Pomology
B. Kaviani; M. Jamali; M.R. Safari Motlagh; A.R. Eslami
Abstract
Introduction Pears have a high nutritional and economic value worldwide. One of the major problem in growing pear cultivars is their late fertility on seed bases. To solve this problem, using asexual propagation methods can lead to the production of root trees. Cuttings are commonly used for proliferation ...
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Introduction Pears have a high nutritional and economic value worldwide. One of the major problem in growing pear cultivars is their late fertility on seed bases. To solve this problem, using asexual propagation methods can lead to the production of root trees. Cuttings are commonly used for proliferation either softwood, semi-hardwood or hardwood. Clonal propagation is considered proper in rapid propagation of shrubs and trees species. Adventitious root formation in stem cuttings is a crucial physiological process for vegetative propagation of many plant species. Rooting ability of tree species through stem cuttings is affected by several factors particularly plant growth regulators. Rooting of pear stem cuttings is time consuming. Auxin is effective in stimulating root formation on cuttings. The most widely used auxins in rooting of stem cuttings are indole-3-butyric acid (IBA) and naphtaleneacetic acid (NAA). Of these two auxins, IBA is the most widely used root promoting chemical, because it is nontoxic over a wide range of concentrations. Applied concentration is an important factor. Typically, a concentration of 2000 to 4000 ppm will result in good rooting for most shrubs and trees.Materials and Methods In this experiment, pear (Pyrus communis) was used as mother plants. Stem cuttings were used as plant materials in this experiment. The effect of different levels of indolebutyric acid (IBA) and naphthalene acetic acid (NAA) was studied on the rooting of pears in a factorial experiment based on a randomized complete block design with 16 treatments and 4 replications. The experimental treatments included IBA and NAA at the rates of 0, 1000, 2000 or 4000 mg L-1. Rooting percentage, rooting time, root number, root length, root volume, plant height, leaf number and fresh and dry weights of cuttings were measured after about 130 days.Results and Discussion The results showed that the highest rooting (3.56 per seedling) was observed in cuttings treated with 4000 mg L-1 IBA. Also, the highest root number was obtained from the treatment of 1000 mg L-1 NAA and 2000 mg L-1 IBA with an average number of 0.16 roots per plant. According to the means comparison for the simple effect of IBA on the rooting time, the highest rooting time was related to the application of 4000 mg L-1 IBA. The results revealed that plants treated with 4000 mg L-1 NAA and 2000 mg L-1 IBA grew the longest roots. Also, ANOVA showed that among the applied factors, only the simple effect of IBA was significant on root volume. Means comparison for the simple effect of IBA on root volume showed that the highest was related to the application of 2000 mg L-1 IBA. According to the means comparison for the interactive effect of IBA × NAA on cutting fresh weight, the highest fresh weight was, on average, 8.36 g in plants treated with 4000 mg L-1 NAA and 2000 mg L-1 IBA. As well, means comparison the effect of IBA × NAA on cutting dry weight showed that the highest dry weight was 15.9 g related to the application of 4000 mg L-1 NAA × 2000 mg L-1 IBA. It was also observed that 2000 mg L-1 NAA × 1000 mg L-1 IBA was related to the longest cutting with an average length of 2.82 cm. Finally, plants treated with 4000 mg L-1 NAA and 2000 mg L-1 IBA produced the highest number of leaves (15.9 g, on average). One of the effective factors in the success of vegetative propagation of plants with stem cuttings, especially woody plants with hard-rooting stems, is the production of more roots in a short time. Plant growth regulators, including auxins, play an important role in this regard. The effect of auxins on the percentage and number of roots produced on stem cuttings has been shown by many researchers on various plants, including plants with hard-rooting cuttings particularly in trees. The most widely used auxins in this regard are IBA and NAA, respectively. The individual or combined effect of auxins for successful rooting depends on a number of factors, including plant type, cuttings type, cuttings size, cuttings age, and the time of year the cuttings were removed. In the present study, the combined effect of IBA and NAA had the greatest effect on most of the measured traits.
