大花海棠“比哥”扦插繁殖试验

对引进的大花海棠绿叶红花、铜叶红花2个花色品种分别采用萘乙酸、ABT 2种植物激素进行插穗基部浸泡5s处理,扦插7d后对其生根情况进行观测.结果表明:萘乙酸、ABT生根粉对促进大花海棠各品种扦插生根效果明显,其中以ABT生根粉效果最好,萘乙酸次之.ABT生根粉以100 mg/kg浓度处理最好,大花海棠铜叶红花品种的生根率达94.5％.2个花色品种中铜叶红花各浓度处理的生根率均高于绿叶红花,栽培表现中铜叶红花植株长势强于绿叶红花.     

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.     

The influence of fruiting on the bud sprouting and flower induction responses to chilling in Citrus

Summary

The effect of chilling temperatures on bud sprouting and flower formation was compared on fruiting and non-fruiting ‘Owari’ satsuma mandarin (Citrus unshiu Marc) trees. On non-fruiting trees, bud dormancy was weak, and a significant proportion of buds were able to sprout at high temperatures without being chilled. Separate effects of low temperatures on bud sprouting and flower induction were demonstrated. On fruiting trees these two effects of low temperatures were also demonstrated on summer-flush buds, but not on older (spring-flush) buds. The spring-flush buds from fruiting trees scarcely sprouted without being chilled. These buds required a longer chilling period for dormancy release than for flower induction, and it was not possible to separate the effect of low temperature on flower induction from the effect on dormancy release. The presence of fruit reduced flower formation by reducing bud sprouting. Furthermore, fruit had a direct inhibitive effect on vernalization which resulted in increased formation of vegetative shoots. The effect of fruit and low temperature on flowering was unrelated to carbohydrate accumulation in the leaves or the roots.     

Production and growth analysis of plants from leaf cuttings,and from tissue cultures of disks from mature leaves and young axenic leaves of African Violet (Saintpaulia ionantha Wendl.)

Details of common media and procedures are given for the regeneration of plants from disks of mature leaves and young axenic leaves of African Violet.Growth analysis of the progeny plant populations show differences in plant diameter, leaf number, leaf area and petiole length between tissue culture progenies and those derived from leaf cuttings. Both the tissue culture progeny poulations had similar character means. Intra-population variation was high for all three progeny populations. Leaf shape, number of flowering plants, number of peduncles and number of flowers and flower buds per plant did not vary among the three progeny populations, but intrapopulation variation was high in the latter characteristic.     

Propagation temperature,PPFD, auxin treatment,cutting size and cutting position affect root formation,axillary bud growth and shoot development in miniature rose (Rosa hybrida L.) plants and alter homogeneity

Summary

Rooting and growth responses of miniature rose cuttings were investigated in an experiment in which four propagation temperatures, two photosynthetic photon flux densities (PPFDs) with five auxin (IBA) concentrations, cutting sizes and cutting positions, were combined factorially in a response-surface design. Most prominently, temperature, cutting size and auxin and their interactions, influenced root and shoot growth. A propagation temperature of 24.6°C, and IBA concentrations between 10^–3 and 10^–1M, depending on temperature, were optimal for root formation. Root formation in extra short cuttings was delayed at low IBA concentrations. Regarding root formation, IBA could substitute for increased temperature as well as for increased cutting size. Onset of axillary bud growth was fastest at 24.6°C, and delayed in extra short cuttings. Application of IBA at 10^–4 to 10^–3M was optimal for axillary bud growth. By increasing the IBA concentration both time to flowering and plant height increased at 24.6°C. In cuttings from higher positions on stock plants, axillary shoots enhanced their growth to flowering, became shorter, and weighed less, suggesting occurrence of positional effects (topophysis). The growth rate increased with increasing IBA concentration, as well as from medial to low positioned cuttings. Increasing propagation PPFD from 46 to 72 µmol m^–2s^–1 did not affect the parameters. Time to axillary bud growth and time to first flower were related to time-to-visible root. Fast formation of roots apparently resulted in fast axillary bud growth. In time-to-visible root and axillary bud growth, the smallest variation between plants was found at optimal ranges for temperature, IBA concentration and cutting size, and further factors optimal for root formation and axillary bud growth provided the most synchronized plant development.     

