High CO2 effects on postharvest biochemical and textural properties of white asparagus (Asparagus officinalis L.) spears

The effects of high CO₂ concentration (10% CO₂, 17% O₂) on the changes of functional cell wall components (pectic substances, hemicellulose, cellulose, lignin), mechanical properties, content of free soluble sugars (sucrose, glucose, fructose), and respiration activity were studied in harvested white asparagus spears stored at 10 and 20 °C, respectively, for up to 7 d. Spears stored at 2, 10 and 20 °C in air were studied as controls, where the 2 °C condition indicated the effects of cold storage. During storage, respiration activity declined only slightly, irrespective of the CO₂ and temperature regime. Spears stored at 20 °C under both CA and normal air became less stiff and more elastic, however, tissue toughness increased significantly. Changes in toughness were associated primarily with the dynamics of lignin and cellulose, revealing a strong correlation (r² = 0.81). High CO₂ concentration inhibited the synthesis of cellulose and, to some extent, lignin accumulation at 20 °C. Additionally, elevated CO₂ inhibited the degradation of soluble carbohydrates. In contrast, slightly lower temperatures of 10 °C in combination with high CO₂ did not have a pronounced effect on changes in structural carbohydrates (lignin, cellulose, hemicellulose and pectins). The effect low temperature (2 °C) under normal atmosphere conditions resulted in the inhibition of cell wall changes in asparagus spears.     

Sex characteristics and inheritance of sex in asparagus (Asparagus officinalis L.)

Summary The results of this study show that male plants have considerable advantages as compared with females. Unfortunately, the number of male plants in a field can only be increased genetically, which enables us to obtain an absolutely male crop. A hypothesis for the inheritance of andromonoecy is presented. Besides the effect is studied of external and internal conditions on the degree of andromonoecy.     

Breeding of Polyploid Asparagus (Asparagus officinalis L.)

Asparagus is especially suitable for polyploidy breeding. The aim is to develop clone-based hybrid varieties, in particular male 4 × varieties. For this purpose, genetically divergent diploid idiotypes * * Idiotye (according to Reiger et al. 1976) is the sum of total hereditary determinants of an organism, consisting of its genotype (all determinants localized in the chromosomes) and its plasmotype (all determinants localized extra-chromosomally).
) are subjected to mitotic or meiotic polyploidization. In developing hybrid partners, special attention is paid to resistance in addition to yield and quality characters. Early diagnoses are applied in selection so as to shorten breeding times. Somaclonal variations may occur relatively often on in vitro propagation; these need to be eliminated. Triplex and quadruplex type males are suitable for paternal hybrid partners. Strong inbreeding depressions need to be avoided in their production.     

Assessment of genetic variation among asparagus (Asparagus officinalis L.) populations and cultivars: agromorphological and isozymic data

Summary The morphological variation and the isozymic polymorphism in 19 asparagus accessions currently used in cultivation and breeding are described. Moreover 2 wild populations from Turkey were added in the isozymic study. Characters of ramification height permit to separate accessions usually cultivated for white asparagus and accessions usually cultivated for green asparagus. Starch and polyacrylamide gel electrophoresis was realized to assay 7 enzyme systems. 29 polymorphic bands were taken into account in the study. Four accessions show specific bands for glutamate oxaloacetate transaminase, shikimate dehydrogenase and alcohol dehydrogenase. In particular, the two populations from Turkey and one population traditionally cultivated in local area of Spain are well differentiated from the remaining accessions. Accessions from the United States representing different selections are relatively well separated from each other.     

Carbamate-induced flowering in asparagus (Asparagus officinalis L.) seedlings: optimization of treatment and cultivar variation in flowering response and pollen germination

Optimal carbamate treatment conditions were studied for flower induction in seedlings of an asparagus cultivar ‘Mary Washington 500 W’. Flower induction was most accelerated by soaking seeds in 50 mg l⁻¹ carbamate solution for 12 days at 25 ^°C under the fluorescent light. Longer exposure to carbamate over a 12 day period induced a higher percentage of seedlings to flower. A higher percentage of flowering seedlings were male. Flower induction frequency among seven cultivars through carbamate treatment widely ranged from 13 to 67%. ‘Geynlim’, ‘Mary Washington 500 W’ and ‘Welcome’ exhibited a high percentage of flowering seedlings, while ‘Larac’ and ‘Vulkan’ showed low values. Only male flowers were induced in all-male cultivars. Variation in pollen germination was found within all cultivars. ‘Geynlim’, ‘Cito’ and ‘Mary Washington 500 W’ showed high values of average pollen germination. Application of carbamate compound to induce flower production can rapidly produce homogenic cultivars which include both sexes. This is necessary for genetic studies and breeding purposes. This revised version was published online in August 2006 with corrections to the Cover Date.     

