[Objective] The aim was to explore the effects of drought stress on germination of tall fescue.[Method] Simulation drought experiment on 14 varieties of tall fescue seeds by PEG-6000 researched its germination effect ...[Objective] The aim was to explore the effects of drought stress on germination of tall fescue.[Method] Simulation drought experiment on 14 varieties of tall fescue seeds by PEG-6000 researched its germination effect under drought resistance.[Result] The relative germination rate of all tall fescue varieties declined with intensifying drought stress level with the water potential of-0.6 Mpa as the turning point;the relative germination rate of tall fescue existed linear relationship with drought stress：Y = 70.412X ＋ 103.11,r=0.988 8.The sensible water potential range was ≥-0.40 Mpa for tall fescue under drought stress.LC50 of water potential was-0.76 Mpa,the lethal water potential was-1.33 Mpa.Arid Ⅲ,Crossfire Ⅱ and Traple A had stronger drought resistant ability,but Pixie,Infero and Poppoint had weaker drought resistant ability.[Conclusion] This study had provided reference for cultivated pasture and drought resistant breeding.展开更多
The biological effects during seed germination were investigated after the dry seeds of Stevia rebaudianum Bertoni were implanted with carbon ion beam of 75 keV and 10 14 ions/cm 2. The results showed that the g...The biological effects during seed germination were investigated after the dry seeds of Stevia rebaudianum Bertoni were implanted with carbon ion beam of 75 keV and 10 14 ions/cm 2. The results showed that the germination rate of carbon ion implanted seeds was slightly higher than that of the control, but the survival rate of the treated seedlings, on the contrary, was lower than that of the control (P<0.02), while the height of the treated seedlings was significantly higher than that of the control (P<0.01). On the 4th day after germination, the leaf cell wall in the treated group was thick, some high electron_dense substance deposited in the enlarged plasmodesma; Cell membrane creased with high electron_dense granules deposited on it. The plasma membrane protruded towards cell wall, and the granules shifted via plasmodesma or deposited onto cell wall. These phenomena may be related to the conveyance of implanted ions across cell wall, or be related to the accumulation of callose. In addition, the implantation of carbon ions could increase the lamellae of the chloroplast and cause high development of the chloroplast which sometimes contained two plastid centers in an individual chloroplast. Also, the highly developed cristae, abundant mitochondria and typical crystalloid structure in microbody could be found. All these results indicated that the anabolic and catabolic activities in the seedlings implanted with carbon ions before germination were obviously more active than those in the controls.展开更多
Seeds of Dodonaea viscosa （L.） Jacq, a representative species in dry and hot valleys in Southwest China, were chosen as experimental materials. In this experiment, the D. viscosa seeds were treated at 40, 60, 80 and...Seeds of Dodonaea viscosa （L.） Jacq, a representative species in dry and hot valleys in Southwest China, were chosen as experimental materials. In this experiment, the D. viscosa seeds were treated at 40, 60, 80 and 100℃ respectively before germination to study impacts of high temperature treatment on their generation rate and to further discuss the roles of fire during the process of vegetation formation in dry and hot valley areas of China. The results show that when the temperature was higher than 40 ℃, the germination rate of D. viscosa seeds was significantly higher than that of the control group, and the heat shock effect was apparent. The germination rate was the highest when the seeds were treated at 80 ℃ for 10 min, reaching 63.00%±2.55%. There was still a significant heat shock effect on the D. viscosa seeds which were stored for one year. In comparison with the conventional method of soaking seeds in hot water, the germination rate of D. viscose seeds which were treated at high temperature before germination increased significantly.展开更多
基金Supported by Scientific and Technological Program of Ningxia~~
文摘[Objective] The aim was to explore the effects of drought stress on germination of tall fescue.[Method] Simulation drought experiment on 14 varieties of tall fescue seeds by PEG-6000 researched its germination effect under drought resistance.[Result] The relative germination rate of all tall fescue varieties declined with intensifying drought stress level with the water potential of-0.6 Mpa as the turning point;the relative germination rate of tall fescue existed linear relationship with drought stress：Y = 70.412X ＋ 103.11,r=0.988 8.The sensible water potential range was ≥-0.40 Mpa for tall fescue under drought stress.LC50 of water potential was-0.76 Mpa,the lethal water potential was-1.33 Mpa.Arid Ⅲ,Crossfire Ⅱ and Traple A had stronger drought resistant ability,but Pixie,Infero and Poppoint had weaker drought resistant ability.[Conclusion] This study had provided reference for cultivated pasture and drought resistant breeding.
文摘The biological effects during seed germination were investigated after the dry seeds of Stevia rebaudianum Bertoni were implanted with carbon ion beam of 75 keV and 10 14 ions/cm 2. The results showed that the germination rate of carbon ion implanted seeds was slightly higher than that of the control, but the survival rate of the treated seedlings, on the contrary, was lower than that of the control (P<0.02), while the height of the treated seedlings was significantly higher than that of the control (P<0.01). On the 4th day after germination, the leaf cell wall in the treated group was thick, some high electron_dense substance deposited in the enlarged plasmodesma; Cell membrane creased with high electron_dense granules deposited on it. The plasma membrane protruded towards cell wall, and the granules shifted via plasmodesma or deposited onto cell wall. These phenomena may be related to the conveyance of implanted ions across cell wall, or be related to the accumulation of callose. In addition, the implantation of carbon ions could increase the lamellae of the chloroplast and cause high development of the chloroplast which sometimes contained two plastid centers in an individual chloroplast. Also, the highly developed cristae, abundant mitochondria and typical crystalloid structure in microbody could be found. All these results indicated that the anabolic and catabolic activities in the seedlings implanted with carbon ions before germination were obviously more active than those in the controls.
基金Supported by the National Water Pollution Control and Treatment Science and Technology Major Project(2012ZX07101-003-04-04)~~
文摘Seeds of Dodonaea viscosa （L.） Jacq, a representative species in dry and hot valleys in Southwest China, were chosen as experimental materials. In this experiment, the D. viscosa seeds were treated at 40, 60, 80 and 100℃ respectively before germination to study impacts of high temperature treatment on their generation rate and to further discuss the roles of fire during the process of vegetation formation in dry and hot valley areas of China. The results show that when the temperature was higher than 40 ℃, the germination rate of D. viscosa seeds was significantly higher than that of the control group, and the heat shock effect was apparent. The germination rate was the highest when the seeds were treated at 80 ℃ for 10 min, reaching 63.00%±2.55%. There was still a significant heat shock effect on the D. viscosa seeds which were stored for one year. In comparison with the conventional method of soaking seeds in hot water, the germination rate of D. viscose seeds which were treated at high temperature before germination increased significantly.
