Open AccessPath analysis of phenotypic traits in young cacao plants under drought conditions
Author(s) -
Emerson Alves dos Santos,
Alex-Alan Furtado de Almeida,
Márcia Christina da Silva Branco,
Ivanildes Conceição dos Santos,
Dário Ahnert,
V. C. Baligar,
R. R. Valle
Publication year - 2018
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0191847
Subject(s) - theobroma , biology , randomized block design , path analysis (statistics) , irrigation , diallel cross , drought tolerance , biomass (ecology) , agronomy , phenotypic trait , phenotypic plasticity , horticulture , greenhouse , botany , phenotype , mathematics , hybrid , ecology , biochemistry , statistics , gene
Drought is worldwide considered one of the most limiting factors of Theobroma cacao production, which can be intensified by global climate changes. In this study, we aimed to investigate the phenotypic correlation among morphological characteristics of cacao progenies submitted to irrigation and drought conditions and their partitions into direct and indirect effects. Path analysis with phenotypic plasticity index was used as criteria for estimation of basic and explanatory variables. The experiment was conducted in a greenhouse at the Cacao Research Center (CEPEC), Ilhéus, Bahia, Brazil, in a randomized block 21 x 2 factorial arrangement [ 21 cacao progenies obtained from complete diallel crosses and two water regimes (control and drought)] and six replications. In general, drought conditions influenced biomass production in most progenies, causing significant reductions in total leaf area, leaf number, leaf biomass, fine-roots length (diameter <1 mm), root volume and root area for considered drought intolerant. All progenies showed alterations in growth due to drought. Phenotypic plasticity was most strongly pronounced in root volume. Stem and root diameters, as well as stem dry biomass were the growth variables with the greatest direct effects on root volume under drought conditions, these characters being indicated in screening of cacao progenies drought tolerant.