物种多样性(SD)与功能多样性(FD)之间存在多种关系,但由于生态系统功能主要由物种的功能属性决定,因而功能多样性对生态系统功能的影响大于物种多样性的影响。但在种间性状差异和物种均匀度这两个构成功能多样性的基本成分中,何者对功...物种多样性(SD)与功能多样性(FD)之间存在多种关系,但由于生态系统功能主要由物种的功能属性决定,因而功能多样性对生态系统功能的影响大于物种多样性的影响。但在种间性状差异和物种均匀度这两个构成功能多样性的基本成分中,何者对功能多样性影响更大,并进而决定SD-FD关系尚不明确。通过在高寒矮嵩草(Kobresia humilis)草甸为期6a的刈割(留茬1 cm、3 cm及不刈割)和施肥(尿素7.5 g m^(-2)a^(-1)+磷酸二胺1.8 g m^(-2)a^(-1)、不施肥)控制实验,研究了种间性状差异(33个物种13个性状)和物种均匀度(所有物种)对物种多样性(所有物种)与功能多样性(33个物种13个性状)之间关系的影响。研究结果显示:(1)物种多样性与功能多样性正相关,它们与多性状种间差异负相关,而与物种均匀度正相关。物种均匀度是导致功能多样性变化的主要因素,也是导致SD-FD正相关的原因,这是因为随着物种多样性增加,物种均匀度的增加程度大于多性状种间差异的减少程度,因而功能多样性增加,SD-FD正相关;(2)功能多样性指数(FD_(Rao)和FDis)随物种多样性指数(H')减速递增,表明群落存在一定的功能冗余,且功能冗余随物种多样性的增大而增大,但尚未达到产生SD-FD无相关性的极限H'值;(3)功能多样性对高寒草甸生态系统地上净初级生产力(ANPP)的影响大于物种多样性的影响,二元线性回归显示在同时考虑二者对ANPP的影响时,可排除物种多样性的作用。但由于物种多样性下降或物种丧失引起的物种功能性状丢失或性状空间维度减小将导致功能多样性降低,表明它们之间存在一定互补性,在研究生物多样性与生态系统功能关系时,同时考虑物种多样性和功能多样性的影响仍十分必要。展开更多
Both Brassica juncea(mustard)and B.napus(rapeseed)are allotetraploid species of Brassica.Although these two species have their unique characters,they possess a common A genome and a few homeologous chromosomes bet...Both Brassica juncea(mustard)and B.napus(rapeseed)are allotetraploid species of Brassica.Although these two species have their unique characters,they possess a common A genome and a few homeologous chromosomes between the genomes B and C,which provide the foundation for transfer of superior traits from B.juncea into worldwide cultivated B.napus.The unique characters of B.juncea were summarized,breeding procedure for introgression of superior traits from B.juncea into B.napus by the interspecific crossing proposed,and some recently developed rapeseed germplasm lines with novel traits such as yellow seed and super oil content,restorer of fertility for pol CMS,extreme early maturity,high oleic acid content and short-staure plant briefly introduced in this paper.展开更多
[Objective] This study aimed to investigate the genetic effects and heterosis of plant height and internode traits of japonica-indica hybrid rice. [Methed] Incomplete diallel crosses were made between six japonica CMS...[Objective] This study aimed to investigate the genetic effects and heterosis of plant height and internode traits of japonica-indica hybrid rice. [Methed] Incomplete diallel crosses were made between six japonica CMS lines and nine indica widecompatibility restorer lines; the genetic effects of plant height and internode traits of japonica-indica hybrid rice were analyzed using the additive-dominance genetic model. [Result] The ple, nt height, panicle length and the length of internode 1 of japonica-in- dica hybrid rice were mainly controlled by the additive effects; but the length of in- ternode 3, internode 4 and internode 5 were mainly controlled by dominance effects. Both the narrow sense heritability and broad sense heritability of plant height, panicle length, number of elongated internodes and length of most internodes reached signifi- cance level. The positive phenotypic correlation, genetic correlation, additive correla- tion and dominance correlation between plant height and panicle length, number of e- longated internodes and internode length were significant; and most of the other paired traits were significantly positively correlated. Heterosis analysis showed that the positive heterosis value over mid-parent and positive heterosis value over better- parent of the length of internode 3, internode 4, internode 5 and internode 6 reached significant level, and the heterosis value over mid-parent of plant height reached extreme significance level. [Conclusion] This study will provide reliable theoretical basis for the genetic improvement and heterosis utilization of plant height and internode traits in japonica-indica hybrid rice.展开更多
