕊的败育情况。结果表明,早美丽李的雌雄蕊结构分化前期能够正常完成。但在进一步的性细胞生长和分化过程中,早美丽李雌雄蕊的继续发育受阻,并在开花前24d雄蕊的花药囊壁外层细胞先发生异常,最终出现多方面的畸形——成为整个花芽退化的形式。对照皇家宝石李在花前20d,雄蕊进入小孢子母细胞主要时期,雌蕊进入胚珠突起主要时期;花前10d进入幼嫩花粉粒出现主要时期,花前7d分化出完整的胚珠。根据其雌雄蕊败育发生时期和败育特征情况,结合2005—2006年和2006-2007年2个冬季较其他年份出现的明显的暖冬天气情况,作者认为导致早美丽李花器严重败育与这2a冬季低温量不足有关。     

Flower initiation and development in the glasshouse rose

The initiation and development of a rose flower has been divided into a sequence of ten developmental stages. These numbered stages were used as a standard scale to follow flower development in various treatments for a number of cultivars. Flower initiation took place soon after stem extension occurred in a previously inactive bud, usually about two weeks after removal of the marketable flowering shoot above the bud. All actively growing buds appeared to initiate flowers, indicating that the abnormality known as ‘blind-wood’ is caused by the subsequent abortion of developing flower buds. There were seasonal differences in the rates of development which varied considerably between cultivars. The scale of development outlined here may provide a useful criterion for the selection of cultivars for year-round production programmes.The importance of light level as a factor determining development and productivity is discussed and some comparisons are made between rates of development with continuous production and with a period of inactivity. It is concluded that the latter technique does not enhance development and if growth is resumed too slowly, development may be delayed by the lower temperatures and abnormalities may occur.A correlation between apical development and apical size is demonstrated.     

Effects of growth-regulating chemicals on two cultivars of Mid-Century Hybrid lily

The effects on growth and flowering of Mid-Century Hybrid lilies ‘Enchantment’ and ‘Joan Evans’ of soil drench applications of ancymidol at 0, 5, 10 and 15 ppm have been compared with those produced by drenches of chlormequat chloride, chlorphonium chloride and ethephon at 25 000, 1000 and 1000 ppm, respectively.Ancymidol inhibited stem growth more effectively than a 5000-fold greater quantity of chlormequat chloride. Chlorphonium chloride had little dwarfing effect, and ethephon, although producing height reductions similar to those obtained with 5 ppm ancymidol, delayed flowering slightly in both cultivars (significantly in ‘Enchantment’), and adversely affected overall plant appearance.Ancymidol reduced the lateral spread of foliage, increased the proportion of the total stem length bearing dead leaves, did not significantly delay flowering in either cultivar and appeared to favour the initiation and survival of secondary flowers in ‘Enchantment’.     

Anatomy of flower differentiation and abortion,in relation to the growth and development of hybrid tea-rose seedlings

From germination until anthesis or flower bud abortion, seedlings from ‘Sonia’ × ‘Hadley’ were grown in both a greenhouse (full daylight, 20° C) and a growth room (8 Wm^?2, 8 h, 20°C) of the IVT-phytotron. Plastochron was an external indication of the stage of flower differentiation. Flower differentiation in flowering and aborting seedlings ran parallel up to petal-segregation. Flower differentiation in aborting seedlings did not proceed beyond stamen formation. Early abortion, which also caused absence of the upper leaf, occurred without, later abortion with, an abscission zone in the flowerstalk.     

甜椒植株摘叶处理对落花落果的影响

甜椒植株摘去 50 %叶片比不摘叶处理生物学产量大幅下降 ,落果率高。初果生长速率在相同节位和相同时期 ,摘叶和不摘叶间表现相似 ,初果坐果节位为 5和 7的生长速率最大 ,其第 10节位试验果落果率最高。无性器官与试验果的生长量之和与试验果落果率呈直线相关。     

Growth and abortion of flower buds in gynoecious cucumber plants in relation to temperature

The growth of flower buds in a gynoecious cucumber cultivar was studied at 15, 21 and 27°C. Competition between buds in the same node was measured as the ratio of the growth rates of individual buds. This competition was stronger at 21 and 27 than at 15°C. At 15°C, at least 3 buds were about equally strong; at 21°C, 2 buds developed fast and suppressed the other buds; at 27°C, the first bud which developed suppressed all other buds. When plants were transferred from one temperature to another, the growth-rate ratio between buds in older nodes was maintained. In nodes formed in the new temperature regime, the growth-rate ratio was determined by the new temperature.     

The responses of early-flowering chrysanthemums to daylength

In a study of photoperiod response 30 early (summer)-flowering chrysanthemum cultivars from Britain and Japan reacted as quantitative short-day plants. Both flower bud initiation and development occurred more rapidly in short days (SD) as compared with long days (LD). The early-flowering cultivars differed from late-flowering chrysanthemums in that lateral flower buds, and often the terminal flower buds, develop to anthesis in LD. Internodes were shorter in SD and flowers had fewer florets. There was an increased number and proportion of disc florets in SD in all cultivars except one. Two cultivars, ‘Mezame’ and ‘Pennine Yellow’, closely approached day-neutrality.All cultivars produced fewer leaves in LD on upper lateral shoots than on main stems. Either the presence of the terminal flower bud induces earlier flowering of the upper lateral shoots, or the change which causes the terminal apical meristem to initiate a flower in LD influences the axillary meristem also.SD could be used to speed up the flowering of glasshouse-grown crops of early-flowering cultivars. The advantages and disadvantages which may be associated with treatment at different stages of growth are discussed.     

