By using the principles and methods of fractal geometry theory, the relationship between aboveground biomass and plant length or sheath height of Carex lasiocarpa population was studied. The results showed that there ...By using the principles and methods of fractal geometry theory, the relationship between aboveground biomass and plant length or sheath height of Carex lasiocarpa population was studied. The results showed that there was a good static fractal relationship between them, and the resulted fractal dimension was an efficient description of the accumulation of aboveground biomass in each organ. The dynamic fractal relationship showed that during the whole growing season, the increase of aboveground biomass had a self-similarity, being a fractal growth process, and the pattern of its increase was the fractal dimension D. Based on these results, a fractal growth model of Carex lasiocarpa population was established, which regarded the bigger grass as the result of the amplification of seedling growth.展开更多
五柱绞股蓝 新种 图1 Gynostemma pentagynum Z. P. Wang, sp. nov. Species isolata, a congenera caulis et petiolia longe villosa, floribus masculis in panicula parva 3—5 cm longa dispositis, foemineis solitariis vel 2 (3...五柱绞股蓝 新种 图1 Gynostemma pentagynum Z. P. Wang, sp. nov. Species isolata, a congenera caulis et petiolia longe villosa, floribus masculis in panicula parva 3—5 cm longa dispositis, foemineis solitariis vel 2 (3) in raeemo aggregatis, pedicellis usque 4 cm longis, gynoeciis e carpellis 5 (4)constatis differt.展开更多
叶面积指数（leaf area index,LAI）是表征植被冠层结构和光合面积的重要参数。实时动态的植被LAI监测对于诊断植被生长状况及趋势具有重要作用。本研究旨在通过对高光谱数据的数学变换与特征分析,构建东洞庭湖苔草LAI的最佳估算模型。...叶面积指数（leaf area index,LAI）是表征植被冠层结构和光合面积的重要参数。实时动态的植被LAI监测对于诊断植被生长状况及趋势具有重要作用。本研究旨在通过对高光谱数据的数学变换与特征分析,构建东洞庭湖苔草LAI的最佳估算模型。通过分析52组苔草样本640~780 nm波段范围内的反射率、一阶微分及倒数的对数的光谱特征,选择特征波段,运用多元逐步线性回归法与偏最小二乘回归法建立估算模型。研究发现特征波段为707～758 nm,以上3种光谱数据的多元逐步线性回归模型决定系数分别为0.526、0.815、0.565,均方根误差分别为0.320、0.269、0.273,3者偏最小二乘回归模型的决定系数均高达0.9以上,均方根误差分别为0.189、0.262、0.134。结果表明：偏最小二乘回归法优于多元逐步线性回归法,该估算模型可有效估算苔草LAI。展开更多
Carex rigescens （Franch.） V. Krecz is a wild turfgrass perennial species in the Carex genus that is widely distributed in salinised areas of northern China. To investigate genome-wide salt-response gene networks in ...Carex rigescens （Franch.） V. Krecz is a wild turfgrass perennial species in the Carex genus that is widely distributed in salinised areas of northern China. To investigate genome-wide salt-response gene networks in C. rigescens, transcriptome analysis using high-throughput RNA sequencing on C. rigescens exposed to a 0.4% salt treatment （Cr_Salt） was compared to a non-salt control （Cr_Ctrl）. In total, 57 742 546 and 47 063 488 clean reads were obtained from the Cr Ctrl and Cr Salt treatments, respectively. Additionally, 21 954 unigenes were found and annotated using multiple databases. Among these unigenes, 34 were found to respond to salt stress at a statistically significant level with 6 genes up-regulated and 28 downregulated. Specifically, genes encoding an EF-hand domain, ZFP and AP2 were responsive to salt stress, highlighting their roles in future research regarding salt tolerance in C. rigescens and other plants. According to our quantitative RT-PCR results, the expression pattern of all detected differentially expressed genes were consistent with the RNA-seq results. Furthermore, we identified 11 643 simple sequence repeats （SSRs） from the unigenes. A total of 144 amplified successfully in the C. rigescens cultivar LOping 1, and 69 of them reflected polymorphisms between the two genotypes tested. This is the first genome-wide transcriptome study of C. rigescens in both salt-responsive gene investigation and SSR marker exploration. Our results provide further insights into genome annotation, novel gene discovery, molecular breeding and comparative genomics in C. rigescens and related grass species.展开更多
文摘By using the principles and methods of fractal geometry theory, the relationship between aboveground biomass and plant length or sheath height of Carex lasiocarpa population was studied. The results showed that there was a good static fractal relationship between them, and the resulted fractal dimension was an efficient description of the accumulation of aboveground biomass in each organ. The dynamic fractal relationship showed that during the whole growing season, the increase of aboveground biomass had a self-similarity, being a fractal growth process, and the pattern of its increase was the fractal dimension D. Based on these results, a fractal growth model of Carex lasiocarpa population was established, which regarded the bigger grass as the result of the amplification of seedling growth.
