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51.
耕作方式对东北雨养区玉米光合与叶绿素荧光特性的影响 总被引:5,自引:0,他引:5
在东北地区设置大田试验,研究不同耕作方式下玉米全生育期耕层土壤温度、土壤含水量、叶片光合性能及叶绿素荧光参数的变化特征.结果表明:耕作方式对土壤水热性能的影响主要体现在播种-拔节阶段,2010-2011年平地播种中耕起垄(PL)和全生育期平作(PP)处理0~40 em土层土壤体积含水量在出苗期、苗期和拔节期比传统垄作(LL)处理平均提高5.6%和5.2%、4.6%和7.3%及3.9%和4.8%,苗期5 cm土壤最低温度分别比LL处理高1.4和1.3℃.由于土壤水热条件的改善,拔节期PL和PP处理的叶片净光合速率(Pn)、蒸腾速率(Tr)等指标显著高于LL处理,而PSⅡ潜在活性(Fv/Fo)和PSⅡ最大光化学效率(Fv/Fm)无显著差异,表明气孔导度和气孔限制值等气孔因素是导致光合作用差异的主要原因;灌浆期叶片Pn和Tr则以LL和PL处理显著高于PP处理,这主要是由于PP处理在强降雨时期经历了涝渍灾害,光合作用受到抑制.可见PL处理通过改善土壤水热条件增强了玉米光合性能,进而提高了籽粒产量. 相似文献
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In order to investigate the effect of large isoform of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) activase (RuBPCO-A)
on photosynthesis, cDNA of the enzyme (rca) was transferred to rice cultivars (Oryza sativa f. japonica cv. Nipponbare) under the control of RuBPCO small subunit gene promoter (rbcS) via Agrobacterium tumefaciens-mediated transformation. Transgenic rice plants were identified by polymerase chain reaction (PCR) and Southern and Western
blot analyses. Net photosynthetic rate (P
N) values of the T1 transgenic lines 34 (T34) and 40 (T40) were 45.26 and 46.32 % higher than that of the control plants, respectively. At the
same time, their carboxylation efficiency and RuBPCO initial activity, quantum yield of electron transport in photosystem
2 (ΦPS2), and steady state photochemical fluorescence quenching (qP) increased. In addition, heading time of the transgenic rice was advanced. Thus increasing the amount of large isoform of
RuBPCO-A in the transgenic rice might have a stimulatory effect on both photosynthesis and plant growth. 相似文献
54.
QTL analysis of leaf morphology in tetraploid Gossypium (cotton) 总被引:13,自引:0,他引:13
C. Jiang R. J. Wright S. S. Woo T. A. DelMonte A. H. Paterson 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(3-4):409-418
Molecular markers were used to map and characterize quantitative trait loci (QTLs) determining cotton leaf morphology and
other traits, in 180 F2 plants from an interspecific cross between a Gossypium hirsutum genotype carrying four morphological mutants, and a wild-type Gossypium barbadense. The prominent effects of a single region of chromosome 15, presumably the classical ”Okra-leaf” locus, were modified by
QTLs on several other chromosomes affecting leaf size and shape. For most traits, each parent contained some alleles with
positive effects and others with negative effects, suggesting a large potential for adapting leaf size and shape to the needs
of particular production regimes. Twenty one QTLs/loci were found for the morphological traits at LOD≥3.0 and P≤0.001, among which 14 (63.6%) mapped to D-subgenome chromosomes. Forty one more possible QTLs/loci were suggested with 2.0≤LOD<3.0
and 0.001<P≤0.01. Among all of the 62 possible QTLs (found at LOD≥2.0 and P≤0.01) for the 14 morphological traits in this study, 38 (61.3%) mapped to D-subgenome chromosomes. This reinforces the findings
of several other studies in suggesting that the D-subgenome of tetraploid cotton has been subject to a relatively greater
rate of evolution than the A-subgenome, subsequent to polyploid formation.
Received: 26 April 1999 / Accepted: 30 July 1999 相似文献
55.
How do Mediterranean shrub species cope with shade? Ecophysiological response to different light intensities 下载免费PDF全文
M. C. Díaz‐Barradas M. Zunzunegui L. Alvarez‐Cansino M. P. Esquivias J. Valera H. Rodríguez 《Plant biology (Stuttgart, Germany)》2018,20(2):296-306
- Under natural conditions, light exposure for Mediterranean shrubs can be highly variable, especially during cloudy days or under a canopy, and can interfere with other environmental factors such as temperature and water availability.
- With the aim of decoupling the effect of radiation and temperature from water availability, we conducted an experiment where two perennial and three summer semi‐deciduous shrub species were subjected to different levels of irradiation. In order to follow plant responses to light exposure, we measured gas exchange, photosystem II photochemical efficiency, photosynthetic pigments and leaf mass area in spring and summer.
