scholarly journals Stomatal Traits and Barley (Hordeum Vulgare L.) Forage Yield in Drought Conditions of Northeastern Mexico

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1318
Author(s):  
Foroughbakhch Pournavab Rahim ◽  
Torres Tapia María Alejandra ◽  
Zamora Villa Víctor Manuel ◽  
Treviño Ramirez José Elías ◽  
Ngangyo Heya Maginot

Infrared technology is a practical, fast, non-destructive method that helps in forecasting plant development and can be used to select physiological traits, instead of other methodologies that require more time and breeding efforts. According to the statistical analyses and the relationship between the direct and indirect effects of the variables, this technology could serve as the basis for implementing a genotype selection methodology. Awnless barley was assessed in a randomized block design with three replicates in two crop seasons at Mexico’s northeastern region. Two samplings were carried out during crop development: at 75 and 90 days after sowing. The infrared and stomatal sensors were used to identify the direct and indirect effects of stomata’s traits on dry forage yield. The data were analyzed in a subdivided plot design, using mean comparison tests, correlation coefficients and path analyses, finding significant differences (p < 0.05) among localities and among samplings. Dry forage yield was significant and positively correlated with plant height (r = 0.578) and canopy temperature (r = 0.724), and negatively correlated with the leaf upper side stomatal width (r = −0.409) and the leaf lower side stomatal width (r = −0.641), chlorophyll content and vegetation index. Temperature, chlorophyll, density and leaf lower side stomatal index had the strongest direct effects on yield. Therefore, the infrared technology appears as a way to select high yielding awnless forage barley, to obtain the correlation, the positive direct effect of temperature and the negative effect of chlorophyll. Due to their direct effects, low density and low leaf underside stomatal indexes can also help in the indirect selection of higher yielding forage barley genotypes.

2019 ◽  
Vol 11 (4) ◽  
pp. 142
Author(s):  
Alexsander Rigatti ◽  
Daniela Meira ◽  
Tiago Olivoto ◽  
Carine Meier ◽  
Maicon Nardino ◽  
...  

This study aimed to evaluate direct and indirect effects of agronomic traits importance on grain yield with focus in pre-harvest sprouting. Experiment was conducted in 2017 crop season, and conducted in a randomized block design, with three replications, with eight wheat cultivars (BRS S&aacute;bia, CD 105, CD 1104, CD 1440, Frontana, Jade&iacute;te 11, Mirante and ORS Vintecinco). Grain yield and its components were evaluated, as well as other important traits such as pre-harvest sprouting. Data were submitted to variance analysis; and phenotypic, genotypic and environmental correlations were estimated to understand grain yield expression, direct and indirect effects of its components were evaluated through path analysis. Cultivar BRS Sabi&aacute; showed shorter cycle, cultivar CD 1104 was highlighted in number of spikes per area, hectoliter weight and grain yield. And cultivars Frontana, CD 1440 and ORS Vintecinco presented the best tolerances pre-harvest sprouting. Grain yield showed high and positive phenotypic and genotypic correlations with number of ears per square meter. Furthermore, high positive direct effect of pre-harvest sprouting on grain yield, revels lower tolerance for cultivars with high grain yield. Number of spikes per square meter showed intermediate and positive direct effect and pre-harvest sprouting had the greatest direct effect on grain yield.


Author(s):  
Rhitisha Sood ◽  
R.K. Mittal ◽  
V.K. Sood ◽  
Shailja Sharma

Background: Blackgram despite of being a highly nutritious and short duration legume crop, it is not cultivated on large scales due to many constraints. Considering this, the research was aimed to develop blackgram genotypes with wider adaptability, genetic variability and high yielding potential by studying nature and magnitude of association among yield and related traits for effective production. Methods: The present investigation was carried out at Experimental Farm of the Department of Genetics and Plant Breeding, College of Agriculture, CSK HPKV, Palampur (H.P.) to assess the character association and direct and indirect effects among yield and related traits in 14 crosses and ten parents for 11 quantitative characters during Kharif 2018 and 2019 in randomized complete block design with three replications. Result: Correlation studies highlighted that seed yield per plant had significant and positive association with pods per plant, biological yield per plant, pod length, plant height and 100 seed-weight at genotypic and phenotypic levels in both generations. Study of path analysis revealed that biological yield per plant and pods per plant exhibited maximum positive direct and indirect effects to the total association between yield and other component traits in both the generations. These traits could be suggested as best selection indices on priority basis which would be commendable to improve the performance of genotypes during breeding programme.


