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Agronomic performance of mini-tomato hybrids from dwarf lines

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Little is known about the commercial potential of mini-tomato hybrids obtained from one dwarf parent. Thus, our objective was to evaluate the agronomic performance of mini-tomato hybrids obtained by crossing a dwarf line (A) with normal lines with indeterminate (I), determinate (D) and semi-determinate (SD) growth habits. The experiment was conducted in a greenhouse at the Estação Experimental de Hortaliças at the Universidade Federal de Uberlândia-UFU in Monte Carmelo, Brazil. The experiment was completely randomized with 17 treatments and four repetitions. The genetic material consisted of 16 experimental mini-tomato hybrids from the tomato germplasm bank at UFU, and a commercial hybrid (Mascot) as a control. The following variables were used to evaluate agronomic performance: fruit weight (g); number of fruits plant-1; productivity (kg plant-1); number of bunches plant-1; number of fruits bunch-1; stem diameter (mm); distance between first bunch and soil (cm); internode length (cm) and total soluble solids (°Brix). The growth habit of the parents influenced the performance of the hybrids. In general, the mini-tomato hybrids from dwarf lines differed from the control with respect to all variables except number of fruits plant-1, number of fruits bunch-1 and stem diameter. On average, hybrids from dwarf lines showed higher productivity (20%), shorter internodes (11%) and a shorter distance between the first bunch and the ground (30%), relative to the control. Using dwarf lines to obtain mini-tomato hybrids was shown to be viable since the hybrids demonstrated better agronomic performance.
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http://dx.doi.org/10.1590/1413-70542017411021416
Agronomic performance of mini-tomato hybrids from dwarf lines
Desempenho agronômico de híbridos de minitomate
provenientes de linhagens anãs
Rafael Resende Finzi1, Gabriel Mascarenhas Maciel2*, Ernani Clarete da Silva3,
Jose Magno Queiroz Luz1, Monique Ellis Aguilar Borba1
1Universidade Federal de Uberlândia/UFU, Instituto de Ciências Agrárias, Uberlândia, MG, Brasil
2Universidade Federal de Uberlândia/UFU, Instituto de Ciências Agrárias, Monte Carmelo, MG, Brasil
3Universidade Federal de São João del-Rei/UFSJ, Sete Lagoas, MG, Brasil
*Corresponding author: gabrielmaciel@iciag.ufu.br
Received in May 20, 2016 and approved in September 28, 2016
ABSTRACT
Little is known about the commercial potential of mini-tomato hybrids obtained from one dwarf parent. Thus, our objective was to
evaluate the agronomic performance of mini-tomato hybrids obtained by crossing a dwarf line (A) with normal lines with indeterminate
(I), determinate (D) and semi-determinate (SD) growth habits. The experiment was conducted in a greenhouse at the Estação Experimental
de Hortaliças at the Universidade Federal de Uberlândia-UFU in Monte Carmelo, Brazil. The experiment was completely randomized with
17 treatments and four repetitions. The genetic material consisted of 16 experimental mini-tomato hybrids from the tomato germplasm
bank at UFU, and a commercial hybrid (Mascot) as a control. The following variables were used to evaluate agronomic performance:
fruit weight (g); number of fruits plant-1; productivity (kg plant-1); number of bunches plant-1; number of fruits bunch-1; stem diameter
(mm); distance between rst bunch and soil (cm); internode length (cm) and total soluble solids (°Brix). The growth habit of the parents
inuenced the performance of the hybrids. In general, the mini-tomato hybrids from dwarf lines diered from the control with respect to all
variables except number of fruits plant-1, number of fruits bunch-1 and stem diameter. On average, hybrids from dwarf lines showed higher
productivity (20%), shorter internodes (11%) and a shorter distance between the rst bunch and the ground (30%), relative to the control.
Using dwarf lines to obtain mini-tomato hybrids was shown to be viable since the hybrids demonstrated better agronomic performance.
Index terms: Brix; dwarsm; growth habit; Solanum lycopersicum.
RESUMO
Pouco se sabe a respeito do potencial comercial de híbridos de minitomate obtidos a partir de um genitor anão. Assim, o objetivo deste
trabalho foi avaliar o desempenho agronômico de híbridos de minitomate obtidos pelo cruzamento entre linhagens anãs (A) versus
linhagens normais de crescimento indeterminado (I), determinado (D) e semideterminado (SD). O experimento foi conduzido em casa de
vegetação, na Estação Experimental de Hortaliças da Universidade Federal de Uberlândia (UFU), Monte Carmelo. Utilizou-se o delineamento
inteiramente casualizado com 17 tratamentos e quatro repetições. O material genético consistiu de 16 híbridos experimentais de minitomate
pertencentes ao Banco de germoplasma de tomateiro da UFU, e um híbrido comercial Mascot (testemunha). As variáveis utilizadas para
analisar o desempenho agronômico foram: peso do fruto (g); número de frutos planta-1; produtividade (kg planta-1); número de pencas
planta-1; número de frutos penca-1; diâmetro do caule (mm); distância do primeiro cacho ao solo (cm); comprimento de internódios
(cm) e sólidos solúveis totais (ºBrix). O hábito de crescimento dos genitores inuenciou o desempenho dos híbridos provenientes de
linhagens anãs. De maneira geral, os híbridos de minitomate provenientes de linhagens anãs e a testemunha se diferenciaram em todas
as variáveis, exceto no número de frutos planta-1, número de frutos penca-1 e no diâmetro do caule. Em média, os híbridos provenientes
de linhagens anãs apresentaram maior produtividade (20%), internódios mais curtos (11%) e menor distância da primeira penca ao solo
(30%) em relação à testemunha. A exploração de linhagens anãs demonstra ser viável na obtenção de híbridos de minitomate, uma vez
que estes apresentam potencial comercial.
