共查询到20条相似文献，搜索用时 15 毫秒
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Carlos R. Figueroa Hernán G. Rosli Pedro M. Civello Gustavo A. Martínez Raúl Herrera María A. Moya-León 《Scientia Horticulturae》2010
Chilean strawberry (Fragaria chiloensis) is arising as a new fruit crop that can diversify the world supply of berries. Fruit softening is thought to be linked to an extensive modification of pectin and hemicellulosic cell wall fractions which in turn is determined to a great extent by the action of some cell wall-modifying enzymes. The objective of this work was to compare cell wall changes and the enzyme activities of pectin methylesterase (PME), polygalacturonase (PG), endoglucanase (EGase), α-arabinofuranosidase (AFase), β-galactosidase (βGal), and β-xylosidase (βXyl) between F. chiloensis and Fragaria ×ananassa (cv. Chandler) at three fruit developmental stages: large green (LG), turning (T) and ripe (R). A rapid decrease in fruit firmness between LG and T stages was observed in both species; nevertheless firmness reduction in F. chiloensis was steeper than in F. ×ananassa. This could be related to a faster loss of HCl-soluble polymers (HSP fraction) presented in F. chiloensis fruit. However, commercial F. ×ananassa showed a greater depolymerization of HSP polymers than F. chiloensis. With the exception of PME, the activity of all assayed enzymes was higher in F. chiloensis than in F. ×ananassa fruits. The role of PG and EGase seems to be central in both species: these enzymes are correlated to the decrease in the content of HSP and NaOH-soluble polymers (NSP fraction), respectively. In addition, activity levels of βGal and βXyl were significantly correlated with fruit firmness reduction in F. chiloensis and F. ×ananassa, respectively. 相似文献
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以蝴蝶兰‘大辣椒’为试验材料,对花芽分化进程及期间光合特性和碳水化合物、可溶性蛋白及激素含量的变化进行研究。结果表明：花芽长度为0、2、4、8、16和24 cm时,分别处于花芽分化初始期、花序原基分化期、花原基分化期、萼片原基分化期和花瓣原基分化期（16和24 cm）。蝴蝶兰叶片的净CO2吸收速率在花芽发育前期（0 ~ 4 cm）没有显著变化,花芽8 cm时显著降低。花芽中的碳水化合物和可溶性蛋白的含量显著高于叶片,碳水化合物在花芽长度为4 cm时达到稳定水平,可溶性蛋白含量在花芽8 cm时达到叶片与花芽的平衡;赤霉素（GA）的含量在花芽2 cm时达到最大值,生长素（IAA）含量在花芽4 cm时显著升高,玉米素（ZT）含量在花芽8 cm时显著降低,而ABA含量在花芽发育的过程中并没有显著变化。由此可知,当蝴蝶兰花芽开始分化萼片原基（8 cm）时,光合生理及生化物质基本达到一个相对稳定的水平,此阶段的蝴蝶兰花芽已彻底完成成花分化。 相似文献
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为了解杏花药和花粉发育的主要特征及发育进程与花芽冬眠的关系,对不同发育阶段的花药和花粉进行了显微观察。结果表明,花药壁形成于11月上旬,由5层细胞构成,包括表皮、药室内壁、中层（含2层细胞）和绒毡层（分泌型）。小孢子母细胞形成于11月上旬,减数分裂完成于2月上旬,即小孢子发生过程历时约3个月。减数分裂开始时小孢子母细胞积累大量脂滴,减数分裂产生的4个小孢子在四分体内排列成四面体形。小孢子阶段约1个月,2–细胞花粉阶段约0.5个月,即雄配子体发育历时约1.5个月。3月初花蕾与芽鳞等长时小孢子发生有丝分裂产生2–细胞花粉。成熟花粉为2–细胞型,含脂滴而不含淀粉,属脂质花粉。小孢子母细胞形成时花芽开始冬眠,减数分裂完成时花芽结束冬眠,即小孢子发生与花芽冬眠同步。杏花粉发育历时4.5个月,其特征包括小孢子母细胞减数分裂时积累脂滴,小孢子发生与花芽冬眠同步,花蕾与芽鳞等长是雄配子体发生第一次有丝分裂的形态学标志。 相似文献
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黄金树花器官发生及发育的形态解剖学研究 总被引：1，自引：0，他引：1
利用普通光学显微镜和扫描电镜技术对黄金树花器官的发生及发育过程进行了观察。结果显示：（1）黄金树花器官的形态发生及发育过程集中于3月下旬～5月上旬进行,速度较快,历时较短。（2）花原基分化形成花的整个过程符合一般的分化顺序：花萼原基－花冠原基－雄蕊原基－雌蕊原基,且各原基在分化顺序上存在交叉。（3）花药及胚珠的发育与花器官的形态发生之间有明显的连续性,当花蕾直径为3.0 mm左右时花粉母细胞及完整的花粉囊壁形成,直径达到3.5 mm左右时胚珠中出现孢原细胞的分化,它直接起大孢子母细胞的功能。 相似文献
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S.J. Mcartney M. Hoover P.M. Hirst I.R. Brooking 《The Journal of Horticultural Science and Biotechnology》2013,88(5):536-540
SummaryThe formation of bud scales, transition leaves, true leaves, bracts and flower primordia were observed in buds removed from non-flowering sites on one year old shoots of apple ‘Royal Gala’. Buds were sampled from trees in Hawke's Bay, New Zealand (latitude 398S) during six successive seasons. The onset of flower development varied between seasons from 72 to 99.d after full bloom. Floral development was poorly synchronized within the populations of sampled buds, lasting 22 to 50.d. Differences in the onset and duration of flower development could not be related to seasonal differences in heat accumulation from full bloom. There was significant variation between seasons in the minimum number of appendages observed within buds that exhibited doming, which indicates floral development. In the 1998/99 season, doming was observed in buds that had only 15.7 appendages, whereas in the 1999/2000 season the minimum number of appendages within a bud that had initiated flowers was 17.5. When the data from all seasons were considered, the rate of appendage formation within developing buds was not consistently related to heat accumulation. 相似文献
