Commercial F1 Hybrids Research Articles

Genetic Diversity Analysis and DNA Fingerprinting of Elite Chilli Pepper Lines Using SSR Markers

Hybrid cultivars of chilli pepper (Capsicum annuum L.) have become very popular due to their superior performance. Punjab Agricultural University, Ludhiana, India, developed a genetic male sterile (GMS) line ‘MS-12’ by introducing a nuclear male sterility gene ms509 (redesignated as ms10) from a French introduction. Subsequently, ‘MS-12’ has successfully been used to develop commercial F1 hybrids. However, ‘MS-12’ has outlived its utility and there is a need to diversify the maternal parent. The investigation was carried out to identify the most divergent genotype from ‘MS-12’ among the six elite lines of chilli pepper by employing 58 SSR markers. Thirty produced polymorphic bands, revealing a total of 83 alleles with an average of 2.67 alleles per locus. Polymorphic information content (PIC) varied from 0.21 to 0.84, with an average value of 0.51. Based on PIC values and number of alleles amplified, the primer CAMS-072 was the most informative, followed by CAMS-311 and Hpms CaSIG-19. Lines under evaluation had more than 70% similar fragments. Dice similarity coefficients between any two genotypes varied from 0.70 to 0.95, with the lowest between ‘PBC-535’ with ‘VR-16’ and the highest between ‘MS-12’ sterile with ‘MS-12’ fertile. ‘SL-412’ and ‘DCL-524’ had a similarity coefficient of 0.93. Among the six elite lines assayed, ‘PBC-535’ was the most diverse from ‘MS-12’, followed by ‘VR-16’ with, similarity coefficients of 0.71 and 0.75, respectively. Some fragments were unique and can be used as cultivar specific markers for rapid discrimination. The discriminating power of these markers will be helpful in testing purity of F1 hybrids and for registering elite germplasm.

Assessment of fruit quality variation in doubled haploids of minipaprika (Capsicum annuum L.)

This study was performed to investigate the fruit quality characters including the fruit color, appearance, taste quality, fruit firmness, dry matter content, total soluble content, titratable acidity, vitamin C content, total phenolic compounds and antioxidant activity in fifteen doubled haploids (homozygous) lines of minipaprika along with its standard commercial F1 hybrid cv. Vine sweet (red, yellow, and orange). Results revealed that significant variation of fruit color, visual, taste quality, fruit firmness, total soluble content and titratable acidity among the doubled haploids and standard varieties of minipaprika. VS-Y had the highest vitamin C followed by the doubled haploid lines MY-5, MY-2 and MY-8 and VS-O. MY-3 had the highest phenolic content (18.8 mg·g−1 of fresh weight) whereas antioxidant activity was the highest in MY-4 (54.5%) followed by MY-5 (53.0%). As compared to standard varieties, the doubled haploids exhibited higher visual and taste quality, fruit firmness, dry matter content, total soluble content, titratable acidity, phenolic content, and antioxidant activity. The results of the study are helpful for selecting the doubled haploids and integrating them into breeding for developing quality compounds-rich cultivar in minipaprika.

Identification of markers tightly linked to tomato yellow leaf curl disease and root-knot nematode resistance by multiplex PCR

Seven different commercial F₁ hybrids and two F₂ populations were evaluated by multiplex PCR to identify plants that are homozygous or heterozygous for Ty-1 and Mi, which confer resistance to tomato yellow leaf curl disease and root-knot nematode, respectively. The Ty-1 and Mi markers were amplified by PCR and identified by digestion of the amplicons with the TaqI enzyme. The hybrids E13 and 288 were found to be Ty/ty heterozygous plants with 398-, 303-, and 95-bp bands, and B08, 314, 198, and A10 were found to be ty/ty homozygous plants with a 398-bp band; whereas 098 did not give any PCR products. The hybrids E13 and 198 were found to be Mi/Mi homozygous plants with 570- and 180-bp bands, and 288 and A10 were found to be Mi/mi heterozygous plants, with 750-, 570- and 180-bp bands, and B08, 109 and 314 were found to be mi/mi homozygous plants with only a 750-bp band. We additionally developed a multiplex PCR technique for JB-1 and Mi, which confer resistance to tomato yellow leaf curl disease and root-knot nematode. The JB-1 marker identified the genotype of the Ty gene, and the plants that produced the 400-bp band were ty/ty homozygous plants, whereas the plants that produced 400- and 500-bp bands were resistant to tomato yellow leaf curl disease. We conclude that multiplex PCRs can be used to reproducibly and efficiently detect these resistance genes.