2021 ◽  
Author(s):  
Diego Rodrigues Guilherme ◽  
Pedro Aurélio Costa Lima Pequeno ◽  
Fabrício Beggiato Baccaro ◽  
Elizabeth Franklin ◽  
Cláudio Rabelo dos Santos Neto ◽  
...  

Abstract To understand better the effects of niche and neutral processes is important to disentangle the direct and indirect effects of each process, mainly if the environmental factors are geographically structured neglecting important indirect and synergic effects. We sampled ground-dwelling ant species on 126 plots distributed across eight sampling sites along a broad environmental gradient in Central Amazonia. Structural equation modelling was employed to quantify direct and indirect effects of geographic distance, the Amazon River’s opposite margins, and environmental differences in temperature, precipitation and vegetation structure (Normalized Difference Vegetation Index) on ant beta diversity (Jaccard’s dissimilarity). We found that geographic distance and NDVI differences had major direct effects on ant beta diversity. The major effect of temperature was indirect through NDVI, whereas precipitation had no detectable effect on beta diversity. The Amazon River had a weak influence on the ant composition dissimilarity. Our results challenge the major role often ascribed to riverine barriers in the diversification and distribution of Amazonian biota. Rather, ant compositional dissimilarity seems to be mainly driven by a combination of dispersal limitation and selection imposed by vegetation features and, indirectly, by temperature. We suggest that as NDVI differences decrease with geographic distance in the region, isolation by distance may have favoured phenotypic convergence between ant communities in the northern and southern borders of the Amazon Basin.


2020 ◽  
Vol 117 (51) ◽  
pp. 32476-32483
Author(s):  
Riikka Rinnan ◽  
Lars L. Iversen ◽  
Jing Tang ◽  
Ida Vedel-Petersen ◽  
Michelle Schollert ◽  
...  

Volatile organic compounds (VOCs) are released from biogenic sources in a temperature-dependent manner. Consequently, Arctic ecosystems are expected to greatly increase their VOC emissions with ongoing climate warming, which is proceeding at twice the rate of global temperature rise. Here, we show that ongoing warming has strong, increasing effects on Arctic VOC emissions. Using a combination of statistical modeling on data from several warming experiments in the Arctic tundra and dynamic ecosystem modeling, we separate the impacts of temperature and soil moisture into direct effects and indirect effects through vegetation composition and biomass alterations. The indirect effects of warming on VOC emissions were significant but smaller than the direct effects, during the 14-y model simulation period. Furthermore, vegetation changes also cause shifts in the chemical speciation of emissions. Both direct and indirect effects result in large geographic differences in VOC emission responses in the warming Arctic, depending on the local vegetation cover and the climate dynamics. Our results outline complex links between local climate, vegetation, and ecosystem–atmosphere interactions, with likely local-to-regional impacts on the atmospheric composition.


Utilitas ◽  
2012 ◽  
Vol 24 (1) ◽  
pp. 126-138 ◽  
Author(s):  
ANDREW WALTON

In this article I consider two consequentialist positions on whether individuals in affluent countries ought to purchase Fair Trade goods. One is a narrow argument, which asserts that individuals should purchase Fair Trade goods because this will have positive direct effects on poverty reduction, by, for example, channelling money into development. I argue that this justification is insufficient to show that individuals should purchase Fair Trade goods because individuals could achieve similar results by donating money to charity and, therefore, without purchasing Fair Trade goods. The second position has a wider focus. It notes both the direct effects of purchasing Fair Trade goods and possible indirect effects, such as the impact this might have on other individuals. I argue that certain actions, of which Fair Trade is one example, will be more likely to encourage individuals who would not otherwise contribute to poverty reduction to contribute and that this may produce additional positive value. Although space prohibits specific conclusions about Fair Trade, I note that considerations of this kind could give us reason to purchase such goods beyond those that issue from the direct effects of doing so and that, as such, they are crucial for determining whether individuals should purchase Fair Trade goods.


1969 ◽  
Vol 90 (3-4) ◽  
pp. 183-191
Author(s):  
Miguel Espitia-Camacho ◽  
Franco A. Vallejo-Cabrera ◽  
Diosdado Baena-Garcia ◽  
Linda Wessel-Beaver

Path coefficient analysis was carried out in tropical pumpkin (Cucurbita moschata Duchesne) for yield per plant as a function of number of fruit per plant and weight per fruit, using phenotypic and genetic correlations from two diallels: one using five varieties (variety diallel) and a second using five S1 lines derived from the varieties (line diallel). A randomized complete block design with five replications was used to evaluate 15 genotypes from each diallel, not including reciprocals. Direct effects were 300 to 500% greater than indirect effects in the line diallel. In contrast, direct effects were only 17 to 68% greater than indirect effects in the variety diallel. Effects (direct and indirect) were greater (17 to 500%) when genetic correlations rather than phenotype correlations (42 to 440%) were used in the path analysis. Fruit weight showed a greater effect on yield than did number of fruit, with values between 3.2 to 4.9 times the residual effects. Fruit weight and number of fruit can be used as selection criteria to increase yield in tropical pumpkin.  