中国芦笋栽培研究进展及展望

芦笋是一种食药兼用型蔬菜,中国芦笋栽培面积和出口量居世界首位。随着劳动力成本的增加,传统的粗放式栽培与劳动密集型生产模式制约了芦笋生产的发展。笔者从育苗、田间种植与管理、肥水运筹、病虫害防治、设施栽培模式等方面综述了中国芦笋栽培的研究进展。展望了中国芦笋产业的发展趋势,提出了新品种培育、无公害标准化栽培、机械化生产、延长产业链是芦笋产业持续发展的根本途径。     

影响芦笋产量性状的相关性分析

对芦笋的6个农艺学性状指标进行相关性分析,并对产量和一级笋率进行了多重比较。结果表明,影响芦笋产量的重要因子有茎粗、株高和茎数。影响芦笋一级笋率的重要因子有茎粗、株高、产量。植株越高,产量越高,一级笋率也越高。茎粗、株高、茎数构成芦笋产量、品质特性,同时也是新品种选育的必备性状。通过对产量和一级笋率的多重比较发现,全雄品种在产量、一级笋率和其它农艺性状方面明显优于其它常规种,因此芦笋全雄品种的选育已成为目前芦笋育种的重中之重。     

生物技术在芦笋育种中的应用

旨在为今后芦笋遗传育种工作提供参考和理论依据。本文综述了近几十年来国内外生物技术在芦笋育种研究中的应用主要进展,内容包括芦笋的组织培养、花药培养、小孢子培养、原生质体培养、多倍体诱导、分子标记技术及遗传转化等方面的研究,重点总结了生物技术在芦笋育种中发挥的作用及应用现状,并分析芦笋生物技术育种存在的问题。最后根据芦笋生物学特性与产业需求,探讨了未来芦笋生物技术育种工作的发展方向。     

芦笋重要真菌病害研究进展

芦笋是重要的功能型蔬菜,芦笋真菌病害是威胁其生产的主要瓶颈之一,主要包括茎枯病、根腐病、枯萎病、褐斑病等。其中茎枯病是危害芦笋生产的世界性病害,特别是在中国,已成为生产中的突出问题。笔者简述了茎枯病等芦笋重要真菌病害在病原菌生物学特性、致病性、芦笋品种抗病性及病害关键防控技术等方面的研究进展,并展望了其发展趋势,认为今后应加强病原菌的致病和芦笋的抗病分子机制研究,为开展芦笋抗茎枯病分子育种提供基础。     

The significance of andromonoecism for the breeding of Asparagus officinalis L. II

Summary Following a previous publication in this periodical (3), indicating the lines along which an entirely male asparagus variety can be obtained, the above article further discusses the difficulties to be overcome. The combination of andromonoecism and homozygosis for the male sex (andromonoecious MM-plants) is discussed in more detail. These plants, some hundreds of which are now in the possession of the Institute of Horticultural Plant Breeding, have the great advantage that they can be readily used to produce large numbers of MM plants. There is the danger, however, that andromonoecism is transmitted to the commercial seed of the male variety. Although the available figures do not yet provide certainty as to the genetic behaviour of andromonoecism, transmission is likely to depend on some dominant factors. Proceeding from this assumption we could already indicate in principle how to prevent andromonoecism in commercial seed.     

