Adaptability, stability and environmental stratification of genetically and nongenetically modified corn in the Cerrado

ABSTRACT Crop yield depends on interaction between genetic and environmental factors, making it essential to study adaptability, stability and environmental stratification in order to mitigate the effects of this interaction. Four experiments were conducted to assess competition between corn cultivars in the 2018/19 growing season, two in Paraíso do Tocantins and two in Palmas, with sowing performed on November 5, 2018 and January 15, 2019. Cultivar-environment interaction was analyzed in genetically modified (GM) and non-GM commercial corn cultivars in the Vale do Araguaia region of Tocantins state (TO), Brazil, A randomized block design was used for all the experiments, in 3 × 12 factorial scheme, with three doses of nitrogen fertilizer as topdressing (50, 100 and 150 kg of N ha-1) and 12 commercial cultivars (six non-GM, 1CHD, 2CV, 3CV, 4CV, 5CTH, 6CDH and six GM, 7GTH, 8GTH, 9GSH, 10GSH, 11GSH, 12GSH. For statistical analysis, the N dose in each experiment represented a different environment. The characteristic studied was grain yield, using the adaptability and stability methods as well as environmental stratification. Different responses were observed between the GM and non-GM cultivars. Most of the GM and non-GM cultivars were better adapted to favorable and unfavorable environments, respectively. All the environments exhibited similar behavior regardless of location, sowing time and the N dose used, demonstrating that fewer environments can be used in future breeding research.

Environmental Stratification in Trials of Unbalanced Multiyear Soybean (Glycine max (l.) Merril) via the Integration of GGE Biplot Graphs and Networks of Environmental Similarity

Genotype x enviroment (GE) interaction can difficult soybean breeding programs to atieve the aim of obtain more productive cultivars. Enviroment stratification is a way to circunvent this problem. This work aimed to gather GGE Biplot graphs of a network of trials unbalance multiyear soybean via matrices of coincidence and networks of enviroment to optimize environmental stratification. Data from an experimental network of 43 trials was used, these experiments were implanted during the crop seasons of 2011/12, 2012/13, 2013/14 and 2015/16 in Brazil. The GE interaction were statistically significant for all 43 trials. The step by step of our analses was: GGE Biplots graphs were obtained; the enviroment coincidence matrices were calculated; the values of matrices were used for to obtain the networks of environmental similarity. The study demonstrated that by the method was possible to identify, using unbalanced multiyear data, the formation of four mega-environments. Therefore, integrating GGE Biplot graphs and networks of environmental similarity is an efficient method to optimize a soybean program by environment stratification.

Factor analysis and environmental stratification in the assessment of grain sorghum adaptability and stability

The environmental stratification studies are crucial when releasing hybrids for different growing regions. An outstanding performance of a genotype in one environment does not qualify it for indication to all environments, due the occurrence of GxE interaction. Environmental stratification aim the breeders to form groups of environments that minimize GxE interaction. The purpose of this work was to evaluate the use of factor analysis in preliminary environmental stratification assisting at the recommendation of grain sorghum cultivars. Twenty-five hybrids were evaluated, using a randomized block design, in 12 locations during the 2015/16 season. Initially, the individual analysis of the experiments was carried out and later the joint analysis, aiming to examine the existence of G×E interaction. The means of the hybrids in the individual analyses were used to obtain the correlation matrix between pairs of environments. The factorization of this matrix was also carried out via factor analysis in order to group together the environments that most correlated with respect to the hybrids performance. Thus, differential performance between hybrids was observed through individual analyses for all the environments, with the exception of Sete Lagoas and Teresina. The joint analysis revealed the existence of a significant G×E interaction, that is, a differential behavior of the hybrids in relation to the evaluated environments. Based on the criterion of the analysis of the proportion of explained variance, it was found that six factors captured an accumulated variation of 86.29%, and the average communality observed was of 0.86. Considering the geographic and edaphoclimatic variables in the cultivation period, a pattern was not observed among the grouped places, but it is noteworthy that the grouping of places is a function of the performance of the evaluated genotypes, which can be similar even under different conditions. Given the results presented, factor analysis proved to be a tool with potential to perform environmental stratification and assist in the recommendation of grain sorghum cultivars for different regions.

