The ability of triadimefon （TDM）, a triazolic fungicide, to alter the biochemical constituents and thereby minimizing the days required for sprouting in white yam （Dioscorea rotundata Poir.） tubers during storage ...The ability of triadimefon （TDM）, a triazolic fungicide, to alter the biochemical constituents and thereby minimizing the days required for sprouting in white yam （Dioscorea rotundata Poir.） tubers during storage under （30±2） ℃ in the dark, was studied. TDM at 20 mg/L was given to tubers by dipping the tubers in treatment solution containing 20 mg/L TDM on 10, 25 and 40 d after storage （DAS）. Starch, sugars, protein, amino acid contents as well as protease and a-amylase activities were estimated on 15, 30 and 45 DAS from two physiological regions viz., apical and basal regions of the tubers. In normal conditions （control） sprouting occurred on 70 to 80 DAS. The starch content decreased, while protein, amino acid, sugar contents and protease and a-amylase activities were increased due to TDM treatment and led to early sprouting.展开更多
Among orchids, Cymbidiums have got a very high demand in both cut flower and pot plant trade. In the present study the effect of some polysaccharides such as chitosan and NAG （n-acetyl-glucosamine） on organogenesis ...Among orchids, Cymbidiums have got a very high demand in both cut flower and pot plant trade. In the present study the effect of some polysaccharides such as chitosan and NAG （n-acetyl-glucosamine） on organogenesis in protocorm-like-bodies （PLBs） of C. insigne was studied. Synthetic phytohormones such as BA and TDZ （cytokinins） and NAA （auxin） were used for comparison. PLBs of C. insigne were explanted on modified Murashige and Skoog medium supplemented with the single addition of chitosan and NAG, and the combination of BA （benzyladenine） and NAA （1-naphthaleneacetic acid） also with the combination of NAA and TDZ （thidiazuron） among different concentrations. Combination treatments of auxin and cytokinins, the highest percentage of PLBs formation was 73% and shoot formation was 67% when cultured on the medium supplemented with 1.0 mg L1 BA without NAA. Combination treatment of NAA and TDZ, the PLBs formation was 90% and shoot formation was 60% obtained from medium supplemented with 1.0 mg Lt of NAA ＋ 0.1 mg L^-1 TDZ. Single addition of chitosan and NAG with modified MS medium was more effective for new PLBs and shoot formation. The highest percentage of PLBs formation was 87% and shoot formation was 80% obtained from the medium supplemented with 0.1 mg L^-1 chitosan. On the other hand, the PLBs formation rate reached 93% and shoot formation rate was 87% obtained from the medium supplemented with 0.01 mg L^-1 NAG. Application of polysaccharides to in vitro orchid PLBs allows developing new PLBs and shoot to form plantlet without synthetic phytohormones.展开更多
Cherry regeneration via somatic embryogenesis is a powerful tool to breeding. In this way, the embryogenic capacity of Prunus incisa specie has been tested from leaves under different interactions of picloram concentr...Cherry regeneration via somatic embryogenesis is a powerful tool to breeding. In this way, the embryogenic capacity of Prunus incisa specie has been tested from leaves under different interactions of picloram concentrations and darkness exposures. Induction culture was achieved on MS medium supplemented with picloram concentrations at 0.5, 1 and 1.5 mg.L1 and submitted to 10, 20, 30 and 40 days of darkness. The best rate of embryogenic leaves was obtained with the interaction of 30 days darkness exposure＊ 1 mg.L^-1 picloram. According to their age, leaves were differently reacted to somatic embryogenesis; indeed, the 2nd expanded leaf from the apex was the most embryogenic one. Concerning the effect of additional auxin to picloram （1 mg·L^-1）, IAA at 0.1 mg·L^-1 and IBA at 0.1 mg·L^-1 gave significantly higher induction rates than all other concentrations, but regenerating somatic embryos showed some teratological abnormalities probably due to seconda;y embryogenesis. At the opposite, NAA at 0.5 mg·L^-1 didn＇t improve embryogenic rate but affected positively embryo development. Furthermore, embryogenesis preferentially took place on the basal part of leaf. Satisfactory rates of somatic embryogenesis are obtained but further improvement remains possible.展开更多