Ahmad Sharifi; Azadeh Khadem; Maryam Moradian; Mahdiyeh Kharrazi
Abstract
Introduction: Application of stress-tolerant rootstocks is known as one of the effective methods to enhance the productivity of fruit gardens. Pear is one of the four or five major classes of fruits that are produced worldwide. Among pear cultivars, Pyrodwarf rootstock is tolerant to alkaline soil and ...
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Introduction: Application of stress-tolerant rootstocks is known as one of the effective methods to enhance the productivity of fruit gardens. Pear is one of the four or five major classes of fruits that are produced worldwide. Among pear cultivars, Pyrodwarf rootstock is tolerant to alkaline soil and low temperatures of winter. In addition, many cultivars of pear with high productivity could be grafted to this rootstock. These advantages result in widespread culture of pyrodwarf rootstock in pear gardens. The increasing market demand of this rootstock presents an opportunity to investigate alternative methods for efficient production of pyrodwarf. Therefore, this study has been conducted to increase the efficiency of pyrodwarf propagation through tissue culture methods.
Materials and Methods: For this experiment, sterile plantlets of pyrodwarf rootstocks in a same growth phase were used. Plantlets were cultured in different 12 media including MS, WPM, KNOP, modified KNOP, QL and modified QL basal media supplemented with 0.5 mg.L-1 BA and 0.05 mg.L-1 IAA or IBA and solidified with 8 g.L-1 agar. After that, cultures were transferred to the growth room at 25 ± 1°C under a 16/8h light/dark photoperiod (light intensity 30 μmol.m−2.s−1, cool-white fluorescent light). In the next step for rooting optimization, two separate experiments were conducted. In the first, 10 different basal media containing various nutritional compounds were examined for rooting properties of pyrodwarf plantlets. The following experiment was performed to reveal the effects of IAA and active charcoal on the efficiency of plantlets rooting. All the experiments were carried out in acompletelyrandomized design. The study of propagation efficiency of plantlets was arranged in a factorial approach with twofactors including the type of basal media (sixlevels) and auxins (twolevels) with threereplications. The both experiments of plantlet rooting were performed with sevenreplications. Data were analyzed using JMP-8 statistical software and the meanswere compared by using LSD test at 5% probability.
Results and Discussion: All explants were regenerated 15 days after cultivation. The number of buds per explants indicates that nutritional compounds significantly affected bud formation. MS basal media induced the most number of adventitious buds and decreasing amount of nitrogen in the culture medium (either in its ammonium or nitrate form) leads to 50%-decrease in the number of buds induced per explant. Previous reports mentioned that macronutrients have the most significant effect on bud formation of peach hybrid rootstock GF677. In addition, high amount of nitrogen is necessary to achieve the highest height of pyrodwarfin vitro plantlets. In contrast to the basal media, neither bud formation nor height of plantlets did not affected by the type of auxins, IAA and IBA. Also weight of plantlets was similar in all treatments and shows the effect of basal media and auxins were not significant on biomass production. According to the results of rooting experiment, plantlets that were cultured in MS and DKW had higher height than QL and Knop in rooting phase. Also, 1/2 MS-cultured plantlets have the lowest height among all treatments. These results showed that macronutrients have positive effects on the growth of pyrodwarf plantlets as decreasing concentration; the growth of plantlets was inhibited. In contrast to shoot growth, number of roots per explants in 1/2 MS medium was significantly higher than the other media. These results are expected as shoots and roots of plants have different response to environmental stimuli. Data obtained from the following experiment of rooting indicated that IAA improved root induction similar toother functional traits of plants but the presence of both of those compounds in medium have inhibitory effect on the functional traits of plants.
