Variation in climatic tolerance, but not stomatal traits, partially explains Pooideae grass species distributions

2021 ◽  
Author(s):  
Aayudh Das ◽  
Anoob Prakash ◽  
Natalie Dedon ◽  
Alex Doty ◽  
Muniba Siddiqui ◽  
...  
Keyword(s):  
Stomatal Closure ◽  
Aridity Index ◽  
Species Distributions ◽  
Grass Species ◽  
Fitness Traits ◽  
Terrestrial Environments ◽  
Use Efficiency ◽  
Stomatal Traits ◽  
The Relationship ◽  
Measured Water

Abstract Background and Aims Grasses in subfamily Pooideae live in some of the world’s harshest terrestrial environments, from frigid boreal zones to the arid wind-swept steppe. It is hypothesized that the climate distribution of species within this group is driven by differences in climatic tolerance, and that tolerance can be partially explained by variation in stomatal traits. Methods We determined aridity index (AI) and minimum temperature of the coldest month (MTCM) for 22 diverse Pooideae accessions and one outgroup, and used comparative methods to assess predicted relationships for climate traits versus fitness traits, stomatal diffusive conductance to water (gw), and speed of stomatal closure following drought and/or cold. Key Results Results demonstrate that AI and MTCM predict variation in survival/regreening following drought/cold, and gw under drought/cold is positively correlated with ẟ 13C-measured water use efficiency (WUE). However, the relationship between climate traits and fitness under drought/cold was not explained by gw or speed of stomatal closure. Conclusions These findings suggest that Pooideae distributions are at least partly determined by tolerance to aridity and above freezing cold, but that variation in tolerance is not uniformly explained by variation in stomatal traits.

scholarly journals Optimizing Grain Yield and Water Use Efficiency Based on the Relationship between Leaf Area Index and Evapotranspiration

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 313
Author(s):  
Guoqiang Zhang ◽  
Bo Ming ◽  
Dongping Shen ◽  
Ruizhi Xie ◽  
Peng Hou ◽  
...  
Keyword(s):  
Grain Yield ◽  
Water Use Efficiency ◽  
Leaf Area Index ◽  
Water Use ◽  
Plant Density ◽  
Maize Yield ◽  
Area Index ◽  
Irrigation Level ◽  
Use Efficiency ◽  
The Relationship

Achieving optimal balance between maize yield and water use efficiency is an important challenge for irrigation maize production in arid areas. In this study, we conducted an experiment in Xinjiang China in 2016 and 2017 to quantify the response of maize yield and water use to plant density and irrigation schedules. The treatments included four irrigation levels: 360 (W1), 480 (W2), 600 (W3), and 720 mm (W4), and five plant densities: 7.5 (D1), 9.0 (D2), 10.5 (D3), 12.0 (D4), and 13.5 plants m−2 (D5). The results showed that increasing the plant density and the irrigation level could both significantly increase the leaf area index (LAI). However, LAI expansion significantly increased evapotranspiration (ETa) under irrigation. The combination of irrigation level 600 mm (W3) and plant density 12.0 plants m−2 (D4) produced the highest maize yield (21.0–21.2 t ha−1), ETa (784.1–797.8 mm), and water use efficiency (WUE) (2.64–2.70 kg m−3), with an LAI of 8.5–8.7 at the silking stage. The relationship between LAI and grain yield and evapotranspiration were quantified, and, based on this, the relationship between water use and maize productivity was analyzed. Moreover, the optimal LAI was established to determine the reasonable irrigation level and coordinate the relationship between the increase in grain yield and the decrease in water use efficiency.

scholarly journals Structure of pond vegetation of a vereda in the Brazilian Cerrado

Rodriguésia ◽  
2011 ◽  
Vol 62 (4) ◽  
pp. 721-729 ◽  
Author(s):  
Suzana Neves Moreira ◽  
Arnildo Pott ◽  
Vali Joana Pott ◽  
Geraldo Alves Damasceno-Junior
Keyword(s):  
Water Depth ◽  
Rainy Season ◽  
Life Form ◽  
Mato Grosso ◽  
Relative Cover ◽  
Dry Seasons ◽  
The Relationship ◽  
Measured Water ◽  
Mato Grosso Do Sul ◽  
New Occurrences