In rice, 2,4-Dichlorphenoxyacetic acid （MS2） has been considered best for callus induction and combination ofNAA, IAA, ABA （MS3） for somatic embryogenesis. Efficient plant regeneration was observed when MS basal s...In rice, 2,4-Dichlorphenoxyacetic acid （MS2） has been considered best for callus induction and combination ofNAA, IAA, ABA （MS3） for somatic embryogenesis. Efficient plant regeneration was observed when MS basal salts supplied with 3% sorbitol and 3% maltose as carbon sources without hormones （MSac）. During this experiment, effect of sodium chloride （NaCl） and abscisic acid （ABA） was assessed on callus growth, plant regeneration and root induction efficiency of rice （Oryza sativa L.） varieties IR-6 and Basmati-370. Callus proliferation rate was highly decreased in both varieties on MS2b （100 mol.m3 NaCl ＋ 0.5 mg＇L1 ABA） than MS2a （100 mol＇m3 NaCl） cultures significantly. Proline, glycine-betaine and reducing sugars were increased significantly in MS2a and MS2b callusing cultures. However, total proteins were decreased in MS2a, while slightly increased in MS2b. Maximum plant regeneration （9.42 ±0.54 and 10.67 ±0.50 plantlets.callus1） from somatic embryos was observed on MS4c in IR-6 and Basmati-370, while 1.56 ± 0.06 （IR-6） and 0.95 ±0.05 （Basmati-370） plantlets callus1 were observed on MSab （100 mol·m3 NaCl）. No plant regeneration was observed on MS4b （100 mol·m3 NaCl ＋ 0.5 mg·L-1 ABA） medium in both varieties. Inhibition of root induction efficiency was high in MSsb （100 mol·m3 NaCl ＋ 0.5 mg·L-1 ABA） than MS5a （100 mol·m3 NaCl） in the stressed cultures （P 〈 0.05）. In this experiment, it was concluded that ABA involved in somatic embryogenesis and elevation of NaCl stress, while it causes inhibition of cell＇s growth as well as its regeneration into plantlets from somatic embryos.展开更多
In usual cases of significant pressure gradients and strong shocks, the front shock takes a fixed location along the wall, at which separation starts. Usually the rear shock is responding to vortex sheding by its defl...In usual cases of significant pressure gradients and strong shocks, the front shock takes a fixed location along the wall, at which separation starts. Usually the rear shock is responding to vortex sheding by its deflection angle. In consequence main shock and rear shocks are moving whilst front shock is stable. The goal of the measurements presented here is to find out how the k-foot behaves during shock oscillations in the case when front shock is not fixed by the pressure gradient. Unsteady shock behaviour is also investigated when air jet vortex generators （AJVG） are used. Counteraction of the separation is directly related to the influence on unsteady processes in the shock wave induced separation.展开更多
文摘The ability of triadimefon （TDM）, a triazolic fungicide, to alter the biochemical constituents and thereby minimizing the days required for sprouting in white yam （Dioscorea rotundata Poir.） tubers during storage under （30±2） ℃ in the dark, was studied. TDM at 20 mg/L was given to tubers by dipping the tubers in treatment solution containing 20 mg/L TDM on 10, 25 and 40 d after storage （DAS）. Starch, sugars, protein, amino acid contents as well as protease and a-amylase activities were estimated on 15, 30 and 45 DAS from two physiological regions viz., apical and basal regions of the tubers. In normal conditions （control） sprouting occurred on 70 to 80 DAS. The starch content decreased, while protein, amino acid, sugar contents and protease and a-amylase activities were increased due to TDM treatment and led to early sprouting.
文摘Among orchids, Cymbidiums have got a very high demand in both cut flower and pot plant trade. In the present study the effect of some polysaccharides such as chitosan and NAG （n-acetyl-glucosamine） on organogenesis in protocorm-like-bodies （PLBs） of C. insigne was studied. Synthetic phytohormones such as BA and TDZ （cytokinins） and NAA （auxin） were used for comparison. PLBs of C. insigne were explanted on modified Murashige and Skoog medium supplemented with the single addition of chitosan and NAG, and the combination of BA （benzyladenine） and NAA （1-naphthaleneacetic acid） also with the combination of NAA and TDZ （thidiazuron） among different concentrations. Combination treatments of auxin and cytokinins, the highest percentage of PLBs formation was 73% and shoot formation was 67% when cultured on the medium supplemented with 1.0 mg L1 BA without NAA. Combination treatment of NAA and TDZ, the PLBs formation was 90% and shoot formation was 60% obtained from medium supplemented with 1.0 mg Lt of NAA ＋ 0.1 mg L^-1 TDZ. Single addition of chitosan and NAG with modified MS medium was more effective for new PLBs and shoot formation. The highest percentage of PLBs formation was 87% and shoot formation was 80% obtained from the medium supplemented with 0.1 mg L^-1 chitosan. On the other hand, the PLBs formation rate reached 93% and shoot formation rate was 87% obtained from the medium supplemented with 0.01 mg L^-1 NAG. Application of polysaccharides to in vitro orchid PLBs allows developing new PLBs and shoot to form plantlet without synthetic phytohormones.