Controlling the growth and development of rose plants after planting

The effects of pinching and lateral bud removal (deshooting) on the development of structural shoots, the number of flowers, and the average flower stem length in young rose plants were examined, using the cultivars ‘Baccara’, ‘Sonia’ and ‘Belinda’. The effect of deshooting on flower yield varied with each cultivar. It did not affect the number of ‘Baccara’ flowers, but increased ‘Sonia’ and ‘Belinda’ flower production by 50% and 75%, respectively. Leaving flowers to bloom out on plants before the start of commercial harvest resulted in a decrease in the length of the flower stems and also reduced the beneficial effect of deshooting on flower yield. Deshooting enhanced structural shoot formation (“bottom breaks”). Pinching flower buds of structural shoots increased the number of ‘Baccara’ flowers in comparison with pruning these shoots to 40–60 cm, as in common practice. Deshooting of the structural shoots of ‘Sonia’ and ‘Belinda’ increased the number of flowers in both cultivars.     

‘四季桂’不同季节的花芽分化与发育比较

利用显微解剖和石蜡切片技术,对四季桂品种群中‘四季桂’(Osmanthus fragrans‘Sijigui’)不同季节的花芽分化及开花特性进行研究。‘四季桂’一年成花3次,分别于3月初、6月上旬和10月底开始花芽分化,4月下旬、8月底和11月底完成,分别历时约2个月、2个半月和1个月。6月开始的花芽分化和开花过程与秋桂品种群基本相似,分化后需要低温才能开花,最终形成聚伞花序,无总梗,花粉发育正常。而10月底分化的花芽在完成分化后随即开花,形成的花序有总梗,且有伸长与未伸长之分,长度分别为(0.80±0.11)cm和(3.50±0.71)cm。3月分化的花芽与新梢同时生长发育,分化完成后随即开花。春季和冬季的两次分化形成的均是圆锥状花序,具总梗,花粉均败育。结果表明‘四季桂’自身存在着不同的成花机制。     

Effect of day and night temperatures during short photoperiods on growth and flowering of Chrysanthemum morifolium Ramat

The effect of day and night temperatures of 10, 14 and 18°C on growth and flowering under short days was studied with six cultivais of chrysanthemum. A high day temperature resulted in earlier flowering and taller stems, but did not influence flower number and final total fresh weight, and only slightly influenced the distribution of fresh matter over stem, leaves and flowers. A high night temperature resulted in earlier flowering, more flowers and reduced stem and leaf weight. It did not affect leaf number and it influenced height and total fresh weight only slightly. Except for height, the day temperature acted independently from the night temperature. The cultivars responded similarly, except for two cultivars which generally did not flower at 10/10,10/14 and 14/10°C D/N. One cul-tivar produced more flowers at 14 than at 18°C.     

Rapid vegetative propagation of conifers

Factors influencing the rooting-potential of stem cuttings of conifers were studied for the purpose of improving methods of rapid vegetative propagation. Within the bounds of hereditary limits, root regeneration depends, to a considerable extent, on the qualities of rooting-media, date of cutting excision, age and physiological conditions of the stock plant, age of the cutting-wood, its position on the plant, and chemical treatment. Hardwood cuttings, which have a relatively high content of endogenous auxin and carbohydrates, and morphological root initials, gave the best results. This method made it possible to increase the growth rate of cuttings 2.5–5 times that of cuttings taken from shoots of current growth.     

Effects of pre-blossom temperatures on flower development and fruit set in apricot

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.     

Fruit set is inversely related to flower and fruit weight in olive (Olea europaea L.)