Abstract This is the first report on aquatic macrophytes in ponds of veredas (palm swamps) in the Cerrado (Brazilian savanna). We studied a pond in a vereda in Terenos, Mato Grosso do Sul state, central-western Brazil, during drought and flood periods to assess plant community structure and the relationship between species distribution and water depth. Sampling was carried out in five permanent transects, along which we placed sampling units of 1 m2 quadrats every 5 m. We estimated visually the relative cover of each species, bare ground, dead matter, and exposed water. We also measured water depth. We recorded 77 species of 49 genera and 31 families. The number of species varied between seasons, and in the rainy season the amphibious life form was predominant. The richest families were Poaceae (15 species), Cyperaceae (11), Asteraceae (4) and Lentibulariaceae (4). The richest genera were Rhynchospora (4), Utricularia (4), Eleocharis (4), Aeschynomene (3), Bacopa (3), Ludwigia (3) and Panicum (3). We found six new occurrences for the cerrado. Eleocharis acutangula had the highest relative cover (rainy and dry seasons), followed by Bacopa reflexa (rainy season), Paspalum lenticulare (rainy and dry seasons), Leersia hexandra (rainy and dry seasons), and Sagittaria rhombifolia (rainy season). Some species were distributed mainly at shallower depths, others occurred in deeper water, whereas some species varied greatly in terms of depth. Heliotropium filiforme and Ludwigia nervosa were found only in the dry season. In the rainy season, as expected, the exclusive species were mostly true aquatics.

Potential yield and water-use efficiency benefits in sorghum from limited maximum transpiration rate

2005 ◽  
Vol 32 (10) ◽  
pp. 945 ◽  
Author(s):  
Thomas R. Sinclair ◽  
Graeme L. Hammer ◽  
Erik J. van Oosterom
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Transpiration Rate ◽  
Simulation Analysis ◽  
Stomatal Closure ◽  
Risk Attitude ◽  
Potential Yield ◽  
Yield Increase ◽  
Use Efficiency ◽  
Yield Responses

Limitations on maximum transpiration rates, which are commonly observed as midday stomatal closure, have been observed even under well-watered conditions. Such limitations may be caused by restricted hydraulic conductance in the plant or by limited supply of water to the plant from uptake by the roots. This behaviour would have the consequences of limiting photosynthetic rate, increasing transpiration efficiency, and conserving soil water. A key question is whether the conservation of water will be rewarded by sustained growth during seed fill and increased grain yield. This simulation analysis was undertaken to examine consequences on sorghum yield over several years when maximum transpiration rate was imposed in a model. Yields were simulated at four locations in the sorghum-growing area of Australia for 115 seasons at each location. Mean yield was increased slightly (5–7%) by setting maximum transpiration rate at 0.4 mm h–1. However, the yield increase was mainly in the dry, low-yielding years in which growers may be more economically vulnerable. In years with yield less than ∼450 g m–2, the maximum transpiration rate trait resulted in yield increases of 9–13%. At higher yield levels, decreased yields were simulated. The yield responses to restricted maximum transpiration rate were associated with an increase in efficiency of water use. This arose because transpiration was reduced at times of the day when atmospheric demand was greatest. Depending on the risk attitude of growers, incorporation of a maximum transpiration rate trait in sorghum cultivars could be desirable to increase yields in dry years and improve water use efficiency and crop yield stability.

scholarly journals Water stress coefficient determined by orbital remote sensing techniques

2020 ◽  
Vol 24 (12) ◽  
pp. 847-853
Author(s):  
Élvis da S. Alves ◽  
Roberto Filgueiras ◽  
Lineu N. Rodrigues ◽  
Fernando F. da Cunha ◽  
Catariny C. Aleman
Keyword(s):  
Remote Sensing ◽  
Water Stress ◽  
Irrigation Management ◽  
Simple Algorithm ◽  
Landsat 8 ◽  
Stress Coefficient ◽  
Use Efficiency ◽  
Remote Sensing Techniques ◽  
Water Stress Coefficient ◽  
The Relationship

