Genetic variability and expression of agro-morphological traits among genotypes of Coffea arabica being promoted by supplementary irrigation

Abstract

The use of supplementary irrigation to sustain the plantation during moments of severe water stress or moments of high water demand is becoming almost a norm to keep sustainable crops, especially due to the climate changes and the high frequency in which climate extremes are occurring lately. The objective of this study was to evaluate the agronomic performance and expression of genetic variability among genotypes of Coffea arabica L. cultivated in farming systems with different levels of water supply, focusing on rainfed or supplementary irrigated systems. The experiment was developed in competition field, testing 8 genotypes of C. arabica L. in rainfed or supplementary irrigated systems. The growth and production were evaluated during 2 consecutive cycles (2014-2015 and 2015-2016). Among the growth gains, it was observed large gains in coffee yield, but the magnitude of the gains varied among genotypes. For crop yield, for example, Paraíso MG/H 419-1 presented 136% gain, while Oeiras MG-6851 was capable of yielding as much more coffee in rainfed conditions than in irrigated system. The expression of variability for some agronomic traits (such as coffee yield, canopy size, growth rate, and number of new buds) may be intensified by the supplementary water supply, which promotes gains in production and growth, increases the magnitude of variation among genotypes and allows to identify different patterns for selection, which may not be observed in the rainfed systems.

Genetic divergence based on leaf vegetative and anatomical traits of Coffea canephora clones

“…The genetic coefficient of variation (CVg) is a relationship between the genetic standard deviation and the experimental mean, interpreted compared with the experimental coefficient of variation. Relationships between CVg and CVe close to or higher than the unity indicate a favorable condition for obtaining gains from plant selection, as they are more associated with the contribution of genetic components than with environmental variations (Nascimento et al, 2014;Rodrigues et al, 2017). This condition was observed for stomatal density, total dry mass, root system volume, leaf area, number of stomata, and polar diameter (Table 2).…”

“…Estimates of heritability (h 2 ), which measures the relationship between genotypic and phenotypic variance, showed high values for almost all the evaluated traits, except for equatorial diameter (h 2 =39.52) (Nascimento et al, 2014;Rodrigues et al, 2017). These results reinforce the possibility of selecting superior genotypes with a higher degree of safety for the desired traits, as they represent less environmental interference on traits and higher participation of the genotype in total variability (N. S. Oliveira et al, 2015;Ferreira, Viana, Silva, Santos, & Santos, 2016).…”

“…In fact, this criterion has been observed in studies aimed at characterizing the genetic variability among coffee genotypes to select superior materials for desired traits Notably, studies have pointed out the importance of using different methodologies to evaluate genetic variability aiming to ensure higher reliability of results (Azevedo et al, 2013(Azevedo et al, , 2015 and consistency in the clustering pattern (Nascimento et al, 2014). In fact, this criterion has been observed in studies aimed at characterizing the genetic variability among coffee genotypes to select superior materials for desired traits (Covre et al, 2016;W. N. Rodrigues et al, 2017;Starling et al, 2019;Giles et al, 2019).…”

“…In this scenario, methodologies based on principal components are used seeking to reduce the dimensionality of the original variables, representing the original variability in a scatter in the plane with few axes (Covre et al, 2016;W. P. Rodrigues, Vieira, Teodoro, Partelli, & Barbosa, 2016a;Rodrigues, Brinate, Martins, Colodetti, & Tomaz, 2017;Starling et al, 2019). Thus, this study aimed to quantify the genetic divergences between Coffea canephora genotypes based on leaf vegetative and anatomical traits to establish criteria for the early selection of water deficittolerant genotypes.…”

Research Article Genetic diversity in nutritional parameters in response to drought of <i>Coffea</i> <i>canephora</i> cultivated in Rondonia state, Brazil

“…The response to changes in soil moisture and the magnitude of expression of the genetic variability being modulated by the amount of water available in the soil for several agronomic traits of coffee plants have been reported by studies assessing other genotypes (Silva et al, 2015;Carvalho et al, 2017;Rodrigues et al, 2017;Bonomo et al, 2018;Starling et al, 2018).…”