Induction of bulb maturity of Ornithogalum thyrsoides

The influence of bulb maturity at bulb harvest on growth and flowering response of Ornithogalum thyrsoides Jacq. ‘Chesapeake Starlight’ was investigated. Experiments were designed to determine if bulb maturity can be induced by bulb storage temperatures and whether bulb maturity can be evaluated by flowering responses. Bulbs with all senesced leaves at harvest were considered “mature” or with emerging young leaves and re-growing young roots were considered “immature”. Bulbs were potted after 0, 3, and 6 weeks of 30 °C or 2 weeks of 10 °C given either in the middle or at the end of 6 weeks of 30 °C. Mature bulbs, as compared to immature bulbs, took longer for leaves to emerge when control bulbs that did not receive any temperature treatment after harvest were planted upon harvest. Leaf emergence of the immature bulbs was significantly earlier than that of the mature bulbs. Mature bulbs which received 30 °C for 3 weeks (30 °C/3 week) flowered 31 days faster than immature bulbs and all bulbs flowered. Leaf emergence and flowering of mature and immature bulbs that received 30 °C/6 weeks or 2 weeks of 10 °C in the middle of 6 weeks of 30 °C (30 °C/2 weeks–10 °C/2 week–30 °C/3 weeks) did not differ from each other. Maturity can be induced by storing immature bulbs at 30 °C/6 weeks. Maturity, as evaluated by flowering percentage and days from leaf emergence to flowering, can be induced in O. thyrsoides. Immature bulbs can, therefore, be harvested for later forcing as long as bulbs are treated with 30 °C/6 weeks. It is proposed that maturity can be correlated with the speed of flowering and bulbs can be harvested at immature physiological state for forcing. Postharvest high-temperature treatment can be used to force immature bulbs that were harvested before the senescence of the leaves.     

Micropropagation of Cryptanthus with leaf explants with attached intercalary meristems excised from greenhouse stock plants

By using the leaves with attached intercalary meristems from greenhouse grown stock plants, five cultivars of Cryptanthus were cultured on modified MS media with 4.5 μM NAA and IBA and 3 μM BA to induce adventitious shoot formation from callus tissue. Contamination was 17–21% for explants taken from stock plants which were sprayed weekly with Agribrom and 27–75% for those taken from stock plants which were not treated. More than 99% true to type plantlets were obtained from non-chimeric plants. Green and albino plantlets were obtained from chimeric plants. The chimeric C. ‘Coster's Favorite’ DeCoster also produced a few chimeric plantlets with intermarginal pink stripes in addition to the green and albino plantlets. Most of the non-chimeric plants took a shorter time to produce plantlets of transplantable size (8–12 mm) than the chimeric ones. Except for albino plantlets, survival rate of plantlets exceeded 95%. A minimum average of 500 rooted plantlets can be obtained in a year from a single well-callused leaf explant. The protocol in this report should speed up the mass production and introduction of desirable new cultivars and hybrids of non-chimeric Cryptanthus.     

Effects of N–P–K deficiency and temperature regime on the growth and development of Lilium longiflorum ‘Nellie White’ during bulb production under phytotron conditions

