Traits In Eggplant Research Articles

Validation and identification of new QTLs for plant and fruit developmental and composition traits in eggplant under low N conditions

Enhancing plant adaptation to low input conditions is a fundamental goal for implementing sustainable agriculture. In the present study, two eggplant (Solanum melongena) accessions (MEL1 and MEL5), two introgression lines (ILs) derived from eggplant wild relatives S. dasyphyllum (IL-M1-D1) and S. insanum (IL-M5-I9), and a heterozygous version of this last IL (ILHet-M5-I9), along with hybrids among them were evaluated under low N (LN) conditions. IL-M1-D1 carries an introgressed fragment of 4.9 Mb in homozygosis from S. dasyphyllum on chromosome 2, while IL-M5-I9 and ILHet-M5-I9 carry an introgression of 21.5 Mb on chromosome 9 in homozygosis and heterozygosis, respectively, from S. insanum. Multiple quantitative trait loci (QTLs) for several traits of interest were associated with both introgressions under LN conditions in a previous study with segregating advanced backcrosses. Here we evaluated the performance of these materials for 22 agronomic and developmental traits under low N fertilization (LN) conditions. Hybrids with the ILs enabled the study of genetic background effects on QTLs expression. The materials evaluated showed a significant phenotypic variation, particularly within hybrids segregating for the introgression from S. insanum in chromosome 9. Statistical analysis revealed no significant differences among hybrids carrying or not the introgression on chromosome 2 of S. dasyphyllum, and only slight differences were observed between the IL-M1-D1 and its recurrent parent S. melongena MEL1, suggesting a limited impact of this introgression on chromosome 2 on the phenotype variation. However, the differences observed between IL-M5-I9 and its recurrent parent S. melongena MEL5, together with the association between genotypic and phenotypic variation in hybrids segregating for this introgression, allowed the identification of 13 QTLs on chromosome 9. These results successfully validated the previously identified QTLs for flavonol content in leaves, nitrogen balanced index, fruit mean weight, and nitrogen content in leaves and, also revealed nine new QTLs associated with the introgressed genomic region in chromosome 9. This study emphasizes the influence of environmental conditions, genotypes, and genetic backgrounds on the phenotypic expression of eggplant QTLs introgressed from wild relatives and highlights the importance of QTL validation. These findings contribute valuable insights for developing new eggplant cultivars for a more sustainable agriculture, particularly with adaptation to LN conditions.

Generation mean analysis of quantitative traits in eggplant (Solanum melongena L.) utilizing diverse parents under high rainfall areas of Northwestern Himalayas

Generation mean analysis of quantitative traits in eggplant (Solanum melongena L.) utilizing diverse parents under high rainfall areas of Northwestern Himalayas

Assessment of Bacterial wilt-resistant Solanum genetic resources as rootstocks for yield and fruit quality traits in eggplant

Assessment of Bacterial wilt-resistant Solanum genetic resources as rootstocks for yield and fruit quality traits in eggplant

Phenotypic and genotypic association of yield and yield-related traits in eggplant (Solanum melongena L.) evaluated for two seasons

Research on phenotypic and genotypic and associations between traits of eggplants provide valuable insights into the intricate dynamics of breeding programs. By understanding the relationships between different traits, breeders can effectively plan, evaluate, and establish selection criteria to cultivate desired characteristics in eggplant. The aim of this experiment was to determine the correlation coefficients, both phenotypic and genotypic, among various characters related to yield and to analyse the direct and indirect effects of these traits on yield per plant using path analysis. A randomized complete block design (RCBD) was used to arrange the plants and replicated three times. The results across the seasons indicated significant variations (p≤0.05) of all the traits examined. Research on correlation has indicated a significant and strong relationship between the main traits that contribute to crop yield (fruit length and fruit weight) at both the phenotypic and genotypic levels. Furthermore, several traits including the number of fruits, fruit weight, fruit length, stomata conductance, transpiration rate, and photosynthetic rate have demonstrated a significant and positive correlation with yield per plant. These traits have also exhibited a direct influence on yield. Conversely, traits such as fruit diameter and stomata conductance have displayed a strong and positive indirect impact on yield through their influence on fruit weight, number of fruits, and number of branches. In tropical conditions, the variables of yield component and physiological traits have been found to be positively correlated with higher eggplant yields. Consequently, these variables can serve as reliable indicators for indirect selection for yield in eggplant cultivation.

