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1.
Physiologic and Yield Responses of Shaded Cotton to the Plant Growth Regulator PGR-IV 总被引:2,自引:0,他引:2
The plant growth regulator PGR-IV has been reported to improve the growth, boll retention, and yield of cotton (Gossypium hirsutum L.) under optimum growing conditions. However, little is known about the response of cotton to PGR-IV under low light stress.
A 3-year field study was conducted to determine if applying PGR-IV before an 8-day period of shade (63% light reduction) benefitted
the growth and yield of shaded cotton. Shading during early squaring did not affect yield. Shading after the first flower
stage significantly increased leaf chlorophyll concentration and fruit abscission and decreased the leaf photosynthetic rate,
nonstructural carbohydrate concentrations, and lint yield. Foliar application of PGR-IV at 292 mL ha−1 at early squaring and first flower did not improve the leaf photosynthetic rate of shaded cotton. However, shaded plants
receiving PGR-IV had higher nonstructural carbohydrate concentrations in the floral buds and significantly lower fruit abscission
than the shaded plants without PGR-IV. Applying PGR-IV to the foliage before shading resulted in a numeric increase (6–18%)
in lint yield compared with shaded plants without PGR-IV. The decreased fruit abscission from the application of PGR-IV was
associated with improved assimilate translocation. The yield enhancement from foliar application of PGR-IV was attributed
to increased fruit retention. However, the average boll weight of shaded plants with PGR-IV tended to be lower than that of
shaded plants without PGR-IV. Lint percentage was not affected by PGR-IV. Foliar application of PGR-IV appears beneficial
for increasing the fruit retention of shaded cotton.
Received June 12, 1997; accepted January 19, 1998 相似文献
2.
Milena de Luna Alves Lima Cláudio Lopes de Souza Jr Dyeme Antonio Vieira Bento Anete Pereira de Souza Luciana Aparecida Carlini-Garcia 《Molecular breeding : new strategies in plant improvement》2006,17(3):227-239
The vast majority of reported QTL mapping for maize (Zea mays L.) traits are from temperate germplasm and, also, QTL by environment interaction (QTL × E) has not been thoroughly evaluated
and analyzed in most of these papers. The maize growing areas in tropical regions are more prone to environmental variability
than in temperate areas, and, therefore, genotype by environment interaction is of great concern for maize breeders. The objectives
of this study were to map QTL and to test their interaction with environments for several traits in a tropical maize population.
Two-hundred and fifty-six F2:3 families evaluated in five environments, a genetic map with 139 microsatellites markers, and the multiple-environment joint
analysis (mCIM) were used to map QTL and to test QTL × E interaction. Sixteen, eight, six, six, nine, and two QTL were mapped
for grain yield, ears per plant, plant lodging, plant height, ear height, and number of leaves, respectively. Most of these
QTL interacted significantly with environments, most of them displayed overdominance for all traits, and genetic correlated
traits had a low number of QTL mapped in the same genomic regions. Few of the QTL mapped had already been reported in both
temperate and tropical germplasm. The low number of stable QTL across environments imposes additional challenges to design
marker-assisted selection in tropical areas, unless the breeding programs could be directed towards specific target areas. 相似文献
3.
Ecological risk assessments of chemicals are often based on simple measurements of toxicity in individuals. However, the protection goals are often set at the population and community levels. Population models may be a useful tool to extrapolate from individual-level measurements to population-level endpoints. In the present study, the population growth rate (λ) was calculated for three sets of full life-cycle data (Tetranychus urticae exposed to agrimek, and Daphnia pulex exposed to spinosad and diazinon). The results were compared to λ from population models, where survival and/or reproduction were adjusted according to 4 d of data from the same life-cycle data. This was done to determine whether truncated demographic data can give results similar to that obtained with full life-cycle data. The resulting correlations were strong when both effects on survival and reproduction were included in the model (p < .001, 0.93 < R2 < 1.00). There were also strong correlations in several cases when only effects on survival or reproduction were considered, although the total risk to the population tended to be underestimated. The results of the present study show that population models can be useful to extrapolate truncated data on the individual level to more ecologically relevant population-level endpoints. 相似文献
4.
Van Nguyen Dong Nguyen Huong Mai Le Nga Thanh Nguyen Kien Huu Nguyen Hoa Thi Le Huong Mai Nguyen Anh Trung Dinh Ngan Thi Thu Hoang Son Anh Van Ha Chien 《Journal of Plant Growth Regulation》2022,41(1):364-375
Journal of Plant Growth Regulation - Abiotic stresses, including drought, detrimentally affect the growth and productivity of many economically important crop plants, leading to significant yield... 相似文献
5.