One-year-old scale bulblets of Lilium longiflorum Thunb. ‘Nellie White’ (Easter lily) were grown under a combination of six constant day/night temperature regimes and five N–P–K nutrient treatments under short days for 107 d (growing period 1 or GP-1) to compare the effects on growth and development and bulb production. Results during GP-1 were as follows: failure of bulblets to produce a shoot (“no-shows”) was found at high temperatures (30/26 and 26/22 °C) and not influenced by the nutrient treatments. Flower bud abortion was observed in the minus-N, minus-P, and minus-N–P–K treatments at high temperatures (30/26 or 26/22 °C), but not observed at any temperatures in the complete and minus-K treatments. The loss of bulb fresh weight in minus-N treated bulblets was less than in the other treatments resulting in less root and shoot growth in the minus-N treatment. At the intermediate temperatures where growth was highest, omission of N, P, K, or all three resulted in losses in stem bulb fresh weight, stem plus leaf fresh weight, number of flowers, and stem root fresh weight. Omission of N, P, or all three nutrients resulted in lowest basal root fresh weight. Bulb N and K concentrations were lowest in plants grown with complete nutrient solution at the two coldest temperature regimes (14/10 and 10/6 °C). Bulb P concentration was lowest at the three coldest (18/14, 14/10 and 10/6 °C) and the warmest (30/26 °C) temperature regimes. Stem length was shorter when P was omitted. Omission of any of the three nutrients resulted in lower concentrations of the other nutrients. The one exception was where low K did not affect N concentration. In the second phase of the experiment, plants grown at 18/14 °C and irrigated with the complete nutrient solution for 107 d (GP-1) were continued at this day/night temperature regime and five N–P–K nutrient treatments for another 89 d under long days (growing period 2 or GP-2). Results during GP-2 were as follows. Basal bulb yield was not impacted by omission of N, P, or K, or all three. Of all growth measurements, only stem plus leaf fresh weight was lower and only when all three nutrients (minus-N–P–K) were omitted. At the end of GP-2, basal bulb concentrations of N and P did not differ from the concentrations in bulbs at the beginning of GP-1; however, K concentration was lower at the end of GP-2. Omission of N or P further resulted in lower bulb K concentration, suggesting that a moderate supply of N, P, and K be applied during GP-2 since an additional year of bulb production is needed to produce forcing-sized bulbs.     

Physico-chemical and antioxidant properties of cornelian cherry fruits (Cornus mas L.) grown in Turkey

Cornus mas L. is a naturally growing dogwood species in Anatolia. In present study, physical, chemical and antioxidant properties of cornelian cherry fruits were studied. The fruit weight was in the range of 0.39–1.03 g, fruit length 14.24–22.20 mm, fruit width 9.59–13.21 mm, flesh/seed ratio 1.34 to 6.72. Hunter L values of the samples ranged between 10.82 and 19.69, and a value was between +6.25 and +15.59, and b value was between +3.46 and +6.64. In addition to the levels of dry matter, soluble solids, pH, total acidity, total sugar content, reduced sugar content, unreduced sugar content, ascorbic acid, total anthocyanin and total phenolics were within the range of 15.88–28.19%, 12.50–21.00%, 3.11–3.53, 1.10–2.53%, 76.80–154.00 g kg⁻¹, 52.80–120.00 g kg⁻¹, 0.00–32.30 g kg⁻¹, 0.16–0.88 mg g⁻¹, 1.12–2.92 mg g⁻¹ and 2.81–5.79 mg g⁻¹, respectively. On the other hand, ferric reducing antioxidant power (FRAP) and EC₅₀ values were between 16.21 mmol g⁻¹ and 94.43 mmol g⁻¹, 0.29–0.69 mg mL⁻¹. Anthocyanin extracts of the fruits were analysed by high-performance liquid chromatography (HPLC) with UV–vis detection. Pelargonidin 3-glucoside was the main pigment found in cornelian cherry fruits.     

Increases in ethylene and carbon dioxide production by Tulipa gesneriana L. ‘Prominence’ after completion of the cold-requirement

Bulbs of Tulipa gesneriana L. ‘Prominence’ were either specially pre-cooled at 5 ± 0.5°C or held at 17 ± 0.5°C in a flow-through system equipped for atmospheric sampling. Bulbs at 17°C had low CO₂ and C₂H₄ production rates until January when they began to increase. An initial peak of C₂H₄ production occurred during the 2nd week of pre-cooling, followed by a major increase after 12 weeks. In addition, bulbs were specially pre-cooled for periods of 2–16 weeks (2-week increments). The bulbs were then transferred to 17 ± 0.5°C, where initial periods of special pre-cooling of greater than 12 weeks resulted in a dramatic increase in respiration rate over bulbs cooled for less than 12 weeks. These increases in C₂H₄ and CO₂ liberation appeared to be related to completion of the bulb cold-requirement. However, no surge of shoot elongation occurred after 12 weeks of pre-cooling and transfer to 17°C.     

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.     