Genetic analysis in eggplant (Solanum melongena) hybrids for high‐rainfall areas utilizing diverse germplasm with respect to fruit shape and colour

AbstractIn the present study, 20 F1 cross combinations developed through diallel mating design utilizing five diverse parents, namely, Res‐1, Res‐2, Hisar Shyamal, Arka Nidhi, and Arka Keshav, with respect to shape and colour of the fruits were evaluated to derive information on combining ability and heterosis for yield and yield contributing traits in eggplant. Parents Res‐2, Hisar Shyamal, and Arka Nidhi were recognized as good general combiners for most of the horticultural traits. Cross combinations, namely, Res‐2 × Arka Nidhi, Hisar Shyamal × Res‐1, and Arka Nidhi × Hisar Shyamal, recorded high SCA values for fruit yield and related traits. Cross combinations Res‐2 × Arka Nidhi, Arka Nidhi × Hisar Shyamal, Hisar Shyamal × Res‐1, and Res‐2 × Res‐1 were found to be superior based on estimates of heterosis for fruit yield. Heterosis was positively correlated with SCA, the sum of the parental GCA indicating more effective predictions of the performance of various cross combinations. These unique cross combinations, Res‐2 × Res‐1 (medium–long shape and mixed colour), Res‐2 × Arka Nidhi (long and purple), Hisar Shyamal × Res‐1 (round and purple), and Arka Nidhi × Hisar Shyamal (oblong and purple), were found to be superior based on specific combining ability and heterosis for most of the horticultural traits. Therefore, these can be utilized for fixing genes in subsequent generations to increase the chance of recovering desirable transgressive segregants with improved traits for high rainfall areas in eggplant for better economic returns.

Yield and Compositional Profile of Eggplant Fruits as Affected by Phosphorus Supply, Genotype and Grafting

The present experiment addressed the effects of two phosphorus regimes (30 and 90 kg ha−1, hereafter P30 and P90) on yield and composition of eggplant fruits in ‘Birgah’ and ‘Dalia’, whether or not these cultivars were grafted onto Solanum torvum ‘Espina’. The P30 regime did not reduce yield, and promoted fruits’ dry matter and total phenols content, along with their concentrations of macronutrients, mesonutrients (S and Na) and micronutrients (mostly Cu, B, Zn); however, their Fe concentrations were depressed. The rootstock ‘Espina’ increased fruit yield, dry matter content, epicarp chroma (in ‘Birgah’) and Ca content, together with their concentrations of B and Zn (especially at P30), but reduced their Fe content, mostly under P30. Thus, the reduced P supply and grafting proved to be effective tools to enhance fruit yield, carpometric and almost all nutritional traits in eggplant, in a framework of more sustainable crop management. However, the reduced fruit concentration of Fe suggests that the affinity of the rootstock with specific micro minerals should be taken into account, along with the option to adopt complementary practices (e.g., targeted micronutrient fertilizations) to manage the micro mineral composition of eggplants.

A high-quality chromosome-level genome assembly reveals genetics for important traits in eggplant

