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1.
Studies were conducted with rice varieties developed in recent years in Liaoning Province of China as test materials. Results showed that the varieties tested could be divided into three types: (1) the high-yielding (HYV), (2) the mediumyielding (MYV), and (3) the low-yielding (LYV). The panicle population was in the order of HYV〈 MYV 〈 LYV, while the grain number per panicle and seed-setting rate were just opposite. There was no significant difference in the 1 000-grain weight. Biomass was higher in HYV than in MYV and LYV, while the harvest index was higher in HYV and MYV than in LYV. Yield was inversely correlated with panicle population, but positively correlated with the grain number per panicle, seed-setting rate, the number of primary and secondary branch grains, seed density and harvest index. Yield was most closely linked with the grain number per panicle which was determined chiefly by the number of secondary branch grains and to a lesser degree by seed density and the number of primary branch grains. The seed-setting rate of the secondary branches was positively correlated with that of the whole panicle and yield. The peak value of primary branches for HYV, MYV and LYV was 12-14, 10-13 and 8-12, respectively. LYV had fewer secondary branch grains, while MYV and HYV had more. Such grains distributed mainly in the middle and lower parts of panicle axis for LYV and in the middle and upper parts for MYV and HYV.  相似文献   

2.
With the background of severe rocky desertification in the west of China and the objective of ecological environment construction and poverty elimination,the management information system of rocky desertification was designed according to the natural and humane characteristics in Nanchuan of Sichuan Province. The system was composed of data management module,information query module for rocky desertification,spatial analysis module and dynamic monitoring module.  相似文献   

3.
With the background of severe rocky desertification in the west of China and the objective of ecological environment construction and poverty elimination,the management information system of rocky desertification was designed according to the natural and humane characteristics in Nanchuan of Sichuan Province. The system was composed of data management module,information query module for rocky desertification,spatial analysis module and dynamic monitoring module.  相似文献   

4.
Two strains of Gallibacterium, isolated from one laying hen flock in Zhengzhou City of Henan Province, were identified by the morphological observation, genus-specific PCR, and analysis of 16S rRNA gene, which was used to generate the phylogenetic tree, with the 21 members of the 12 genera belonging to Pasteurellaceae to analyze the homology. Two strains were named Yu-ZZ-HL-I-SLG and Yu-ZZ-HL-II-GZ. The comparative result of the 16S rDNA sequence shows that the 2 isolated strains are identical in sequence; the highest identity (99.9%) was observed between the isolated strain and one of the strains of Gallibacterium anatis (AF228002), the homologies between the isolated strain and 3 strains of gallibacterium accessed in NCBI (AF228016, Gallibacterium genomosp.1, AF228017, Gallibacterium genomosp.2, AF228018, Gallibacterium genomosp.1) were above 97.1%, higher than that of the isolated strain and the other strains of the other 11 genera which were between 90.7%-93.2%. It can be seen from the phylogenetic tree that the 2 isolated strains and the other 4 strain of gallibacterium fell into the same branch, furthermore the 2 isolated strains and the strain of Gallibacterium anatis locate in an internal branch, indicating that the 2 isolated strains belong to Gallibacterium anatis.  相似文献   

5.
Leymus chinensis (Trin.) Tzvel is the characteristic of the Eastern Asia, and is a perennial herbaceous rhizome species on L. chinensis steppe of the Northern China, the Eastern Mongolia, and area of Outer-Baikal of Russia. It has both vegetative and sexual reproductions, and results in complexity of the population structure. Thus, it is difficult to identify distinct clones. Author used the randomly amplified polymorphic DNA (RAPD) technique to identify the clonal structure of heterogeneous and homogeneous habitats in two populations of Leymus chinensis, analyzed 260 ramets samples using 12 primers and 60 polymorphic markers (reproducible RAPD bands). The results proved clonal diversity described using PD, D, and E was higher in the HCS habitat than that in the HPS habitat. The PD, D, and E in the HCS of Songzhan population were 0.21, 0.90, and 0.91, respectively, whereas the PD, D, and E in the HPS of Songzhan population were only 0.09, 0.68, and 0.77, respectively; the PD, D, and E in the HCS of Yongle population were 0.19, 0.92 mad 0.90, respectively, correspondingly, these measures in the HPS of Yongle population were only 0.09, 0.63, and 0.79, respectively. The results also indicated that clonal population of L. chinensis in HPS habitat had lower genetic dissimilarity index than that in the HCS habitat.  相似文献   

6.
《农业科学学报》2012,11(12):1933-1939
A mutant was isolated from the M2 of 60Co-γ ray mutagenized male-fertility restorer line Zao-R974 in rice. The mutant showed pleiotropic phenotypes including dwarfism, delayed heading time, short and partially enclosed panicles, short uppermost internode, decreased grain and secondary branch numbers per panicle, and partially degenerated spikelets. The mutant was named as esp1 (enclosed shorter panicle 1). Genetic analysis indicated that the mutant phenotype was controlled by a recessive locus. Spraying exogenous GA3 did not rescue the panicle enclosure. Using an F2 and a BC1 population of the cross between esp1 and a japonica cultivar Nipponbare, we mapped the ESP1 locus to a region of ~260 kb on chromosome 11. This result provides a basis for further map-based cloning of the ESP1 locus.  相似文献   

