Consumers in the fresh fruit market choose fruits mainly following criteria related to the external appearance. However, the introduction of new material for planting depends on the productive capacity of the plant as well as on the formation of fruit that meets consumer desires. Given the above, the objective of this study was to morphoagronomically characterize tomato genotypes using multivariate statistics. The genotype seedlings (Ellus, Black Mauri, Green Zebra, Green Tomato, Pomodoro Marmande, Pomodoro Fiorentino, Pitanga, and Black Krim) were transplanted 30 days after sowing. The morphoagronomic characterization of the genotypes was carried out by evaluating plants and fruits. The data were analyzed using descriptive analysis, namely, position and variability measurements. In addition, a multivariate cluster analysis and a principal component analysis were carried out for plant and fruit attributes. The cluster and principal component analyses were efficient in characterizing plants and/or fruits of different tomato genotypes. Such efficiency enhances result interpretation and proposed inferences, with applied relevance for the producers. The genotype Ellus has a combination of morphoagronomic plant and fruit traits superior to other genotypes. Such superior traits enable a high productivity.
The tomato (
Consumers in the fresh fruit market choose fruits mainly following criteria related to the external appearance [
In general, the phytotechnical characterization of plants and fruits of different tomato genotypes is carried out by tests that distinguish the phytotechnical characteristics using only analysis of variance and mean comparison tests. Studies on the existing relationship among phytotechnical characteristics, among genotypes, and within genotypes are deficient in the scientific literature. Therefore, the proposed inferences are somewhat superficial.
An approach appropriate for a thorough study on such relationships is the use of multivariate techniques [
Given the above, the objective of this study was to morphoagronomically characterize tomato genotypes using multivariate statistics (exploratory techniques such as cluster analysis and principal component analysis).
The study was carried out in a greenhouse present in organic system (16°57′51.79′′ S; 49°11′02.09′′ O; 865 m altitude). The soil is classified as Red Oxisol and has the following physical and chemical attributes: texture (clay 26%, silt 7%, and sand 67%), pH (6.3), organic matter (27%), cation exchange capacity (CEC) (7.5), base saturation (81.36%), K (214 ppm), and Ca (4.0 mE/100 mL).
The genotype seedlings (Ellus, Black Mauri, Green Zebra, Green Tomato, Pomodoro Marmande, Pomodoro Fiorentino, Pitanga, and Black Krim) were transplanted 30 days after sowing. The plantation was fertilized applying a kilogram of poultry manure (26.4 g Kg−1 of nitrogen, 84.0 g Kg−1 of P2O5, 23.0 g Kg−1 of K2O, 112 g Kg−1 of Ca, 6.4 g Kg−1 of Mg, 2.5 g Kg−1 of S, and a 7.25 pH) per meter. The lines were separated by a distance of 1 meter and the plants by 0.6 meters. The tomato support system consisted of a double rod with a narrow ribbon. The removal of excess shoots was held weekly as of 30 days after transplanting (DAT).
The morphoagronomic characterization of the genotypes was carried out by evaluating plants and fruits. The growth habit, shoot height, number of flowers, and number of fruits were determined in eight plants of each genotype, randomly picked, at 35 DAT.
At 80 DAT, 24 fruits were harvested from eight plants of each genotype and the following measures were obtained: fresh mass weight (gravimetry), longitudinal diameter (direct measurement with calipers), transversal diameter (direct measurement with calipers), epicarp, mesocarp, and endocarp coloring (visual method), number of locules, mesocarp thickness (direct measurement with calipers), epicarp firmness (texturometry), and seed quantity per fruit. The number of fruits per plant was again counted 80 DAT to estimate the yield per plant (number of fruits
The data were analyzed using descriptive analysis, namely, position (mean) and variability (coefficient of variation) measurements. In addition, a multivariate cluster analysis and a principal component analysis (PCA using correlation matrices) were carried out for plant and fruit attributes. The cluster dendrogram was obtained through the UPGMA (Unweighted Pair Group Method using Arithmetic Averages), using the Euclidean distance as a similarity coefficient.
A large variation in the number of fruits per plant (35 DAT), number of locules, and firmness was observed among the evaluated genotypes (coefficient of variation of 64.90%, 37.40%, and 28.73%, resp.; Tables
Height 35 DAT (
Genotypes |
|
FLO-35 | FRU-35 | FRU-80 | EST-PRO | EST-PROD | GHAB |
---|---|---|---|---|---|---|---|
cm | Plant | Plant | Plant | kg plant−1 | ton ha−1 | — | |
Ellus | 180.75 | 11.00 | 11.00 | 39.50 | 3.77 | 62.95 | Undetermined |
Black Mauri | 175.87 | 11.87 | 12.62 | 79.00 | 1.38 | 23.04 | Undetermined |
Green Zebra | 118.00 | 5.75 | 2.12 | 27.12 | 1.42 | 23.73 | Undetermined |
Green Tomato | 168.12 | 11.25 | 9.50 | 24.62 | 1.47 | 24.53 | Undetermined |
Pitanga | 142.25 | 13.50 | 4.12 | 20.87 | 1.63 | 27.25 | Undetermined |
Black Krim | 79.50 | 31.00 | 13.25 | 19.87 | 1.37 | 22.84 | Determined |
Pomodoro Fiorentino | 117.75 | 12.87 | 4.00 | 23.50 | 1.69 | 28.25 | Undetermined |
Pomodoro Marmande | 103.50 | 10.37 | 5.87 | 13.87 | 1.27 | 21.29 | Undetermined |
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CV (%) | 5.94 | 24.26 | 64.90 | 19.22 | — | — | — |
CV: coefficient of variation.
