The effect of ventilation rate on proliferation and hyperhydricity of Dianthus caryophyllus L

Summary Comparative studies of carnation micropropagation under four different ventilation rates showed that using gas-permeable filters, with gelled or liquid media and modifying the volume of culture medium, it was possible to establish a suitable hydric state to obtain good proliferation rates with gelled and liquid medium, as well as optimal acclimatization of microcuttings. The following parameters were measured: ventilation rate, gas exchange coefficients, relative water loss, increase of agar concentration, micropropagation rates, percentage of hyperhydricity, and acclimatization rates. Our results confirm that it is possible to avoid hyperhydric plants cultured in liquid medium with the use of ventilated culture vessels through the control of the water relations during the multiplication phase and, at the same time, keeping the micropropagation rate.     

Factors influencing the production of hardened glaucous carnation plantlets in vitro

Medium type, its water status and the relative humidity in the culture vessel modified carnation leaf development in vitro. Carnation shoot apices cultured on liquid or on 0.8% agar solidified media developed into plantlets having succulent and translucent leaves which are not transplantable to non-aseptic conditions. Increasing the agar and/or sucrose concentration in the medium as well as decreasing the relative humidity in the culture vessel by a desiccant promoted glaucous leaf production. Increased water status (H₂O and relative humidity) increased shoot proliferation and translucency of leaves. Decreased water status reduced shoot proliferation but induced the formation of glaucous leaves. The culture of apices for 5–6 days on liquid medium prior to their sub-culture to 1.5% agar medium improved shoot proliferation and normal leaf development. An agar slant prevented the submergence of apices in water accumulating on the medium and thus reduced leaf translucency. Survival was further increased by the transfer of plantlets in uncapped culture vessels to a desiccator for 1–2 weeks prior to transplanting to soil.     

Stomatal and cuticular traits on carnation tissue culture under different ventilation conditions

Establishment of microplants is related to the moisture vapourtransmission of the culture vessel lid. In this respect, stomatal andcuticular physiology were characterized in detached leaves from Dianthuscaryophyllus grown in the glasshouse or in vitro at different rates ofventilation. In vitro plants grown in non-ventilated culture vessels hadless waxes and therefore higher RWL compared to in vitro plants grown at Vr0.86 changes.h^–1. The improvement of stomatal function inleaves obtained in ventilated vessels can be due to a performance of ionicrelations between guard and subsidiary cells, mainly by an increasingK⁺ concentration in the guard cells as ventilation decreases.Moreover, data showthat there is an increase in free ABA in the leavesfromventilated culture vessels to compensate for the conjugated ABA lostduring desiccation. If the proliferation stage proceeds in ventilatedculture vessels, the physiological characteristics of the plants producedare better than those obtained in non-ventilated culture vessels, confirmedby higher survival after soil transplantion.     

中国石竹属的分类,演化和分布

本文报道我国石竹属植物有１７种１亚种９变种（其中１新变种）,分属于４组。石竹、瞿麦和长萼瞿麦分布最广。新疆种类最多（１１种１变种）,是我国本属植物的分布和分化中心。新疆和哈萨克斯坦有１０共有种,说明新疆的中亚的植物区系联系密切。     

In vitro production of flowering shoots in ‘German Red’ carnation: effect of uniconazole and gibberellic acid

Summary Callus regenerated near the base of senescing petals of flower bud explants of German Red carnation (Dianthus caryophyllus L.) produced adventitious flowering microshoots on MS-medium containing benzylaminopurine (8.9 M) and naphthaleneacetic acid (2.7 M). When these microshoots were subcultured with some callus, additional adventitious flowering microshoots were produced from the callus. The production of adventitious flowering shoots continued for many subcultures spanning a period of more than two years. Uniconazole (6.9 M) increased the number of adventitious shoots formed by as much as two-fold but decreased shoot length by about 50%. In contrast, GA₃ (2.9 M) decreased adventitious shoot formation and increased shoot length. Regardless of the growth regulator treatment, virtually all of the adventitious shoots produced flower buds. Thus, the growth regulators influenced flowering only indirectly by altering the number of adventitious shoots produced in vitro. These results demonstrate that the flowering habit of the adventitious shoots of German Red carnation is highly persistent and the flowering stimulus continues to be transmitted to the newly formed microshoots through the callus.     

