Dissertation
Dissertation > Agricultural Sciences > Crop > Cereal crops > Buckwheat

Physiological Ecology Responses of Fagopyrum Diabotrys (D.Don) Hara and F.esculentum Moench. under Enhanced UV-B Radiation and Drought Stress Conditions

Author ZhangYiFeng
Tutor HePing
School Southwestern University
Course Botany
Keywords Fago Buckwheat Enhanced UV-B radiation Drought Stress Physiology and Ecology
CLC S517
Type PhD thesis
Year 2010
Downloads 396
Quotes 4
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The world's arid and semi-arid regions account for about half of the arable land, these areas lack of water supply, forest vegetation is sparse thin, the deterioration of the ecological environment, serious soil erosion and frequent natural disasters. Global climate change and local drought will lead to more and more arid, semi-arid areas subject to more severe drought stress affected. Drought stress on plants is multifaceted, including biomass accumulation and distribution of photosynthetic pigments to protect the material and protective enzyme system. The attenuation of the stratospheric ozone layer will directly lead to the surface of UV-B radiation (280-315 nm) enhanced to cause inevitable impact on plant growth and development. Therefore, enhanced UV-B radiation is bound to affect the response or sensitivity of plants to drought stress. Gold buckwheat (Fagopyrum dibotrys (D.Don) Hara) is not only a national II level key protected wild plants, and pharmacological and clinical aspects have high medicinal value because of its medicinal value, Fago increasing demand. Buckwheat (Fagopyrum esculentum Moench.) Is a country and widely cultivated crops with high nutritional value. In this paper, the simulation of enhanced UV-B radiation and drought stress under gold buckwheat and buckwheat biomass accumulation and distribution, leaf photosynthetic pigments, leaf protection material and protective enzymes response compared two buckwheat species under the above conditions of plasticity differences, in order to explore means of enhancing the impact of UV-B radiation in the dry plants under drought stress, in order to provide a theoretical basis for the protection and utilization and buckwheat cultivation of Fago. 1) drought stress led to gold buckwheat and buckwheat vegetative organs biomass and total biomass accumulation reduced, and with the deepening of the degree of drought stress, this decreasing trend is more obvious. Buckwheat root biomass allocation with the aggravation of drought stress significantly increased, the Fago no obvious rule. Gold buckwheat and buckwheat stem mass with configuration and Biomass Distribution of drought stress deepening downward trend. Large adequate moisture conditions: enhanced UV-B radiation significantly reduced the gold buckwheat and buckwheat root biological amount of leaf biomass and total biological amount of accumulation: enhanced UV-B radiation equally reduce the gold buckwheat stem biomass accumulation, and buckwheat stems biomass accumulation is not sensitive to enhanced UV-B radiation: enhanced UV-B radiation buckwheat inflorescence biomass accumulation increased; enhanced UV-B radiation reduces the the Fagopyrum root biomass allocation, and buckwheat root biomass allocation not sensitive to enhanced UV-B radiation; enhanced UV-B radiation can increase the gold buckwheat and buckwheat stem biomass allocation; gold buckwheat leaf biomass allocation is not sensitive to enhanced UV-B radiation, enhanced UV-B radiation reduces buckwheat leaf biomass allocation; enhanced UV-B radiation can improve the buckwheat inflorescence biomass allocation. In moderate drought stress: Enhanced UV-B radiation increased gold buckwheat and buckwheat root biomass accumulation; enhanced UV-B radiation can make gold buckwheat and buckwheat stem biomass accumulation improved, but this effect only in specific reached a significant level processing point in time; enhanced UV-B radiation causes the the Fago leaf biomass accumulation of first and then decreased, but increased the buckwheat leaf biomass accumulation; enhanced UV-B radiation buckwheat inflorescence biomass accumulation liter high; enhanced UV-B radiation to improve the Fago root biomass allocation, but lower buckwheat root biomass allocation; gold buckwheat and buckwheat stem biomass configuration is not sensitive to enhanced UV-B radiation; gold buckwheat leaf biomass allocation to enhance UV-B radiation is not sensitive, enhanced UV-B radiation specific period of time can improve the buckwheat leaf biomass allocation: Buckwheat inflorescence biomass allocation is not sensitive to UV-B radiation enhanced. Under severe drought stress: Enhanced UV-B radiation increased gold buckwheat and buckwheat root biomass accumulation; enhanced UV-B radiation can make gold buckwheat and buckwheat stem biomass accumulation of a certain increase, but this effect only in the specific treatment time point reached significant level; gold buckwheat leaf biomass enhanced UV-B radiation is not sensitive, enhanced UV-B radiation has significantly enhanced the accumulation of buckwheat leaf biomass; enhanced UV-B radiation to make buckwheat The the the inflorescence biomass accumulation increased; gold buckwheat root biomass allocation is not sensitive to enhanced UV-B radiation, enhanced UV-B radiation has increased the buckwheat root biomass allocation; enhanced UV-B radiation on gold buckwheat and buckwheat stems biological The amount of configuration had no significant effect; gold buckwheat leaf biomass configuration is not sensitive to enhanced UV-B radiation radiation and enhanced UV-B radiation significantly improve the buckwheat leaf biomass configuration; enhanced UV-B radiation to reduce the buckwheat inflorescence biomass configuration . From the the plasticity index point of view of the biomass characteristics, UV-B radiation or drought treatment gold buckwheat biomass characteristics plasticity than buckwheat, Fago in biomass characteristics showed the plasticity higher than the buckwheat. 