Eggplant (Solanum melongena L.) is an economically important vegetable crop in the Solanaceae family, with extensive diversity among landraces and close relatives. Here, we report a high-quality reference genome for the eggplant inbred line HQ-1315 (S. melongena-HQ) using a combination of Illumina, Nanopore and 10X genomics sequencing technologies and Hi-C technology for genome assembly. The assembled genome has a total size of ~1.17 Gb and 12 chromosomes, with a contig N50 of 5.26 Mb, consisting of 36,582 protein-coding genes. Repetitive sequences comprise 70.09% (811.14 Mb) of the eggplant genome, most of which are long terminal repeat (LTR) retrotransposons (65.80%), followed by long interspersed nuclear elements (LINEs, 1.54%) and DNA transposons (0.85%). The S. melongena-HQ eggplant genome carries a total of 563 accession-specific gene families containing 1009 genes. In total, 73 expanded gene families (892 genes) and 34 contraction gene families (114 genes) were functionally annotated. Comparative analysis of different eggplant genomes identified three types of variations, including single-nucleotide polymorphisms (SNPs), insertions/deletions (indels) and structural variants (SVs). Asymmetric SV accumulation was found in potential regulatory regions of protein-coding genes among the different eggplant genomes. Furthermore, we performed QTL-seq for eggplant fruit length using the S. melongena-HQ reference genome and detected a QTL interval of 71.29–78.26 Mb on chromosome E03. The gene Smechr0301963, which belongs to the SUN gene family, is predicted to be a key candidate gene for eggplant fruit length regulation. Moreover, we anchored a total of 210 linkage markers associated with 71 traits to the eggplant chromosomes and finally obtained 26 QTL hotspots. The eggplant HQ-1315 genome assembly can be accessed at http://eggplant-hq.cn. In conclusion, the eggplant genome presented herein provides a global view of genomic divergence at the whole-genome level and powerful tools for the identification of candidate genes for important traits in eggplant.

Genetic Variability of Eggplant Germplasm Evaluated under Open Field and Glasshouse Cropping Conditions

Knowledge of agro-morphological genetic variation and cropping conditions on vegetative and yield-related traits plays a significant role in varietal improvement and production of eggplant (Solanum melongena L.). Following this premise, the current study was conducted to critically asses the genetic variation of 29 eggplant accessions by using agro-morphological characterization evaluated under two cropping conditions, namely, glasshouse and open field. The experiments were laid out in randomized complete block design (RCBD) with three replications. Data on vegetative and yield characteristics were collected and subjected to analysis of variance (ANOVA) using SAS 9.4, while variance components were estimated manually. The results obtained from the analysis of variance indicated a highly significant difference (p ≤ 0.01) for all characteristics studied in both cropping conditions. The evaluated accessions were grouped into six major clusters based on agro-morphological traits using Unweighted Pair Group Method with Arithmetic mean (UPGMA) dendrogram. Hence, crosses between group I with VI or V could be used to attain higher heterosis and vigor among the accessions. Also, this evaluation could be used as a selection criterion for important yield agronomic traits in eggplant. The methodology and the approaches used may provide a model for the enhancement of other vegetable crop diversity towards adaptability to the cropping condition decision. This result displayed importance for preserving eggplant germplasm for future varietal development and revealed that open field cropping condition is more suitable under Malaysia’s agroecology.

High-density genetic linkage map based on arbitrary and microsatellite markers using inter-specific recombinant inbred lines in eggplant (Solanum melongena L.)

Eggplant is an important Solanaceous vegetable crop with distinct morphological forms, colours, and shape of the fruits. Limited genomic coverage of the crop is a major constraint to unfold the cause of morphological variations underlying the contrasting traits. Therefore, with the aim to initiate targeted breeding efforts and to render ready-to-use markers for application in mapping quantitative trait loci (QTLs)/genes and to facilitate MAS, arbitrary and microsatellite molecular markers were used to map an inter-specific mapping population of 114 F8-recombinant inbred lines (RILs) developed using two contrasting lines, Ramnagar Giant (Solanum melongena L.) and W-4 (S. incanum L.). The arbitrary and microsatellite markers were screened for polymorphism with aim to cover the whole genome of eggplant. Of the total 1443 number of markers investigated, 6.07% RAPDs, 25% ISSR, 46.25% SCoT, and 22.46% SSRs revealed polymorphism between the parental lines, and were used for genotyping the RILs population. The results exhibit robust and sturdy nature of SCoT and microsatellite markers in unwrapping variations between both genotypes. Further, a high-density genetic linkage map was constructed with LOD threshold ≥ 4 clustered into 12 tentative linkage groups and spanning 1165 cM of the eggplant genome with an average marker density of 4.13 cM. The results shall further be used in mapping QTLs of agri-horticultural traits in eggplant.

Single Marker Analysis and Mapping of QTLs Governing Fruit Weight in Eggplant (Solanum melongena L.)