芦笋单倍体染色体加倍技术研究

研究了芦笋单倍体染色体加倍的方法。在离体培养条件下,以秋水仙素为诱变剂,分别用浸泡法和培养基添加法处理芦笋单倍体幼苗的茎尖,比较了秋水仙素不同浓度、不同处理时间的诱导效果。结果表明,培养基添加法的诱导效果好于浸泡法,当在培养基中添加0.3%秋水仙素并处理7天时诱导效果最佳,染色体加倍频率与成活率分别可达82.50%和80%。加倍后的二倍体植株与单倍体植株相比,茎干变粗,气孔与保卫细胞增大,保卫细胞内的叶绿体数增多。     

L-精氨酸对绿芦笋贮藏品质及生理生化特性的影响

以绿芦笋为试材,研究浓度为0.1 mmol/L的L-精氨酸对其在4℃贮藏过程中品质及生理生化特性的影响。结果表明,0.1 mmol/L的L-精氨酸浸泡30 min处理,能有效地降低绿芦笋的腐烂率、失重率和残渣率,减缓叶绿素的消耗及丙二醛(MDA)的生成,并通过有效抑制苯丙氨酸解氨酶(PAL)活性从而延缓了木质素的生成,提高绿芦笋的总抗氧化能力,说明0.1 mmol/L浓度的L-精氨酸处理能有效维持采后绿芦笋的品质,且L-精氨酸作为食品添加剂应用于果蔬保鲜具有安全性高的优势。     

芦笋组织培养中玻璃化苗逆转的初步研究

为探讨芦笋(Asparagus officinalis L.)玻璃化试管苗的逆转恢复途径,对培养温度、光照强度、蔗糖浓度、琼脂浓度等因素对玻璃化苗逆转效果的影响进行研究。结果显示：玻璃化苗的恢复率随着培养温度的降低而有所升高,培养温度为15℃时,恢复率为33.01%;玻璃化苗的恢复率随光照强度的增强而明显升高,当光照强度为5200 lx时,逆转率可达70.55%;玻璃化苗的恢复率随着蔗糖浓度的升高而逐渐升高,当蔗糖浓度为50 g/L时,恢复率可达48.20%;玻璃化苗的恢复率随琼脂浓度的增加而升高,琼脂浓度为9 g/L时,恢复率达38.18%。说明在4种影响因素中,光照强度对玻璃化苗逆转的影响最大,而培养温度、蔗糖浓度、琼脂浓度对玻璃化苗的逆转也有一定的影响。     

芦笋SRAP反应体系优化及引物筛选

本研究以芦笋基因组总DNA为模板,通过对芦笋SRAP反应体系的重要参数进行优化,建立了一套适用于芦笋的SRAP反应体系:25μL的反应体系中,模板DNA量80ng、Mg2+浓度3.0mmol/L、上下游引物各0.2μmol/L、dNTPs0.3mmol/L、Taq DNA聚合酶1U以及1×Buffer。扩增程序为:94℃预变性3min;94℃30s、35℃30s、72℃1.5min,5个循环;然后退火温度提高到50℃,35个循环;最后72℃延伸10min。比较琼脂糖凝胶和变性聚丙烯酰胺凝胶电泳检测SRAP扩增产物的多态性,结果发现:6%变性聚丙烯酰胺凝胶电泳检测扩增产物比琼脂糖的效果好。利用该优化体系筛选引物,从256个SRAP引物组合中筛选出239个,它们具有扩增条带清晰、丰富、重复性好的优点,证明了此优化体系稳定可靠。     

石刁柏幼胚胚状体发生与细胞学研究

以3个来自国外的石刁柏品种(C.IL,PURPLE和APOLLO)为试材,研究不同基因型以及培养基中添加2,4-D、KT、6-BA和NAA等生长物质对石刁柏幼胚胚状体发生的影响.结果表明,幼胚在MS 2,4-D 1.0 mg/L KT 0.5 mg/L 6-BA 2.0 mg/L培养基中可直接诱导产生体细胞胚.降低2,4-D的浓度,将诱导产生的体细胞胚组织块继代培养2～3次可诱导产生出米黄色颗粒状的胚性愈伤组织,继而有胚状体的发生.胚性细胞继续分裂形成多细胞原胚,经球形胚、梨形胚、长形胚、子叶分化期到成熟胚,其发生的胚状体与单子叶合子胚形成具有相似的过程.     

