Influencing factors to seed dormancy and germination characteristics of Sorbus pohuashanensis were studied. These factors included the morphological development of embryos,the mechanical obstruction of the seed coat,t...Influencing factors to seed dormancy and germination characteristics of Sorbus pohuashanensis were studied. These factors included the morphological development of embryos,the mechanical obstruction of the seed coat,the water and air permeability of seed coat,and the biologic inhibition of extracts from different parts of seed. The results showed that when the seeds of Sorbus pohuashanensis became mature,the morphological development of the embryos was complete. The influencing effect of the mechanical obstruction,the water and permeability of seed coat for seed germination was little; there were inhibited substances to the seed of cabbage germination in seed coat and embryo,the germination depressor could be fat soluble substances. This indicated that the dormant degree was different for the different embryo parts. Cotyledon and hypocotyl was in low degree dormancy,whereas radicle and epicotyl was in high degree dormancy. To some extent,the germination rate of in vitro cultured embryos was increased with detruncating cotyledon and radicle treament. A 1∶3 mixture of seeds and sharp sand at low temperature in favor of removing dormancy. Treated by 200 mg·L -1 6-BA for 24 h,then remained in low temperature (0～5 ℃),seeds could germinated well (the germination rate could reached 31.56% in 3 month treatment). ABA completely inhibited the germination of seed,warm-cold varied temperature treatment did not promote the removing of dormancy of seed.展开更多
Populus tomentosa was crossed with P.tremuloidis, P.grandidentata, P.alba×P.grandidentata and P.alba×Ulmuspumila in order to maintain its rapid growth and high wood quality and improve its resistance to cold...Populus tomentosa was crossed with P.tremuloidis, P.grandidentata, P.alba×P.grandidentata and P.alba×Ulmuspumila in order to maintain its rapid growth and high wood quality and improve its resistance to cold. Two methods were used to increase the germination rate from 1.5% to 41.1% and the remaining rate from 1.7% to 44.2%. Forty crossing combinations were conducted and 2744 hybrid seedlings were obtained. MX4×P.grandidentata （G-1-58）, MX3×P.tremuloidis （T-44-60）, MX2×P.tremuloidis （1-13-87-37） and MX2×（P.alba×P.grandidentata） were regarded as superior combinations after analysis and selection. Thirty seedlings of these combinations and 11 triploid seedlings identified by counting their chromosomes were selected as super plants.展开更多
The objective of this study was to establish an efficient system of producing early monozygotic twin bovine embryos in vitro using the blastomere separation and coculture technique. In this study, early eight-cell emb...The objective of this study was to establish an efficient system of producing early monozygotic twin bovine embryos in vitro using the blastomere separation and coculture technique. In this study, early eight-cell embryos were chosen to optimize the separation method, and multi-coculture tactics were applied to improve the efficiency of this production system. Bovine embryo blastomeres（groups of at least 30 at the eight-cell stage） were separated into eight segments（to regard an eight-cell embryo as a tangerine, a blastomere as one segment） and one, two and four segments（blastomeres） were cultured respectively in microwells on the bottom of the four-well dish（Nunc, Denmark） with 400 μL of culture medium under paraffin oil. Four different types of coculture tactics（cocultured with nothing, intact embryos, bovine cumulus cells（b CCs）, intact embryos ＆ b CCs） were applied to the group of four segments（blastomeres）. Finally, diameter and inner cell mass（ICM）：trophectoderm（TE） cell ratio was measured as a criterion to assess the quality of the twin embryos which were derived from bovine separated blastomeres. Our results showed that rate of blastocyst formation of the four segments group was significantly greater than one or two group（P〈0.05）. In addition, rate of blastocyst formation was significantly increased when the four segments were cocultured with intact embryo ＆ b CCs（P〈0.05）. Although the ICM, TE and total cells of blastocysts derived from separated blastomeres was less than the control group from intact embryo（P〈0.05）, more important quality indicator of the blastocyst diameter and ICM：TE cell ratio was similar between our experimental group and the control group（P〉0.05）. Thus, these results suggest that combined with intact embryos ＆ b CCs coculture system, culturing four isolated segments（blastomeres） per microwell is an efficient system of producing early monozygotic twin bovine embryos. Furthermore, our results also indicate that展开更多
The present study reports a protocol for germination of Strychnos potatorum （ver. Tel. Chilla） using zygotic embryo culture as an embryo rescue method. A 100% germination rate was obtained by culturing the embryos o...The present study reports a protocol for germination of Strychnos potatorum （ver. Tel. Chilla） using zygotic embryo culture as an embryo rescue method. A 100% germination rate was obtained by culturing the embryos on full-strength Murashige and Skoog＇s medium （MS） containing 20 g/L sucrose in comparison to McCown and Lloyd＇s Woody Plant Medium （WPM）. Germination rates decreased when the sucrose concentration was lower or higher than 20 g·L-1 . WPM/MS medium containing glucose at levels 30, 20, 15 g·L-1 showed a smaller percentage of germination and at quarter strength, WPM/MS medium with glucose did not respond. Multiple shoot formation was found at 1.0 2.0 mg/L BAP; 3.0 mg/L Kn; 2.0 mg/L TDZ on MS medium with 20 g·L-1 sucrose. Germination rates improved when the embryos were placed upright （vertically） in the medium. The in vitro germinated seedlings were acclimatized in a walk-in-chamber and maintained in the green house with the survival rate of 65% 75%. These plants were transferred to the field and were found to be phenotypically normal, healthy and similar to donor plants. This protocol will be useful to overcome seed dormancy and for rapid multiplication and conservation of S. potatorum using zygotic embryo culture.展开更多
文摘Influencing factors to seed dormancy and germination characteristics of Sorbus pohuashanensis were studied. These factors included the morphological development of embryos,the mechanical obstruction of the seed coat,the water and air permeability of seed coat,and the biologic inhibition of extracts from different parts of seed. The results showed that when the seeds of Sorbus pohuashanensis became mature,the morphological development of the embryos was complete. The influencing effect of the mechanical obstruction,the water and permeability of seed coat for seed germination was little; there were inhibited substances to the seed of cabbage germination in seed coat and embryo,the germination depressor could be fat soluble substances. This indicated that the dormant degree was different for the different embryo parts. Cotyledon and hypocotyl was in low degree dormancy,whereas radicle and epicotyl was in high degree dormancy. To some extent,the germination rate of in vitro cultured embryos was increased with detruncating cotyledon and radicle treament. A 1∶3 mixture of seeds and sharp sand at low temperature in favor of removing dormancy. Treated by 200 mg·L -1 6-BA for 24 h,then remained in low temperature (0～5 ℃),seeds could germinated well (the germination rate could reached 31.56% in 3 month treatment). ABA completely inhibited the germination of seed,warm-cold varied temperature treatment did not promote the removing of dormancy of seed.