1979 ◽  
Vol 45 (3) ◽  
pp. 803-810 ◽  
Author(s):  
James L. Taylor ◽  
Richard M. Durand

Oliver (1977) recently analyzed the direct effects of consumers' expectations and disconfirmation on posttrial evaluations of products using a hierarchical analysis of variance design. The research reported by Oliver is reevaluated and extended in this paper. A causal model is presented and path analysis used to assess both direct and indirect effects of consumers' expectations and a disconfirming experience on ratings of posttrial affect and intentions to purchase. Results suggest that (1) both expectations and disconfirmation influence postexposure ratings of affect with the experience of disconfirmation exerting the greater effect; (2) disconfirmation only indirectly influences intentions to purchase through its impact on affective evaluations; and, (3) expectations influence intentions to purchase in two different ways—both directly and indirectly through posttrial judgments of affect.


2015 ◽  
Vol 44 (1) ◽  
pp. 147-150
Author(s):  
R Prakash ◽  
C Vanniarajan

Path coefficient analysis was studied in 65 genotypes of barnyard millet to find out the association studies of characters and their direct and indirect effects on grain yield/plant. Results exhibited that single earhead weight had maximum direct effects on grain yield/plant followed by straw yield/plant, earhead length and plant height. DOI: http://dx.doi.org/10.3329/bjb.v44i1.22739 Bangladesh J. Bot. 44(1): 147-150, 2015 (March)


2012 ◽  
Vol 12 (4) ◽  
pp. 245-252 ◽  
Author(s):  
Jeane de Oliveira Moura ◽  
Maurisrael de Moura Rocha ◽  
Regina Lúcia Ferreira Gomes ◽  
Francisco Rodrigues Freire Filho ◽  
Kaesel Jackson Damasceno e Silva ◽  
...  

The objective of this study was to estimate the direct and indirect effects of agronomic and culinary traits on iron and zinc contents in 11 cowpea populations. Correlations between traits were estimated and decomposed into direct and indirect effects using path analysis. For the study populations, breeding for larger grain size, higher number of grains per pod, grain yield, reduced cooking time, and number of days to flowering can lead to decreases in the levels of iron and zinc in the grain. Genetic gains for the iron content can be obtained by direct selection for protein content by indirect effects on the number of grains per pod, 100-grain weight and grain yield. The positive direct effect of grain size and protein content on the zinc content indicates the possibility of simultaneous gain by combined selection of these traits.


2014 ◽  
Vol 32 (1) ◽  
pp. 215-225
Author(s):  
K.F. Mendes ◽  
M.R. Reis ◽  
A.A. Pereira ◽  
A.R.S. Nunes ◽  
C.E.M. Santos ◽  
...  

The objective of this study was to evaluate oxadiazon sorption in different soils of the Brazilian Cerrado, highlighting the correlations of lethal doses of this herbicide capable of inhibiting 50% of the dry matter accumulation of the bio-indicator (LD50) among the chemical characteristics of the soil and its direct and indirect effects. The experiment was carried out in a greenhouse in a randomized block design and four repetitions. Each experimental unit consisted of a pot with increasing rates of oxadiazon and oat (Avena sativa), as the bio-indicator species. For sorption evaluation, washed sand and 22 soils (substrates) from Cerrado Brazilian's Alliaceae cultivated areas were used. LD50 and sorption ratio (SR) = [(LD50soil - LD50sand)/LD50sand] to the substrates were determined. Pearson correlation analysis was performed between the chemical characteristics of the substrates and the LD50 of oxadiazon. A path analysis was quantified, to deploy only the significant correlations estimated in direct and indirect effects of the characters on LD50, which is a basic variable. A more pronounced LD50 (528.09 g ha-1) for the Cerrado soil sample resulted in higher SR (> 53.00), while in the washed sand substrate, LD50 corresponded only to 9.74 g ha-1 of the oxadiazon (available in soil). It was concluded that oxadiazon sorption is influenced by the chemical characteristics of the soils, highlighting the correlation with pH (CaCl2), magnesium content, aluminum, organic matter, organic carbon, and aluminum saturation.


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