贮藏条件对彩色马蹄莲种球生长和开花的影响

球茎萌芽率与贮藏温度正相关,且品种间差异明显,在6℃和12℃贮藏8周后,"黑眼睛"萌芽率分别为45.9%和49.2%,"佳人"萌芽率分别为27.9%和50.0%.开花数随贮藏时间延长而减少,"黑眼睛"种球12℃贮藏8周,12周,16周开花数最多,"佳人"种球12℃贮藏16周开花数最多.     

郁金香在赣南地区栽培及不同基质对其生长发育的影响

为探索不同基质对赣南地区郁金香生长发育的影响,以晚花郁金香品种"领英"为材料,通过人工冷藏处理球和自然球的栽培,调查其在赣南地区的生长状况。栽培于不同基质中,通过观测植株的生长状况,分析比较不同基质对郁金香生长和开花的影响。结果表明:在赣南地区,郁金香自然球的栽种不能满足其开花所需的冷量,最终盲花,而经过人工冷藏的郁金香满足其开花所需冷量,可以正常开花。在不同的栽培基质中,郁金香以泥炭︰园土=1︰1的盆栽效果最佳。     

辽宁地区郁金香多年留地栽培退化研究

以“白梦”“塞克”“逃离”等15个郁金香品种为试材,以留地栽培1年植株为对照,通过对留地栽培5年植株生物学性状和种球繁育的调查,研究了多年留地栽培后不同郁金香品种的退化情况,以期为辽宁地区郁金香品种引进和种球扩繁提供参考依据.结果 表明:经过5年留地栽培,“牛津精华”未出现退化现象,开花植株数量增加了100％,株高、叶宽等5个性状指标与对照差异不显著,收获的种球总数为144个,周径≥11 cm的种球数量达到30个;“白梦”“塞克”“逃离”“国王的礼物”“比赛”5个品种退化程度较轻,开花植株数量减少了10％～20％,至少4个性状指标与对照差异不显著;“普瑞斯玛”“金阿波罗”“撒哈拉赛车”3个品种退化较重,开花植株数量分别减少90％、80％和70％,但“金阿波罗”获得的种球总数最多,达到153个;“小黑人”“阿波罗”“斯纳达之爱”“朱迪思”“构思的印记”“里约嘉年华”6个品种退化严重,其中,“小黑人”和“阿波罗”2个品种种球全部消失,其它4个品种植株矮小,无开花植株.     

郁金香引种栽培研究

调查比较了荷兰4个郁金香品种在目光温室栽培条件下的植物学特性、物候期和生长发育规律.结果表明:品种Large Copper的种球高度和花径均最小,茎上白色柔毛最长;品种Toronto的显著特征是种球的膜质鳞片为桔红色,无光泽,叶片上有红褐色条纹,花被片基部为黑色舌形;品种Pink Impression植株高,花大,叶片长而宽,叶缘有短毛.沈阳地区郁金香在日光温室12月中旬萌芽,2月下旬至3月上旬现蕾,3月上、中旬为盛花期,花期为1周左右.但品种Large Copper在1月中旬才萌芽,花期达2周.品种Apricot Beauty在盛花期生长最快,Large Copper从现蕾到末花迅速生长,Toronto的旺盛生长期为展叶至始花期,Pink Impression萌芽后期到展叶生长最快.     

郁金香促成水培技术研究

郁金香促成水培,根系生长是关键,前期一定时间的低温和黑暗条件可以极大地诱导水生根的发生,培育壮苗,提高开花率;阴雨天气通过人工补光,可以减少促成水培郁金香盲花率;合理的水培营养添加能够提高非壮实种球的开花率。     

光照强度对郁金香生长和开花的影响

通过对郁金香进行遮荫处理,研究不同光照条件对郁金香生长和开花的影响。结果表明:光照强度影响了郁金香的生长和开花。遮荫条件下,郁金香叶片叶绿素含量大大降低,植株变高,叶片变窄、变长,遮荫使郁金香花期延迟,花冠变小,花葶变高,适度遮荫能提高郁金香开花率,但重度遮荫下其开花率显著降低,花质量下降。综合分析认为,55%~60%的光照强度比较适合郁金香生长。     