Biometrics of tomato fruits, of different genotypes: fresh weight (FW), longitudinal diameter (LD), transverse diameter (TD), longitudinal and transverse diameter ratio (LD/TD), firmness (FIR), mesocarp thickness (THICK), number of locules (LOC), and seed quantity (SEM).
Genotypes | FW | LD | TD | LD/TD | FIR | THICK | LOC | SEM |
---|---|---|---|---|---|---|---|---|
g | mm | mm | — | kgf | mm | Fruit | Fruit | |
Ellus | 95.62 | 54.52 | 62.23 | 1.01 | 2.79 | 6.19 | 2.87 | 83.12 |
Black Mauri | 17.50 | 28.54 | 38.03 | 0.75 | 2.06 | 2.85 | 2.17 | 50.69 |
Green Zebra | 52.50 | 47.16 | 43.53 | 1.07 | 1.71 | 3.25 | 2.96 | 40.33 |
Green Tomato | 59.79 | 50.62 | 40.18 | 1.25 | 1.89 | 3.79 | 4.92 | 95.56 |
Pitanga | 78.33 | 57.53 | 53.66 | 1.06 | 1.86 | 4.69 | 5.67 | 24.47 |
Black Krim | 68.96 | 52.58 | 51.86 | 1.02 | 1.94 | 4.41 | 4.52 | 29.13 |
Pomodoro Fiorentino | 72.14 | 63.76 | 38.34 | 1.67 | 1.39 | 3.82 | 6.90 | 58.47 |
Pomodoro Marmande | 92.08 | 63.14 | 44.99 | 1.40 | 1.82 | 4.25 | 7.62 | 99.81 |
|
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CV (%) | 15.82 | 7.22 | 5.34 | 27.12 | 28.73 | 22.43 | 37.40 | 23.89 |
CV: coefficient of variation.
The genotype Ellus stood out among the others for having a higher estimated fruit production per plant and area (Table
The genotypes Ellus, Black Mauri, Pitanga, Black Krim, Pomodoro Fiorentino, and Pomodoro Marmande had fruit with a reddish epicarp, with tonal variations (Table
Epicarp, mesocarp, and endocarp color of fruits from eight tomato genotypes.
Genotypes | Color | |
---|---|---|
Epicarp | Mesocarp and endocarp | |
Ellus | Rosy red | Rosy red |
Black Mauri | Brownish red | Brownish red |
Green Zebra | Yellow with green stripes | Green |
Green Tomato | Light green | Green |
Pitanga | Cherry red | Cherry red |
Black Krim | Intense red | Rosy red |
Pomodoro Fiorentino | Red | Red |
Pomodoro Marmande | Rosy red | Rosy red |
Lycopene is the most abundant carotene in red tomato fruits [
The genotypes Green Zebra and Green Tomato stood out from the others due to the yellowish and greenish epicarp, respectively, and the green pulp (Table
Several enzymatic complexes, especially the lycopene cyclase, mediate carotenogenesis, in tomato fruits [
The first and second components of the multivariate analysis of plant traits explained 73.38% of the total variance (Figure
Biplot of plant variables (height, flowers, number of fruits, and production) and tomato genotypes relative to principal components 1 and 2.
The production of fruits per plant/area was positively correlated with plant height at 35 DAT. According to Piotto and Peres [
The first and second components of the multivariate analysis conducted for the fruit traits (Figure
Biplot of fruit variables (fresh weight, longitudinal and transverse diameter, longitudinal and transverse diameter ratio, epicarp firmness, mesocarp thickness, locules, and number seeds) and tomato genotypes relative to principal components 1 and 2.
The Italian genotypes Pomodoro Marmande and Fiorentino, located in the fourth quadrant, stood out from the others, especially by having a high number of locules and longitudinal/transverse diameter ratio. The locules are cavities within the fruit, derived from the ovary, where seed are submerged in placental mucilage. The number of locules is positively correlated with the number of seeds and fruit size in the fourth quadrant (Figure
The genotype Black Mauri, represented in the first quadrant, differed mainly by the low mass and fruit size (Figure
Genotypes of specific growth, as Black Krim, are suitable for the production of fruits for industrial use. The combination of small size (Table
Cluster analysis of plant traits enabled grouping the eight genotypes in only two groups (Figure
Similarity dendrogram of tomato genotypes associated with plant characteristics (height, flowers, fruits, and production).
Similarity dendrogram of tomato genotypes associated with fruit characteristics (fresh mass weight, longitudinal and transverse diameter, relationship between longitudinal and transverse diameter, epicarp firmness, loci, and number of seeds).
The cluster and principal component analyses were efficient in characterizing plants and/or fruits of different tomato genotypes. Such efficiency enhances result interpretation and proposed inferences, with applied relevance for the producers.
The genotype Ellus has a combination of morphoagronomic plant and fruit traits superior to other genotypes. Such superior traits enable a high productivity.
The authors declare that there is no conflict of interests regarding the publication of this paper.