- Results showed that all study species presented a plastic response to different light conditions, and that light‐related traits varied in a coordinated manner. Summer semi‐deciduous species exhibited a more opportunistic response, with higher photosynthesis rates in full sun, but under shade conditions, the two strategies presented similar assimilation rates. Stomatal conductance did not show such a drastic response as photosynthetsis, being related to changes in WUE. Daily cycles of Fv/Fm revealed a slight photoinhibitory response during summer, mainly in perennial species. In all cases photosynthetic pigments adjusted to the radiation level; leaves had lower chlorophyll content, higher pool of xanthophylls and higher proportion of the de‐epoxydaded state of xanthophylls under sun conditions. Lutein content increased in relation to the xanthophyll pool under shade conditions.
- Our results evidenced that radiation is an important driving factor controlling morphological and physiological status of Mediterranean shrub species, independently of water availability. Summer semi‐deciduous species exhibit a set of traits with higher response variability, maximising their photosynthetic assimilation under different sun conditions.
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Andrew Ferguson Thomas E. Reed Tom F. Cross Philip McGinnity Paulo A. Prodöhl 《Journal of fish biology》2019,95(3):692-718
Brown trout Salmo trutta is endemic to Europe, western Asia and north-western Africa; it is a prominent member of freshwater and coastal marine fish faunas. The species shows two resident (river-resident, lake-resident) and three main facultative migratory life histories (downstream–upstream within a river system, fluvial–adfluvial potamodromous; to and from a lake, lacustrine–adfluvial (inlet) or allacustrine (outlet) potamodromous; to and from the sea, anadromous). River-residency v. migration is a balance between enhanced feeding and thus growth advantages of migration to a particular habitat v. the costs of potentially greater mortality and energy expenditure. Fluvial–adfluvial migration usually has less feeding improvement, but less mortality risk, than lacustrine–adfluvial or allacustrine and anadromous, but the latter vary among catchments as to which is favoured. Indirect evidence suggests that around 50% of the variability in S. trutta migration v. residency, among individuals within a population, is due to genetic variance. This dichotomous decision can best be explained by the threshold-trait model of quantitative genetics. Thus, an individual's physiological condition (e.g., energy status) as regulated by environmental factors, genes and non-genetic parental effects, acts as the cue. The magnitude of this cue relative to a genetically predetermined individual threshold, governs whether it will migrate or sexually mature as a river-resident. This decision threshold occurs early in life and, if the choice is to migrate, a second threshold probably follows determining the age and timing of migration. Migration destination (mainstem river, lake, or sea) also appears to be genetically programmed. Decisions to migrate and ultimate destination result in a number of subsequent consequential changes such as parr–smolt transformation, sexual maturity and return migration. Strong associations with one or a few genes have been found for most aspects of the migratory syndrome and indirect evidence supports genetic involvement in all parts. Thus, migratory and resident life histories potentially evolve as a result of natural and anthropogenic environmental changes, which alter relative survival and reproduction. Knowledge of genetic determinants of the various components of migration in S. trutta lags substantially behind that of Oncorhynchus mykiss and other salmonines. Identification of genetic markers linked to migration components and especially to the migration–residency decision, is a prerequisite for facilitating detailed empirical studies. In order to predict effectively, through modelling, the effects of environmental changes, quantification of the relative fitness of different migratory traits and of their heritabilities, across a range of environmental conditions, is also urgently required in the face of the increasing pace of such changes. 相似文献
58.
猪的基因图谱及数量性状位点定位 总被引:7,自引:0,他引:7
在人类基因组计划的带动下,猪的遗传连锁图谱和细胞遗传学图谱有了较大的进步,利用目前猪基因组图谱的研究成果,通过基因组扫描法和候选基因法,可以对猪重要经济性状的主效基因位点进行区域定位,进而图位克隆,找到主效基因,为现代遗传育种奠定理论基础。 相似文献
59.
通过设置自然光与遮阴(60%自然光)两种光环境, 观测了遮阴60天后疏叶骆驼刺(Alhagi sparsifolia)叶形态、光合生理参数和脯氨酸(Pro)含量的变化。结果表明: 与自然光照下的叶片相比, 遮阴叶的比叶面积显著增大(p < 0.01), 比叶干重、比叶鲜重和叶片厚度明显降低(p < 0.01); 叶绿素(a + b)和类胡萝卜素含量有所增加, 其中叶绿素a含量增加显著(p < 0.01); 光补偿点、光饱和点和暗呼吸速率降低, 表观量子效率提高, 最大净光合速率明显增大, 光能利用效率高于自然光叶; 强光照下遮阴叶的净光合速率明显降低, 易发生光合光抑制现象。上述结果说明: 遮阴处理后, 疏叶骆驼刺在叶形态和光合生理上表现出对遮阴弱光条件的一定程度的驯化适应。另外, 遮阴叶片Pro的大量积累, 说明Pro在疏叶骆驼刺驯化适应弱光环境中起着重要作用。遮蔽环境下疏叶骆驼刺植株死亡率明显偏高, 表明塔克拉玛干沙漠南缘荒漠区的疏叶骆驼刺属于专性阳生植物不耐阴品种。 相似文献
60.