Most studies of density dependent regulation in plants consider a single target species, but regulation may also occur at the level of the entire community. Knowing whether a community is at carrying capacity is essential for understanding its behaviour because low density plant communities may behave quite differently than their high density counterparts. Also, because the intensity of density dependence may differ considerably between species and physical environments, generalizations about its effects on community structure requires comparisons under a range of conditions. We tested if: (1) density dependent regulation occurs at the level of an entire plant community as well as within individual species; (2) the intensity (effect of increasing community density on mean plant mass) and importance (the effect of increasing density, relative to other factors, on mean plant mass) of competition increases, decreases or remains unchanged with increasing fertilization; (3) there are species-specific responses to changes in community density and productivity. In 63 1 m2 plots, we manipulated the abundance of the nine most common species by transplanting or removing them to create a series of Initial Community Densities above and below the average natural field density, such that the relative proportion of species was consistent for all densities. Plots were randomly assigned to one of three fertilizer levels. At the community level, negative density dependence of mean plant size was observed for each of the 4 years of the study and both the intensity and importance of competition increased each year. At the species level, most species'' mean plant mass were negatively density dependent. Fertilizer had a significant effect only in the final year when it had a negative effect on mean plant mass. Our data demonstrate a yield-density response at the entire community-level using perennial plant species in a multi-year experiment. 相似文献
6.
A series of greenhouse, phytotron, field, and microplot experiments evaluated factors that influenced plant-growth.stimulation associated with the use of the pesticide aldicarb. A phytotron experiment showed.that aldicarb increased growth, of Ransom soybean at all temperatures but was somewhat phytotoxic to Coker 156 soybean at 30 C. Soybean gave the greatest response to this nematicide at 22 C in a commercially available medium, Metromix 220. Soybean cultivars Ransom and Coker 156. exhibited increased growth in response to aldicarb or, to a lesser extent aldicarb sulfone treatments under greenhouse and microplot conditions. Enhanced soybean growth, however, did not always result in significantly greater soybean seed yield. Soil type affected soybean sensitivity to aldicarb, with. the greatest growth and yield increases generally occurring in fine-textured soils or those with high.organic matter. Plant-growth stimulation by aldicarb occurs in the absence of pests but is dependent upon concentration and edaphic and other environmental factors. 相似文献
7.
Interactions among the foraging behaviours of co-occurring animal species can impact population and community dynamics; the consequences of interactions between plant and animal foraging behaviours have received less attention. In North American forests, invasions by European earthworms have led to substantial changes in plant community composition. Changes in leaf litter have been identified as a critical indirect mechanism driving earthworm impacts on plants. However, there has been limited examination of the direct effects of earthworm burrowing on plant growth. Here we show a novel second pathway exists, whereby earthworms (Lumbricus terrestris L.) impact plant root foraging. In a mini-rhizotron experiment, roots occurred more frequently in burrows and soil cracks than in the soil matrix. The roots of Achillea millefolium L. preferentially occupied earthworm burrows, where nutrient availability was presumably higher than in cracks due to earthworm excreta. In contrast, the roots of Campanula rotundifolia L. were less likely to occur in burrows. This shift in root behaviour was associated with a 30% decline in the overall biomass of C. rotundifolia when earthworms were present. Our results indicate earthworm impacts on plant foraging can occur indirectly via physical and chemical changes to the soil and directly via root consumption or abrasion and thus may be one factor influencing plant growth and community change following earthworm invasion. More generally, this work demonstrates the potential for interactions to occur between the foraging behaviours of plants and soil animals and emphasizes the importance of integrating behavioural understanding in foraging studies involving plants. 相似文献
8.
J. A. Lamondia 《Journal of nematology》2002,34(1):38-42
Field microplot experiments were conducted from 1995 to 1998 to determine the relationship between fresh shoot weight of stalk-cut broadleaf and shade-grown cigar wrapper tobacco types (Nicotiana tabacum L.) and initial density of Globodera tabacum tabacum second stage juveniles (J2) per cm³ soil. Total shoot weight was negatively correlated with initial nematode densities of 12.3 to 747.3 J2/cm³ soil (r = -0.53 and -0.70 for broadleaf and shade-grown tobacco, respectively). Nonlinear damage functions were used to relate initial G. t. tabacum densities to shoot weight. The models described shoot weight losses of less than 14% or 39% for broadleaf and shade tobacco, respectively, at G. t. tabacum densities below 50 J2/cm³ soil. Total shoot weights were reduced by 40% and 60% of uninfested plots as preplant nematode densities approached maximum levels (>600 J2/cm³ soil) for broadleaf and shade tobacco, respectively. Globodera t. tabacum population increase over a growing season was described by a linear relation on a log/log plot (R² = 0.07 and 0.61 for broadleaf and shade, respectively). These experiments demonstrate that G. t. tabacum can directly reduce shoot weight of stalk-cut broadleaf tobacco. Broadleaf is more tolerant to nematode infection than shade tobacco, as shade tobacco shoot weight reductions were greater at the same initial nematode densities in the same years. 相似文献
9.
