In Latin America the forestry of exotic species such as teak has been increasing in recent decades, due to their advantages in wood quality, rapid growth;and the relative ease of producing clones and their multiplicat...In Latin America the forestry of exotic species such as teak has been increasing in recent decades, due to their advantages in wood quality, rapid growth;and the relative ease of producing clones and their multiplication with respect to native species. Therefore, there is great interest in developing larger-scale propagation strategies that reduce costs and intensive manual labor. Culture in liquid media with temporary immersion and the semi-automation of the system has raised expectations for large-scale micropropagation. We report a protocol for teak, which reuses the primary explants in several culture cycles in semi-solid medium to produce nodal explants for the multiplication phase in temporary immersion bioreactors (RITA®). The control of factors such as cytokinin concentration, explants density, immersion frequencies and culture duration was analyzed. The number of shoots increased with 0.5 mg·l-1 of BA (6-Benzyladenine), alone or in combination with 0.5 mg·l-1 of Kinetin, with 2 daily immersions of 1 minute each;however, these shoots showed a high degree of hyperhydricity. When 0.05 mg·l-1 of BA was used with 1 immersion of 1 minute every 2 days, the hyperhydricity decreased. Although the number of shoots was lower, they showed good length to be used during multiplication and rooting ex vitro. Our results suggest that teak micropropagation can be simplified in two phases in vitro, the establishment and multiplication;followed by rooting ex vitro and acclimatization. This would imply a reduction in production costs, since most of the multiplication would take place in RITA®containers.展开更多
Pineapple (Ananas comosuss, var. Smooth cayenne), which is a popular tropical fruit, is propagated vegetatively. Conventional propagation alone does not provide clean and adequate planting material demanded in Ethiopi...Pineapple (Ananas comosuss, var. Smooth cayenne), which is a popular tropical fruit, is propagated vegetatively. Conventional propagation alone does not provide clean and adequate planting material demanded in Ethiopia. Recently, in vitro multiplication has become a promising technique for large-scale production. However, the acclimatization to the external environment procedure impedes the efficiency, which needs carefully optimized acclimatization techniques. We report optimized acclimatization procedures following first- and second-stage hardening methods for in vitro pineapple plantlets. Primarily, Jiffy-7 peat pellet allowed growing plants vigorously and provided above 8% survival rate over soil mix. Nevertheless, in Ethiopia, soil mix is cheaper and locally accessible. The primarily acclimatized plantlets are needed to be hardened further for better establishment and survival in the field. Black polybag and polysleeve pots filled with soil mix were evaluated in the greenhouse. A significant difference was obtained between pots for number of roots and substrate weight. Polybags had higher root number than polysleeves and saved about 27% of substrates per plant, which is a reduction of 25% of total transportation cost. Hence, the soil mix and polybags were found to be preferable over substrates and pots, for subsequent in vitro pineapple acclimatization.展开更多
This work describes the evaluation of morpho-physiological and biochemical changes in “MD-2” micro-propagated pineapple plants (Ananas comosus (L.) Merr.) grown after 30 days under low light intensity (LL, greenhous...This work describes the evaluation of morpho-physiological and biochemical changes in “MD-2” micro-propagated pineapple plants (Ananas comosus (L.) Merr.) grown after 30 days under low light intensity (LL, greenhouse light conditions at 250 μmol·m-2·s-1) or high light intensity (HL, field light conditions at 800 μmol·m-2·s-1). Gas exchange, leaf pH, protein content and superoxide dismutase activity (SOD) (EC 1.15.1.1) were measured every 3 h during one day. Chlorophylls content and succulence index (SI) were determined at 9 h. Results showed significant differences in CO2 exchange rates, with a maximum occurring at 6 h (3.00 and 8.25 μmol CO2 m-2·s-1 for leaves under LL and HL conditions respectively). Plants under HL conditions had higher CO2 uptake and lower pH values between 0 h and 6 h respective to LL plants. The maximum pH value was attained 3 h before in HL plants. Leaf SI was increased and chlorophyll content decreased by HL conditions. SOD activity was higher in plants under HL conditions, near doubling those of LL plants at 18 h (2.8 versus 1.5 U·mg-1 Protein respectively). Both groups showed a typical CAM phenotype, but it was stronger in HL conditions, which may confer these plants with a better acclimation to transfer to the field.展开更多