不同栽培方式对二代郁金香生长和开花的影响

以郁金香品种‘金色牛津’为试材,分别栽种于种植箱、花盆和露地苗床上,在出芽期、开花期和采收期分别观测其出芽率、开花率、株高、叶片数、叶宽、叶长、花葶高、花纵径、花横径、子球个数和子球直径。结果表明:不同的栽培方式影响了二代郁金香的生长和开花,采用箱栽方式的二代郁金香生长情况和开花性状要明显好于采用盆栽栽培方式;而采用地栽方式的子球生长状况要明显好于盆栽方式和箱栽方式。栽培方式中箱栽的总体性状最好,盆栽的总体性状最差,地栽的介于二者之间。研究表明二代郁金香种球在浙江丽水地区可采用箱式栽培,且在园林美化方面有一定的利用价值。     

低温处理对黄心菜种子春化的影响

以3个在生产上表现优良的黄心菜品种为试材,将萌动种子置于4℃低温处理6、12、18、24 d,研究了种子春化处理对黄心菜植株抽薹开花的影响,以期为黄心菜种子繁育、单倍体育种等提供参考依据。结果表明：低温春化处理后,3个黄心菜品种的抽薹、现蕾、初花期、盛花期均显著提前,处理时间超过18 d以后,尽管植株抽薹开花更早,但植株及花薹表现更瘦弱;处理时间与各个表型性状均显著相关,处理时间与叶片数、叶片宽、叶柄长、株幅呈极显著负相关,与叶片长、叶柄宽、薹粗呈显著负相关,与株高、薹长呈极显著正相关。综合分析表明,处理6、12 d抽薹开花时间较晚,而处理24 d虽开花较早,但植株及花薹表现瘦弱,不利于花粉或种子培育,处理18 d植株抽薹开花时间显著提前且综合性状较好。     

60Co-γ射线辐照百合鳞茎诱变育种研究

以切花"西伯利亚"种球为试材,采用60Co-γ射线辐照处理进行辐射诱变育种试验,研究了不同的诱变剂量对百合种球成活及植株生长发育的影响。结果表明:用60Co-γ射线辐射剂量为5Gy诱变"西伯利亚"种球比较合适。经4、5、6Gy 60Co-γ处理对百合植株的生长和发育出现较明显的辐射损伤,随着辐照剂量的增加,植株成活率、株高、叶片数、花蕾数、开花株率、花径相应减少,而出苗时间则增加,成活率分别为80%、52%、20%。     

冷藏对郁金香生物学性状及F1种子萌发的影响

以‘AAFKE’‘Eskimo Chief’等5个郁金香品种为试材,研究了冷藏对其生物学性状及F_1种子萌发的影响。结果表明:增加冷藏时间可以有效推迟郁金香花期,冷藏时间每增加2周,盛花期就会相应的推迟10d,生育周期也缩短。但冷藏时间对植株的生物学性状、杂交结实率、F_1代种子萌发率影响不大。杂交结实率与品种倍性有关,郁金香二倍体与二倍体的杂交结实率高于二倍体与三倍体的杂交结实率。     

Changes in endogenous abscisic acid and soluble sugars levels during dormancy-release in bulbs of Lilium rubellum

Changes in endogenous abscisic acid and soluble sugars levels during dormancy-release of lily bulbs of Lilium rubellum were investigated. Shoot emergence and flowering of the bulbs stored for 14 weeks at 4 °C occurred more synchronously, and the time span from first to last flower in the plants was shorter than those of bulbs stored for 10 weeks at 4 °C. Longer duration of bulb storage showed accelerating effects of increasing leaf number and stem length but negatively affected flower size. Flower number per plant was not much influenced by bulb storage duration. Concentration of endogenous abscisic acid (ABA) level in the bulbs during bulb storage decreased as storage duration increased, and it remained at a constant level after being stored for 10 weeks. This result suggests that the decrease in the endogenous ABA level during bulb storage is correlated with dormancy-release. Concentrations of soluble sugars also changed during bulb cold storage. Sucrose concentration increased as the chilling term increased to 10 weeks but decreased afterward. Glucose and fructose increased from the beginning of chilling to the end of a 14-week cold storage.     