文摘Cherry regeneration via somatic embryogenesis is a powerful tool to breeding. In this way, the embryogenic capacity of Prunus incisa specie has been tested from leaves under different interactions of picloram concentrations and darkness exposures. Induction culture was achieved on MS medium supplemented with picloram concentrations at 0.5, 1 and 1.5 mg.L1 and submitted to 10, 20, 30 and 40 days of darkness. The best rate of embryogenic leaves was obtained with the interaction of 30 days darkness exposure＊ 1 mg.L^-1 picloram. According to their age, leaves were differently reacted to somatic embryogenesis; indeed, the 2nd expanded leaf from the apex was the most embryogenic one. Concerning the effect of additional auxin to picloram （1 mg·L^-1）, IAA at 0.1 mg·L^-1 and IBA at 0.1 mg·L^-1 gave significantly higher induction rates than all other concentrations, but regenerating somatic embryos showed some teratological abnormalities probably due to seconda;y embryogenesis. At the opposite, NAA at 0.5 mg·L^-1 didn＇t improve embryogenic rate but affected positively embryo development. Furthermore, embryogenesis preferentially took place on the basal part of leaf. Satisfactory rates of somatic embryogenesis are obtained but further improvement remains possible.
文摘In rice, 2,4-Dichlorphenoxyacetic acid （MS2） has been considered best for callus induction and combination ofNAA, IAA, ABA （MS3） for somatic embryogenesis. Efficient plant regeneration was observed when MS basal salts supplied with 3% sorbitol and 3% maltose as carbon sources without hormones （MSac）. During this experiment, effect of sodium chloride （NaCl） and abscisic acid （ABA） was assessed on callus growth, plant regeneration and root induction efficiency of rice （Oryza sativa L.） varieties IR-6 and Basmati-370. Callus proliferation rate was highly decreased in both varieties on MS2b （100 mol.m3 NaCl ＋ 0.5 mg＇L1 ABA） than MS2a （100 mol＇m3 NaCl） cultures significantly. Proline, glycine-betaine and reducing sugars were increased significantly in MS2a and MS2b callusing cultures. However, total proteins were decreased in MS2a, while slightly increased in MS2b. Maximum plant regeneration （9.42 ±0.54 and 10.67 ±0.50 plantlets.callus1） from somatic embryos was observed on MS4c in IR-6 and Basmati-370, while 1.56 ± 0.06 （IR-6） and 0.95 ±0.05 （Basmati-370） plantlets callus1 were observed on MSab （100 mol·m3 NaCl）. No plant regeneration was observed on MS4b （100 mol·m3 NaCl ＋ 0.5 mg·L-1 ABA） medium in both varieties. Inhibition of root induction efficiency was high in MSsb （100 mol·m3 NaCl ＋ 0.5 mg·L-1 ABA） than MS5a （100 mol·m3 NaCl） in the stressed cultures （P 〈 0.05）. In this experiment, it was concluded that ABA involved in somatic embryogenesis and elevation of NaCl stress, while it causes inhibition of cell＇s growth as well as its regeneration into plantlets from somatic embryos.
基金the UFAST project financed by the European Commission within a cooperation sectorunder number:012226
文摘In usual cases of significant pressure gradients and strong shocks, the front shock takes a fixed location along the wall, at which separation starts. Usually the rear shock is responding to vortex sheding by its deflection angle. In consequence main shock and rear shocks are moving whilst front shock is stable. The goal of the measurements presented here is to find out how the k-foot behaves during shock oscillations in the case when front shock is not fixed by the pressure gradient. Unsteady shock behaviour is also investigated when air jet vortex generators （AJVG） are used. Counteraction of the separation is directly related to the influence on unsteady processes in the shock wave induced separation.