基金the support provided by the National Institute of Forest Science(NIFoS)of the Republic of South Korea
文摘In Latin America the forestry of exotic species such as teak has been increasing in recent decades, due to their advantages in wood quality, rapid growth;and the relative ease of producing clones and their multiplication with respect to native species. Therefore, there is great interest in developing larger-scale propagation strategies that reduce costs and intensive manual labor. Culture in liquid media with temporary immersion and the semi-automation of the system has raised expectations for large-scale micropropagation. We report a protocol for teak, which reuses the primary explants in several culture cycles in semi-solid medium to produce nodal explants for the multiplication phase in temporary immersion bioreactors (RITA®). The control of factors such as cytokinin concentration, explants density, immersion frequencies and culture duration was analyzed. The number of shoots increased with 0.5 mg·l-1 of BA (6-Benzyladenine), alone or in combination with 0.5 mg·l-1 of Kinetin, with 2 daily immersions of 1 minute each;however, these shoots showed a high degree of hyperhydricity. When 0.05 mg·l-1 of BA was used with 1 immersion of 1 minute every 2 days, the hyperhydricity decreased. Although the number of shoots was lower, they showed good length to be used during multiplication and rooting ex vitro. Our results suggest that teak micropropagation can be simplified in two phases in vitro, the establishment and multiplication;followed by rooting ex vitro and acclimatization. This would imply a reduction in production costs, since most of the multiplication would take place in RITA®containers.
文摘Pineapple (Ananas comosuss, var. Smooth cayenne), which is a popular tropical fruit, is propagated vegetatively. Conventional propagation alone does not provide clean and adequate planting material demanded in Ethiopia. Recently, in vitro multiplication has become a promising technique for large-scale production. However, the acclimatization to the external environment procedure impedes the efficiency, which needs carefully optimized acclimatization techniques. We report optimized acclimatization procedures following first- and second-stage hardening methods for in vitro pineapple plantlets. Primarily, Jiffy-7 peat pellet allowed growing plants vigorously and provided above 8% survival rate over soil mix. Nevertheless, in Ethiopia, soil mix is cheaper and locally accessible. The primarily acclimatized plantlets are needed to be hardened further for better establishment and survival in the field. Black polybag and polysleeve pots filled with soil mix were evaluated in the greenhouse. A significant difference was obtained between pots for number of roots and substrate weight. Polybags had higher root number than polysleeves and saved about 27% of substrates per plant, which is a reduction of 25% of total transportation cost. Hence, the soil mix and polybags were found to be preferable over substrates and pots, for subsequent in vitro pineapple acclimatization.
文摘This work describes the evaluation of morpho-physiological and biochemical changes in “MD-2” micro-propagated pineapple plants (Ananas comosus (L.) Merr.) grown after 30 days under low light intensity (LL, greenhouse light conditions at 250 μmol·m-2·s-1) or high light intensity (HL, field light conditions at 800 μmol·m-2·s-1). Gas exchange, leaf pH, protein content and superoxide dismutase activity (SOD) (EC 1.15.1.1) were measured every 3 h during one day. Chlorophylls content and succulence index (SI) were determined at 9 h. Results showed significant differences in CO2 exchange rates, with a maximum occurring at 6 h (3.00 and 8.25 μmol CO2 m-2·s-1 for leaves under LL and HL conditions respectively). Plants under HL conditions had higher CO2 uptake and lower pH values between 0 h and 6 h respective to LL plants. The maximum pH value was attained 3 h before in HL plants. Leaf SI was increased and chlorophyll content decreased by HL conditions. SOD activity was higher in plants under HL conditions, near doubling those of LL plants at 18 h (2.8 versus 1.5 U·mg-1 Protein respectively). Both groups showed a typical CAM phenotype, but it was stronger in HL conditions, which may confer these plants with a better acclimation to transfer to the field.