ABSTRACT In regions where the irrigated area is increasing and water availability is reduced, such as the West of the Bahia state, Brazil, the use of techniques that contribute to improving water use efficiency is paramount. One of the ways to improve irrigation is by improving the calculation of actual evapotranspiration (ETa), which among other factors is influenced by soil drying, so it is important to understand this relationship, which is usually accounted for in irrigation management models through the water stress coefficient (Ks). This study aimed to estimate the water stress coefficient (Ks) through information obtained via remote sensing, combined with field data. For this, a study was carried out in the municipality of São Desidério, an area located in western Bahia, using images of the Landsat-8 satellite. Ks was calculated by the relationship between crop evapotranspiration and ETa, calculated by the Simple Algorithm for Evapotranspiration Retrieving (SAFER). The Ks estimated by remote sensing showed, for the development and medium stages, average errors on the order of 5.50%. In the final stage of maize development, the errors obtained were of 23.2%.

Natural variation and genomic prediction of growth, physiological traits, and nitrogen-use efficiency in perennial ryegrass under low-nitrogen stress

2020 ◽  
Vol 71 (20) ◽  
pp. 6670-6683
Author(s):  
Xiongwei Zhao ◽  
Gang Nie ◽  
Yanyu Yao ◽  
Zhongjie Ji ◽  
Jianhua Gao ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Nitrogen Use Efficiency ◽  
Ridge Regression ◽  
Genomic Prediction ◽  
Prediction Accuracy ◽  
Prediction Models ◽  
Physiological Traits ◽  
Grass Species ◽  
Nitrogen Use ◽  
Use Efficiency

Abstract Genomic prediction of nitrogen-use efficiency (NUE) has not previously been studied in perennial grass species exposed to low-N stress. Here, we conducted a genomic prediction of physiological traits and NUE in 184 global accessions of perennial ryegrass (Lolium perenne) in response to a normal (7.5 mM) and low (0.75 mM) supply of N. After 21 d of treatment under greenhouse conditions, significant variations in plant height increment (ΔHT), leaf fresh weight (LFW), leaf dry weight (LDW), chlorophyll index (Chl), chlorophyll fluorescence, leaf N and carbon (C) contents, C/N ratio, and NUE were observed in accessions , but to a greater extent under low-N stress. Six genomic prediction models were applied to the data, namely the Bayesian method Bayes C, Bayesian LASSO, Bayesian Ridge Regression, Ridge Regression-Best Linear Unbiased Prediction, Reproducing Kernel Hilbert Spaces, and randomForest. These models produced similar prediction accuracy of traits within the normal or low-N treatments, but the accuracy differed between the two treatments. ΔHT, LFW, LDW, and C were predicted slightly better under normal N with a mean Pearson r-value of 0.26, compared with r=0.22 under low N, while the prediction accuracies for Chl, N, C/N, and NUE were significantly improved under low-N stress with a mean r=0.45, compared with r=0.26 under normal N. The population panel contained three population structures, which generally had no effect on prediction accuracy. The moderate prediction accuracies obtained for N, C, and NUE under low-N stress are promising, and suggest a feasible means by which germplasm might be initially assessed for further detailed studies in breeding programs.

Simulation Study about Impact of Building Density on Heat Island Effect

2014 ◽  
Vol 590 ◽  
pp. 353-357
Author(s):  
Xiao Yu Luo ◽  
Jian Ge ◽  
Yun Zhang
Keyword(s):  
Thermal Conductivity ◽  
Rapid Development ◽  
Decision Makers ◽  
Management Decision ◽  
Heat Island ◽  
Building Density ◽  
Land Use Efficiency ◽  
Island Effect ◽  
Use Efficiency ◽  
The Relationship

Along with the rapid development of urbanization, high density city is becoming more and more common. The dense buildings cause the high intensity of heat island effect, resulting in a large amount of energy consumption. In this research the relationship between the heat island effect and the building density has been studied by CFD software with other factors such as the building height and construction shape unchanged. Through a series of simulation and data analysis it is revealed that the effect of building density on the thermal conductivity is obvious. And the study put forward the measure to alleviate the effects of the thermal conductivity by controlling building density in a certain percentage under the premise of maintaining the land use efficiency. This result can provide scientific references for planners, architects, and government management decision makers.

scholarly journals Differences in xylem development between Dutch and Japanese tomato (Solanum lycopersicum) correlate with cytokinin levels in hypocotyls