Phenotypic Changes in Different Spinach Varieties Grown and Selected under Organic Conditions

Organic and low-input agriculture needs flexible varieties that can buffer environmental stress and adapt to the needs of farmers. We implemented an experiment to investigate the evolutionary capacities of a sample of spinach (Spinacia oleracea L.) population varieties for a number of phenotypic traits. Three farmers cultivated, selected and multiplied one or several populations over two years on their farms. The third year, the versions of the varieties cultivated and selected by the different farmers were compared to the original seed lots they had been given. After two cycles of cultivation and on-farm mass selection, all the observed varieties showed significant phenotypic changes (differences between the original version and the version cultivated by farmers) for morphological and phenological traits. When the divergence among versions within varieties was studied, the results show that the varieties conserved their identity, except for one variety, which evolved in such a way that it may now be considered two different varieties. The heterogeneity of the population varieties was assessed in comparison with a commercial F1 hybrid used as control, and we found no specific differences in phenotypic diversity between the hybrid and population varieties. The phenotypic changes shown by the population varieties in response to on-farm cultivation and selection could be useful for the development of specific adaptation. These results call into question the current European seed legislation and the requirements of phenotypic stability for conservation varieties.

Use of Cf-9 gene-based markers in marker-assisted selection to screen tomato cultivars with resistance to Cladosporium fulvum

Identification of the PCR markers tightly linked to genes that encode important agronomic traits is useful for marker-assisted selection (MAS). The Cf-9 locus confers resistance to most races of the leaf mold fungus Cladosporium fulvum and belongs to a large gene family. We developed three gene-based markers (8F/10R, 8F/12R, and 10F/10R) from the Cf-9 gene sequence. Of the 101 tomato genotypes tested, 9 commercial F1 hybrids carried 8F/10R-, 8F/12R-, and 10F/10R-specific bands. Our results demonstrate the usefulness of these markers for MAS for C. fulvum resistance.

Development of new DNA markers linked to the Fusarium wilt resistance locus Fom‐1 in melon

With 5 figures and 2 tables AbstractUse of resistance genes would be the most effective way to address Fusarium wilt caused by Fusarium oxysporum f.sp. melonis in melon. In this study, based on the BAC 31O16 sequence which contains the cluster of melon resistance gene homologue, we developed four new DNA markers linked to Fom‐1, a dominant resistance gene against F. oxysporum f.sp. melonis races 0 and 2. Linkage analysis using 125 F2 plants derived from the cross between P11 (fom‐1fom‐1) and MR‐1 (Fom‐1Fom‐1) indicated that Fom‐1 was located between CAPS markers C‐MRGH12 and 62‐CAPS at a distance of 0.4 and 1.2 cM, respectively. Map position of Fom‐1 was confirmed using another mapping population consisting of 104 recombinant inbred lines derived from the cross P11 × MR‐1. The analysis of 43 fixed lines and 27 commercial F1 hybrids showed that the developed DNA markers linked to Fom‐1 correctly predicted the genotype in relation to the variety, suggesting that the region around the Fom‐1 locus is very polymorphic or there is no linkage disequilibrium between the locus and the marker loci.

Haplotype analysis of CMS-associated DNA markers in sweet peppers

Cytoplasmic male sterility (CMS)/restorer-of-fertility (Rf) is an economical and efficient system to produce F1 hybrid seeds. Although the CMS/Rf system has been used to produce hybrid seeds of hot peppers, this system has never been used for sweet pepper seed production, presumably due to the inability to select stable restorer lines during the breeding process. To test the feasibility of the CMS/Rf system in sweet pepper breeding, we investigated the distribution of haplotypes of previously developed, CMS-associated markers (orf456, ψ atp6-2, CRF-SCAR, OPP13-CAPS, PR-CAPS, and PR-SNP) in 27 commercial sweet pepper F1 hybrids and 12 breeding lines. When CMS-associated cytoplasmic markers orf456 and ψ atp6-2 were applied, male sterile cytoplasm was not detected in commercial sweet pepper cultivars. When nuclear haplotype markers linked to Rf were applied, all sweet pepper cultivars showed haplotype 3, haplotype 1, and the rf genotype for OPP13-CAPS, PR-CAPS, and CRF-SCAR, respectively. In contrast, we were able to detect male sterile cytoplasm in some breeding lines, and we were also able to detect polymorphisms for PR-CAPS between stable and unstable maintainer lines. The 17T7-SNP also showed polymorphisms between unstable and stable maintainer (or restorer) lines. In conclusion, we expect that it will be possible to develop stable A, B, and C sweet pepper lines using CMS-associated markers and that this will eventually lead to successful implementation of the CMS/Rf system to produce F1 hybrid sweet pepper seeds.