Eggplant is one of the most popular solanaceous vegetable crops in India and across the world. Development of high-yielding varieties and hybrids is the major focus of breeders. Yield is a very complex trait affected by various genetic and external factors. The lack of knowledge of the inheritance of fruit traits in eggplant has limited the use of molecular markers to fasten breeding programme. The authors conducted the present investigation at the research field of Vegetable Science Division, ICAR-IARI, New Delhi, India. A total of 168 F2 plants derived from Pusa Safed Baingan 1 × Pusa Uttam were phenotyped for fruit weight. Wide variations were observed for this trait ranging from 15.2 to 248.3 g, and the skewness was less than 1, suggesting that the trait followed a normal distribution in F2 and suitable for QTL analysis. Polymorphism survey using 241 SSR markers showed 18 polymorphic markers, which were subjected to bulked segregant analysis. Single-marker analysis using genotypic data revealed the positions of 3 QTLs influencing fruit weight. One QTL (qsfwpu1) was detected in linkage group 1, and two QTLs (qsfwpu3 and qsfwpu2) were identified in linkage group 4. These QTLs explained 14.06–19.44% to total phenotypic variation and were classified as major QTLs, suggesting that these QTLs play an important role in controlling yield. These QTLs may be very useful in the future molecular marker-assisted breeding of eggplant to develop a variety and cloning of target genes of interest.

Genetic analysis of nutritional and antioxidant traits in eggplant (S. melongena)

Six generations of eggplants (P1, P2, F1, F2, BC1 and BC2) obtained from two crosses SM001-07 x ST004-03 and SM001-07 x San005-01 were grown in an open field using Randomized complete Block Design with four replications. The experiment was conducted to determine gene effects for the inheritance of twelve nutritional and antioxidant traits in eggplant using generation mean analysis. The analysis of variance showed significant differences for most traits indicating the presence of sufficient variation in the eggplant materials under study. Additive-dominance effect was adequate to demonstrate the genetic variation and its significance in the inheritance of protein and magnesium contents, while non-allelic interactions were observed to be important for iron, zinc and total phenol in both crosses. The study also showed low values for dominance and environmental variances that resulted in high heritability values for most traits. Therefore, to improve these traits population improvement approaches (recurrent selection or pure line) followed by delayed selection in segregating generation would yield better results.

Diallel Analyis of morphological and agronomic traits in eggplant

Diallel Analyis of morphological and agronomic traits in eggplant

Comparative Transcriptome Analysis in Eggplant Reveals Selection Trends during Eggplant Domestication.

Eggplant (Solanum melongena L.) is an economically and nutritionally important fruit crop of the Solanaceae family, which was domesticated in India and southern China. However, the genome regions subjected to selective sweeps in eggplant remain unknown. In the present study, we performed comparative transcriptome analysis of cultivated and wild eggplant species with emphasis on the selection pattern during domestication. In total, 44,073 (S. sisymbriifolium) to 58,677 (S. melongena cultivar S58) unigenes were generated for the six eggplant accessions with total lengths of 36.6-46 Mb. The orthologous genes were assessed using the ratio of nonsynonymous (K a) to synonymous (K s) nucleotide substitutions to characterize selective patterns during eggplant domestication. We identified 19 genes under positive selection across the phylogeny that were classified into four groups. The gene (OG12205) under positive selection was possibly associated with fruit-related traits in eggplant, which may have resulted from human manipulation. Eight positive selected genes were potentially involved in stress tolerance or disease resistance, suggesting that environmental changes and biotic stresses were important selective pressures in eggplant domestication. Taken together, our results shed light on the effects of artificial and natural selection on the transcriptomes of eggplant and its wild relatives. Identification of the selected genes will facilitate the understanding of genetic architecture of domesticated-related traits and provide resources for resistant breeding in eggplant.