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梨果实在贮藏过程中细胞壁成分的变化 总被引：1，自引：0，他引：1
为了比较耐贮性不同的梨在贮藏过程中细胞壁成分的变化,以苹果梨和新高为试材,利用乙醇不溶性物质(alcoholinsolublesolids,AIS)分析了梨果实细胞壁组成成分的变化。结果表明,2品种在贮藏过程中AIS含量差异和变化不明显;耐贮性强的苹果梨的AIS中总果胶含量和碱溶性果胶含量高,水溶性果胶含量极显著低,而EDTA可溶性果胶含量在贮藏过程中均很少,且在整个过程中无多大变化;纤维素在梨贮藏中变化不大,而半纤维素含量有较大变化,但似乎与梨的耐贮性的关系不大。 相似文献
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《Scientia Horticulturae》2002,92(2):125-135
The influence of pre-blossom temperatures on flower development and fruit set is ascertained in apricot (Prunus armeniaca L.), a species without previous records on the effect of pre-blossom temperature on fruit set, but that is particularly prone to erratic fruit set. A polyethylene cage was used during pre-blossom development of flower buds to increase maximum temperatures by 6–7 °C and mean temperatures by 3 °C in orchard conditions. This increase in temperature accelerated flower bud development, caused a hastening in flowering time and following hand-pollination, reduced fruit set. At anthesis, flowers that had developed in warmer conditions weighed less and showed less development of the pistil than control flowers. Pistil growth of flowers under warm conditions did not differ from that of the control flowers when both the populations were compared on a real time scale in spite of the fact that warmed buds were at an advanced external phenological stage. Thus, hastening of external floral development by warm pre-blossom temperatures was not accompanied by advance in pistil development. This lack of synchrony resulted in premature flowering of flowers with underdeveloped pistils that had a reduced capability to set fruit. The results are discussed in terms of flower quality and its implications in fruit set and subsequent crop load. 相似文献
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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. 相似文献
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《Scientia Horticulturae》2005,105(2):223-240
Endogenous carbohydrate contents and availability in structures near the meristematic zone (scales, cushion, part of stem) during winter with and without sufficient chilling were investigated. Insufficient chilling is known to provoke an abnormal pattern of budbreak and development in temperate zone fruit trees cultivated in warm climates. Mild temperatures applied during winter to strictly floral buds, as is the case in peach, are known to provoke the necrosis of flower primordia in the buds. One of the hypotheses to explain this is that carbohydrate fluxes to the buds are impeded and/or that internal reserves are completely used up. Carbohydrate availability and bud survival were compared between peach trees under natural temperate conditions and under complete deprivation of cold, by keeping trees in a greenhouse with temperature constantly above 15 °C from early October to the first sign of necrosis in flower buds. Concentrations and carbohydrate contents were compared during a little more than 2 months (beginning mid-December) before the first signs of necrosis in flower buds. Results showed that cold deprivation deeply disturbed carbohydrate dynamics, blocking the import of carbohydrates into vegetative and floral primordia, even though sucrose and sorbitol concentrations within these structures remained high. Conversely, soluble carbohydrates accumulated strongly in bud scales and in the cushion beneath the primordia. This suggests a strong diversion towards structures close to the primordia under cold deprivation. However, since sucrose and sorbitol concentrations in the floral primordia remained high, necrosis could be the consequence of the inability to use sucrose and sorbitol reserves rather than the result of a lack of available carbohydrates. 相似文献