A codominant SCAR marker linked to the genic male sterility gene (ms1) in chili pepper (Capsicum annuum)

With 3 figures Abstract As one of the genic male sterility (GMS) materials in chili pepper (Capsicum annuum L.), GMS1 has been used for commercial F1 hybrid seed production. The male sterility of GMS1 is controlled by a recessive nuclear gene, named ms1. In this study, we developed DNA markers linked to the ms1 locus using a combination of bulked segregant analysis and amplified fragment length polymorphism (AFLP) in a segregating sibling population. From the screening of 1024 AFLP primer combinations, the AFLP marker E-AGC/M-GTG (514 bp) was identified as being linked to the ms1 locus at a distance of about 3 cM. Based on internal sequencing analysis of the E-AGC/M-GTG marker between male fertile and sterile plants, we identified three small deletions with a size of altogether 42 bp in the male-fertile plant and developed a codominant sequence characterized amplified region (SCAR) marker. This SCAR marker may be valuable for marker-assisted breeding in the hybrid seed production system of chili pepper using the GMS1 line.

Improvement ofSclerotiniaresistance of a Polima CMS restorer line of rapeseed via phenotypic selection, marker-assisted background selection and microspore culture

With 4 figures and 2 tables Abstract Sclerotinia stem rot caused by Sclerotinia sclerotiorum is one of the most severe diseases of rapeseed in China and other major growing regions. The objective of this study was to improve the S. sclerotiorum resistance of ‘Hui5200’, an elite ‘Polima’ CMS restorer line, by introgression and fixation of resistance alleles from the partially resistant cultivar ‘NingRS-1’ via phenotypic selection (PS), marker-assisted background selection (MAB) and microspore culture. A progeny designated as ‘RSH’ with greatly improved Sclerotinia resistance and a similar genetic background as ‘Hui5200’ was obtained by two backcrosses and one selfing. From a selected elite progeny line (named as 7-5) double haploid (DH) lines were developed. By three cycles of PS considering economic traits and genetic distance analysis, four resistant DH restorer lines with elite economic traits were finally selected. The obtained resistant restorer lines have been used to produce commercial F1 hybrids. The results indicated that backcrossing plus PS and MAB is effective and suitable for improving resistance of rapeseed to S. sclerotiorum.

Diversity in commercial varieties and landraces of black eggplants and implications for broadening the breeders’ gene pool

AbstractBlack‐coloured eggplants (Solanum melongena) represent the commercially most important group of eggplants in Europe and North America. Most of the modern varieties of black eggplants correspond to F1 hybrids, which at the same time constitute an elite gene pool for the development of new varieties. However, there are many black landraces and old varieties, which could be useful as sources of variation for black eggplant breeding programmes as well as for the broadening of the genetic diversity of the breeders’ gene pool. We have studied the morphological and molecular [amplified fragment length polymorphism and simple sequence repeat (SSR)] diversity in a collection of 38 black eggplant accessions, including commercial (modern F1 hybrid and old nonhybrid) varieties and landraces as well as in six nonblack control eggplants, from different origins. The results show that black eggplants contain a considerable morphological and molecular diversity, but commercial varieties, and in particular F1 hybrids, display a reduced morphological and molecular diversity when compared with landraces. The principal components analysis morphological and principal coordinates analysis molecular analyses show that commercial F1 hybrids group together, indicating that they share a common and narrow gene pool. Commercial F1 hybrids present a series of productive advantages, like early production, intense black colour (low L*, a* and b*) values and absence of fruit calyx prickles. However, several of the landraces and old nonhybrid varieties studied present a high yield as well as other traits of interest for eggplant breeding. Furthermore, given the low genetic diversity of F1 hybrids and the moderate level of SSR heterozygosity found in these materials (0.382), introduction of black landraces and old varieties in the present breeding programmes could contribute to broadening the gene pool used by breeders and this could help increase the heterosis for yield of F1 hybrids, which is greatly favoured by high heterozygosity levels.