Accelerated storage losses in onion subjected to water deficit during bulb filling

Withholding irrigation during last stages of onion crops is a common practice to minimize losses in storage due to rots. However, it is unclear whether extended periods of water deprivation may affect bulb postharvest behaviour. In this study we analyze the effects of water deficit during the crop cycle on bulb weight loss and sprouting during storage. Two experiments were conducted: one in a glasshouse with two onion cultivars subjected to three treatments of water availability (100%, 80% and 60% of field capacity); the other in the field, with one of these cultivars, subjected to two water availability treatments (dryland and irrigated twice during bulb filling). In both experiments five destructive samplings were done along crop development to assess plant height, number of green leaves, bulb and neck diameter, and whole-plant dry weight. Bulbs were harvested when 50% or more of the tops fell over. Harvested bulbs were classified by weight and then kept in a ventilated chamber at a mean temperature of 15 °C and weighted every two weeks, up to six months. Water deficit led to a significant reduction of bulb size, an acceleration of sprouting and an increased rate of weight loss during storage in both cultivars and under both experimental conditions. Hence, restricted irrigation during extended periods may have negative effects on the conservation of stored onion bulbs which suggests the need to finely adjust water management in this crop.     

Adaptation of endemic mediterranean Sternbergia candida Mathew Et T. Baytop in the continental climate of central anatolia

Sternbergia candida is an important endemic bulbous plant with beautiful white flowers. It grows on the rock slopes of Baba mountains under Lebanon Cedars in the Mugla province of Turkey with Mediterranean climate. The plant is vulnerable and endangered due to illegal collection for local and foreign flower industry. Fast developing tourism industry and rapid urbanization has also shown negative implications on its population. The study reports three years successful adaptation results of S. candida in the continental climate of Ankara in the Central Anatolia. Four groups of bulbs based on diameter (>2.45, 2.15–2.44, 1.85–2.14 and <1.84 cm) were collected from its natural habitat during March, April and May 1998 and were evaluated for frequency (%) of emergence, mean number of leaves per plant, mean plant height, frequency (%) of flowering, frequency (%) of fruit setting. mean number of bulbs per plant, and mean diameter (cm) of regenerated bulbs. All categories of bulbs could be multiplied and adapted successfully with variable frequency of fruit setting. However, the highest fruit set was recorded from 2.15–2.44 cm April collected bulbs. This indicated that the bulb diameter and collection time had clear implications on multiplication, propagation and adaptation of the plant.     

Storage conditions and ripening of chiku fruits Achras sapota L.

Chiku fruits (Achras sapota L.) were found to be climacteric with the respiratory peak occurring at the same time, or 1–2 days after peak ethylene production. The optimum storage temperature was near 20° C. Storage life at this temperature could be increased by removing ethylene (C₂H₄) and adding 5–10% (v/v) carbon dioxide (CO₂) to the storage atmosphere. Extreme relative humidities or high concentrations of CO₂ impaired the quality of stored fruits. Ripening was not affected by treatment with oxygen, C₂H₄ or indoleacetic acid. Ascorbic acid and glucose levels increased with ripening but ascorbic acid decreased when the fruit became over ripe. Recommended storage conditions are about 20° C with 5–10% CO₂ coupled with the complete removal of C₂H₄ from the storage atmosphere. Short-term holding of the fruit at lower temperatures is also possible.     

洋葱新品种‘艾利姆1号’

 ‘艾利姆1号’洋葱是以细胞质雄性不育系‘HG409A’为母本,自交系‘T608C’为父本配组育成的杂交一代新品种。长日照、中晚熟类型,生育期120 ~ 125 d。鳞茎圆球形,外皮黄色有光泽,辣味适中,口感甜脆,可溶性固形物含量高,紧实度好,耐贮运。单鳞茎质量240 ~ 260 g,产量达77 300 kg · hm^-2。抗紫斑病、霜霉病、灰霉病等,适合黑龙江省春季栽培。     