Fruit weight is strongly correlated to ovary weight in olive as big-fruited cultivars have larger ovaries and flowers at bloom. We tested the hypothesis that larger ovaries imply stronger sinks and therefore reduce fruit set, expressed as number of fruits. Flower/fruit load per centimeter of shoot was assessed every month from flowering to harvest, on sample shoots of many different olive cultivars differing in fruit size. Data were taken for two years: 2007 and 2008. Additionally, in 2008, a fruit thinning experiment was carried out by leaving a single fruit per shoot, to assess the maximum potential fruit weight achievable by each cultivar. Results indicated that fruit size was mostly genetically determined as thinned fruits of small-fruited cultivars, although bigger than control fruits, never got as big as fruits from large-fruited cultivars, confirming that large ovaries are a prerequisite for large fruits. Among all cultivars, the number of flowers per inflorescence, the number of inflorescences, and the number of flowers per centimeter of shoot were not correlated to average flower weight while total flower mass per centimeter of shoot was positively correlated to average flower weight (i.e. large flowered/fruited cultivars had greater total flower mass). However, one month after bloom and thereafter, all parameters were negatively and exponentially correlated with fruit average weight across cultivars, except fruit mass per centimeter of shoot which was generally not correlated to fruit average weight, except in one year, at harvest, when fruit mass per centimeter of shoot was positively correlated to fruit average weight. These results suggest that fruit set is a consequence of, and inversely proportional to flower/fruit size in olive.     

Effect of photoperiod on flower bud initiation and development in myoga (Zingiber mioga Roscoe)

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.     

Rooting of chrysanthemum cuttings. Influence of irradiance during stock plant growth and of decapitation and disbudding of cuttings

Stock plants of Chrysanthemum morifolium Ramat. cultivar ‘Improved Mefo’ were grown in a controlled-environment room at different levels of irradiance (9, 23, 53 or 90 W m^?2). After 3 weeks, cuttings were excised and rooted for 3 weeks at an irradiance of 16 W m^?2. Cuttings from stock plants grown at the highest irradiance had the highest number of roots, while cuttings from the lowest irradiance had the lowest number of roots.The importance of the presence of shoot meristems for root formation was investigated through disbudding and decapitation at different times after the excision of the cuttings. Removing the buds on the day of excision had no effect on the number of roots formed, while the removal of the buds on day 2 to day 5 after excision had a promotive effect. Removal later than 7 days after excision had no effect at all.The results are discussed from the point of view that an interaction between nutritional and hormonal factors regulates the process of root formation.     

蜡梅不同品种和花期香气变化及其花茶适制性

采用顶空固相微萃取结合气相色谱质谱联机分析方法研究了蜡梅4个品种不同开花期的香气成分,并分析了其花茶适制性。结果表明：4个品种主要香气成分为别罗勒烯、罗勒烯、乙酸苄酯和水杨酸甲酯,相对含量之和占总量80%以上。从花蕾期到盛开期,香气成分变化不大,在开花过程中萜烯类化合物相对含量增加,而酯类化合物相对含量减少。随着蜡梅花内被片紫色条纹数量增加,香气中萜烯类和酯类化合物相对含量比值（T/E）减小,而在开花过程中,T/E值增加。花蕾期和盛开期香气相似率达0.990以上,表明开花过程中香气类型变化不大。花蕾期和萎蔫期的鲜花窨制的花茶香气弱,香气和滋味得分低于盛开期,红心品种窨制的花茶幽香不足,香气和滋味得分低于其他品种。在花茶生产上,以选择内被片紫色条纹较少的素心和乔种品种,且盛开的鲜花为宜。     

Gibberellic acid and flower bud development in loquat (Eriobotrya japonica Lindl.)

The application of gibberellic acid (GA₃) to the whole loquat tree from mid-May to early June and from early August to the onset of flowering, significantly reduced the number of premature flowering shoots per current shoot and per m³ of canopy, and so reduced the total number of panicles per m³ of canopy. The number of vegetative shoots per m³ of canopy was also significantly reduced by applying GA₃. The response depended on the concentration applied and produced optimal results at 50 mg l⁻¹. Differences in the number of flowers per panicle and leaves per shoot were not significantly modified by the treatment. Nevertheless, GA₃ applied directly to the developing apex near to flower differentiation reduced the number of flowers per panicle by 25–35% and without modifying the morphological characteristics of the panicle. Results suggest that less sprouting of lateral buds was largely responsible for the reduction in flowering intensity caused by GA₃. Best treatments reduced thinning costs (60%, approximately) of premature flowering shoots, slightly increased fruit diameter and significantly improved fruit colour and juice quality, thus advancing harvest date.     

Influence of cutting position and temperature during rooting on adventitious root formation and axillary bud break of Stephanotis floribunda

Stock plants were grown in a glasshouse under standard growing conditions. Single-node leafbud cuttings were excised and numbered according to the position on the stock plant. Rooting took place at basal temperatures of 17,20 or 23°C and at different durations at 17 or 20°C followed by 23°C. The rooting period lasted 9 weeks.