7.
重庆都市区铁山坪国家森林公园内残存常绿阔叶林是中亚热带低海拔地区典型的常绿阔叶林.选择代表性地段,设置了2 000 m2的永久样方,并应用相邻格子法进行每木调查.对群落的结构进行了分析,划分了基于主要树种种群结构的特征种组,以此为基础,结合树种的生物学、生态学特征,分别讨论了其更新类型,同时对调查群落所处的演替阶段进行了诊断,并进一步探讨了其多样性特征.基于胸径级频率分布,将各树种的种群年龄结构归纳为5种类型,同时,依据树冠深度随树高的变化,将各树种的种群树冠结构归纳为3种类型.在此基础上,将群落内主要树种归纳为6种特征种组类型,各特征种组类型均对应相应的更新方式.最后分析得出该群落已处于演替的顶级阶段,具有重要的生态价值.
Abstract:
The remnant evergreen broad-leaved forest fragment in Tieshanping National Forest Park in Chongqing is one of the typical evergreen broad-leaved forest types distributed in the hilly and lower mountainous regions in mid-subtropical China. This type of evergreen broad-leaved forest has seldom been reported and the fragment is very rare for its survival from the quick urbanization process. In this study, a 0.2-ha permanent plot (29°37. 606′N, 106°41. 737′E) was established in the fragment and was divided into 20 subplots in 2006. All the trees taller than 1.5 m were identified and measured to quantify the community structure of the forest. Five population age structure types were categorized based on the DBH size-class frequency distribution patterns of the tree species. Three population crown structure types were categorized based on crown depth and tree height. Then six species types were categorized according to the population age structure types and the population crown structure types. Every type of trees had its own successional niche and homologous regeneration type. The community was classified as a climax community and it was a right model and rich species source for the restoration of damaged vegetation in the regional scale.  相似文献   

8.
绒山羊瘤胃甲烷菌mcrA基因的RFLP分析(英文)   总被引:3,自引:0,他引:3  
[Objective] The aim of this study is to understand the population composition of methanogens in rumen fluid of grazing Inner Mongolian cashmere goat. [Method] Total DNAs of various bacteria in rumen fluid were isolated for PCR amplification using the specifically designed primers based on conservative mcrA sequence of methanogens; then mcrA specific clone library was accordingly established. The restriction fragment length polymorphism(RFLP) of the library was further analyzed by digestion of restriction enzyme Taq I. [Result] One hundred and five randomly selected specific colonies were classified into six RFLP types, among which the dominant type accounts for 38%, and other types account for 27%, 18%, 5.5% and 4.5%, respectively. [Conclusion] There are at least six different methanogens in rumen fluid of grazing Inner Mongolian cashmere goat.  相似文献   

9.
[Objective] Using molecular biotechnology to clone the sus scrofa GPX2 gene.[Method] Using total RNA of sus scrofa duodenum as template,degenerated primer pairs were designed according to the homology alignment analysis of GPX2 gene of human,rat,mouse,dog and cattle.A sus scrofa GPX2 gene sequence of 330 bp was obtained by RT-PCR application method.Primes were designed respectively according to the known sequence,sus scrofa GPX2 gene was isolated and cloned by 3-RACE and 5-RACE method and analyzed the gene sequence.[Result] A mRNA sequence of 924 bp was successfully cloned and isolated in this research.This sequence contained complete 3' end and had higher sequence homology with human,mouse,cattle and dog GPX2 gene,and there was codon called TGA which encoding Sec on the position of No.114-116 gene.[Conclusion] Sequence alignment analysis showed that the cloned gene was sus scrofa GPX2 gene(NCBI GenBank database,the sequence number was DQ98982).  相似文献   

10.
Leaf population chlorophyll content in a population of crops, if obtained in a timely manner, served as a key indicator for growth management and diseases diagnosis. In this paper, a three-layer multilayer perceptron (MLP) artificial neural network (ANN) based prediction system was presented for predicting the leaf population chlorophyll content from the cotton plant images. As the training of this prediction system relied heavily on how well those leaf green pixels were separated from background noises in cotton plant images, a global thresholding algorithm and an omnidirectional scan noise filtering coupled with the hue histogram statistic method were designed for leaf green pixel extraction. With the obtained leaf green pixels, the system training was carried out by applying a back propagation algorithm. The proposed system was tested to predict the chlorophyll content from the cotton plant images. The results using the proposed system were in sound agreement with those obtained by the destructive method. The average prediction relative error for the chlorophyll density (μg cm^-2) in the 17 testing images was 8.41%.  相似文献   

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