In vitro propagation of Symphytum species

Methods are described for the in vitro propagation of Symphytum × uplandicum Nyman from bud, root and stem explants. Highest shoot numbers were produced from root explants > 4 mm in diameter, cultured vertically with their distal cut surface on the medium. The most suitable medium for shoot production was Murashige and Skoog's (MS) with 0.3 mg l⁻¹ 6-benzylaminopurine (BAP). These shoots developed roots on MS medium without hormones and were successfully transplanted into pots. Subculturing shoots onto MS medium containing BAP, kinetin (K), 6-λ,λ-(dimethylallylamino)-purine or gibberellic acid (GA₃) at 0.5, 1.0, 5.0, 10.0 or 30.0 mg l⁻¹ failed to stimulate outgrowth of axillary buds in culture. In vitro propagation from root explants was also achieved with S. asperum Lepech., S. officinale L. and S. × uplandicum cultivars ‘Bocking 1’, ‘Bocking 2’, ‘Bocking 4’ and ‘Bocking 17’, but not with S. bohemicum, S. grandiflorum DC, S. tuberosum L. or S. × uplandicum ‘Bocking 7’ and ‘Variegatum’.     

Onion growth and yield are influenced by transplant tray cell size and age

Transplant tray cell size (volume) and age of containerized onion (Allium cepa L. cv. ‘Texas Grano 1015Y') transplants were evaluated for effects on survival, root and shoot growth, yield, and size. Transplant ages of 5, 7, 9, and 11 weeks and cell volume of 6.5 and 20.0 cm³ were used in Florida, and 6, 8, 10 and 12 wk, and 4.0 and 7.1 cm³ were used in Texas. Total yield in Florida was unaffected by transplant age in two planting seasons, but larger size bulb yield increased with increasing transplant age from 5 to 9 wk in 6.5 cm³ cells, and for 11-wk compared to ≤9-wk transplants in 20.0 cm³ in one season. Seed stem initiation was greatest in bulbs from 11-wk transplants in 20 cm³ cells. Survival in Texas was reduced for 6-wk compared to ≥8-wk containerized transplants. At planting, root number increased linearly with transplant age. Transplant cell volume in Texas did not affect root number, plant height or leaf number, but shoot dry weight was greater for seedlings grown in 7.1 cm³ cells compared to 4.0 cm³ cells. Total, jumbo and large size transplant yields in Texas were higher for 10 and 12-week transplants in 7.1 cm³ cells and 8, 10 and 12-week in 4.0 cm³ cells than yields in younger transplants. Total yields were unaffected by transplant cell volume but seedlings in 4.0 cm³ cells had a 16% decrease of jumbo size compared to those grown in 7.1 cm³ cells. Larger cell sizes are appropriate for 10–12-week transplants. The use of 8–10-week containerized transplants grown in small cell volume may be viable for onion stand establishment. Younger transplants may produce more large bulb yields if grown in larger cells, but they also have greater risk of reduced survival.     

东方百合盆栽新品种‘喜来临’

 ‘喜来临’是以‘元帅’（Acpulco）为母本,‘迈阿密’（Miami）为父本杂交选育出的盆栽东方百合新品种。植株矮小,平均株高52 cm。花朵数量较多,围径12 ~ 14 cm的种球种植后花朵数量3 ~ 4朵,围径16 ~ 18 cm的种球种植后花朵数量5 ~ 8朵。花粉色,花苞大,品质好,花期长。茎杆粗壮,无叶烧,抗性强,易繁殖,种球繁育周期短。     

High-Temperature Treatment (Blindstoken) of Bulbs of Tulip cv Rose Copland for Flower Killing and Yield Improvement

A three-year experiment on the high-temperature treatment of tulip bulbs established that yield could be increased by between 8 and 31 % for bulb weight or between 14 and 29 % for numbers of large bulbs, depending upon season, associated with a near-complete flower kill. The optimum pre-treatment storage temperature was 17°C, and the best date (of the five tested) for starting blindstoken at 33°C for one week was 20th-21st September.

Yield increases were greater when the blindstoken treatment was applied to bulbs whose shoots were short; later treatment, or treatment after pre-treatments which allowed faster shoot growth, were less effective. For optimum flower kill and yield increase the shoot should be about 1 cm high at treatment. Bulb weight and large bulb number were correlated, suggesting that the treatment increases total bulb weight by increasing bulb size rather than by differentially affecting the growth of daughter bulbs.

No adverse effects of the treatments were observed when the bulbs were forced in a glasshouse the following season.     