Theoretically, the functional traits of native species should determine how natives respond to invader-driven changes. To explore this idea, we simulated a large-scale plant invasion using dead spotted knapweed (Centaurea stoebe) stems to determine if native spiders’ web-building behaviors could explain differences in spider population responses to structural changes arising from C. stoebe invasion. After two years, irregular web-spiders were >30 times more abundant and orb weavers were >23 times more abundant on simulated invasion plots compared to controls. Additionally, irregular web-spiders on simulated invasion plots built webs that were 4.4 times larger and 5.0 times more likely to capture prey, leading to >2-fold increases in recruitment. Orb-weavers showed no differences in web size or prey captures between treatments. Web-spider responses to simulated invasion mimicked patterns following natural invasions, confirming that C. stoebe’s architecture is likely the primary attribute driving native spider responses to these invasions. Differences in spider responses were attributable to differences in web construction behaviors relative to historic web substrate constraints. Orb-weavers in this system constructed webs between multiple plants, so they were limited by the overall quantity of native substrates but not by the architecture of individual native plant species. Irregular web-spiders built their webs within individual plants and were greatly constrained by the diminutive architecture of native plant substrates, so they were limited both by quantity and quality of native substrates. Evaluating native species traits in the context of invader-driven change can explain invasion outcomes and help to identify factors limiting native populations. 相似文献
10.
11.
Binary additive series experiments involving various pairedcombinations of barnyardgrass (BYG), redroot pigweed (RPW),green foxtail (GFT) and rape (RPS) were undertaken in fieldplots in 1980 and 1981. The experimental design used permittedinvestigation of the performance of a one species (the competitor) over a range of densities, in the presenceof different constant densities of a second species (the indicator),and as pure stands. Top growth (d.wt after approximately 95d) in monoculture was found to be well-described by de Wit'sspacing formula
where Ms is yield, s is space per seed or plant, is maximum(asymptotic) yield at infinite density and ß is spaceper seed or plant at half the maximum yield (i.e. /2). The formulawas also found to fit the observed yields of a competing speciesover the entire range of densities of an indicator. Correlationcoefficients between observed yields and values calculated bymeans of the spacing formula ranged from 0.934 to 0.999, withmost greater than 0.990. The changes in the slopes of a competingspecies' yield curves as indicator density increases reflectthe competitive abilities of the pair of species present. Barnyardgrassand RPS were found to be strong competitors against RPW andGFT, and RPW strongly competed against GFT. The spacing formulacan thus be used to predict the performance of a competing speciesin additive series experiments, and thereby provides anothermeans of investigating crop-weed and other interactions. Echinochloa crusgalli (L.) Beauv., Setaria viridis (L.) Beauv., Amaranthus retroflexus L., Brassica napus L., barnyardgrass, green foxtail, redroot pigweed, rape, competition, binary additive series, yield/density relationships 相似文献
12.
13.
The rates of reproduction and multiplication of Meloidogyne hapla decreased as a result of self-regulatory, density-dependent processes with time and nematode population increase in the soil and roots of Medicago sativa cv. Cuf 101. Juvenile, egg, and mature female population densities increased at a maximum rate until damage to the host resulted in alfalfa yield reductions. Temporal differences in multiplication and reproduction rates of M. hapla were observed to be a function of initial population density (Pi), host damage, and root biomass, indicating increased levels of competition for a constant but limited number of feeding sites. Over time, a log linear relationship emerged between multiplication rate of M. hapla and Pi. Slopes of -0.90953 for combined eggs and juveniles and -0.71349 for mature females indicated a gradual approach to ceiling densities. Reproductive rates decreased exponentially from an initial maximal value of 200 to a relatively constant rate of 53 eggs per female. 相似文献
14.
拟南芥漆酶基因AtLAC4参与生长及非生物胁迫响应 总被引:2,自引:0,他引:2
植物漆酶基因家族在拟南芥(Arabidopsis thaliana)中共有17个成员,目前各基因的具体功能尚不十分清楚.该研究利用过量表达的方法初步分析了拟南芥AtLAC4的功能.GUS染色显示AtLAC4在拟南芥的维管组织中有较强的表达,并在叶片排水器中特异表达.AtLAC4过量表达导致植株木质素含量增多、次生壁加厚、植株变小和莲座叶叶柄变短.ABA对AtLAC4的表达具有明显的诱导作用,AtLAC4过量表达植株对外源ABA敏感;干旱处理后,AtLAC4过量表达植株的耐旱能力比野生型明显增强.以上结果表明,AtLAC4基因在调控植物生长发育及非生物胁迫响应中具有重要作用. 相似文献
15.
