Population means and correlation analyses of growth parameters in lisianthus (Eustoma grandiflorum Shinn.)

Summary The variation in growth characteristics among lisianthus (Eustoma grandiflorum Shinn.) genotypes was investigated. The genetic control of several growth parameters was studied by analysing parental, F1, BC1 and F2 populations. The parameters analysed were stem elongation rate (SE), stem diameter (SD), leaf width (LW), number of nodes (NN), node length (NL) and days to flowering (DF). The genotypes tested exhibited great variation for all parameters. A particularly wide variation was noted for SE, ranging from 3 to 56 mm/week. This variation was partially attributed to a differential sensitivity to rosette formation. There was a marked positive heterosis for SE, SD, LW and NN; these parameters proved to be genetically correlated within segregating populations. DF was slightly negatively correlated with SE, NN and NL. It was concluded that SE and DF were independently controlled.Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No. 1196-E, 1993 series.     

LED不同光质对洋桔梗组培苗淀粉含量的影响

洋桔梗组培苗生长是洋桔梗组织培养环节中很重要的环节。该试验以洋桔梗组培苗为试验材料,将试验材料分为8组,研究不同光质对洋桔梗组培苗淀粉含量的影响。结果表明:LED处理中1 RB光照下的洋桔梗组培苗淀粉含量最高,为2.313 7 mg/g,2 RB光照下的洋桔梗组培苗淀粉含量最低,为1.008 7 mg/g。因此,组合光1 RB较传统光源荧光灯更能促进组培苗淀粉生成,该试验结果可为洋桔梗组培苗培育提供一定的理论指导。     

Balance and concentration of nitrogen and potassium affect growth and nutrient status in soilless cultivated lisianthus

Purpose: Nitrogen (N) / potassium (K) nutrient balance has been studied for some ornamental plants, however, available information is limited. Here we investigate the optimum N and K balance and concentration for lisianthus production in soilless medium.

Materials and methods: The effect of three N / K balances: 1.43, 2.14 and 4.29, prepared by varying the concentration of N and K, were evaluated in lisianthus grown in soilless medium (volcanic rock).

Results: Plants fertigated with a N / K balance of 2.14 exhibited enhanced height and stem dry weight when compared to plants fertigated with a balance of 4.29, and a higher flower buds count and total dry weight than those fertigated with a balance of 1.43 or 4.29. Plants fertigated with a balance of 2.14 exhibited increased dry weight when N was reduced from 15 to 9?meq?L^?1 and K from 7 to 4.2?meq?L^?1, suggesting that lisianthus does not require high levels of these nutrients. Although shoot N concentration was not correlated with N concentration in the nutrient solution or balance, increasing N in the shoot was associated with higher P and Mg in the plant tissues. In general, P, Ca, and Mg in plant tissues were unaffected by the external N / K balance, however, the internal P and Mg concentrations were positively correlated with shoot dry weight. Shoot K concentration significantly increased when the N / K balance decreased, which is related to the higher concentrations of external K when the balance decreased.

Conclusions: The optimum N / K balance for lisianthus was 2.14. However, there was a concentration effect, as fertigation with solutions containing a N / K balance of 2.14 and an N and K concentration of 9 and 4.2?meq?L^?1 respectively, resulted in plants with the greatest dry weight.     

洋桔梗基因工程研究进展

对近10年来国内外洋桔梗遗传工程方面的研究进展进行了综述,提出了洋桔梗转基因过程中存在的问题,并就其应用前景进行了展望。     

不同浓度赤霉素对打破洋桔梗簇叶化的影响

试验研究不同浓度的赤霉素对打破洋桔梗簇叶化的影响。结果表明:摘心处理2个月后,CK(清水)处理的洋桔梗90%发生簇叶化,表明赤霉素对降低洋桔梗簇化率有效。赤霉素浓度对洋桔梗生长势的影响为150 mg/L100 mg/L50 mg/L清水,150 mg/L赤霉素处理对洋桔梗株高、茎粗和小花数影响显著,但对叶片数影响不显著,从而证明赤霉素是通过促进节间的伸长来促进整株植株生长,而不是通过促进节数的增加来促进植株的生长。     

洋桔梗离体快繁技术研究

[目的]建立洋桔梗高效的快速繁殖体系,为工厂化生产提供可行的操作程序。[方法]以国外进口的洋桔梗F1代种子(品种名称为Polestar yellow)无菌苗的叶片为外植体,对不定芽的诱导、单芽增殖、无菌苗生根等进行了研究。[结果]结果表明:6-BA和IBA组合对洋桔梗叶片不定芽的诱导效果较6-BA和NAA组合好,叶片最佳的分化培养基为MS+6-BA0.6 mg/L+IBA0.04 mg/L,1个月内正常芽平均分化数为8.3;最佳的单芽增殖培养基为MS+6-BA0.8 mg/L+NAA0.04 mg/L,1个月内正常芽的增殖倍数为7.4;无菌苗在含有IBA0.25 mg/L的1/2 MS培养基上,生根率、平均每苗的根数均最大。[结论]该结果为洋桔梗的工厂化生产奠定了基础。     

国内洋桔梗组培快繁技术的研究进展

通过查阅现有洋桔梗组织培养资料,对洋桔梗组培快繁技术体系的研究进展进行了综述,主要介绍了洋桔梗组织培养中的外植体的选择、初代培养、增殖培养、生根培养及练苗移栽等程序的研究进展.     

Powdery Mildew of Prairie Gentian: Characteristics,Molecular Phylogeny and Pathogenicity

In March 1999, we found prairie gentian (Eustoma grandiflorum) infected with powdery mildew in a greenhouse in Oita Prefecture, Japan. Morphological observation revealed that the causal fungus belongs to the mitosporic genus Oidium subgenus Pseudoidium [teleomorph: Erysiphe sensu Braun and Takamatsu (2000)]. Precise taxonomic position of the fungus, however, is uncertain due to lack of the perfect stage. We determined the nucleotide sequence of the rDNA ITS region of the fungus. Comparison of the sequence with those obtained from DNA databases of this fungal group revealed that the sequence is identical to those of powdery mildews from garden four-o'clock (Mirabilis jalapa) and broad bean (Vicia faba). Inoculation of an isolate from garden four-o'clock caused mildew on prairie gentian and broad bean, suggesting that the prairie gentian mildew originates from garden four-o'clock or broad bean. Molecular phylogenetic analysis indicated a close relationship of this fungus to Erysiphe baeumleri on Vicia spp. and E. trifolii on Trifolium pratense. From these results, we propose that prairie gentian mildew diverged from a Fabaceae-parasitic ancestor. Received 14 March 2002/ Accepted in revised form 28 May 2002