2020 ◽  
Vol 126 (2) ◽  
pp. 315-322 ◽  
Author(s):  
Xiaohua Qi ◽  
Hirokazu Takahashi ◽  
Yasushi Kawasaki ◽  
Yuya Ohta ◽  
Masahide Isozaki ◽  
...  
Keyword(s):  
High Yield ◽  
Growth Stages ◽  
Cytokinin Biosynthesis ◽  
Xylem Development ◽  
Isopentenyl Adenine ◽  
Use Efficiency ◽  
The Difference ◽  
Leaf Photosynthetic Rate ◽  
The Relationship ◽  
Different Growth Stages

Abstract Background and Aims Dutch tomato cultivars tend to have a greater yield than Japanese cultivars even if they are grown under the same conditions. Factors contributing to the increased yield of the Dutch cultivars were a greater light use efficiency and greater leaf photosynthetic rate. On the other hand, the relationship between tomato yields and anatomical traits is still unclear. The aim of this study is to identify the anatomical traits related to the difference in yield between Dutch and Japanese cultivars. Methods Anatomical properties were compared during different growth stages of Dutch and Japanese tomatoes. Hormone profiles and related gene expression in hypocotyls of Dutch and Japanese cultivars were compared in the hypocotyls of 3- and 4-week-old plants. Key results Dutch cultivars have a more developed secondary xylem than Japanese cultivars, which would allow for greater transport of water, mineral nutrients and phytohormones to the shoots. The areas and ratios of the xylem in the hypocotyls of 3- to 6-week-old plants were larger in the Dutch cultivars. In reciprocal grafts of the Japanese and Dutch cultivars, xylem development at the scion and rootstock depended on the scion cultivar, suggesting that some factors in the scion are responsible for the difference in xylem development. The cytokinin content, especially the level of N6-(Δ 2-isopentenyl) adenine (iP)-type cytokinin, was higher in the Dutch cultivars. This result was supported by the greater expression of Sl-IPT3 (a cytokinin biosynthesis gene) and Sl-RR16/17 (a cytokinin-responsive gene) in the Dutch cultivars. Conclusions These results suggest that iP-type cytokinins, which are locally synthesized in the hypocotyl, contribute to xylem development. The greater xylem development in Dutch cultivars might contribute to the high yield of the tomato.

scholarly journals Arabidopsis thaliana trehalose-6-phosphate phosphatase gene TPPI enhances drought tolerance by regulating stomatal apertures

2020 ◽  
Vol 71 (14) ◽  
pp. 4285-4297 ◽  
Author(s):  
Qingfang Lin ◽  
Song Wang ◽  
Yihang Dao ◽  
Jianyong Wang ◽  
Kai Wang
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Stomatal Closure ◽  
Primary Root ◽  
Stomatal Aperture ◽  
Wild Type ◽  
Trehalose Metabolism ◽  
Use Efficiency ◽  
Responsive Element ◽  
Primary Root Length

Abstract Transpiration occurs through stomata. The alteration of stomatal apertures in response to drought stress is an important process associated with water use efficiency (WUE). Trehalose-6-phosphate phosphatase (TPP) family genes have been reported to participate in adjustment of stomatal aperture. However, there have been no reports of the trehalose metabolism pathway genes improving WUE, and the upstream signalling pathway modulating these genes is not clear. Here, we demonstrate that a member of the TPP gene family, AtTPPI, confers drought resistance and improves WUE by decreasing stomatal apertures and improving root architecture. The reduced expression of AtTPPI caused a drought-sensitive phenotype, while its overexpression significantly increased drought tolerance. Abscisic acid (ABA)-induced stomatal closure experiments confirmed that AtTPPI mutation increased the stomatal aperture compared with that of wild-type plants; in contrast, overexpression plants had smaller stomatal apertures than those of wild-type plants. Moreover, AtTPPI mutation also caused stunted primary root length and compromised auxin transport, while overexpression plants had longer primary root lengths. Yeast one-hybrid assays showed that ABA-responsive element-binding factor1 (ABF1), ABF2, and ABF4 directly regulated AtTPPI expression. In summary, the way in which AtTPPI responds to drought stress suggests that AtTPPI-mediated stomatal regulation is an important mechanism to cope with drought stress and improve WUE.

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