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The objective of this work was to estimate the genetic parameters and genetic divergence of two species of Physalis based on fruit traits, as well as the correlations between these traits. The experiment was carried out in a randomized complete block, with three treatments (P. philadelphica and the green and purple varieties of P. ixocarpa), and six replicates. The following traits were evaluated: average fruit mass (AFM), soluble solids (SS), longitudinal fruit diameter (LFD), transversal fruit diameter (TFD), total fruit mass (TFM), number of fruit per plant (NF), reducing sugars (RS), and total sugars (TS). Genetic divergence was estimated by Tocher’s and the UPGMA methods. There was genetic divergence between the Physalis species, with a higher contribution of AFM, LFD, and TFD, mainly by Tocher’s method. A positive correlation was observed between AFM x LFD, AFM x TFD, and LFD x TFD, and a negative correlations between LFD x TFM, TFD x TFM, and NF x RS. The species were discriminated by total sugars. The AFM, LFD, TFD, and TS traits show significant genetic variation and high values of heritability; therefore, they are suitable targets for the genetic breeding of the evaluated Physalis species. Resumo O objetivo deste trabalho foi estimar os parâmetros genéticos e a divergência genética de duas espécies do gênero Physalis com base nas características de frutos, bem como as correlações entre essas características. O experimento foi realizado em blocos ao acaso, com três tratamentos (P. philadelphica e as variedades verde e roxa de P. ixocarpa) e seis repetições. Avaliaram-se as características: massa média de frutos (AFM), sólidos solúveis (SS), diâmetro longitudinal do fruto (LFD), diâmetro transversal do fruto (TFD), massa total de frutos (TFM), número de frutos por planta (NF), açúcares redutores (RS) e açúcares totais (TS). A divergência genética foi estimada pelos métodos de Tocher e UPGMA. Houve divergência genética entre as espécies de Physalis, com maior contribuição de AFM, LFD e TFD, principalmente pelo método de Tocher. Observou-se correlação positiva entre AFM x LFD, AFM x TFD e LFD x TFD, e correlação negativa entre LFD x TFM, TFD x TFM e NF x RS. As espécies foram discriminadas por açúcares totais. As características AFM, LFD, TFD e TS apresentam variação genética significativa e altos valores de herdabilidade; portanto, são alvos adequados para o melhoramento genético das espécies de Physalis avaliadas.

Soybean oil is one of the most important vegetable oils in world. Increasing oil content and improve its composition is an important aim of many soybean breeding programs. In this context, the objective of this study was to identify QTLs controlling oil and fatty acid contents in soybean seed in different locations. For this, we developed F2-derived populations by crossing CS303TNKCA and FA22 lines, and analyzed oil and fatty acid content in four locations in Brazil. We evaluated the correlations of traits in each location and between locations and used 1536 SNPs to molecular characterize this population. QTLs associated with the average values of four environments were identified by using simple interval mapping. A linkage map was generated using 534 SNP markers, and 25 linkage groups were formed. A total of 20 QTLs controlling oil, palmitic, stearic, oleic, linoleic and linolenic contents were found, varying from one (linolenic content) to six (palmitic content), and explaining from 7.02% (qSte-13) to 70.37% (qLin-14) of phenotypic variation. We could not associate eight QTLs (qPal-02, qOle-02, qLol-02, qOle-04, qLol-04, qPal-13.2, qSte-15 and qSte-17) with reported QTLs and genes, so these could be set as new QTLs controlling fatty acid composition. The results found in the present work can help understand the genetic basis of these traits and help breeders to modify oil content and composition in soybean seed, especially in tropical conditions.

We molecularly characterized a new mutation in the GmFAD3A gene associated with low linolenic content in the Brazilian soybean cultivar CS303TNKCA and developed a molecular marker to select this mutation. Soybean is one of the most important crops cultivated worldwide. Soybean oil has 13% palmitic acid, 4% stearic acid, 20% oleic acid, 55% linoleic acid and 8% linolenic acid. Breeding programs are developing varieties with high oleic and low polyunsaturated fatty acids (linoleic and linolenic) to improve the oil oxidative stability and make the varieties more attractive for the soy industry. The main goal of this study was to characterize the low linoleic acid trait in CS303TNKCA cultivar. We sequenced CS303TNKCA GmFAD3A, GmFAD3B and GmFAD3C genes and identified an adenine point deletion in the GmFAD3A exon 5 (delA). This alteration creates a premature stop codon, leading to a truncated protein with just 207 residues that result in a non-functional enzyme. Analysis of enzymatic activity by heterologous expression in yeast support delA as the cause of low linolenic acid content in CS303TNKCA. Thus, we developed a TaqMan genotyping assay to associate delA with low linolenic acid content in segregating populations. Lines homozygous for delA had a linolenic acid content of 3.3 to 4.4%, and the variation at this locus accounted for 50.83 to 73.70% of the phenotypic variation. This molecular marker is a new tool to introgress the low linolenic acid trait into elite soybean cultivars and can be used to combine with high oleic trait markers to produce soybean with enhanced economic value. The advantage of using CS303TNKCA compared to other lines available in the literature is that this cultivar has good agronomic characteristics and is adapted to Brazilian conditions.