With super hybrid rice cultivar Y Liangyou 1 as the experimental material, seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight were investigated for continuous 10 days since the first day po...With super hybrid rice cultivar Y Liangyou 1 as the experimental material, seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight were investigated for continuous 10 days since the first day post-harvest to reveal the correlation between differences in seed-setting characters of rice and seed investiga- tion time. The results indicated that seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight varied at different seed investigation time. With the postponement of seed investigation, seed-setting rate and 1 000-seed weight showed downward trends, abortive grain rate showed an upward trend, while empty grain rate exhibited a significant correlation with seed investigation time. Seed-setting rate, abortive grain rate and 1 000-seed weight exhibited no significant differences within the first three days after the harvest; since day 4, seed-setting rate and 1000-seed weight declined remarkably, while abortive grain rate increased signifi- cantly. Based on the correlation between seed-setting characters of rice and seed investigation time, the analysis of seed-setting characters of rice and other cereal crops should be completed within the first three days after the harvest, thereby im- proving the accuracy of relative conclusion.展开更多
While recent studies have shown the importance of intraspecific trait variation in the processes of community assembly,we still know little about the contributions of intraspecific trait variability to ecosystem funct...While recent studies have shown the importance of intraspecific trait variation in the processes of community assembly,we still know little about the contributions of intraspecific trait variability to ecosystem functions.Here,we conducted a functional group removal experiment in an alpine meadow in Qinghai-Tibetan Plateau over 4 years to investigate the relative importance of inter-and intraspecific variability in plant height for productivity.We split total variability in plant height within each of 75 manipulated communities into interspecific variability(TV_(inter))and intraspecific variability within a community(ITV_(within)).Community-weighted mean height among communities was decomposed into fixed community-weighted mean(CWM_(fixed))and intraspecific variability among communities(ITV_(among)).We constructed a series of generalized additive mixed models and piecewise structural equation modeling to determine how trait variability(i.e.TV_(inter),ITV_(within),CWM_(fixed) and ITV_(among))indirectly mediated the changes in productivity in response to functional group removal.Community productivity was not only affected directly by treatment manipulations,but also increased with both inter-and intraspecific variability(i.e.CWM_(fixed) and ITV_(among))in plant height indirectly.This suggests that both the‘selection effect’and a‘shade-avoidance syndrome’can incur higher CWM_(fixed) and ITV_(among),and may simultaneously operate to regulate productivity.Our findings provide new evidence that,besides interspecific variability,intraspecific trait variability in plant height also plays a role in maintaining net primary productivity.展开更多
Understanding how population sizes vary over time is a key aspect of ecological research. Unfortunately, our under- standing of population dynamics has historically been based on an assumption that individuals are ide...Understanding how population sizes vary over time is a key aspect of ecological research. Unfortunately, our under- standing of population dynamics has historically been based on an assumption that individuals are identical with homogenous life-history properties. This assumption is certainly false for most natural systems, raising the question of what role individual variation plays in the dynamics of populations. While there has been an increase of interest regarding the effects of within popula- tion variation on the dynamics of single populations, there has been little study of the effects of differences in within population variation on patterns observed across populations. We found that life-history differences (clutch size) among individuals ex- plained the majority of the variation observed in the degree to which population sizes of eastern fence lizards Sceloporus undula- tus fluctuated. This finding suggests that differences across populations cannot be understood without an examination of differences at the level of a system rather than at the level of the individual展开更多
