From the breeding of conventional dwarf rice varieties in the 1960 s to rice heterosis utilization in the 1970 s, the improvement of yield traits has been a primary goal of rice breeding. However, the yield potential ...From the breeding of conventional dwarf rice varieties in the 1960 s to rice heterosis utilization in the 1970 s, the improvement of yield traits has been a primary goal of rice breeding. However, the yield potential of multiple hybrid rice varieties bred successfully in recent twenty years is not significantly higher than that of early bred rice varieties. Due to continuous development and application of new germplasm resources, the yield of conventional rice varieties has been improved constantly. Currently, the yield of some conventional rice varieties is higher than that of hybrid rice. In order to clarify differences between the yield of conventional rice and hybrid rice, and reevaluate conventional rice varieties, in this study, conventional rice and hybrid rice combinations with the same genetic background were compared to analyze the yield and related traits of these 12 combinations. In the comparative experiments of 12 combinations of conventional rice and hybrid rice, the combinations in which yield of hybrid rice was significantly higher than that of conventional rice accounted for 41.7%; the combinations in which yield of conventional rice was higher than that of hybrid rice accounted for 16.6%; the combinations in which no significant differences were found between the yield of conventional rice and hybrid rice accounted for 41.7%. The yield of several conventional rice varieties was equal to or even higher than that of hybrid rice with the same genetic background. This study could provide theoretical reference for the genetic breeding, popularization and application of conventional rice.展开更多
In this paper, Hardy operator H on n-dimensional product spaces G = (0, ∞)n and its adjoint operator H* are investigated. We use novel methods to obtain two main results. One is that we characterize the sufficient an...In this paper, Hardy operator H on n-dimensional product spaces G = (0, ∞)n and its adjoint operator H* are investigated. We use novel methods to obtain two main results. One is that we characterize the sufficient and necessary conditions for the operators H and H* being bounded from Lp(G, xα) to Lq(G, xβ), and the bounds of the operators H and H* are explicitly worked out. The other is that when 1 < p = q < +∞, norms of the operators H and H* are obtained.展开更多
基金Supported by Key Scientific and Technological Project of Chongqing Municipality(cstc2012gg B80005)Scientific and Technological Talent Training Project of Chongqing Municipality(cstc2013kjrc-qnrc80002,cstc2013kjrc-tdjs80004)~~
文摘From the breeding of conventional dwarf rice varieties in the 1960 s to rice heterosis utilization in the 1970 s, the improvement of yield traits has been a primary goal of rice breeding. However, the yield potential of multiple hybrid rice varieties bred successfully in recent twenty years is not significantly higher than that of early bred rice varieties. Due to continuous development and application of new germplasm resources, the yield of conventional rice varieties has been improved constantly. Currently, the yield of some conventional rice varieties is higher than that of hybrid rice. In order to clarify differences between the yield of conventional rice and hybrid rice, and reevaluate conventional rice varieties, in this study, conventional rice and hybrid rice combinations with the same genetic background were compared to analyze the yield and related traits of these 12 combinations. In the comparative experiments of 12 combinations of conventional rice and hybrid rice, the combinations in which yield of hybrid rice was significantly higher than that of conventional rice accounted for 41.7%; the combinations in which yield of conventional rice was higher than that of hybrid rice accounted for 16.6%; the combinations in which no significant differences were found between the yield of conventional rice and hybrid rice accounted for 41.7%. The yield of several conventional rice varieties was equal to or even higher than that of hybrid rice with the same genetic background. This study could provide theoretical reference for the genetic breeding, popularization and application of conventional rice.
基金supported by National Natural Science Foundation of China (Grant Nos.11071250 and 10931001)
文摘In this paper, Hardy operator H on n-dimensional product spaces G = (0, ∞)n and its adjoint operator H* are investigated. We use novel methods to obtain two main results. One is that we characterize the sufficient and necessary conditions for the operators H and H* being bounded from Lp(G, xα) to Lq(G, xβ), and the bounds of the operators H and H* are explicitly worked out. The other is that when 1 < p = q < +∞, norms of the operators H and H* are obtained.