No abstract

-Knowledge about associations between traits is fundamental for plant breeding, since indirect selection can accelerate the development of promising genotypes. This study assessed the magnitude of associations between agronomically important traits in fisális (Physalis peruviana L). The experiment was conducted in Lages, Santa Catarina, and the treatments consisted of six fisális populations. The experiment was arranged in a randomized block design, with two replications and seven plants per plot. The correlations between traits were estimated based on the Pearson correlation coefficients and partitioned into direct and indirect effects through path analysis. Fruit weight was positively correlated with number of seeds (0.874), equatorial fruit diameter (0.738) and polar fruit diameter (0.672). By path analysis, number of seeds was identified as the trait with the highest direct contribution to fruit weight. The high phenotypic correlations between the equatorial and polar fruit diameters with fruit weight were mainly due to the indirect effect via number of seeds (0.505 and 0.459). The selection for heavier fisális fruits was strongly influenced by number of seeds, i.e., this trait should be taken into account for selection. Index terms: phenotypic correlation, path analysis, plant breeding, Physalis peruviana L. ASSOCIAÇÃO ENTRE CARACTERES EM FISÁLIS: UMA FERRAMENTA PARA SELEÇÃO INDIRETA DE PLANTAS SUPERIORESRESUMO -O conhecimento da associação entre caracteres é de fundamental importância no melhoramento de plantas, uma vez que a seleção indireta pode acelerar a obtenção de genótipos promissores. Este trabalho teve como objetivo quantificar a magnitude da associação entre caracteres de importância agronômica na cultura da fisális. O experimento foi conduzido em Lages-SC, e os tratamentos foram constituídos de seis populações de fisális. O delineamento experimental foi em blocos casualizados, com duas repetições e sete plantas por parcela. A correlação entre os caracteres foi estimada com base nos coeficientes de correlação de Pearson e particionados em efeitos diretos e indiretos por meio da análise de trilha. Houve associação positiva entre a massa do fruto e o número de sementes (0,874), diâmetro equatorial do fruto (0,738) e diâmetro polar do fruto (0,672). Por meio da análise de trilha, foi possível verificar maior contribuição direta do caráter número de sementes sobre a massa do fruto. A elevada magnitude de correlação fenotípica entre diâmetro equatorial do fruto e diâmetro polar do fruto com a massa do fruto deve-se, principalmente, ao efeito indireto via número de sementes (0,505 e 0,459). A seleção de frutos de fisális com maior massa é fortemente influenciada pelo número de sementes, de maneira que este caráter deve ser considerado no momento da seleção. Termos para indexação: correlação fenotípica, análise de trilha, melhoramento de plantas, Physalis peruviana L.

The objective of this work was to estimate the phenotypic correlation and the direct and indirect effects of the aerial part components of common bean (Phaseolus vulgaris) that are associated with root distribution, in order to facilitate the indirect selection for this character. Sixteen genotypes were used, from which 12 are segregating populations in the F6 generation and four are fixed populations, which were conducted in field conditions in a randomized complete block design, with two replicates. The root system evaluation was performed according to Böhm’s method. Pearson’s phenotypic correlation was estimated by the path analysis. The characters stem diameter, leaf area index, first pod set, and root angle showed the highest positive correlations with root distribution and, therefore, may help the indirect selection for this character. The residual effect was higher than the determination coefficient, which indicates that the independent characteristics do not have a total influence on root distribution, and the low values of the determination coefficients can be attributed to environmental effects, competition for nutrients, and to different physiological mechanisms that control the expression of several genes with minor effects.

RESUMO O objetivo foi avaliar os componentes da variância fenotípica e estimar a influência da interação genótipo*ambiente no rendimento de grãos em feijão. Os componentes da variância fenotípica foram estimados pelo método da máxima verossimilhança restrita e do melhor preditor linear não viesado (REML/BLUP