Conclusion: These data suggest that macronutrients and hormonal compounds have impressive impact on the regeneration of pyrodwarf plantlets. In this regard, MS medium supplemented with 0.5 mg.L-1 BA and 0.05 mg.L-1 IAA or IBA induced most number of buds and the regenerated plantlets hadthe highest height in that medium compared to the other treatments. Also, 1/2 MS medium containing 1 mg.L-1 IAA was identified as the best media in case of rooting parameters.
ahmad sharifi; fatemeh keykha; mahboobeh yazdi; abdolreza bagheri
Abstract
Introduction: Lily (Lilium spp.) is a genus of herbaceous flowering plants, which consisted of many beautiful ornamental species with large prominent flowers. Most species are native to the Northern hemisphere temperate, though their range extends into the Northern subtropics. Some specific hybrids of ...
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Introduction: Lily (Lilium spp.) is a genus of herbaceous flowering plants, which consisted of many beautiful ornamental species with large prominent flowers. Most species are native to the Northern hemisphere temperate, though their range extends into the Northern subtropics. Some specific hybrids of Lilium spp. have been developed as cut flower in controlled conditions and in some cases can be grown as pot plant. Propagation rate of lily in natural clonal propagation methods is very low and one year produces of 1-2 bulblets per bulb scale. There is also possibility of disease transmission; so that, tissue culture techniques has provided an efficient method for its micropropagation.
Materials and Methods: In this study, two separate experiments under In vitro conditions the bulblet regeneration from thin cell layer (TCL) explants of Lilium spp. was investigated. In the first experiment, after two months the effect of TCL explants with 1, 3 and 5 mm thickness on MS medium containing 1 mg/l BA, 2ip and kin in combination with 0.5 mg/l NAA on regeneration parameters were assayed. In the second experiment to determine the effect of cultivar and cytokinin types, 3mm thickness TCL explants of five cultivars (Robina, Donato, Nymph, Lessoto and Roxana) were tested on MS medium containing different plant growth regulator (PGR) compounds including BA, kin, 2ip and TDZ at concentration of 1 mg/l in combination with 0.5 mg/l NAA. The regeneration parameters were assayed after four months. In all experiments, the medium was adjusted to pH 5.8 and autoclaved at 121°C for 15 min. All cultures were incubated at 25 ± 2°C with a 16 h photoperiod under cool white flourescent lights (30 µmol/m2).
Results and Discussion: According to the first experiment results, plant growth regulator of BA in all of surveyed parameters except root number was better than other PGRs and explants with 3 mm thickness was the best in all of parameters. The interaction of PGR and explants was significant, however maximum bulblet regeneration was observed in TCL explants with 3 mm thickness in all of PGR treatments (100%). While 1 mm thickness TCL in 2ip and 1 and 5 mm thickness TCL in Kin had the least regeneration percentage. Results revealed that the interaction of explants and medium is a key factor for suitable establishment, regeneration and growth of TCLs. Bulb dormancy is one of the limiting factors in regeneration of bulbous crop species. It seems under In vitro condition explants size and PGR combination of media especially cytokinin affected on breaking of dormancy. Maximum number of leaves and dry weight of bulblets in medium containing BA was significantly higher compared with other treatments. Most of studies confirmed the positive effect of BA on regeneration of lily. The function of cytokinin in plant promoted cell division and differentiation, which lead to growth and maintaining cells in meristematic status.
Result of second experiment showed that cultivar was one of the effective factors on regeneration trait. Oriental lily cultivar "Roxana" had the highest number of roots, bulblets, dry weight and length of plantlets and "Nymph" cultivar showed the lowest percentage of regeneration, dry weight, length of plantlets and rooting obtained. In all of cultivars BA induced more organogenesis percentage and plantlet dry weight, while TDZ induced more rooting percentage.The interaction of cultivar and PGR treatments on percentage of regenerated bulblets and rooting were significant. "Nymph" cultivar had minimum percentage of regeneration and rooting in medium containing TDZ and Kin. Furthermore, "Roxana" cultivar in medium containing BA showed the best dry weight comparison to other treatments.
