[Objective] The aim of this study was to compare the morphological char- acteristics of rice （Oryza sativa L.） with different cultivation methods and investigate the dynamics of organ growth and development characte...[Objective] The aim of this study was to compare the morphological char- acteristics of rice （Oryza sativa L.） with different cultivation methods and investigate the dynamics of organ growth and development characteristics of different rice culti- vars. [Method] Based on continuous field observation and destructive sampling over a growing season, detailed organ morphological data were obtained including leaf length, node number, plant height, tiller number, leaf angle, leaf area and specific leaf weight, to compare organ morphological differences among 4 rice cultivars of Baidao （indica）, Jinnanfeng （japonica）, 9325 （japonica） and 9915 （japonica） with 3 cultivation methods of field planting in Weigang, pot planting in Weigang, and field planting in Jiangpu. [Result] Maximum leaf length of each node gradually increased at the early growth stage and decreased at the later growth stage, the relationship between maximum leaf length and node position can be described by the equations y=a,,-~ and y=ax＋b; node number, growth duration, leaf length and plant height of pot planting rice in Weigang were smaller than that of the other two field planting meth- ods; the relationship between plant height and sunshine duration, plant height and GDD （growing degree days） can be described by the equation y=ax＋b, 19.23 ℃.d of GDD （≥10 ≥-d） and 8.12 h of sunshine duration were required to increase 1 cm of plant height; plant height, tiller number, and leaf area of Baidao were higher than that of the other 3 laponica rice cultivars, but the specific leaf weight and leaf angle were smaller. [Conclusion] Comparison of morphological characteristic differ- ences among rice cultivars is an important way to select water-saving and drought- tolerant rice varieties. In this study, the experimental results can be integrated into a rice functional-architectural model to simulate rice organ growth dynamics in a three- dimensional space, thereby providing reference for selecting water-saving and drought-tolerant rice cultivars.展开更多
A fundamental result in the theory of minimal rational curves on projective manifolds is Cartan- Fubini extension theorem proved by Hwang and Mok, which describes the extensibility of biholomorphisms between connected...A fundamental result in the theory of minimal rational curves on projective manifolds is Cartan- Fubini extension theorem proved by Hwang and Mok, which describes the extensibility of biholomorphisms between connected open subsets of two Fano manifolds of Picard number 1 which preserve varieties of minimal rational tangents （VMRT）, under a mild geometric assumption on the second fundamental forms of VMRT＇s. Hong and Mok have developed Cartan-Fubini extension for non-equidimensional holomorphic immersions from a connected open subset of a Pano manifold of Picard number 1 into a uniruled projective manifold, under the assumptions that the map sends VMRT＇s onto linear sections of VMRT＇s and it satisfies a mild geometric condition formulated in terms of second fundamental forms on VMRT＇s. In the current paper, we give a generalization of Hong and Mok＇s result, under the same condition on second fundamental forms, assuming only that the holomorphic immersions send VMRT＇s to VMRT＇s. Our argument is different from Hong and Mok＇s and is based on the study of natural foliations on the total family of VMRT＇s. This gives a substantially simpler proof than Hong and Mok＇s argument.展开更多
基金Supported by National Natural Science Foundation of China(31101084)Scientific Research Foundation of the Education Ministry for Returned Chinese Scholars~~
文摘[Objective] The aim of this study was to compare the morphological char- acteristics of rice （Oryza sativa L.） with different cultivation methods and investigate the dynamics of organ growth and development characteristics of different rice culti- vars. [Method] Based on continuous field observation and destructive sampling over a growing season, detailed organ morphological data were obtained including leaf length, node number, plant height, tiller number, leaf angle, leaf area and specific leaf weight, to compare organ morphological differences among 4 rice cultivars of Baidao （indica）, Jinnanfeng （japonica）, 9325 （japonica） and 9915 （japonica） with 3 cultivation methods of field planting in Weigang, pot planting in Weigang, and field planting in Jiangpu. [Result] Maximum leaf length of each node gradually increased at the early growth stage and decreased at the later growth stage, the relationship between maximum leaf length and node position can be described by the equations y=a,,-~ and y=ax＋b; node number, growth duration, leaf length and plant height of pot planting rice in Weigang were smaller than that of the other two field planting meth- ods; the relationship between plant height and sunshine duration, plant height and GDD （growing degree days） can be described by the equation y=ax＋b, 19.23 ℃.d of GDD （≥10 ≥-d） and 8.12 h of sunshine duration were required to increase 1 cm of plant height; plant height, tiller number, and leaf area of Baidao were higher than that of the other 3 laponica rice cultivars, but the specific leaf weight and leaf angle were smaller. [Conclusion] Comparison of morphological characteristic differ- ences among rice cultivars is an important way to select water-saving and drought- tolerant rice varieties. In this study, the experimental results can be integrated into a rice functional-architectural model to simulate rice organ growth dynamics in a three- dimensional space, thereby providing reference for selecting water-saving and drought-tolerant rice cultivars.
基金supported by National Researcher Program of National Research Foundation of Korea(Grant No.2010-0020413)
文摘A fundamental result in the theory of minimal rational curves on projective manifolds is Cartan- Fubini extension theorem proved by Hwang and Mok, which describes the extensibility of biholomorphisms between connected open subsets of two Fano manifolds of Picard number 1 which preserve varieties of minimal rational tangents （VMRT）, under a mild geometric assumption on the second fundamental forms of VMRT＇s. Hong and Mok have developed Cartan-Fubini extension for non-equidimensional holomorphic immersions from a connected open subset of a Pano manifold of Picard number 1 into a uniruled projective manifold, under the assumptions that the map sends VMRT＇s onto linear sections of VMRT＇s and it satisfies a mild geometric condition formulated in terms of second fundamental forms on VMRT＇s. In the current paper, we give a generalization of Hong and Mok＇s result, under the same condition on second fundamental forms, assuming only that the holomorphic immersions send VMRT＇s to VMRT＇s. Our argument is different from Hong and Mok＇s and is based on the study of natural foliations on the total family of VMRT＇s. This gives a substantially simpler proof than Hong and Mok＇s argument.