Plant Molecular Biology Reporter - A Correction to this paper has been published: https://doi.org/10.1007/s11105-020-01265-4 相似文献
16.
Three techniques used to investigate whole-plant growth areplant growth analysis, yield component analysis and demographicanalysis. Each subdivides growth into morphological or physiologicalcomponents. This paper derives several relationships which definethe contributions made by components to the performance of thewhole plant. For example, the additive contributions by differentplant parts to overall unit leaf rate may be determined. Also,for multiplicative components, the relative growth rate of yieldis the sum of the relative growth rates of yield components.The relationships developed here serve to link different approachesto growth analysis, and they are illustrated using data fromgrowth studies of bean and sunflower. Plant growth analysis, yield component analysis, demographic analysis, Phaseolus vulgaris L., Helianthus annus L. 相似文献
17.
Cavite Harry Jay M. Mactal Ariel G. Evangelista Editha V. Cruz Jayvee A. 《Journal of Plant Growth Regulation》2021,40(2):494-508
Journal of Plant Growth Regulation - This study evaluated the effects of plant growth-promoting rhizobacteria (PGPR) isolates in enhancing upland rice growth and yield. Bacteria were isolated,... 相似文献
18.
Kevin A. Wood Richard A. Stillman Ralph T. Clarke Francis Daunt Matthew T. O’Hare 《PloS one》2012,7(11)
Understanding plant community responses to combinations of biotic and abiotic factors is critical for predicting ecosystem response to environmental change. However, studies of plant community regulation have seldom considered how responses to such factors vary with the different phases of the plant growth cycle. To address this deficit we studied an aquatic plant community in an ecosystem subject to gradients in mute swan (Cygnus olor) herbivory, riparian shading, water temperature and distance downstream of the river source. We quantified abundance, species richness, evenness, flowering and dominance in relation to biotic and abiotic factors during the growth-, peak-, and recession-phases of the plant growth cycle. We show that the relative importance of biotic and abiotic factors varied between plant community properties and between different phases of the plant growth cycle. Herbivory became more important during the later phases of peak abundance and recession due to an influx of swans from adjacent pasture fields. Shading by riparian vegetation also had a greater depressing effect on biomass in later seasons, probably due to increased leaf abundance reducing light intensity reaching the aquatic plants. The effect of temperature on community diversity varied between upstream and downstream sites by altering the relative competitiveness of species at these sites. These results highlight the importance of seasonal patterns in the regulation of plant community structure and function by multiple factors. 相似文献
19.
创建了一个关于大丰自然保护区半散养麋鹿种群增长的Logistic模型,该模型准确地预测了麋鹿种群的增长规律.作者通过对比和分析相关数据揭示了种群密度对糜鹿种群增长的影响并给出两个导致种群增长发生改变的临界值. 相似文献
20.
Yuriko Osakabe Naoko Arinaga Taishi Umezawa Shogo Katsura Keita Nagamachi Hidenori Tanaka Haruka Ohiraki Kohji Yamada So-Uk Seo Mitsuru Abo Etsuro Yoshimura Kazuo Shinozaki Kazuko Yamaguchi-Shinozaki 《The Plant cell》2013,25(2):609-624
Osmotic adjustment plays a fundamental role in water stress responses and growth in plants; however, the molecular mechanisms governing this process are not fully understood. Here, we demonstrated that the KUP potassium transporter family plays important roles in this process, under the control of abscisic acid (ABA) and auxin. We generated Arabidopsis thaliana multiple mutants for K+ uptake transporter 6 (KUP6), KUP8, KUP2/SHORT HYPOCOTYL3, and an ABA-responsive potassium efflux channel, guard cell outward rectifying K+ channel (GORK). The triple mutants, kup268 and kup68 gork, exhibited enhanced cell expansion, suggesting that these KUPs negatively regulate turgor-dependent growth. Potassium uptake experiments using 86radioactive rubidium ion (86Rb+) in the mutants indicated that these KUPs might be involved in potassium efflux in Arabidopsis roots. The mutants showed increased auxin responses and decreased sensitivity to an auxin inhibitor (1-N-naphthylphthalamic acid) and ABA in lateral root growth. During water deficit stress, kup68 gork impaired ABA-mediated stomatal closing, and kup268 and kup68 gork decreased survival of drought stress. The protein kinase SNF1-related protein kinases 2E (SRK2E), a key component of ABA signaling, interacted with and phosphorylated KUP6, suggesting that KUP functions are regulated directly via an ABA signaling complex. We propose that the KUP6 subfamily transporters act as key factors in osmotic adjustment by balancing potassium homeostasis in cell growth and drought stress responses. 相似文献