A major QTL associated with preharvest sprouting in rapeseed (Brassica napus L.)

Preharvest sprouting (PHS) is one of the most important factors affecting the cereal production worldwide, in regions characterized by rainfall and high humidity during harvest season. It is sometimes a problem in rapeseed (Brassica napus L.), especially in production of commercial F1 hybrids. To detect quantitative trait loci (QTL) controlling PHS, a F2 population consisting of 269 F2:3 lines was created from the cross between a PHS-tolerant line (117AB) and a PHS-susceptible line (7,605). A linkage map was constructed using 35 Simple Sequence Repeat markers and 242 Amplified Fragment Length Polymorphism markers. PHS was measured as a percentage of sprouted seeds on the mother plant, 7 days after physiological maturity. Five putative QTLs for PHS were detected and located on LG2 (N11) and LG7 (N3), respectively. Phenotypic variance explained by each QTL ranged from 4.11 to 50.78% and the five putative QTLs explained about 75.63% of the total phenotypic variance. A major QTL was identified on LG2 (N11) flanked by P3C4180 and C6C13160, which explained 50.78% of the total phenotypic variance. Meanwhile, we detected four significant epistatic interactions with a total contribution of 17.16% of the total phenotypic variance.

Use of Composts Derived from Winery Wastes in Tomato Crop

The effects of fertigation levels on parameters related to fruit quality were studied, using compost derived from winery wastes as growing media for a tomato crop. We evaluated five growing substrates: perlite and four composts derived from winery‐distillery residues. Two levels of fertigation were applied: a standard fertigation for tomato crop and a half‐level of fertigation obtained by a 50/50 v/v dilution. Our objective was to evaluate the possibilities of winery waste composts as an alternative to perlite as growing substrate. We tried to measure the effect of these organic substrates on yield and on the parameters more strongly related with fruit quality: tomato solid soluble content and titratable acidity. The commercial F1 hybrid variety of tomato “Boludo” was used. Significant differences among the levels of fertigation were found, but only small differences among the substrates could be observed. These results have been obtained under two different fertigation levels, one of them probably causing a slight level of salinity. The composts evaluated have shown adequate characteristics when used as substrates for a tomato crop, indicating the suitability of winery waste composts as an alternative to the growing media currently used.

Yields of Organically Grown Sweet Pepper Cultivars and Lines during the Hot-wet and Cool-dry Season in the Tropics

Organic production is considered by many researchers to be a viable alternative to conventional farming systems. Equivalent yields already have been demonstrated in several studies. The major objective of our study was to collect data on total and marketable fruit yields of sweet pepper (Capsicum annuum) under organic farming conditions in the tropics. Experiments were conducted during the hot-wet season from 7 Mar. 2007 to 30 July 2007 and during the cool-dry season from 27 Nov. 2007 to 7 Apr. 2008. The six experimental entries included four commercial F1 hybrids and two genotypes bred at AVRDC–The World Vegetable Center (Shanhua, Taiwan). During the hot-wet season, high total (44.6–55.7 t·ha−1) and marketable yields (36.9–45.6 t·ha−1) were achieved under organic farming conditions in the open field similar to yields of conventionally produced sweet pepper in previous field experiments at AVRDC. The total yield of the commercial cultivars Queen Star and Hercules exceeded 50 t·ha−1; however, this was not significantly different compared with the other trial entries. During the cool-dry season, the total (25.4–45.7 t·ha−1) and marketable yields (21.1–37.8 t·ha−1) of all trial entries were reduced, probably because the relatively late planting date in November and relatively low air temperature resulted in reduced fruit set. The commercial cultivars Andalus and Green Bell Improved realized in both seasons a total fruit yield of more than 40.0 t·ha−1, suggesting that these can be grown successfully in hot-wet and cool-dry seasons. The relatively high yields of sweet pepper achieved on-station under tropical climatic conditions may encourage farmers and agricultural stakeholders to consider organic farming approaches as a viable alternative to conventional farming systems.