Termos para indexação: Brix; nanismo; hábito de crescimento; Solanum lycopersicum.
INTRODUCTION
The tomato (Solanum lycopersicum L.) is one of the
vegetables most economically important in the world. Among
the types of tomatoes, mini-tomatoes stand out from the rest
because of their smaller fruit and sweeter taste. Their appealing
taste has led to greater demand in grocery stores (Maciel et al.,
2016). Moreover, this type of tomato is distinguished by the
higher margins it commands in the market (Abraham; Boas;
Bull, 2014; Maciel et al., 2016). Thus, increasing investment
in mini-tomatoes has led to greater demand for new hybrids
with improved agronomic performance.
Ciência e Agrotecnologia 41(1):15-21, Jan/Feb. 2017
16 FINZI, R. R. et al.
Heterosis is mainly manifested in tomatoes by an
increased number of fruits per plant, resulting in greater
productivity (Borém; Miranda, 2009; Graça et al., 2015).
Higher fruit quantity is closely related to the genes that
control the growth habit of tomato plants belonging to
the self-pruning family (SP) (Piotto; Peres, 2012). Some
studies have shown that the hybrid vigor of tomatoes may
stem from a single growth habit gene in heterozygous
genotypes [owering gene - single ower truss (SFT)],
representing increases in tomato yield of up to 60%
(Krieger; Lippman; Zamir, 2010).
Plant breeders have explored the heterotic
potential of contrasting parents on tomato growth habit.
Nevertheless, there is currently no information on crossing
dwarf homozygote lines with normal lines (determinate,
semi-determinate and indeterminate), especially due
to the divergence between these parents (dwarf versus
normal) (Maciel; Silva; Fernandes, 2015). Moreover,
assuming that a single allele can change the hybrid vigor
of a tomato (Krieger; Lippman; Zamir, 2010), the study
of other genes in heterozygosity (e.g. dwarsm genes)
gains relevance. However, there are few studies on the
agronomic performance of mini-tomato hybrids from a
dwarf parent (Gardner; Panthee, 2012; Panthee; Gardner,
2013a, 2013b).
In Brazil, there are no reports of mini-tomato
hybrids with commercial potential that come from one
dwarf parent. Few dwarf lines of mini-tomatoes with
high Brix values are available for direct use in breeding
(Maciel; Silva; Fernandes, 2015). Therefore, the objective
of this study was to evaluate the agronomic performance
of mini-tomato hybrids obtained by crossing dwarf lines
with normal lines of indeterminate, determinate and semi-
determinate growth.
MATERIAL AND METHODS
The experiment were conducted from November,
2014 to May, 2016 at the Estação Experimental de
Hortaliças at the Federal University of Uberlandia
Monte Carmelo Campus, MG, Brazil (18º42’43.19”S,
47º29’55.8” and 873 m above sea level). The plants were
grown in a hoop-style greenhouse (7 x 21 m, 4 m ceiling
height), with a roof of 150-micron polyethylene that had
been treated against ultraviolet raysand lateral curtain walls
made from white anti-aphid screens.
The genetic material that was evaluated consisted
of 16 experimental mini-tomato hybrids (UFU-1502,
UFU-1503, UFU-1504, UFU-1505, UFU-1506, UFU-
1507, UFU-1509, UFU-1510, UFU-1511, UFU-1512,
UFU-1513, UFU-1514, UFU-1516, UFU-1518, UFU-
1519, UFU-1520) and a commercial hybrid (Mascot).
The hybrid Mascot (Topseed®) has fruit of intense red
color, small (18g), and indeterminate growth habit. All 16
experimental hybrids were obtained by crossing different
normal lines [determinate (D), semi-determinate (SD)
and indeterminate (I) growth habit] with dwarf lines
(A) from the tomato germplasm bank at the Federal
University of Uberlandia. The dwarf lines has fruit of
intense red color, small (10g), and indeterminate growth
habit (Maciel; Silva; Fernandes, 2015). The UFU-1502,
UFU-1503, UFU-1504, UFU-1505, UFU-1506, UFU-
1507 and UFU-1513 hybrids came from an SDxA cross;
UFU-1509, UFU-1510, UFU-1511, UFU-1512 and UFU-
1514 from IxA; and UFU-1516, UFU-1518, UFU-1519,
UFU-1520 from DxA.