Line × Tester Analysis for Morphological and Fruit Biochemical Traits in Eggplant (Solanum melongena L.) Using Wild Relatives as Testers

Wild relatives of eggplant are commonly exploited for eggplant improvement, but the genetic improvement relies on the information of the genetic basis of inheritance of traits. In this study, two eggplant lines, one with oriental and another with occidental cytoplasm, were crossed with four testers representing three wild species, namely, Solanum insanum, S.anguivi, and S. lichtensteinii. The Line × Tester cross produced a total of eight interspecific hybrids. Parents and their hybrids were evaluated for 3 biochemical, 12 morphological, and 8 Tomato Analyzer-based descriptors. A significant amount of variation was noticed for all 23 traits studied. The higher values for the specific combining ability (SCA) component were determined as compared to the general combining ability (GCA) component. The testers were more significant for most of the traits than the cultivated varieties. Positive heterosis was determined for the 12 characteristics and negative heterosis for the 11 attributes. Overall, S.anguivi, and S. lichtensteinii were better for the biochemical traits’ improvement, whereas S. insanum was a better tester for the morphological traits.

Heterosis and inbreeding depression for fruit yield attributing traits in eggplant

An experiments was performed to study heterobeltiosis and relative heterosis in F1 and inbreeding depression in F2 generation in eggplants. A set of four F1 hybrids were generated by crossing six parents. In all crosses (Doli 5 × GBL1, Doli 5 × KS 331, Pusa Uttam × KS 331, AB-07-02 × GOB 1), fruit length, fruit volume and fruit yield per plant exhibited significantly positive heterobeltiosis which indicates that the hybrid vigor can be utilized on commercial scale for these traits. The higher magnitude of heterobeltiosis for all the morphological traits suggested the presence of over-dominance. In F2 generation, negatively significant estimates of inbreeding depression was observed for plant height and days to first picking in cross Doli 5 × KS 331; fruit per plant, fruit weight and fruit yield per plant in cross Pusa Uttam × KS 331; primary branches per plant, fruit volume and fruit weight in cross Doli 5 × GBL1 and fruit weight in cross (AB-07-02 × GOB 1) indicated the possibilities to get the desired segregants to improve the traits. The cross with least inbreeding depression and high heterosis should be further exploited at commercial scales.

Diallel genetic analysis for multiple traits in eggplant and assessment of genetic distances for predicting hybrids performance.

Evaluation and prediction of the performance of hybrids is important in eggplant (Solanum melongena) breeding. A set of 10 morphologically highly diverse eggplant parents, including nine inbred S. melongena and one weedy S. insanum accessions, were intercrossed according to a half-diallel mating design without reciprocals to obtain 45 hybrids. Parents and hybrids were evaluated for 14 morphological and agronomic conventional descriptors and 14 fruit morphometric traits using Tomato Analyzer. Genetic distances among parents were estimated with 7,335 polymorphic SNP markers. Wide ranges of variation and significant differences were observed in the set of 55 genotypes for all traits, although the hybrids group had significantly higher vigour and yield than parents. General and specific combining abilities (GCA and SCA) were significant for most (GCA) or all (SCA) traits, although a wide variation was obtained for GCA/SCA ratios. Many relevant traits associated to vigour and yield had low GCA/SCA ratios and narrow-sense heritability (h2) values, while the reverse occurred for most fruit shape descriptors. Broad-sense heritability (H2) values were generally high, irrespective of GCA/SCA ratios. Significant correlations were found between traits related to size of leaf, flower and fruit, as well as among many fruit morphometric traits. Genetic distances (GD) among parents were coherent with their phylogenetic relationships, but few significant and generally low correlations were found between GD and hybrid means, heterosis or SCA. The results provide relevant information for developing appropriate strategies for parent selection and hybrid development in eggplant and suggest that GD among parents have limited value to predict hybrid performance in this crop.

Effects of gamma irradiation on the agro-morphological traits of selected Nigerian eggplant (Solanum aethiopicum L.) accessions