Yields of Organically Grown Sweet Pepper Cultivars and Lines during the Hot-wet and Cool-dry Season in the Tropics

Organic production is considered by many researchers to be a viable alternative to conventional farming systems. Equivalent yields already have been demonstrated in several studies. The major objective of our study was to collect data on total and marketable fruit yields of sweet pepper (Capsicum annuum) under organic farming conditions in the tropics. Experiments were conducted during the hot-wet season from 7 Mar. 2007 to 30 July 2007 and during the cool-dry season from 27 Nov. 2007 to 7 Apr. 2008. The six experimental entries included four commercial F1 hybrids and two genotypes bred at AVRDC–The World Vegetable Center (Shanhua, Taiwan). During the hot-wet season, high total (44.6–55.7 t·ha−1) and marketable yields (36.9–45.6 t·ha−1) were achieved under organic farming conditions in the open field similar to yields of conventionally produced sweet pepper in previous field experiments at AVRDC. The total yield of the commercial cultivars Queen Star and Hercules exceeded 50 t·ha−1; however, this was not significantly different compared with the other trial entries. During the cool-dry season, the total (25.4–45.7 t·ha−1) and marketable yields (21.1–37.8 t·ha−1) of all trial entries were reduced, probably because the relatively late planting date in November and relatively low air temperature resulted in reduced fruit set. The commercial cultivars Andalus and Green Bell Improved realized in both seasons a total fruit yield of more than 40.0 t·ha−1, suggesting that these can be grown successfully in hot-wet and cool-dry seasons. The relatively high yields of sweet pepper achieved on-station under tropical climatic conditions may encourage farmers and agricultural stakeholders to consider organic farming approaches as a viable alternative to conventional farming systems.

Terminal repeat retrotransposon in miniature (TRIM) as DNA markers in Brassica relatives

We have developed a display system using a unique sequence of terminal repeat retrotransposon in miniature (TRIM) elements, which were recently identified from gene-rich regions of Brassica rapa. The technique, named TRIM display, is based on modification of the AFLP technique using an adapter primer for the restriction fragments of BfaI and a primer derived from conserved terminal repeat sequences of TRIM elements, Br1 and Br2. TRIM display using genomic DNA produced 50-70 bands ranging from 100 to 700 bp in all the species of the family Brassicaceae. TRIM display using B. rapa cDNA produced about 20 bands. Sequences of 11 randomly selected bands, 7 from genomic DNA and 4 from cDNA, begin with about 104 bp of the terminal repeat sequences of TRIM elements Br1 or Br2 and end with unique sequences indicating that all bands are derived from unique insertion sites of TRIM elements. Furthermore, 7 of the 11 unique sequences showed significant similarity with expressed gene. Most of the TRIM display bands were polymorphic between genera and about 55% (132 of 239 bands) are polymorphic among 19 commercial F1 hybrid cultivars. Analysis of phylogenetic relationships shows clear-cut lineage among the 19 cultivars. Furthermore, a combination of 11 polymorphic bands derived from only one primer combination can clearly distinguish one cultivar from the others. TRIM display bands were reproducible and inheritable through successive generations that is revealed by genetic mapping of 6 out of 27 polymorphic TRIM markers on the genetic map of Brassica napus. Collective data provide evidence that TRIM display can provide useful DNA markers in Brassica relatives because these markers are distributed in gene-rich regions, and are sometimes involved in the restructuring of genes.

Effect of Recent Genetic Improvement on Some Analytical Parameters of Tomato Fruit Quality

Poor flavor in tomato fruit is a serious consumer concern. It could be said that tomato flavor has declined as variety selection and tomato production has placed emphasis on yield, fruit size, firmness, disease resistance, and processing performance and not on aspects of organoleptic fruit quality. Consumers frequently associate recent varieties with a lack of flavor, although such an association has not been proven. We have reviewed the scarce available literature on the influence of recent genetic improvement on quality attributes of tomato. As a case study, we have analyzed several parameters related to fruit quality in some traditional Spanish cultivars and commercial F1 hybrids of tomato. Organic acids and sugars were determined by high performance liquid chromatography (HPLC). Sodium (Na), potassium (P), and phosphorus (K) were analyzed by atomic absorption spectroscopy. Levels of respiration and ethylene production were measured, and fruit firmness was determined using a texture analyzer. All determinations were performed at two maturity stages, representing two frequent consumption stages. Differences between traditional cultivars and hybrids were found for respiration rates, ethylene production, P and K fruit contents. We also found important differences between “old” and “modern” cultivars for their organic acids profile. All cultivars showed similar levels of malic and succinic acids, but the modern hybrids showed a ∼75% higher content of citric acid. This could be due to the F1 hybrids carrying chromosomal segments recently introgressed from wild Lycopersicon species. The influence of recent genetic improvement on quality attributes of tomato fruit is discussed.