Apical Dominance and Flower Initiation in the Rose

The initiation of leaves and flowers by selected axillary buds of the glasshouse rose cultivar Sonia (syn. Sweet Promise) has been studied both while their extension growth was inhibited by apical dominance and after the inhibition had been removed at one of two times (“early” or “late”). Leaf initiation occurred during growth inhibition so that leaf primordia accumulated in the axillary buds. Flower initiation began, with both treatment times, only after removing apical dominance. Although the total number of leaf primordia formed before the flower was greater in plants of the “late” treatment, the axillary shoots produced in both treatments had similar numbers of leaves with expanded leaflets. Thus many leaf primordia of the “late” treatment plants became scales. The evidence suggests that flower initiation cannot begin while an axillary bud is subject to apical dominance, and that after its removal another factor results in the production of shoots with a relatively constant number of leaves with expanded leaflets.     

山葡萄雄株花蕾性别转换的形态观察及其内源激素的变化

以山葡萄雄株为试材,花前20d用100mg/L的KT-30S处理雄株花序,以蒸馏水处理为对照,观察处理后的形态变化和坐果情况,并在不同处理时期取样测定内源激素含量,探讨外源细胞分裂素KT-30S对山葡萄雄株花蕾性别转换的效果及其对内源激素的影响。结果表明:KT-30S对山葡萄雄株的性反转效果显著,雄花花蕾在处理6d子房显著膨大。经KT-30S处理,4种内源激素含量和平衡关系表现出不同的变化趋势,由此推断,KT-30S诱导山葡萄雄株性反转可能是通过调节内源激素在不同时期的水平及其之间的平衡关系来实现的。     

Effect of light intensity on stamen development in the strawberry cultivar‘Glasa’

In forcing the strawberry cultivar ‘Glasa’ under poor light conditions in the glasshouse, a sharp drop in light intensity, leading to a low light level for some days, resulted in stamen abortion in those flower buds which were due to open in a few days. This in turn led to poor fruit set.Under controlled light conditions stamen abortion was found to occur when the light intensity dropped to 4400 mW/m² or less.     

钙化合物对苹果疏花疏果的效应

选用蚁酸钙制剂(CFA)、氯化钙制剂(CCOA)、硝酸钙制剂(CNOA)、丙酸钙制剂(CPA)、氯化钙(CaCl2)、硝酸钙犤Ca(NO3)2犦六种钙化合物对红富士苹果进行了疏花疏果试验。结果表明,以浓度为5～10g/L的蚁酸钙制剂效果最好;喷布两次比一次效果好,第一次在顶芽中心花盛开3d后喷布,第二次在顶芽中心花盛开5d后喷布,这样可确保顶芽中心花不受影响,而使顶芽侧花和腋芽花的结果率同时降低。CFA加用1mL/L的界面活性剂KP-4714,可显著提高疏花效果。所用钙化合物的疏花喷布对幼果生长和成熟果的大小、着色程度、果实品质均无不利影响。浓度为10g/L的氯化钙和硝酸钙处理对新梢生长点和幼叶有药害发生。     

低温对'寒富'苹果花芽呼吸和抗氧化酶活性的影响

以‘寒富’苹果花芽为试材,设置梯度低温(-25-、30-、35和-40℃)处理,研究顶花芽和腋花芽的呼吸速率和抗氧化酶活性对低温的响应特点。结果表明:顶花芽呼吸速率随着温度的下降表现出先升高后显著下降再升高的趋势,在-30℃顶花芽呼吸速率降到最低点,且明显低于腋花芽,此后顶花芽的呼吸速率虽呈上升的趋势,但一直处于较低水平。腋花芽呼吸速率在低温处理的前期呈逐渐降低的趋势,在-30℃降到最低点,此后急速升高,在-35℃达到最高点后快速下降。2种类型花芽的SOD酶活性在-10~-25℃均是快速升高,此后顶花芽的SOD酶活性急剧下降并一直处于较低水平,腋花芽的SOD酶活性下降幅度较小且维持在较高的水平。顶花芽的POD酶活性变化呈升高-下降交替出现的特点,在-25℃和-35℃出现峰值;腋花芽则表现为降低-升高-降低的趋势,在-35℃达到峰值且高于顶花芽。顶花芽的CAT酶活性在低温下呈先升高后降低的变化趋势,在-25℃出现峰值;腋花芽CAT酶活性则呈升高-降低交替出现的特点,在-25℃和-35℃出现峰值。此外,腋花芽的POD和CAT酶活性升高幅度明显高于顶花芽。由此认为,腋花芽的呼吸途径活性受低温抑制的程度低于顶花芽,以及其抗氧化酶清除活性氧的能力高于顶花芽,都有利于减少低温胁迫引起的活性氧伤害。