查看更多>>摘要：The aim of the present study was to improve the vegetative propagation of field elm (Ulmus minor Mill.) by softwood cuttings. In a factorial experiment, the cuttings were quick-dipped (8 s) in aqueous solutions of IBA (0, 1500, and 3000 mg l(-1)) followed by foliar spray of a commercial seaweed extract (Citoking-Anoca Chemistry, Spain) at the concentrations of 0, 1.5, and 3 ml l(-1). Without the application of IBA or seaweed extract (SWE), the percentage of rooting was 20.9 and 40.2%, respectively. The highest percentage of rooting (78.9) was obtained by using 1500 mg l(-1) IBA that showed significant difference compared to the control (20.9). The highest root and shoot length (18.0 cm and 55.8 mm, respectively) was observed in 1500 mg l(-1) IBA + 1.5 ml l(-1) SWE. The application of SWE had no significant effect on root diameter, leaf bud sprouting, and number of new leaves. In contrast, all these traits were increased by using 1500 mg l(-1) IBA. Survival of the cuttings during the rooting period was not affected by SWE. However, increase in the concentration of IBA from 0 to 3000 mg l(-1) reduced the survival from 98.6% to 91.7%, respectively. In conclusion, application of 1500 mg l(-1) IBA alone or in combination with 1.5 ml l(-1) SWE was suitable to enhance vegetative propagation of field elm by softwood cuttings.
查看更多>>摘要：The effect of pyroligneous acid (PA), a byproduct of woody biomass pyrolysis, was researched for both antifungal activity and growth promotion in micropropagated in vitro plantlets during the ex vitro acclimatization process. The micropropagated plantlets of Phormium tenax J. R. Forst. & G. Forst 'Variegatum' were transplanted on a coco peat substrate that was treated with PA. The antifungal test was conducted to assess the ability to acclimatization ex vitro. The results showed that the PA completely inhibited soil-borne fungi activity at the concentrations of 1.5, 1.5, and 2.5% of the Rhizoctonia solani (Kuhn), Verticillum dahliae (Kleb.), and Fusarium oxysporum (f. sp. Vasinfectum), respectively. The PA levels were above 86% of the researched Phormium tenax 'Variegatum'. Therefore, both survival rate of acclimatized plantlets and standard coco peat were consistent considering the PA levels. The application of PA into the potting substrate at a rate of 2% and 5% had positive effects on survival rate of >= 90% in terms of plant height, shoot, and root dry biomass, and seedling quality index, compared to the plants acclimatized on coco peat control. The findings demonstrated that the application of PA in potting media at specific concentrations, can suppress soil-borne pathogens by providing plant nutrients. Furthermore, the growth rate promotes and enhance the seedling growth parameters of micro-propagated plants during ex vitro acclimatization process.
查看更多>>摘要：An effective vitrification procedure was developed for sweet potato cryopreservation, which was applied to three accessions (Tainung Nos. 25, 64, and 66). Effects of 0.4 M sucrose pretreatment as well as durations of loading and dehydration with plant vitrification solution 2 (PVS2) on the survival of shoot tips were examined. In the optimal vitrification procedure, explant pretreatment by stepwise increases in sucrose concentrations up to 1.0 M was used to investigate recalcitrant accessions. Three days of 0.4 M sucrose pretreatment significantly improved the survival rates of shoot tips immersed in liquid nitrogen. The highest cryopreservation survival rates were obtained with 60-min osmoprotection and 75-min PVS2 dehydration. Survival rates of recalcitrant accessions could be improved with a suitable pretreatment concentration. The sucrose pretreatment concentration was optimized for the intact explants of each accession type (TN66: 0.4 M, TN64: 0.5 M, and TN25: 0.8 M). The highest survival rates of 86.6% (TN66), 76.6% (TN64), and 50.0% (TN25) were achieved using pretreatment for 3 days, loading for 60 min, and dehydration in PVS2 for 75 min. This vitrification procedure with high concentrations of sucrose pretreatment can improve the survival rates of shoot tips after cryopreservation.
查看更多>>摘要：Sweet chestnut is considered to be an extremely difficult-to-root species and the main reason has not yet been understood. There is a lack of knowledge about the method of metabolising free endogenous indole-3-acetic acid (IAA) during the early stages of the adventitious root formation (ARF) process. The present study brings some important insights in the understanding of poor rooting success of chestnut and emphasizes the use of terminal types of cuttings. The time-course level of free IAA was studied in an experiment with terminal and basal leafy cuttings of two hybrid (Castanea crenata x Castanea sativa) sweet chestnut cultivars, Marsol and Maraval. The experiment was set in an unheated plastic house using a fog system for achieving sufficient relative humidity during propagation period. Only free IAA could be determined in cutting bases immediately after severance. In some other woody species also some other IAA metabolites (IAA-Asp, OxIAA, indole-3-methanol) have been presented in previous experiments as possible important substances during ARF. These metabolites in chestnut in our experiment could not be determined. Chestnut cuttings generally accumulated low amounts of free IAA in their bases, with values between 11 ng g(-1) to nearly 50 ng g(-1). The profile of free IAA differed between terminal and basal cuttings, regardless of the analysed cultivar, whereby terminal cuttings on average developed qualitatively a better rooting system, with significantly higher number of main roots. The initial IAA concentration tended to higher values in basal cuttings of the `Maraval'. Cuttings of the `Maravar rooted significantly better compared with 'Marsol' cuttings but the initial IAA concentration tended to yield higher values only in basal cuttings of the `Maraval'.
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