The temperature of 17°C for 9 weeks completely suppressed root formation. A temperature of 20°C was decisive for root formation. The optimal rooting temperature was higher than 23°C. Temperature treatments of 17 or 20°C for 2–4 weeks only suppressed rooting slightly compared with the 23°C treatment. Cutting position on the stock plant affected the number of roots formed per cutting but not the rooting percentage. Best rooting was observed in cuttings from the middle part of the stock plant.

Axillary bud break was accelerated with increasing rooting temperature and decreasing duration of the lower temperatures. With increasing cutting position number (numbered from top to base), axillary bud break was considerably delayed.

Temperature treatments which delayed root formation also delayed axillary bud break. On the other hand, the cutting position on the stock plant, which had only a minor effect on the speed of root formation, had a pronounced effect on the speed of axillary bud break.     

Effects of temperature and daylength on growth and flowering of roselle, Hibiscus sabdariffa L.

Hibiscus sabdariffa L. was found to show an ambiphotoperiodic reaction, flowering both in short days and in extremely long days, but remaining vegetative (at least at 21–25° C) in a 16 h day. Flowering had a dual effect on growth. When floral induction was strong, lateral buds developed into flowers and the number of branches was proportionally reduced. The first stage of floral induction, however, was accompanied by a decrease of apical dominance. Plants shifted to long days after only a short stay at an inductive daylength, and plants moved to short days after a prolonged stay in long days, formed many more branches and a much greater vegetative mass than plants grown in continuous short days or long days.Plants were already sensitive to daylength in the cotyledon stage. Floral induction was not carried over from short days into long days. After marginal induction, floral buds reverted to vegetative shoots, or aborted and were replaced by a shoot from the axil of a bract.In short days, seedlings form shallowly three-lobed leaves until the generative stage, when only entire leaves are formed. In long days, the leaves are deeply five-lobed, also when the plant flowers.     

Long-day control of flowering in everbearing strawberries

Summary

Photoperiod and temperature control of flowering in a number of perpetual-flowering or everbearing strawberry cultivars of widely varying pedigree has been studied in controlled environments. Flower bud initiation in the cultivars ‘Flamenco’, ‘Ridder’, ‘Rita’ and ‘Rondo’ was significantly advanced by long-day (LD) conditions at temperatures of 15°C and 21ºC; while, at 27ºC, flowering took place under LD conditions only. Some plants of the seed-propagated F₁-hybrid ‘Elan’, raised at 21°C, also flowered under short-day (SD) conditions at 27°C, but reverted to the vegetative state after a few weeks when maintained under these conditions. When vegetative plants growing in SD at 27°C were transferred to LD conditions at the same temperature, they consistently initiated flower buds and started flowering after about 4 weeks. At such a high temperature, flowering could thus be turned on and off by switching between SD and LD conditions. This applied to all the cultivars studied. Also the cultivar ‘Everest’, which was tested only at 21°C, produced similar results. Night interruption for 2 h was effective in bringing about the LD response. At 9°C, flowering was substantially delayed, especially in ‘Flamenco’ and, at this temperature, flowering was unaffected by photoperiod. Runner formation was generally promoted by high temperature and SD conditions, but the photoperiodic effect varied between experiments. We conclude that everbearing strawberry cultivars, in general, whether of the older European-type or the modern Californian-type originating from crosses with selections of Fragaria virginiana ssp. glauca, are qualitative (obligatory) LD plants at high temperature (27°C), and quantitative LD plants at intermediate temperatures. Only at temperatures below 10°C are these cultivars day-neutral.     

Technology for rapid production of flowering pot-plants of Leucadendron discolor E. Phillips,S. Hutch

Flowering male plants of Leucadendron discolor E. Phillips, S. Hutch were produced in 3–5 months by rooting large branched cuttings with initiated flowers. The data on which cuttings were taken critically affected further development of the capitulum. Taking cuttings after the end of November resulted in most of the apices developing into flower heads, whereas, cuttings taken earlier failed to develop.This technique allows rapid production of flowering pot-plants of L. discolor.     

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.