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SUMMARYThe possibility of using water stress during floral initiation and development, to synchronize flowering in potted coffee trees of cvs Catuai Rojo and Mundo Novo was investigated. Moderate and severe cyclic and constant water stress had little effect on vegetative growth during floral initiation. However, upon rewatering, shoot growth was significantly greater in plants where leaf water potential [¨,] had declined to -2.5 MPa compared with plants where ¨, was maintained above -0.5 MPa. The period of floral initiation was not influenced by water stress and occurred only under short days (<12 h). In contrast, a y, of -2.5 MPa significantly reduced the number of inflorescences compared with plants maintained at a ¨| of -0.5 or -1.5 MPa. This reduction was associated with leaf drop in stressed plants. Therefore, regular irrigation during the period of floral initiation is recommended. Water stress (¨, of -1.5 or -2.5 MPa compared with -0.5 MPa) accelerated floral development with no deleterious effects on floral differentiation. Once flower buds are fully differentiated they enter dormancy and reach anthesis only if trees are stressed and rewa-tered. Flower buds remain dormant if trees are watered regularly or a constant water stress provided. A constant period of water stress in the late stages of floral development after floral initiation is complete provides a means of increasing the proportion of fully differentiated dormant flower buds (mature buds). This could represent a practical method to achieve synchronized flowering in field conditions where there is irrigation and a reliable dry season in the late stages of floral development. 相似文献
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在"早钟6号"枇杷Eriobotrya japonica(Thunb.) Lindl.顶生枝的成花期间,调查其上第一次夏梢顶芽成花时分化出的叶片数量,跟踪顶生枝上两种特异芽体的发育去向,观察顶生枝上4种不同形态顶芽的成花特征.结果表明:第一次夏梢顶芽成花的临界节位超过16节或27节,即第一次夏梢的顶芽先后分化的叶片、小雏叶和鳞片叶数达到16片或27片以上时,生长点即可进入花芽形态分化.观察到两种特异芽体最终成为花芽的结果,同时还观察到4种不同形态的顶芽在成花解剖特征方面存在一定差异,初步确定4种不同形态的顶芽与成花进程之间的对应关系. 相似文献
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设施促早栽培下耐弱光能力不同的葡萄品种冬芽的花芽分化 总被引：1，自引：0，他引：1
为解决设施葡萄促早栽培的“隔年结果”问题,以4年生‘贝达’嫁接的不耐弱光的‘夏黑’和耐弱光的‘京蜜’为试材,通过石蜡切片法观察新梢2 ~ 7节各节位冬芽的花芽分化状况,绘制各节位冬芽群体的花芽分化进程图,研究设施促早栽培条件下耐弱光能力不同的葡萄品种冬芽的花芽分化规律。结果表明：（1）花序主轴的出现是成花起始的标志。（2）冬芽雏梢发育到含有两个叶原基至始原始体开始形成这一阶段是诱导设施葡萄成花的关键时期（生理分化期）,始原始体分化期和始原始体分裂成二分枝之后是设施葡萄成花调节的两个关键时期。（3）始原始体出现之后,冬芽雏梢生长点和始原始体发育同步是成花良好的保证,冬芽雏梢生长点营养生长过旺是抑制成花,造成“隔年结果”的重要原因。（4）‘京蜜’葡萄对设施促早栽培环境具有极佳的适应性,新梢各节位冬芽花芽分化的各阶段持续时间短且重叠阶段少,均具有良好成花能力,节位优势不明显,花芽分化从新梢基部冬芽向上依次进行,高节位冬芽花芽分化稍迟,但速度较快;冬剪采取中短梢修剪即可实现连年丰产;‘夏黑’葡萄对设施促早栽培环境的适应性差,新梢各节位冬芽花芽分化的各阶段持续时间长且多阶段相互重叠,虽然从新梢基部向上成花数量逐渐增加,成花质量逐渐改善,但不能满足生产要求,存在严重的隔年结果现象,必须采取更新修剪等相应措施方能实现连年丰产。 相似文献
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氯酸钾对龙眼成花诱导期叶片和顶芽内源激素含量的影响 总被引：1，自引：0，他引：1
对中熟龙眼品种‘凤梨穗’施用氯酸钾（KClO3）配合环割和拉枝措施,诱导其反季节成花,研究龙眼花芽诱导期叶片和顶芽间激素动态变化以及与成花状况之间的关系。结果表明：KClO3提高了叶片中生长素（IAA）含量,降低了顶芽内含量,而KClO3 + 拉枝处理的植株顶芽内IAA含量处于最低水平,且成花率最高,说明顶芽内低含量的IAA有利于成花;KClO3配合环割和拉枝处理分别降低了顶芽内赤霉素（GA3）和脱落酸（ABA）的相对含量,与IAA类似,龙眼的花芽诱导同样需要一个低水平的GA3和ABA的条件;ZT含量变化与以上激素相反,KClO3处理提高了龙眼花芽诱导期顶芽内玉米素（ZT）含量,降低了叶片中其含量,表明顶芽内ZT的增加可能是龙眼反季节成花的主要因素或信号物质,但3种处理的成花率与ZT含量水平并未呈正相关,说明细胞分裂素促进龙眼成花取决于其浓度或水平。 相似文献