石刁柏幼胚胚状体发生与细胞学研究

以3个来自国外的石刁柏品种（C.IL,PURPLE和APOLLO）为试材,研究不同基因型以及培养基中添加2,4-D、KT、6-BA和NAA等生长物质对石刁柏幼胚胚状体发生的影响。结果表明,幼胚在MS＋2,4-D 1.0 mg/L＋KT 0.5mg/L＋6-BA 2.0 mg/L培养基中可直接诱导产生体细胞胚。降低2,4-D的浓度,将诱导产生的体细胞胚组织块继代培养2-3次可诱导产生出米黄色颗粒状的胚性愈伤组织,继而有胚状体的发生。胚性细胞继续分裂形成多细胞原胚,经球形胚、梨形胚、长形胚、子叶分化期到成熟胚,其发生的胚状体与单子叶合子胚形成具有相似的过程。     

Conversion of a male-specific RAPD marker into an STS marker in Asparagus officinalis L.

Garden asparagus (Asparagus officinalis L.) is an economically important plant. This species is dioecious, and male plants are considered to be more desirable than females due to their higher yields. To reduce the time required for asparagus breeding, molecular marker techniques have been employed to identify sex-linked DNA markers. In the present study, we converted the male-specific random amplified polymorphic DNA marker T35R54-1600 into a sequence tagged site marker. We cloned a male-specific DNA fragment amplified with the T35R54 primer and determined the sequence of the fragment. The size of T35R54-1600 is 1,586 bp, and this fragment is not homologous to known sex-linked BAC sequences, indicating that this fragment is a new sex-linked region. Within this fragment, we designed the primer pair ‘MSSTS710’ to amplify a 710 bp region. This marker could be used to identify the sex of eight cultivars of A. officinalis: ‘Mary Washington 500W’, ‘UC157’, ‘Harumachi Green’, ‘Super Welcome’, ‘F4’, ‘Pacific 2000’, ‘F2’ and ‘Backlim’. We also analyzed the applicability of this marker to two dioecious Asparagus species, A. schoberioides and A. kiusianus, which are cross-compatible with A. officinalis. Although male-specific DNA fragments of two dioecious Asparagus species, A. schoberioides and A. kiusianus, were generated using the existing male-specific marker Asp1T7sp, no amplicon was obtained using the MSSTS710 marker. Since MSSTS710 can be employed for sex identification only in A. officinalis and not in closely related Asparagus species, the DNA region around the MSSTS710 marker must be variable among Asparagus species.     

Somaclonal and chromosomal effects of genotype, ploidy and culture duration in Asparagus officinalis L.

Chromosome and morphological variations of embryogenic calli-derived plants of gynogenic haploid, diploid, triploid and tetraploid asparagus (Asparagus officinalis L.) were investigated. Artificial tetraploids were produced using colchicine treatment of seeds of diploid cultivar, ‘Poultom’. ‘Haidel’ (2X) was crossed with the artificial tetraploids, from which one gynogenic haploid, one diploid, 6 triploid, 3 mixoploids were obtained. Embryogenic calli were first obtained from crown buds, subsequently induced to form somatic embryos, and after 30 days, induced to germinate. Chromosome variation in embryogenic calli-derived plants increased with increasing duration of subculture, particularly when low ploidy levels of plants such as haploid and diploid were used as explants. Approximately 80% of haploid-derived plants showed morphological variations such as dwarfness and abnormal morphological characteristics, although no differences were observed in cladodes and stem characteristics between other polyploid-derived plants and their parents. The data presented here would supply important fundamental information for commercial mass-propagation using somatic embryogenesis. This revised version was published online in July 2006 with corrections to the Cover Date.     

Production and characterization of interspecific hybrids between Asparagus kiusianus Makino and A. officinalis L.

Interspecific hybridization is a useful technique to introduce characteristics from wild species into crops. Garden asparagus (Asparagus officinalis, 2n = 2x = 20) is an economically important vegetable that is native to the Mediterranean region but widely cultivated in many countries. The genus Asparagus is comprised of over 100 species. Asparagus kiusianus (2n = 2x = 20) is a wild asparagus species endemic to Japan. This species occurs on the coast and is likely to be a salt-resistant species. Although the geographic distribution of these two species is not close, molecular phylogenetic analysis demonstrated that these two species are closely related. In this study, a reciprocal cross between A. officinalis and A. kiusianus was carried out by hand pollination, and progeny were obtained from both crossings. These progeny exhibited a morphologically intermediate phenotype in terms of flower shape, and restriction fragment length polymorphism analysis confirmed that these were indeed interspecific hybrids. The interspecific hybrids were fertile, and backcross progeny with garden asparagus was also generated. These interspecific hybrids are expected to supply novel traits to garden asparagus.