When cultured under certain environmental coriditions (25℃, light intensity 80 μmol/m<sup>2</sup> ·s, LD12/12, in enriched seawater medium with 7 × 10<sup>-4</sup>mol/L NO<sub>...When cultured under certain environmental coriditions (25℃, light intensity 80 μmol/m<sup>2</sup> ·s, LD12/12, in enriched seawater medium with 7 × 10<sup>-4</sup>mol/L NO<sub>3</sub>,-N, 1.56× 10<sup>-4</sup>mol/L, PO<sub>4</sub>-P and supplementsof other elements like Mn, Fe, I, etc.), mate and female gametophytes of U pinnatifida keptgrowing vegetatively and propagated fast at average daily fresh weight increase rate of about 20%. Theempirical formula G<sub>m</sub>=G<sub>o</sub>. 3<sup>m</sup> was established to estimate the output of vegeative gametophytes. Vigorousvegetative gametophyte cells began to form reproductive structures (oogonium and spermatangium, whenthe tmperature was lower than 25℃ and other environmental factors wrre kept optimal. The sufficientsupply of gametophyte cells provided enough seeds for raising Undaria sporelings on prodiction scale.Controlled cross-breeding experiments using selcted male and female gametophyte clones which increasetheir cell number by mitosis instead of meiosis were also carried out in vitro. Juvenile sporophytes fromthe展开更多
Field research in this paper was carried out in Baiyinxil State-owned Rangeland （SOR）, which is 55 kms southeast of Xilingol City in Xilingol League, Inner Mongolia Autonomous Region （IMAR）. The area established t...Field research in this paper was carried out in Baiyinxil State-owned Rangeland （SOR）, which is 55 kms southeast of Xilingol City in Xilingol League, Inner Mongolia Autonomous Region （IMAR）. The area established the first grassland nature reserve in China as well as the first SOR in IMAR. By reviewing its 60 years of development, the paper analyzes local herders＇ ecological ideology （the cycle made of human-grassland-livestock and none of which could be neglected） and the modern nation-state＇s policy implementation in ecological resettlement, institutional changes, and livestock cross-breeding. The purpose of the research is to discuss three pairs of socio-ecological relationships in Inner Mongolia grassland： between population flow and regional development, traditional ideology and grassland management ideology, as well as the competition between local knowledge and modern science and technology. The author argues that grassland management is a cyclical process and the deterioration of grassland ecology in IMAR is simply a reflection of the imbalance of three key elements （human-institution-cattle） in maintaining grassland ecology.展开更多
基金Supported by National Natural Science Foundation of China.
文摘When cultured under certain environmental coriditions (25℃, light intensity 80 μmol/m<sup>2</sup> ·s, LD12/12, in enriched seawater medium with 7 × 10<sup>-4</sup>mol/L NO<sub>3</sub>,-N, 1.56× 10<sup>-4</sup>mol/L, PO<sub>4</sub>-P and supplementsof other elements like Mn, Fe, I, etc.), mate and female gametophytes of U pinnatifida keptgrowing vegetatively and propagated fast at average daily fresh weight increase rate of about 20%. Theempirical formula G<sub>m</sub>=G<sub>o</sub>. 3<sup>m</sup> was established to estimate the output of vegeative gametophytes. Vigorousvegetative gametophyte cells began to form reproductive structures (oogonium and spermatangium, whenthe tmperature was lower than 25℃ and other environmental factors wrre kept optimal. The sufficientsupply of gametophyte cells provided enough seeds for raising Undaria sporelings on prodiction scale.Controlled cross-breeding experiments using selcted male and female gametophyte clones which increasetheir cell number by mitosis instead of meiosis were also carried out in vitro. Juvenile sporophytes fromthe
文摘Field research in this paper was carried out in Baiyinxil State-owned Rangeland （SOR）, which is 55 kms southeast of Xilingol City in Xilingol League, Inner Mongolia Autonomous Region （IMAR）. The area established the first grassland nature reserve in China as well as the first SOR in IMAR. By reviewing its 60 years of development, the paper analyzes local herders＇ ecological ideology （the cycle made of human-grassland-livestock and none of which could be neglected） and the modern nation-state＇s policy implementation in ecological resettlement, institutional changes, and livestock cross-breeding. The purpose of the research is to discuss three pairs of socio-ecological relationships in Inner Mongolia grassland： between population flow and regional development, traditional ideology and grassland management ideology, as well as the competition between local knowledge and modern science and technology. The author argues that grassland management is a cyclical process and the deterioration of grassland ecology in IMAR is simply a reflection of the imbalance of three key elements （human-institution-cattle） in maintaining grassland ecology.