Conclusion Lily has widely used in the floral industry as a cut flower or potted plant. In recent years, tissue culture was developed as reliable and highly effective method to overcome its limitations of vegetative propagation. The most advantage of this method is high multiplication rate and disease free propagation. In this study, bulblet regeneration of lilium Spp. from TCL explants under in vitro condition was considered as a highly efficient procedure for its micropropagation. With optimization of TCL system some parameters such as exogenously applied plant growth regulators, cultivar, explants types were investigated. Favorable conditions for bulblet regeneration were achieved with 3 mm thickness TCLs in MS medium containing 1 mg/l BA with 0.5 mg/l NAA. This protocol can be used for rapid micropropagation of many cultivars.
Gh. Davarynejad; A. A. Shokouhian; A. Tehranifar
Abstract
Introduction: Potential almond rootstock and thus main genetic sources for the breeding of its new rootstocks are almond itself, peach and plum, and these species cross-breeds Almond is a source of resistance to limestone and to drought because of its roots, which reach deep layers of soil; it is also ...
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Introduction: Potential almond rootstock and thus main genetic sources for the breeding of its new rootstocks are almond itself, peach and plum, and these species cross-breeds Almond is a source of resistance to limestone and to drought because of its roots, which reach deep layers of soil; it is also more resistant than peach to Na and Bo. Asexual or vegetative propagation is a hereditable characteristic and this paper is a review of sources available on this character for almond rootstock breeding. The bibliographic reference regarding this species, vegetative propagation is very poor. Stem cutting is considered the most simple and economical method of propagation. It is important, particularly in horticulture for mass production of improved material within a short time and to perpetuate the characteristics of the parent plant.
Materials and Methods: In this study the effects of different concentrations of indole-3- butyric acid (IBA) and medium type on rooting of hardwood stem cuttings of two rootstocks natural hybrids of almond × peach and the clone of G.F.677(as control) was investigated in plastic greenhouse with bottom heat, In this research 4 levels of IBA (0.3000,6000 and 9000 mg/l) and three levels of bed (perlait, cocopeat and, mixtures of 2 perlite + 1cocopeat) on rooting of hardwood cuttings of two almond × peach natural hybrids and control was used in a split plot based on a randomized complete blocks design with three replications. Hardwood cuttings were prepared in Department of Horticultural Sciences of Ferdowsi University of Mashhad at January 2011. The basal one inch of cuttings was treated with IBA solution for five seconds at 3000, 6000 and 9000 ppm. the following components were determined, the rooting percentage of cuttings, number of root, length of roots, roots fresh and dry weight and volume of roots
Results and Discussion: Results showed that effects of different concentrations of IBA, on the rooting percentage of cuttings were significantly different at the %1 level compare with control. In this case were observed the highest of rooting percentage (40.9) at concentration of 3000(mg/l) and the lowest percentage (12.7) in control. The observations showed that treating almond hardwood cuttings with 3000 ppm IBA gave the highest significant rooting percentage compared with other treatments. Furthermore, results of many investigations indicated that, IBA increased rooting percentage, number of roots/cutting, length and fresh weight of roots. Also on the trait there were significantly differences in the %1 level between the growing Medias. Rooting percentage of cuttings expanded by bed of perlait. Results showed that effects of different rootstocks on the rooting percentage of cuttings were significantly different at the %1 level. In this trait observed the highest of rooting percentage at G.F.677 and there was no significant difference between the two other rootstocks.Treated with control rootstock with IBA at 3000 mg/l and Perlait resulted in the highest rooting percentage ،the maximum number of roots and root length. In the traits rooting percentage, number of roots and root length was interactions between, concentrations × bed × rootstocks significantly different at the %1 level. The result was better than Gf677× 3000 ppm of IBA × perlite bed. Also effect of treatments concentrations on root volume was significant at the %5 level. Highest root volume obtained in a concentration of 3000 mg/l of IBA.
Conclusion: From our preliminary results, it could be inferred that there is a correlation between types of rootstock, concentrations of IBA and media in rooting ability of hardwood cuttings rootstocks of almond × peach. In this study, the desired result was obtained from the interaction between treatments concentration of 3000 mg per liter of IBA in perlite media and GF677 rootstock.