Flowering and changes in respiration in Asiatic hybrid lilies as influenced by bulb vernalization

Asiatic hybrid lilies, Lilium × elegans Thunb., ‘Red Carpet’ and ‘Sunray’ were used to investigate the effect of bulb vernalization at 2.5 °C on plant growth, flowering, and CO₂ production (respiration), and to use the CO₂ production pattern to monitor the time of flower bud initiation and development. Lily shoot emergence and flowering were accelerated when bulbs received 2.5 °C bulb vernalization; however, flowering was delayed when bulbs were stored at 20 °C before treatment at 2.5 °C; this indicated that bulbs were de-vernalized. The maximum CO₂ level, and the minimum level, reached in 78 h in non-vernalized bulbs and in 110 h in 6 weeks of 2.5 °C (6 weeks/2.5 °C) treated bulbs, was increased as the 2.5 °C duration was increased; this indicated that CO₂ level can be an useful parameter to measure the cold stimulus (i) accumulated in bulbs following bulb vernalization. The respiration rate higher than the predicted values of the best-fit curves derived from the quadratic equations was designated as Blip A and this was correlated to the time of flower bud initiation and development. Shoot elongation may follow the rise in carbon dioxide levels after reaching the minimum level. It is proposed that increased carbon dioxide levels higher than the predicted levels (Blip A), was correlated to the time of flower bud initiation and development. Measurement of carbon dioxide production upon receipt of bulbs may be a useful technique to provide important information for optimum vernalization treatments for bulbs that have accumulated different levels of low temperature stimulus after bulb vernalization.     

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.     

An analysis of the growth of forced tulips. 1. Changes in plant fresh and dry weights during growth at two temperatures

Changes in the fresh and dry weights of the component parts of plants of tulip cv. ‘Apeldoorn’ were followed in bulbs kept at low and high temperatures (9 and 18°C respectively) from the time of completion of flower differentiation until anthesis.There were marked differences between shoot dry weights at the two temperatures. At 9°C the stem, leaves and flower grew exponentially throughout the whole period, but at 18°C the specific growth rate of the stem and leaves declined throughout the period of the experiment. At 9°C the proportion of total dry weight in shoots and daughter bulbs was higher than at 18°C, and the proportion in the mother bulb was correspondingly smaller.At both temperatures the $\text{fresh weight}\text{dry weight}$ ratios of the mother bulb, shoot and daughter bulbs declined during dry storage, the decline being greater at 9°C. After planting, the ratio for all plant parts increased at 9°C, but scarcely changed at 18°C.These results are discussed in relation to dormancy, to the low-temperature requirement for successful and rapid flowering and to flower quality.     

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.     

Effect of precooling at 5 or −1°C on shoot growth,flowering and carbohydrate metabolism in tulip bulbs

Precooling of dry tulip bulbs at ?1°C may be advantageous, compared with precooling at 5°C. Increasing the duration of precooling enhanced the growth of the shoots after planting, improved flower quality, and reduced the number of days to flower. The positive benefit of a stepwise precooling (5°C for 3 weeks, then ?1°C) was evident.Shoot elongation was promoted, and number of days to flower was reduced when the bulbs were precooled at ?1°C for less than 12 weeks. Extension of precooling beyond 12 weeks, however, was more effective with 5°C precooling. With few exceptions, sufficient precooling at either 5 or ?1°C gave a high percentage of flowering plants with first-quality flowers. Short durations (6–8 weeks) of precooling sometimes promoted flower blasting.Precooling at 5 or ?1°C had a similar effect upon the carbohydrate interconversion in scales and shoots of the bulbs, which as a rule is more pronounced at the lower temperature. The shoots accumulated sucrose, and to some extent fructosyl sucroses, during the 15 weeks precooling. Starch was also accumulated, the highest concentration being obtained at 5°C. The amount of starch was reduced in the scales during precooling, while the concentration of sucrose and fructosyl sucroses increased to a maximum value and then slowly diminished after about 9 weeks of precooling. The monosaccharides, glucose and fructose showed very small variations.     

