【作者】 欧祖兰；

【导师】 曹福亮；

【作者基本信息】 南京林业大学 ， 森林培育， 2009， 博士

【摘要】 本文以邳州市银杏种质资源圃20个银杏无性系和其中6个无性系的F1代(6个半同胞家系)幼苗为材料,在比较6个半同胞家系耐热性的基础上,以耐热性有明显差异的2个半同胞家系进行热适应机理研究;以耐热性、种核产量、单核重以及光合生产力等指标对20个无性系进行综合评价。研究结果表明:33#半同胞家系耐热性较差,37#半同胞家系耐热性较强,两者可以作为热适应机理研究的理想对比分析材料。热胁迫下,2个耐热性不同的半同胞家系相比,感热半同胞家系超微结构损伤较严重,相对含水量降幅较大,且O2-产生速率和H2O2、MDA含量及相对电导率增幅较大;耐热半同胞家系SOD活性和ASA含量增幅较大,可溶性糖和脯氨酸积累较多,正常蛋白质合成受阻温度和热激蛋白合成温度较高,光化学效率降幅较小,以及光合速率受热胁迫的影响较小;耐热半同胞家系可以通过加强蒸腾适应高温环境。耐热半同胞家系具有较强的耐热性,可能与热胁迫下特异表达及表达量上升的蛋白质种类多于感热半同胞家系有关,以及与2个半同胞家系Ca2+分布系统对热胁迫的响应不同有关。6个半同胞家系的耐热性与其半致死温度相关性分析可知,半致死温度能够有效评价银杏耐热性的相对差异;半同胞家系间的耐热性排序与无性系间的耐热性排序基本一致;27#、31#、57#无性系作为核用银杏在南移引种过程中具有较大潜力,尤其27#无性系是南移引种材料的最佳选择。更多还原

【Abstract】 In this paper, 20 clones of Ginkgo biloba growing in Ginkgo germplasm nursery in Pizhou city and 6 half-sib families 2a seedlings (the F1 of the above-mentioned 20 clones) were materials for study. First, the heat-tolerance of 6 half-sib families was assessed. Based on the result, the mechanism of heat adaptation was explored by comparing heat-sensitive half-sib family and heat-tolerant half-sib family. Further, 20 clones were assessed comprehensively basing on heat tolerance, nut yield, single nut weight, and photosynthetic productivity. The results were as follows:(1) The heat-tolerance of 33# half-sib familiy was poor, while that of 37# half-sib familie was strong, the two half-sib families were ideal contrast materials for exploring the mechanism of heat adaptation of G. biloba.(2) Under heat stress, the ultrastructuress of leaf mesophyll cells of G. biloba injured significantly, which happened more seriously in heat-sensitive half-sib family than heat-tolerant half-sib family. To a certain extent, there was a correlation between the change of ultrastructure and heat-tolerance.(3) Under heat stress, the physiological and biochemical activities of G. biloba changed dramatically. The leaf relative water content decreased with the increase of heat stress, the decrease range of relative water content of heat-sensitive half-sib family was larger than that of heat-tolerant half-sib family. Compared with heat-tolerant half-sib family, the increase amplitude of the production rate of O2-, the content of H2O2 and MDA, and relative electric conductivity were more. There was an obvious difference in SOD activity and ASA content between different heat-tolerance of materials and stress degree, and the increase amplitude of both SOD activity and ASA content of heat-tolerant half-sib family was more than that of heat-sensivity half-sib family. Heat stress caused soluble sugar and proline accumulate in both half-sib families, but more in heat-tolerant half-sib family compared to heat-sensitive half-sib family. The temperature at which normal proteins synthesis was blocked and the temperature at which heat shock proteins synthesis occurred was higher on heat-tolerant half-sib family than on heat-sensitive half-sib family. With the increasing of heat stress, photochemical efficiency deacreased and the reduction range of heat-sensitive family was larger than that of heat-tolerant family. The photosynthetic rate of heat-tolerant half-sib family was less affected by heat stress than heat-sensitive half-sib family, heat-tolerant half-sib family could strengthen transpiration to reduce leaf temperature in order to adapt to high-temperature environments.(4) Electrophoresis patterns of total proteins in the leaves of G. biloba were significantly affected by heat stress; down-regulated proteins and their ratio to the total proteins were higher in the heat-sensitive half-sib family, on the contrary, Up-regulated proteins and their ratio to the total proteins were higher in the heat-tolerant half-sib family. It suggested that the higher heat-tolerance in the heat-tolerant half-sib family may be related with its ability to produce more up-regulated proteins and special expressing proteins under heat stress.(5) Under heat stress, Ca2+ in leaf mesophyll of G. biloba tended to transport from vacuole to cytoplasm. Compared to control, the calcium antimonite deposits of Ca2+ in cytoplasm of heat-sensitive half-sib family were larger and aggregated abnormally as block shape, but the shape of the calcium antimonite deposits of Ca2+ of heat-tolerant half-sib family hardly changed. Under heat stress, different responses of Ca2+ distribution in two half-sib families on heat stress might be closely related to the heat-tolerance of G. biloba.(6) Based on the correlation between the heat-tolerance and semi-lethal temperature of above-mentioned 6 half-sib families of G. biloba, semi-lethal temperature was regarded as an effective parameter to assess heat tolerance of G. biloba. Hence, further assessment on the heat-tolerance of above-mentioned 20 clones was conducted by measuring the semi-lethal temperatures. The results showed that the heat-tolerance order among half-sib families was in agreement with that among clones. Moreover, to select tolerant superior clones, the nut yield clones, single nut weight, and photosynthetic of 20 strain were measured. The results showed that the clones of 27#, 31#, and 57# for nut-production clones had a great potential to grow in south China. Among them, 27# was the best choice for introduction towards south China.更多还原