慈姑球茎形成与膨大进程的初步研究

对慈姑球茎的形成与膨大进程进行了初步研究。研究结果表明,在武汉地区的气候条件下,慈姑的根状茎从7月上旬开始陆续形成,其后数目不断增加,大约到10月上旬根状茎的数目基本不再变化,根状茎的生长主要是以伸长生长为主,其横径基本不发生变化。9月上旬球茎开始形成,9月中下旬球茎数目迅速增加,到10月中下旬基本无新的球茎形成。单个球茎从形成到成熟大约80d。在球茎形成的30～60d膨大最为迅速。其单个球茎质量的增加遵循＂慢-快-慢＂的变化规律。球茎的淀粉、可溶性总糖含量在40d以前呈缓慢上升,之后快速增加;还原糖呈＂上升-降低-上升＂的变化趋势。     

Morphological and cytological characteristics of protoplast-derived plants of statice (Limonium perezii Hubbard)

Morphological characteristics of 56 protoplast-derived plants (protoclones) of statice (Limonium perezii Hubbard) were compared with meristem-derived plants (controls). Some protoclones had smaller leaf shape index (length/width) and shorter length of flower stalk and calyx than the controls. However, no distinct somaclonal variations were observed in other characteristics such as color of calyx and number of petals and stamens, except for protoclone No. 1–7, which had flowers with abnormal petals and low pollen fertility (25%). Microscopic observation showed that all of the 17 protoclones examined, including clone No. 1–7, had the normal diploid chromosome number of 14.     

Cold treatment modifies the photoperiodic flowering response of Lobelia×speciosa

Lobelia×speciosa Sweet ‘Compliment Scarlet' was grown under a range of photoperiods and low temperature treatments to determine their effects on flowering. In the first experiment, plants were held at 5°C for 0 or 15 weeks, then grown at 20°C under the following photoperiods: 10, 12, 14, 16, or 24 h of continual light or 9 h with a 4 h night interruption (NI). Non-cooled ‘Compliment Scarlet' flowered as a qualitative long-day plant (LDP) with a minimum flowering photoperiod of 14 h. Following cold, flowering was quantitative with respect to photoperiod, until ≈14.2 h, when the calculated rate of progress toward flowering reached a plateau. In cooled plants, node number below the inflorescence decreased from 27 to 16 as the photoperiod increased from 10 to 24 h. Cooled plants developed 61–149% more flowers and were ≥17% taller than non-cooled ones under the same photoperiod. To determine the cold duration required for flowering under short days (SD), plants were held at 0, 3, 6, 9, 12, or 15 weeks at 5°C then grown at 20°C under SD (9 h photoperiod) or long days (9 h photoperiod with a 4 h NI). Under SD, few plants flowered after ≤6 weeks of cold. As cold treatment increased from 9 to 15 weeks, flowering percentage increased, time to flower decreased from 93 to 64 days, and node count decreased from 24 to 13. Cold treatment did not affect flowering percentage or time under NI, but plants always had more flowers and were taller than reproductive ones under 9 h day lengths. Thus, ‘Compliment Scarlet', is a qualitative LDP, but an extended cold treatment can partially substitute for the long day (LD) photoperiodic requirement.     

景观应用百合新品种‘云景红’

‘云景红’是以‘Romano’为母本,‘Claire’为父本杂交选育出的亚洲百合新品种。花色为红色,柱头为紫红色,花苞大,花数量多,花期长。周径14 ~ 16 cm 的种球种植后花朵数量3 ~ 7朵。植株矮小,平均株高43 ~ 52 cm,茎杆粗壮。种球繁育周期短,退化慢。耐干旱,耐湿热,抗病性强。     

Effects of exposure of bulbs to smoke and ethylene on flowering of Narcissus tazetta cultivar ‘Grand Soleil d'Or’

Bulbs of ‘Soleil d'Or’, exposed to smoke generated from smouldering wood and fresh leaves for several hours on each of 4 consecutive days during storage, produced flowers earlier and at a higher rate, even when using bulbs which were too small to flower using normal methods. The smoked bulbs showed an earlier start of floral initiation and faster development. A temperature of 25°C was optimal for storage. Application of ethylene also gave similar promotive effects when repeated 4 times at 10 μl 1^?1 for 1–5 h per day. Longer exposure to ethylene or smoke was less effective or had no promotive effect.