文摘五柱绞股蓝 新种 图1 Gynostemma pentagynum Z. P. Wang, sp. nov. Species isolata, a congenera caulis et petiolia longe villosa, floribus masculis in panicula parva 3—5 cm longa dispositis, foemineis solitariis vel 2 (3) in raeemo aggregatis, pedicellis usque 4 cm longis, gynoeciis e carpellis 5 (4)constatis differt.
文摘叶面积指数（leaf area index,LAI）是表征植被冠层结构和光合面积的重要参数。实时动态的植被LAI监测对于诊断植被生长状况及趋势具有重要作用。本研究旨在通过对高光谱数据的数学变换与特征分析,构建东洞庭湖苔草LAI的最佳估算模型。通过分析52组苔草样本640~780 nm波段范围内的反射率、一阶微分及倒数的对数的光谱特征,选择特征波段,运用多元逐步线性回归法与偏最小二乘回归法建立估算模型。研究发现特征波段为707～758 nm,以上3种光谱数据的多元逐步线性回归模型决定系数分别为0.526、0.815、0.565,均方根误差分别为0.320、0.269、0.273,3者偏最小二乘回归模型的决定系数均高达0.9以上,均方根误差分别为0.189、0.262、0.134。结果表明：偏最小二乘回归法优于多元逐步线性回归法,该估算模型可有效估算苔草LAI。
基金supported by the National Natural Science Foundation of China (31472139)
文摘Carex rigescens （Franch.） V. Krecz is a wild turfgrass perennial species in the Carex genus that is widely distributed in salinised areas of northern China. To investigate genome-wide salt-response gene networks in C. rigescens, transcriptome analysis using high-throughput RNA sequencing on C. rigescens exposed to a 0.4% salt treatment （Cr_Salt） was compared to a non-salt control （Cr_Ctrl）. In total, 57 742 546 and 47 063 488 clean reads were obtained from the Cr Ctrl and Cr Salt treatments, respectively. Additionally, 21 954 unigenes were found and annotated using multiple databases. Among these unigenes, 34 were found to respond to salt stress at a statistically significant level with 6 genes up-regulated and 28 downregulated. Specifically, genes encoding an EF-hand domain, ZFP and AP2 were responsive to salt stress, highlighting their roles in future research regarding salt tolerance in C. rigescens and other plants. According to our quantitative RT-PCR results, the expression pattern of all detected differentially expressed genes were consistent with the RNA-seq results. Furthermore, we identified 11 643 simple sequence repeats （SSRs） from the unigenes. A total of 144 amplified successfully in the C. rigescens cultivar LOping 1, and 69 of them reflected polymorphisms between the two genotypes tested. This is the first genome-wide transcriptome study of C. rigescens in both salt-responsive gene investigation and SSR marker exploration. Our results provide further insights into genome annotation, novel gene discovery, molecular breeding and comparative genomics in C. rigescens and related grass species.