The Sustainability of Thailand’s Protected-Area System under Climate Change

Protected areas are the backbone of biodiversity conservation but vulnerable to climate change. Thailand has a large and well-planned protected area system, covering most remaining natural vegetation. A statistically derived global environmental stratification (GEnS) was used to predict changes in bioclimatic conditions across the protected area system for 2050 and 2070, based on projections from three CMIP5 earth system models and two representative concentration pathways (RCPs). Five bioclimatic zones were identified composed of 28 strata. Substantial spatial reorganization of bioclimates is projected in the next 50 years, even under RCP2.6, while under RCP8.5 the average upward shift for all zones by 2070 is 328–483 m and the coolest zone disappears with two models. Overall, 7.9–31.0% of Thailand’s land area will change zone by 2070, and 31.7–90.2% will change stratum. The consequences for biodiversity are less clear, particularly in the lowlands where the existing vegetation mosaic is determined largely by factors other than climate. Increasing connectivity of protected areas along temperature and rainfall gradients would allow species to migrate in response to climate change, but this will be difficult in much of Thailand. For isolated protected areas and species that cannot move fast enough, more active, species-specific interventions may be necessary.

A kingdom in decline: Holocene range contraction of the lion (Panthera leo) modelled with global environmental stratification

Aim We use ecological niche models and environmental stratification of palaeoclimate to reconstruct the changing range of the lion (Panthera leo) during the late Pleistocene and Holocene. Location The modern (early 21st century) range of the lion extends from southern Africa to the western Indian Subcontinent, yet through the 20th century this range has been drastically reduced in extent and become increasingly fragmented as a result of human impacts. Methods We use Global Environmental Stratification with MaxEnt ecological niche models to map environmental suitability of the lion under current and palaeoclimatic scenarios. By examining modelled lion range in terms of categorical environmental strata, we characterise suitable bioclimatic conditions for the lion in a descriptive manner. Results We find that lion habitat suitability has reduced throughout the Holocene, controlled by pluvial/interpluvial cycles. The aridification of the Sahara 6ka dramatically reduced lion range throughout North Africa. The association of Saharan aridification with the development of pastoralism and the growth of sedentary communities, who practised animal husbandry, would have placed additional and lasting anthropogenic pressures on the lion. Main Conclusions This research highlights the need to integrate the full effects of the fluctuating vegetation and desiccation of the Sahara into palaeoclimatic models, and provides a starting point for further continental-scale analyses of shifting faunal ranges through North Africa and the Near East during the Holocene. This scale of ecological niche modelling does not explain the current pattern of genetic variation in the lion, and we conclude that narrow but substantial physical barriers, such as rivers, have likely played a major role in population vicariance throughout the Late Pleistocene.

Adaptability and stability with multivariate definition of macroenvironments for wheat yield in Rio Grande do Sul

The objective of this work was to evaluate the adaptability, stability, and environmental stratification of wheat (Triticum aestivum) grown in 20 environments, in the state of Rio Grande do Sul, Brazil. The experiments were performed during four crop years, in five wheat growing regions, considering 20 distinct growing environments. In the presence of genotype x environment (GxE) interaction, the additive main effects and multiplicative interaction analysis (AMMI) method was used. This method combines variances of additive effects of genotypes and environments with the multiplicative effects of GxE interaction, and the obtained scores are displayed in biplot graphs, using the principal component analysis. The environments stratified by the factor analysis, and the macroenvironments were defined according to grain yield behavior. The patterns of adaptability and phenotypic stability for genotypes 'BRS 327', 'BRS 331', 'Fundacep Raízes', 'BRS 328', and 'BRS Guamirim' were obtained through the multivariate biometric approaches AMMI and the factor analysis. The definition of macroenvironments is intrinsic to peculiarities of the crop year in the state of Rio Grande do Sul, and there is similarity between the municipalities of Santo Augusto, Cachoeira do Sul, and São Luiz Gonzaga, as well as between Cachoeira do Sul and São Gabriel.

Study over volcanic ash contamination conditions of Romanian air space-Etna

This study is focused on finding the hypothetical conditions under of which the Romanian air space could be affected by a volcanic ash-like pollutant originating from Etna Volcano. We describe the plume transport behaviour, on its way to Romania, using the mass loading distribution displayed by the HYSPLIT (Hybrid Single Lagrangian Integrated Trajectory) model output. From the WLK (Wetterlagen-klassifikation) catalogue we have specific day sequences showing more than three days of a south-western circulation with a wet anticyclonic pattern over Romania. The resulting 24 cases in a period spanning more than a decade (2004-2014) displayed that the chances of contamination would be better for a quiescent environment around Etna’s summit. There were found ten cases in quiescent atmosphere and only four cases in windy atmosphere with Romanian air space contamination. Although it was not possible to determine the effective concentration of the fine ash pollutant it was possible to isolate the mass loading distribution in time. As the study cases displayed one order of magnitude difference between mass loading distributions it became obvious that the behaviour of the mass loading distribution in time has a directly dependence on the environmental stratification of the Etna’s summit atmosphere.