Pepper (Capsicum annuumL.) breeding methods at the turn of the century

One important aim of hybrid breeding is to exploit the heterosis effect appearing in the F1. Nevertheless, the breeders of commercial F1 hybrids have no real information on the extent of heterosis manifested in the combinations they produce, since the mean value of the combination in question is never compared with that of the parents or of the better parent, but only with that of the most popular control variety it is hoped to surpass. The complex variety value of a new hybrid should be greater than that of the control. In the case of pepper hybrids the factors that make up the complex variety value can be divided into four groups: the early and total yield potential predicted from the individual value of the parents (P), special consumption and production traits resulting in F1 quality (Q), F1 resistance value (R) and the heterosis effect (H). The importance of these four factors in the complex variety value of a given pepper hybrid may be summed in innumerable variations, but the individual yield poten...

Analysis of flavor volatile compounds by dynamic headspace in traditional and hybrid cultivars of Spanish tomatoes

A system specifically designed for the non-destructive analysis of volatile organic compounds in fresh tomatoes, based on a dynamic headspace technique, has been set up to quantify the volatile aroma constituents of tomato fruits. This system will reduce the high variability associated to sample selection in post-harvest studies. Volatile compounds with a major contribution to aroma have been quantitatively determined in two traditional tomato cultivars and one commercial F1 hybrid. One of the traditional cultivars, “De la Pera,” got the highest values of odor and aroma in sensory tests performed using a trained panel of 10 assessors. The same cultivar showed significantly higher contents of all eight volatile compounds studied (hexanal, trans-2-hexenal, cis-3-hexenol, 1-hexanol, 1-nitro-3-methylbutane, 6-methyl-5-hepten-2-one, 2-isobutylthiazole, and β-ionone). Significant differences among traditional and hybrid tomato cultivars can be detected for volatile compounds, thus allowing the use of volatile determination as a possible tool in tomato breeding programs.

Micronutrient Composition and Quality Characteristics of Traditional Tomato Cultivars in Southeast Spain

Several traditional tomato cultivars still survive in the orchards in southeastern Spain, which are highly esteemed due to their excellent quality. However, modern tomato hybrid varieties used in intensive agriculture mean that these types of local cultivars are being gradually phased out. This study was conducted to characterize the diversity of tomato micronutrient composition and fruit quality parameters of several traditional cultivars. The experiment was carried out under field conditions using traditional cultivars of the “Muchamiel” and “De la Pera” type and commercial F1 hybrids. Micronutrient fruit concentration (Fe, Cu, Mn, and Zn) was determined by atomic absorption spectroscopy. Fruit quality parameters analyzed were titratable acidity, soluble solid content, and color parameters. Strong differences have been found among the analyzed cultivars, both in terms of micronutrients and also quality parameters, suggesting that there are considerable levels of genetic diversity. Not a single “superior” variety could be identified, because it would depend on type of use, consumers' and growers' preferences. These traditional cultivars are frequently consumed at the breaker maturity stage, but we have found low differences between red and breaker fruits regarding micronutrient concentrations. Through relatively simple chemical analyses, we have detected significant differences among tomato genotypes that we are still not able to detect with molecular tools. Cultivars could be clearly differentiated on the basis of a multivariate data analysis of selected fruit parameters. This knowledge could aid in the efficient conservation of an important part of the agricultural biodiversity in southeastern of Spain. These results are also potentially useful for tomato breeders working on the development of new varieties.

Quantitative analysis of flavour volatiles detects differences among closely related traditional cultivars of tomato

AbstractVolatile compounds with a major contribution to aroma have been quantitatively determined in four traditional tomato cultivars and one commercial F1 hybrid. One of the traditional cultivars was the most appreciated for flavour and overall acceptability in tests performed using a panel of 30 untrained tasters. The same cultivar showed significantly higher contents of hexanal and cis‐3‐hexenal volatile compounds, which have been previously reported to be two of the most important contributors to tomato flavour. On the basis of a small number of fruits per cultivar, significant differences among very closely related tomato cultivars can be detected for volatile aromas, thus allowing the use of the determination of volatiles as a possible tool in tomato breeding programs, making even the selection of single plants possible. Copyright © 2004 Society of Chemical Industry