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11.
本文扼要回顾和评述了雄性生殖单位的发现、意义和研究进展,并对目前存在的问题和今后的研究进行了讨论和展望。 相似文献
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胚乳性状的遗传模型和世代平均数 总被引:25,自引:7,他引:18
谷类作物的胚乳是三倍体组织,胚乳性状受3N遗传控制。本文分析了胚乳性状的遗传特征,建立了相应的遗传模型,推导了世代群体的平均数分量,并提出了研究胚乳性状基因效应的一些简单的交配设计。 相似文献
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The heart as an endocrine organ 总被引:1,自引:0,他引:1
Modern data on atrial natriuretic factor (ANF) are presented. Synthesis of this factor, its storage and release from cardiac atria are described. The role of ANF in the body fluid volume regulation and blood pressure homeostasis is discussed. ANF is regarded as a circulating hormone. 相似文献
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在自生异养条件下,旋扭山绿豆根瘤菌MXDI6菌株的氢酶诱导表达受气相、pH值、镍等因子影响:氢酶表达的最适氧浓度为4%,最适氢浓度为15%,二氧化碳没有明显影响;氢酶表达的pH值以5.0—6.0为宜;0.5μmol/LNiCl2明显促进吸氢活性,但镍浓度大于1μmol/L则抑制吸氢活性. 相似文献
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武汉东湖桡足类的生态学演变 总被引:15,自引:2,他引:13
根据1962-1963,1974-1975,1979-1991年在武汉东湖进行的调查资料,考察了过去三十年内在东湖两个代表性采样站桡足类的种类组成及现存量的变化。结果表明:桡足类种类数由60年代的14种减少为90年代的7种,I、Ⅱ站在种类组成的差别趋于消失。统计结果表明,东湖桡足类现存量以80年代初、中期较高。但在水平分布格局上却发生了根本变化,由1987年前的I站现存量高于Ⅱ站,至1987年后Ⅱ站高于I站。本文还就影响东湖桡足类演变的生态因子进行了讨论。 相似文献
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Francesco Ricci Kshitij Tandon Maria Moßhammer Ellie H.-J. Cho Linda L. Blackall Michael Kühl Heroen Verbruggen 《Environmental microbiology》2023,25(8):1505-1521
The coral skeleton harbours a diverse community of bacteria and microeukaryotes exposed to light, O2 and pH gradients, but how such physicochemical gradients affect the coral skeleton microbiome remains unclear. In this study, we employed chemical imaging of O2 and pH, hyperspectral reflectance imaging and spatially resolved taxonomic and inferred functional microbiome characterization to explore links between the skeleton microenvironment and microbiome in the reef-building corals Porites lutea and Paragoniastrea benhami. The physicochemical environment was more stable in the deep skeleton, and the diversity and evenness of the bacterial community increased with skeletal depth, suggesting that the microbiome was stratified along the physicochemical gradients. The bulk of the coral skeleton was in a low O2 habitat, whereas pH varied from pH 6–9 with depth. Physicochemical gradients of O2 and pH of the coral skeleton explained the β-diversity of the bacterial communities, and skeletal layers that showed O2 peaks had a higher relative abundance of endolithic algae, reflecting a link between the abiotic environment and the microbiome composition. Our study links the physicochemical, microbial and functional landscapes of the coral skeleton and provides new insights into the involvement of skeletal microbes in the coral holobiont metabolism. 相似文献
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Hongxia Liu Xuemei Si Zhenyu Wang Liangjing Cao Lifeng Gao Xiaolong Zhou Wenxi Wang Ke Wang Chengzhi Jiao Lei Zhuang Yunchuan Liu Jian Hou Tian Li Chenyang Hao Weilong Guo Jun Liu Xueyong Zhang 《Plant biotechnology journal》2023,21(6):1159-1175
Grain size and filling are two key determinants of grain thousand-kernel weight (TKW) and crop yield, therefore they have undergone strong selection since cereal was domesticated. Genetic dissection of the two traits will improve yield potential in crops. A quantitative trait locus significantly associated with wheat grain TKW was detected on chromosome 7AS flanked by a simple sequence repeat marker of Wmc17 in Chinese wheat 262 mini-core collection by genome-wide association study. Combined with the bulked segregant RNA-sequencing (BSR-seq) analysis of an F2 genetic segregation population with extremely different TKW traits, a candidate trehalose-6-phosphate phosphatase gene located at 135.0 Mb (CS V1.0), designated as TaTPP-7A, was identified. This gene was specifically expressed in developing grains and strongly influenced grain filling and size. Overexpression (OE) of TaTPP-7A in wheat enhanced grain TKW and wheat yield greatly. Detailed analysis revealed that OE of TaTPP-7A significantly increased the expression levels of starch synthesis- and senescence-related genes involved in abscisic acid (ABA) and ethylene pathways. Moreover, most of the sucrose metabolism and starch regulation-related genes were potentially regulated by SnRK1. In addition, TaTPP-7A is a crucial domestication- and breeding-targeted gene and it feedback regulates sucrose lysis, flux, and utilization in the grain endosperm mainly through the T6P-SnRK1 pathway and sugar–ABA interaction. Thus, we confirmed the T6P signalling pathway as the central regulatory system for sucrose allocation and source–sink interactions in wheat grains and propose that the trehalose pathway components have great potential to increase yields in cereal crops. 相似文献