Effects of agar concentration and vessel closure on the organogenesis and hyperhydricity of adventitious carnation shoots

Carnation plantlets (Dianthus caryophyllus L.) cultured in vitro often develop morphological and physiological anomalies, a phenomenon called hyperhydricity, which impairs their survival ex vitro. When the agar concentration of the growth medium was increased (from 0 to 12 g dm⁻³), thereby reducing water availability, the hyperhydricity of those adventitious shoots regenerated from carnation petals decreased. This was accompanied by a progressive fall in the water content of shoots (94.9 to 91.4 %), fresh mass (from 57.2 to 1.8 mg), number of leaf parenchyma cell layers (from 9.3 to 7.7), and the size of these cells (from 968 to 254 μm²). However, the number of regenerated shoots also decreased (17.7 in 2 g dm⁻³ agar to 4.3 in 12 g dm⁻³). Similarly, in ventilated tubes, which exhibit a lower relative humidity than tightly closed tubes, shoot organogenesis diminished up to 28 %, in tandem with shoot water content. Thus, relative humidity and water availability in culture vessels do not only influence shoot hyperhydricity in carnations, but also greatly affect adventitious shoot organogenesis.     

Study of different antibiotic combinations for use in the elimination of Agrobacterium with kanamycin selection in carnation

The effect of several β-lactam antibiotics on shoot regeneration, growth and rooting of carnation (Dianthus caryophyllus L.), and their use in combination with kanamycin in Agrobacterium-mediated genetic transformation studies, was determined. Carbenicillin, cefotaxime and ticarcillin increased the regeneration rate when added alone in non-inoculated explants; whereas, with inoculated explants, this effect was only observed in ticarcillin-containing medium. Cefotaxime inhibited root growth in both transgenic and non-transgenic shoots. Rooting of non-transgenic shoots was completely inhibited in all culture media containing kanamycin. The different antibiotics used, alone or in combination, did not prevent the occurrence of false positive shoots, but it was possible to select transgenic shoots when rooting was induced in a kanamycin + ticarcillin-containing medium. Regenerated transformed shoots were free of Agrobacterium after culturing in rooting medium, as was proven by the PCR analysis for the nptI gene, the antibiogram and the culture of tissue pieces of transgenic shoots on LB broth. The use of kanamycin and timentin with or without carbenicillin, was very useful in the transformation procedure, for the elimination of Agrobacterium in regenerated shoots before their transfer to greenhouse conditions and also in the selection of transgenic versus false-positive shoots. This revised version was published online in June 2006 with corrections to the Cover Date.     

中国石竹离体快繁与试管苗玻璃化研究

研究了培养基组成成分对中国石竹品种Diana F1 White组培程序中种子萌发、诱芽增殖、试管苗玻璃化及生根等重要环节的影响。结果表明:(1)种子适宜的萌发培养基为1/2MS,在此培养基中种子萌发率为83.33%,播种后30d时无菌苗高度达6.99cm,叶片数达26.7。(2)在芽诱导阶段玻璃化苗发生率最高可达53.85%。将光照强度提高至2000lx后,采用培养基MS+6-BA3.0mg/L+NAA0.3mg/L+琼脂8.0g/L+蔗糖8.0g/L进行诱芽培养,玻璃化苗发生率降至3.33%,外植体出芽率达到90%,单个外植体出芽数达到7.2个。(3)适宜的生根培养基为1/2MS+1.0mg/LIBA+琼脂8g/L+蔗糖40g/L,培养30d时生根率为100%,平均根条数达到24.7条,平均根长度达到4.7cm。试管苗在消毒后的腐殖土中移栽,成活率达95%。该研究结果为DianaF1试管苗的快速繁殖提供科学依据。     

西花蓟马在康乃馨不同品种上的田间分布

调查西花蓟马Frankliniella occidentalis(Pergande)在10个康乃馨(Dianthus caryophyllus)品种上的发生与分布,比较花朵颜色与气味对西花蓟马寄主选择性的影响。结果表明,花朵上的西花蓟马数量在不同品种间存在显著差异。花朵颜色是影响西花蓟马寄主选择的主要原因,而花朵气味也能影响西花蓟马对寄主的选择性。