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Radioimmunoassays were used to quantify the endogenous concentrations of plant growth regulators (PGRs) in pyrethrum during flower initiation and development. The concentrations of gibberellins, abscisic acid, indole acetic acid, zeatin and zeatin riboside, dihydrozeatin and dihydrozeatin riboside, and isopentenyladenine and isopentyladenosine were assayed. Fluctuations in PGR concentrations were correlated with flower bud initiation, flower stem elongation and floral differentiation. The gibberellin concentration increased during vernalization (6°C night temperature), a treatment known to promote floral initiation. A marked increase in gibberellin concentration was correlated with the onset of flower stem elongation. The concentration of the auxin indole acetic acid declined significantly at this time and remained low during flower bud development. Low photon flux density conditions, which retard floral initiation in otherwise inductive vernalizing conditions, failed to induce a decrease in indole acetic acid concentration. 相似文献
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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。 相似文献
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《Scientia Horticulturae》2005,103(4):441-451
The aim of the study was to examine the effects of different photoperiod and light integral on floral initiation, development and subsequent growth of Eustoma grandiflorum (Raf.) Shinn. Six-weeks-old seedlings of ‘Echo Blue’ and ‘Fuji Deep Blue’ were placed under short day (SD, 10 h) and were transferred to long days (LD, 20 h) at 2-week intervals from 6 to 14 weeks after seeding. Plants initiated flower buds regardless of light regimes. Flower bud initiation was delayed by SD compared to LD; plants transferred after 6 weeks from seeding initiated flower buds at least 21 and 10 days earlier at LD at high (HL) and low (LL) daily light integral, respectively, compared to those at SD. Light regimes had little or no effect on time to flower bud development after initiation. Thus, it seems likely that LD and HL affected the initiation rather than development. Both the photoperiod and light integral strongly influenced the subsequent growth after initiation. SD delayed the time to visible bud (VB), increased the number of nodes to first open flower, number of branches, stem diameter and shoot dry weight compared to LD. HL promoted flowering and increased several shoot characteristics and flowering compared to LL.The results indicate that Eustoma is a quantitative long-day plant. LD, and more specifically HL, enhanced flower bud initiation, development and subsequent growth. An initial SD period is preferred to increase the number of branches, number of flowering buds and flowers, stem diameter and shoot dry weight. 相似文献
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《Scientia Horticulturae》2002,95(3):261-268
Selection of suitable production locations in Australia and New Zealand for production of myoga (Zingiber mioga Roscoe) has been limited by lack of information on climatic influences on flowering. This study focused on photoperiod as potential production sites within Australia differ considerably in daylength due to the geographical range. The two cultivars available in Australia (Inferior and Superior) were examined in this trial due to previously observed differences in vegetative and reproductive development.Plants grown under long-day conditions (16 h) and short-day conditions (8 h) with a night break produced flower buds, while those under short-day conditions (8 h) did not. The failure of plants under short-day conditions to produce flower buds was due to abortion of developing floral primordia rather than a failure to initiate inflorescences. It was concluded that for flower development in myoga a qualitative long-day requirement must be satisfied, but that flower initiation was day-neutral.Short-day conditions resulted in abortion of flower primordia, premature senescence of foliage and reduced foliage dry weight in both cultivars. Early senescence and low flower bud yield of the Inferior cultivar, but not the Superior cultivar have been observed in crop evaluation trials in Southern Australia and New Zealand. Differences in critical photoperiod between the two cultivars may explain this observation and therefore photoperiodic requirements may be an important consideration in site and planting date selection for different cultivars. 相似文献