Mapping Quantitative Trait Loci Affecting Biochemical and Morphological Fruit Properties in Eggplant (Solanum melongena L.)

Abstract

Eggplant berries are a source of health-promoting metabolites including antioxidant and nutraceutical compounds, mainly anthocyanins and chlorogenic acid; however, they also contain some anti-nutritional compounds such as steroidal glycoalkaloids (SGA) and saponins, which are responsible for the bitter taste of the flesh and with potential toxic effects on humans. Up to now, Quantitative Trait Loci (QTL) for the metabolic content are far from being characterized in eggplant, thus hampering the application of breeding programs aimed at improving its fruit quality. Here we report on the identification of some QTL for the fruit metabolic content in an F2 intraspecific mapping population of 156 individuals, obtained by crossing the eggplant breeding lines “305E40” × “67/3.” The same population was previously employed for the development of a RAD-tag based linkage map and the identification of QTL associated to morphological and physiological traits. The mapping population was biochemically characterized for both fruit basic qualitative data, like dry matter, °Brix, sugars, and organic acids, as well as for health-related compounds such chlorogenic acid, (the main flesh monomeric phenol), the two peel anthocyanins [i.e., delphinidin-3-rutinoside (D3R) and delphinidin-3-(p- coumaroylrutinoside)-5-glucoside (nasunin)] and the two main steroidal glycoalkaloids, solasonine, and solamargine. For most of the traits, one major QTL (PVE ≥10%) was spotted and putative orthologies with other Solanaceae crops are discussed. The present results supply valuable information to eggplant breeders on the inheritance of key fruit quality traits, thus providing potential tools to assist future breeding programs.

Hybrids and allied species as potential rootstocks for eggplant: Effect of grafting on vigour, yield and overall fruit quality traits

“…Changes in fruit quality traits of self-grafted plants have been also observed in tomato (Khah et al, 2006) and pepper (Gisbert et al, 2010). Recently, the chromosomal region and QTL (Quantitave Trait Loci) associated to the content of anthocyanin, dry matter, solamargine glycoalkaloid, chlorogenic and other organic acid has been identified in eggplant (Gramazio et al, 2014;Toppino et al, 2016). This may allow, by exploiting the synteny in Solanaceae, to better understand the genetic basis of the effect of grafting on the eggplant fruit composition.…”

Quantitative trait loci affecting intensity of violet flower colour in potato

“…Depending on the presence of loci: F (van Eck et al 1993Eck et al , 1994, D (I) (Salaman 1910;De Jong 1987) or Pf ( de Jong 1987), the QTL on chromosome V may cause enhancement of violet colour in corolla, tuber skin and flesh, respectively, which may be useful information for breeding potatoes with pigmented tubers. The eggplant chromosomes V and X harbor QTL for anthocyanin distribution in tissues and organs such as fruit skin, stem, leaf, calyx, corolla, venation or fruit peduncle (Barchi et al 2012;Ge et al 2013;Toppino et al 2016). Although direct comparisons with eggplant QTL maps are hampered by the differences in genome organization between this plant and potato (Wu and Tanksley 2010), this may be an indication of conserved character of QTL on chromosome V (Fukuoka et al 2012;Rinaldi et al 2016), has an upper part orthologous to chromosome V (inversed in tomato) and lower part orthologous to chromosome XII.…”

Genomic Tools for the Enhancement of Vegetable Crops: A Case in Eggplant

“…The development of another eggplant genome by the Italian Eggplant Genome Sequencing Consortium has been presented in several scientific meetings (Barchi et al, 2016), but at the time of writing this work has not yet been published. According to the authors, a high-quality reference genome has been de novo assembled through Illumina sequencing (∼155X), using different genomic libraries sizes (from 270 bp to 10 Kb), of the inbred eggplant line "67/3", which was used as a male parent of a 157 F6 recombinant inbred lines (RILs) mapping Introduction Eggplant (Solanum melongena L., 2n = 2x = 24), also known as common eggplant or brinjal eggplant, belongs to the Leptostemonum clade within the Solanum genus (the "spiny" solanums) and is the second most important solanaceous fruit crop in total production after tomato (S. lycopersicum L.) (Knapp et al, 2013).…”

“…population (Table 1). In addition, to improving the assembly, its transcriptome was also sequenced (Barchi et al, 2016). Moreover, the hybrid assembly was combined with the sequencing of the female parent "305E40" (35X) and the rest (1X) of the RILs mapping population and with a high-resolution restriction optical map.…”