文摘物种多样性(SD)与功能多样性(FD)之间存在多种关系,但由于生态系统功能主要由物种的功能属性决定,因而功能多样性对生态系统功能的影响大于物种多样性的影响。但在种间性状差异和物种均匀度这两个构成功能多样性的基本成分中,何者对功能多样性影响更大,并进而决定SD-FD关系尚不明确。通过在高寒矮嵩草(Kobresia humilis)草甸为期6a的刈割(留茬1 cm、3 cm及不刈割)和施肥(尿素7.5 g m^(-2)a^(-1)+磷酸二胺1.8 g m^(-2)a^(-1)、不施肥)控制实验,研究了种间性状差异(33个物种13个性状)和物种均匀度(所有物种)对物种多样性(所有物种)与功能多样性(33个物种13个性状)之间关系的影响。研究结果显示:(1)物种多样性与功能多样性正相关,它们与多性状种间差异负相关,而与物种均匀度正相关。物种均匀度是导致功能多样性变化的主要因素,也是导致SD-FD正相关的原因,这是因为随着物种多样性增加,物种均匀度的增加程度大于多性状种间差异的减少程度,因而功能多样性增加,SD-FD正相关;(2)功能多样性指数(FD_(Rao)和FDis)随物种多样性指数(H')减速递增,表明群落存在一定的功能冗余,且功能冗余随物种多样性的增大而增大,但尚未达到产生SD-FD无相关性的极限H'值;(3)功能多样性对高寒草甸生态系统地上净初级生产力(ANPP)的影响大于物种多样性的影响,二元线性回归显示在同时考虑二者对ANPP的影响时,可排除物种多样性的作用。但由于物种多样性下降或物种丧失引起的物种功能性状丢失或性状空间维度减小将导致功能多样性降低,表明它们之间存在一定互补性,在研究生物多样性与生态系统功能关系时,同时考虑物种多样性和功能多样性的影响仍十分必要。
文摘Both Brassica juncea(mustard)and B.napus(rapeseed)are allotetraploid species of Brassica.Although these two species have their unique characters,they possess a common A genome and a few homeologous chromosomes between the genomes B and C,which provide the foundation for transfer of superior traits from B.juncea into worldwide cultivated B.napus.The unique characters of B.juncea were summarized,breeding procedure for introgression of superior traits from B.juncea into B.napus by the interspecific crossing proposed,and some recently developed rapeseed germplasm lines with novel traits such as yellow seed and super oil content,restorer of fertility for pol CMS,extreme early maturity,high oleic acid content and short-staure plant briefly introduced in this paper.
基金Supported by National High Technology Research and Development Program of China(863Program,2010AA101301)Chinese Super Rice Breeding and Experiment Demonstration Program,Ministry of Agriculture+1 种基金the 0406 Program of zhejiang ProvinceScientific Research Fund of China National Rice Research Institute(2009RG001-5)~~
文摘[Objective] This study aimed to investigate the genetic effects and heterosis of plant height and internode traits of japonica-indica hybrid rice. [Methed] Incomplete diallel crosses were made between six japonica CMS lines and nine indica widecompatibility restorer lines; the genetic effects of plant height and internode traits of japonica-indica hybrid rice were analyzed using the additive-dominance genetic model. [Result] The ple, nt height, panicle length and the length of internode 1 of japonica-in- dica hybrid rice were mainly controlled by the additive effects; but the length of in- ternode 3, internode 4 and internode 5 were mainly controlled by dominance effects. Both the narrow sense heritability and broad sense heritability of plant height, panicle length, number of elongated internodes and length of most internodes reached signifi- cance level. The positive phenotypic correlation, genetic correlation, additive correla- tion and dominance correlation between plant height and panicle length, number of e- longated internodes and internode length were significant; and most of the other paired traits were significantly positively correlated. Heterosis analysis showed that the positive heterosis value over mid-parent and positive heterosis value over better- parent of the length of internode 3, internode 4, internode 5 and internode 6 reached significant level, and the heterosis value over mid-parent of plant height reached extreme significance level. [Conclusion] This study will provide reliable theoretical basis for the genetic improvement and heterosis utilization of plant height and internode traits in japonica-indica hybrid rice.