文摘Populus tomentosa was crossed with P.tremuloidis, P.grandidentata, P.alba×P.grandidentata and P.alba×Ulmuspumila in order to maintain its rapid growth and high wood quality and improve its resistance to cold. Two methods were used to increase the germination rate from 1.5% to 41.1% and the remaining rate from 1.7% to 44.2%. Forty crossing combinations were conducted and 2744 hybrid seedlings were obtained. MX4×P.grandidentata （G-1-58）, MX3×P.tremuloidis （T-44-60）, MX2×P.tremuloidis （1-13-87-37） and MX2×（P.alba×P.grandidentata） were regarded as superior combinations after analysis and selection. Thirty seedlings of these combinations and 11 triploid seedlings identified by counting their chromosomes were selected as super plants.
基金supported by the China Agriculture Research System (CARS-37)the Agricultural Science and Technology Innovation Program, China (ASTIP-IAS06-2015)
文摘The objective of this study was to establish an efficient system of producing early monozygotic twin bovine embryos in vitro using the blastomere separation and coculture technique. In this study, early eight-cell embryos were chosen to optimize the separation method, and multi-coculture tactics were applied to improve the efficiency of this production system. Bovine embryo blastomeres（groups of at least 30 at the eight-cell stage） were separated into eight segments（to regard an eight-cell embryo as a tangerine, a blastomere as one segment） and one, two and four segments（blastomeres） were cultured respectively in microwells on the bottom of the four-well dish（Nunc, Denmark） with 400 μL of culture medium under paraffin oil. Four different types of coculture tactics（cocultured with nothing, intact embryos, bovine cumulus cells（b CCs）, intact embryos ＆ b CCs） were applied to the group of four segments（blastomeres）. Finally, diameter and inner cell mass（ICM）：trophectoderm（TE） cell ratio was measured as a criterion to assess the quality of the twin embryos which were derived from bovine separated blastomeres. Our results showed that rate of blastocyst formation of the four segments group was significantly greater than one or two group（P〈0.05）. In addition, rate of blastocyst formation was significantly increased when the four segments were cocultured with intact embryo ＆ b CCs（P〈0.05）. Although the ICM, TE and total cells of blastocysts derived from separated blastomeres was less than the control group from intact embryo（P〈0.05）, more important quality indicator of the blastocyst diameter and ICM：TE cell ratio was similar between our experimental group and the control group（P〉0.05）. Thus, these results suggest that combined with intact embryos ＆ b CCs coculture system, culturing four isolated segments（blastomeres） per microwell is an efficient system of producing early monozygotic twin bovine embryos. Furthermore, our results also indicate that
基金supported by UGC,for financial assistance as Project Fellow under UGC-SAP-DRS-I programme(Ref. No. 558/UGC/KU/2010)
文摘The present study reports a protocol for germination of Strychnos potatorum （ver. Tel. Chilla） using zygotic embryo culture as an embryo rescue method. A 100% germination rate was obtained by culturing the embryos on full-strength Murashige and Skoog＇s medium （MS） containing 20 g/L sucrose in comparison to McCown and Lloyd＇s Woody Plant Medium （WPM）. Germination rates decreased when the sucrose concentration was lower or higher than 20 g·L-1 . WPM/MS medium containing glucose at levels 30, 20, 15 g·L-1 showed a smaller percentage of germination and at quarter strength, WPM/MS medium with glucose did not respond. Multiple shoot formation was found at 1.0 2.0 mg/L BAP; 3.0 mg/L Kn; 2.0 mg/L TDZ on MS medium with 20 g·L-1 sucrose. Germination rates improved when the embryos were placed upright （vertically） in the medium. The in vitro germinated seedlings were acclimatized in a walk-in-chamber and maintained in the green house with the survival rate of 65% 75%. These plants were transferred to the field and were found to be phenotypically normal, healthy and similar to donor plants. This protocol will be useful to overcome seed dormancy and for rapid multiplication and conservation of S. potatorum using zygotic embryo culture.