The mutagenic effects of gamma irradiation on the agro-morphological traits of eggplant accessions were investigated to induce useful genetic variability for further breeding programme. Seeds of two eggplant (Solanum aethiopicum L.) accessions (MN/S/02/2015 and NHGB/09/132) were collected from the National Centre for Genetic Resources and Biotechnology (NAGRAB) Ibadan, Nigeria. The seeds were exposed to five different gamma irradiation doses (40 Gy, 60 Gy, 80 Gy, 100 Gy) and un-irradiated (0 Gy) as control at Centre for Energy and Research Training (CERT), Ahmadu Bello University, Zaria, Nigeria. The irradiated and the control seeds were planted in the Department of Plant Biology Garden in a Randomized Complete Block Design (RCBD) with four replicates each. All the plants were characterized on the basis of agro-morphological traits such as germination percentage, plant height, Number of leaves/plant, leaf length, number of branches, number of days to first flowering number of fruit/plant and fruit weigh. The results obtained showed significant differences (P≤0.05) on the agro-morphological traits with the highest number of leaves per plant (62.25), number of fruits per plant (39.50) and fruit weight (2.08g) in MN/S/02/2015 and highest number of leaves per plant (55.75), number of fruits per plant (28.75) and fruit weight (1.44g) in NHGB/09/132 obtained in 60 Gy. Therefore, 40 Gy and 60 Gy doses of gamma irradiation were obtained to be appropriate in creating beneficial traits in eggplant (S. aethiopicum L.) accessions.

Studies on Correlation and Path Analysis for Yield and Yield Contributing Traits in Eggplant (Solanum Melongena L) Involving Bacterial Wilt Resistant Genotypes

A study was conducted with the objective to measure the nature and magnitude of association between different characters in brinjal (Solanum melongena L.). For this purpose 48 biparental and 60 F3 progenies were developed following NCD-1 and they were evaluated for 16 yield and quality traits. The correlation studies has shown that there was a strong positive association between major yield contributing characters like fruits per plant, plant height and fruit weight and fruit yield. It was also observed that genotypic correlations were high as compared to their phenotypic correlations revealing strong inherent association between the these characters. Therefore, the result of path analysis revealed that the fruit weight had maximum direct effect on marketable fruit yield followed by number of fruits per plant and fruit length.

Heritability and gene effects for yield related quantitative traits in eggplant

Knowledge of gene actions and their relative contribution in expression of characters is of great importance. Therefore, four crosses were made among the six parents viz., Doli-5×GBL-1 (cross 1), Doli-5×KS-331 (cross 2), Pusa Uttam×KS-331 (cross 3) and AB 07-02×GOB 1 (cross 4) to study gene actions responsible for inheritance of twelve fruit yield traits. The generation mean analysis in six populations revealed significant digenic interactions for all the characters in majority of the crosses studied. Character-cross combination revealed the adequacy of simple additive dominance model for plant height (in cross 1), primary branches per plant (in cross 2), secondary branches per plant (in cross 3), fruit length (in cross 2), fruit girth (in cross 3) and pedicel length (in cross 3) indicating the absence of non-allelic interactions. Most of the crosses for all the yield traits showed low magnitude of dominance and environmental variances, revealing higher heritabilities. Duplicate epistasis effects controlled all traits in different cross-combinations suggesting the mild selection intensity in the earlier generations while intense in later generations. However, in few cases average dominance ratio was more than unity indicated the importance of dominance gene effects. These results indicated that for eggplant improvement, additive variation is of great importance and makes it possible to successfully select better individuals in segregating populations, since the selective gains will depend only on gametic variation. For this reason, backcross, pedigree, single-seed descent or gametic selection methods are recommended for advancing the segregating populations.

Association Mapping for Fruit, Plant and Leaf Morphology Traits in Eggplant.

An eggplant (Solanum melongena) association panel of 191 accessions, comprising a mixture of breeding lines, old varieties and landrace selections was SNP genotyped and phenotyped for key breeding fruit and plant traits at two locations over two seasons. A genome-wide association (GWA) analysis was performed using the mixed linear model, which takes into account both a kinship matrix and the sub-population membership of the accessions. Overall, 194 phenotype/genotype associations were uncovered, relating to 30 of the 33 measured traits. These associations involved 79 SNP loci mapping to 39 distinct chromosomal regions distributed over all 12 eggplant chromosomes. A comparison of the map positions of these SNPs with those of loci derived from conventional linkage mapping showed that GWA analysis both validated many of the known controlling loci and detected a large number of new marker/trait associations. Exploiting established syntenic relationships between eggplant chromosomes and those of tomato and pepper recognized orthologous regions in ten eggplant chromosomes harbouring genes influencing breeders’ traits.