ABSTRACT

When different gene groups are combined by hybridization, the expression of predominant genes for a trait must be known. This understanding is fundamental to the decisions made by breeders in the stages of cultivation and selection of segregating populations during the breeding program. Thus, the objective of this study was to determine the effects of combining ability and gene action for the root distribution traits of the Andean and Mesoamerican common bean gene groups. Six common bean parents from the Andean and Mesoamerican groups were hybridized in a complete diallel mating scheme, resulting in 30 F1 hybrids. The parents and hybrids were planted in the field in a simple lattice design. The target trait was root distribution, calculated as the relative number of roots in the topsoil. The effect of the general combining ability was significantly higher than that of the specific combining ability (58%) and the reciprocal effect (41%). Particularly, the combination estimates were modified according to the order of the gene groups used. The combinations IPR Uirapuru x BAF53 (Mesoamerican x Andean), BAF53 x CBS14 (Andean x Andean), and CBS14 x IPR Uirapuru (Andean x Mesoamerican) mainly exhibited an increase in the mean root distribution. However, the highest fraction of genetic variance correlated with additive components (60%), even in crosses involving different gene groups. Consequently, the additive gene action was predominant in the expression of root distribution trait in common bean, irrespective of the gene group used.

Heterosis has been one of the most studied phenomena since genetic studies were conceived. Knowledge of this phenomenon for the root distribution trait in beans (Phaseolus vulgaris L.) can favour the development of genotypes that are more tolerant to abiotic stresses. This study aimed to verify the occurrence of heterosis for the root distribution trait in hybrid F1 populations of common bean derived from crosses within and between gene groups. Thirty-six populations (six parents and 30 hybrids) were evaluated under field conditions in the agricultural years 2016/17 and 2017/18. The root distribution was assessed with the adapted Bohm method. The genotypes responded similarly to environmental changes (absence of an interaction). However, the root distribution differed significantly between the agricultural years. Comparisons between the mean of hybrids from crosses within each gene pool and the mean of parents did not reveal heterosis. The comparisons between gene groups showed significant differences only between BRS Embaixador x IPR Uirapuru, CBS 14 x IPR Uirapuru, and BAF 53 x IPR Uirapuru and the mean of parents. The absence of heterosis in the root trait can be explained by the degree of kinship between the gene groups, as well as some epistatic interactions.

-The restricted genetic base in physalis in Southern Brazil is a challenge that requires genetic breeding for the achievement of fruits with superior agronomic quality. Therefore, genetic changes were induced in physalis for the selection of populations with superior fruit quality. To that end, seven populations of physalis were submitted to gamma irradiation (0,100 and 200 Grays -Gy), which provided 21 populations. Significant population difference was observed, which indicates the existence of variability between at least two populations of physalis. The contrasts showed difference for Colômbia01, Colômbia02, Caçador and CAV. The mutation induction was effective at causing genetic variations in these populations. For Colombia01 (100 Gy), it was observed reduction of 3.97 mm and 2.56 mm (200 Gy) in the transverse fruit diameter (DTF).In the Colombia02 population (200 Gy), there was an increase of 2.99 mm in the longitudinal fruit diameter (DLT) and 4.90 mm in the DTF. For CAV (200 Gy), it was found the increase of 1.81 ºBrix. Mutation induction was beneficial in these cases, but fruit quality is still below the potential of the crop, when compared to fruits from Andean countries. It is possible to suggest that quantitative traits, such as fruit mass (MF) and total soluble solids (SST), and the degree of ploidy in physalis (2n = 4x = 48) reduce the mutagenic agent ability to cause variations. Index terms: small fruit, gamma radiation, Cobalt 60 , selection. Indução de mutação como estratégia para a superação da restrita base genética em PhysalisResumo -A restrita base genética em fisális é um desafio a ser superado pelo melhoramento da cultura, na região Sul do Brasil, de modo a obter frutos com qualidade agronômica superior. Diante disso, objetivou-se induzir alterações genéticas em fisális para a seleção de populações com qualidade de fruto superior. Para tanto, sete populações de fisális foram submetidas à irradiação gama (0; 100 e 200 Grays -Gy), resultando em 21 populações. Houve diferença significativa para população, revelando a existência de variabilidade entre, pelo menos, duas populações. Por meio dos contrastes detectou-se diferença para: Colômbia01, Colômbia02, Caçador e CAV. A indução mutação foi eficiente em causar variações genéticas nestas populações. Para Colômbia01 (100 Gy), observou-se redução de 3,97 mm e 2,56 mm (200 Gy) no diâmetro polar do fruto (DPF