The effect of 4 storage treatments on seed yield components of 3 onion inbreds

Onion bulbs of 3 inbred lines were stored during the winter in 4 different storage temperature regimes. Traits directly and indirectly associated with seed production were studied the following summers. The inbred lines differed in their responses and many traits were affected by the storage treatments. The storage treatment of 10°C for 12 weeks followed by 2° C for 12 weeks resulted in a significantly higher seed yield than did storage at 2° C throughout the entire period. Inbred 2399 had a higher seed yield than the other inbreds. Associated with high seed yields of 2399 was early flowering, a high number of leaves/bulb, tall seed stalks and a high number of florets/bulb.     

Factors affecting the response of tulips to gibberellin

Gibberellic acid (GA₃) treatment of forced tulip crops has potential for producing faster growth to anthesis in the glasshouse, for reducing losses due to floral bud blasting, and for reducing the duration of cold storage needed to obtain satisfactory flowers. Using partly and fully cooled direct-forced tulips, cultivar ‘Apeldoorn’, several factors (relevant to the definition of GA₃ treatments) were studied. Experiments confirmed the previously recorded effects of gibberellins in tulips: GA₃ injections reduced the duration of the glasshouse period, enhanced flower survival and flower length, and reduced stem length at flowering.Following bulb storage at temperatures from ?2 to 20°C, GA₃ reduced the glasshouse period by 15–25% and increased flower length, compared to controls, irrespective of storage temperature. Stem length was also reduced by GA₃, this effect being greater following a storage temperature of 5°C or lower. When GA₃ was applied during the period of 17°C-storage which precedes cool storage, or during or after storage at 5°C, it was found that treatments during or at the end of cool storage were more effective in producing the characteristic effects of GA₃ than were pre-cooling applications. In partly cooled bulbs (but not fully cooled ones), the GA₃-induced earliness of flowering was about doubled when GA₃ injections were given repeatedly at 2-week intervals throughout storage. The responses to GA₃ injections were found to be unmodified by early-lifting and heat-treatment (for earlier forcing), by delaying the start of 5°C storage (for later forcing), by glasshouse temperature (16 and 18°C), and by shading treatments; there was little effect of bulb size.     

The Application of Rapid Chemical Tests to The Diagnosis of Mineral Deficiencies in Horticultural Crops: IV. A Comparison Between The Total Nutrients and Those Extracted By Buffer Solutions From Potato Leaves

Two varieties of tulip, Golden Harvest obtained from Cornwall and Lincolnshire and Krelage’s Triumph from Cornwall, were grown in sand culture with deficiency, normal and high levels of major nutrients in various combinations.

Symptoms produced by deficiencies of nitrogen, phosphorus, potassium and magnesium mainly resembled those recorded previously with the variety Rose Copland.

Leaf measurements and bulb yields showed nitrogen deficiency to have the most significant effect on growth, and symptoms were evident several weeks before flowering.

Leaf areas and bulb yields were apparently closely related for Nil, nitrogen and phosphorus deficiency treatments but were less clearly related for other treatments, especially in Krelage’s Triumph.

Cornish stock of Golden Harvest tulip was more sensitive than Lincolnshire stock to deficiencies, especially of phosphorus. Krelage’s Triumph was also less sensitive on the whole, and especially in terms of leaf area, than Golden Harvest from the same source, even though the fanner had the smaller-sized bulbs.

High levels of sodium produced succulent growth and soft bulbs. There were no marked effects of high levels of nitrogen, phosphorus, or potassium on yields, although leaf area of Cornish bulbs particularly was decreased by some of these treatments, possibly in relation to high nitrogen level.