基金Supported by Project of China Meteorological Administration(2010154)Special Fund for Meteorological Research in the Public Interest(GYHY201206020,GYHY201006025)~~
文摘With super hybrid rice cultivar Y Liangyou 1 as the experimental material, seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight were investigated for continuous 10 days since the first day post-harvest to reveal the correlation between differences in seed-setting characters of rice and seed investiga- tion time. The results indicated that seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight varied at different seed investigation time. With the postponement of seed investigation, seed-setting rate and 1 000-seed weight showed downward trends, abortive grain rate showed an upward trend, while empty grain rate exhibited a significant correlation with seed investigation time. Seed-setting rate, abortive grain rate and 1 000-seed weight exhibited no significant differences within the first three days after the harvest; since day 4, seed-setting rate and 1000-seed weight declined remarkably, while abortive grain rate increased signifi- cantly. Based on the correlation between seed-setting characters of rice and seed investigation time, the analysis of seed-setting characters of rice and other cereal crops should be completed within the first three days after the harvest, thereby im- proving the accuracy of relative conclusion.
基金supported by the National Natural Science Foundation of China(31770518,31830009)Hainan University(RZ2000009932)to Shurong Zhou,Anhui Agricultural University(rc522108)and a China Scholarship Council scholarship to Li Zhang.
文摘While recent studies have shown the importance of intraspecific trait variation in the processes of community assembly,we still know little about the contributions of intraspecific trait variability to ecosystem functions.Here,we conducted a functional group removal experiment in an alpine meadow in Qinghai-Tibetan Plateau over 4 years to investigate the relative importance of inter-and intraspecific variability in plant height for productivity.We split total variability in plant height within each of 75 manipulated communities into interspecific variability(TV_(inter))and intraspecific variability within a community(ITV_(within)).Community-weighted mean height among communities was decomposed into fixed community-weighted mean(CWM_(fixed))and intraspecific variability among communities(ITV_(among)).We constructed a series of generalized additive mixed models and piecewise structural equation modeling to determine how trait variability(i.e.TV_(inter),ITV_(within),CWM_(fixed) and ITV_(among))indirectly mediated the changes in productivity in response to functional group removal.Community productivity was not only affected directly by treatment manipulations,but also increased with both inter-and intraspecific variability(i.e.CWM_(fixed) and ITV_(among))in plant height indirectly.This suggests that both the‘selection effect’and a‘shade-avoidance syndrome’can incur higher CWM_(fixed) and ITV_(among),and may simultaneously operate to regulate productivity.Our findings provide new evidence that,besides interspecific variability,intraspecific trait variability in plant height also plays a role in maintaining net primary productivity.
文摘Understanding how population sizes vary over time is a key aspect of ecological research. Unfortunately, our under- standing of population dynamics has historically been based on an assumption that individuals are identical with homogenous life-history properties. This assumption is certainly false for most natural systems, raising the question of what role individual variation plays in the dynamics of populations. While there has been an increase of interest regarding the effects of within popula- tion variation on the dynamics of single populations, there has been little study of the effects of differences in within population variation on patterns observed across populations. We found that life-history differences (clutch size) among individuals ex- plained the majority of the variation observed in the degree to which population sizes of eastern fence lizards Sceloporus undula- tus fluctuated. This finding suggests that differences across populations cannot be understood without an examination of differences at the level of a system rather than at the level of the individual