2) gold buckwheat and buckwheat leaf chlorophyll a content, chlorophyll b and total chlorophyll content with the drought in the severity of reduced: plenty of water conditions, enhanced UV-B radiation reduces the gold buckwheat and buckwheat content of chlorophyll a, chlorophyll B content and total chlorophyll content; under drought stress, in addition to gold buckwheat chlorophyll a content is not sensitive to enhanced UV-B radiation, enhanced UV-B radiation can improve the buckwheat content of chlorophyll a, gold buckwheat and buckwheat chlorophyll b content and total chlorophyll content. Fago chlorophyll a / chlorophyll b with the severity of the drought stress reduced, the most obvious in the mid: moderate drought stress in dealing with the medium-term to improve the buckwheat chlorophyll a / chlorophyll b; plenty of water under drought stress, chlorophyll a / chlorophyll b ratio is not sensitive to UV-B radiation enhanced. Gold buckwheat and buckwheat leaf carotenoid content with the drought stress aggravate reduced; only plenty of water conditions, enhanced UV-B radiation increased gold buckwheat leaf carotenoid content, and other water conditions, gold buckwheat and buckwheat leaf carotenoid content is not very sensitive to enhanced UV-B radiation. A golden buckwheat and buckwheat carotenoids / chlorophyll ratio with the deepening of the degree of drought elevated basic treatment in the late reached a significant level, to the latter; plenty of water conditions, enhanced UV-B radiation significantly increased the gold buckwheat carotenoids / chlorophyll ratio, and other water status, the gold buckwheat and buckwheat class of carotenoids / chlorophyll ratio is not very sensitive to enhanced UV-B radiation. From the plasticity index of photosynthetic pigments, UV-B radiation or drought gold buckwheat photosynthetic pigments plasticity than buckwheat, Fago in photosynthetic pigments showed the plasticity higher than the buckwheat. 3) gold buckwheat and buckwheat SOD activity, total flavonoid content, content of MDA and soluble sugar content with drought stress increased significantly with rising; POD activity increased with deepening drought stress and reached a significant level in the medium-term, and in early and late, this effect seems to have weakened; treatment before the mid-free proline content increased with the aggravation of drought stress, in the late period of treatment had no significant law; of Fago soluble protein content in the pre-treatment with drought the deepening of the stress increased to late with the deepening of drought stress decreased the buckwheat soluble protein content in the deepening of the early stage of the degree with the drought and increased, and in the late period of treatment is just the opposite. Plenty of water conditions, enhanced UV-B radiation treatment increased gold buckwheat and buckwheat leaf SOD activity, total flavonoid content, free proline content and MDA; enhanced UV-B radiation in the treatment of early and late improve Fagopyrum POD activity, buckwheat is different, enhanced UV-B radiation in the treatment of post-reduced POD activity; enhanced UV-B radiation in the early stage of increased gold buckwheat leaf soluble protein content, and reduced in the latter part of Gold buckwheat and buckwheat leaf soluble protein content; enhanced UV-B radiation reduces the gold buckwheat and buckwheat leaf soluble sugar content. Under drought stress, enhanced UV-B radiation in dealing with the mid-gold buckwheat SOD activity is decreased in dealing with pre-and post its SOD activity increased; enhanced UV-B radiation in the treatment of post-gold buckwheat leaf the P.OD activity, but reduce the buckwheat leaf POD activity; enhanced UV-B radiation in the treatment of post-reduced the buckwheat leaf total flavonoid content; enhanced UV-B radiation increased gold buckwheat leaf free proline content in mid- buckwheat leaf free proline content; enhanced UV-B radiation increased gold buckwheat and buckwheat leaf malondialdehyde content; moderate drought stress, enhanced UV-B radiation increased gold of buckwheat leaf soluble protein content, severe drought stress, enhanced UV-B radiation in the treatment before the mid-improve gold the buckwheat leaf soluble protein content, while in the latter part of the reduced leaf soluble protein content, and buckwheat leaf soluble protein content is always enhanced UV -B radiation sensitive; enhanced UV-B radiation significantly reduced the gold buckwheat leaf soluble sugar content, and buckwheat have this effect only under severe drought stress. Fago protective enzymes and protective substances in the processing of UV-B radiation and drought, showed greater plasticity than buckwheat. In short, under drought conditions enhanced UV-B radiation does not exacerbate the damage of gold buckwheat and buckwheat, to some extent help to improve both resistance to drought.

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