Hybrids of the dwarf lines were sown in 200-
cell polystyrene trays on May 27th, 2015. The resulting
seedlings were transplanted into five liter containers
31 days after sowing. A commercial substrate based on
coconut ber was used in both the trays and the containers.
Cultivation of these plants throughout the experiment
followed recommendations for tomato crops grown in
protected environments (Alvarenga, 2013). In addition,
the plants were supported by two stakes and polythene
strips using a string weave system.
A drip fertigation system (SPAGHETTI PEBD
micro-tube) was used for irrigation with one arrow drip
unit per plant and a ow rate of 4.0 l h-1. Irrigation was
carried out three or four times per day depending on the
stage of plant development and environmental conditions.
Macronutrients (commercial formulation of 1.0:1.2:1.0
NPK) were applied between the rst and eighth week after
transplant during the plant development stage. Starting at
the ninth week, a production nutrient solution was used
with an NPK ratio of 1.0:0.7:2.0 (Maciel et al., 2016).
The experiment was completely randomized
with 17 treatments (hybrids) and four replications. The
experimental plots consisted of six plants distributed in
double rows and spaced at 0.4 x 0.4 m. Each double row
(carrier) was spaced 0.8 m from the next for a total of 408
plants covering 147 m² of greenhouse space.
The tomatoes were collected twice per week from
August 29th to November 14th, 2015 (18 harvests). The
fruit from each plot was harvested when it had reached
full maturity (fully ripe fruit). The following agronomic
characteristics were evaluated:
Average fruit weight (g): determined as the ratio
between the weight and the number of all the tomatoes
harvested from a plot.
Agronomic performance of mini-tomato hybrids from dwarf lines 17
Ciência e Agrotecnologia 41(1):15-21, Jan/Feb. 2017
Average productivity (kg plant-1): determined as
the ratio between the weight of the harvested tomatoes
and the number of plants in the plot.
Average number of fruits plant-1: determined as the
ratio between the total number of tomatoes and the number
of plants in a plot.
Number of bunches plant-1: obtained by counting
the total number of bunches on the two centermost plants
from each plot.
Average number of fruits bunch-1: determined as
the ratio of the number of fruits plant-1 to the number of
bunches plant-1.
Stem diameter (mm): measurement of stem
diameter between the third and fourth uorescence of
the two centermost plants from each plot. Diameter was
measured with a digital caliper.
Distance between the first bunch and the soil
(cm): determined as the distance between the rst bunch
and the soil and measured with a ruler (cm) from the two
centermost plants from each plot.
Internode length (cm): determined by measuring
the length between every node between the beginning of
the rst fork in the stem until the rst leaf below the last
inorescence. Internode lengths were measured with a
ruler (cm) on the two centermost plants from each plot.
Total soluble solids (ºBrix): determined as the
mean of 15 tomatoes harvested from each bunch on the
two centermost plants from each plot. After harvesting,
the tomatoes were crushed in a blender and analyzed for
total soluble solids using a Portable Digital Refractometer
(Atago PAL-1 3810).
After checking assumptions using the analyses of
homogeneity of variance (“Levene’s test”) and normality
(“Kolmogorov-Smirnov’s test”), data transformation was
used ( ) on only the number of fruits bunch-1 variable,
for which real values were tabulated. The data were
analyzed using two independent statistical models. The
rst examined the effect of the parent growth habit on
hybrid performance and the second compared performance
among hybrids.
In the rst model, an unconventional analysis using
a hierarchical model (also called a nested model) was
used, which allowed the study of a single isolated factor
(parent growth habit). For both models, the data were
submitted to analysis of variance (F= 0.05) and the means
were compared by the Scott-Knott test (p= 0.05), using
the Sisvar statistical program (Ferreira, 2011). Simple
correlation measurements were also performed (Pearson’s
test) between variables.
RESULTS AND DISCUSSION
Regardless of the parent growth habit, 100% of
the hybrids showed indeterminate growth. This occurred,
as expected, because the dwarf lines have indeterminate
growth (Maciel; Silva; Fernandes, 2015). According to the
review done by Piotto and Peres (2012), the indeterminate
growth habit is controlled by the dominant allele Self
Pruning (SP), which has dominance among the others
growth habits. Despite all the hybrids had indeterminate
growth, the growth habit of the parents had inuenced the
performance of the hybrids.
In general, hybrids from dwarf lines differed from
the commercial hybrid (Mascot) regarding all agronomic
variables except for number of fruits plant-1, number of
fruits bunch-1 and stem diameter. Parent growth habit only
inuenced internode length, number of bunches plant-1,
fruit weight and total soluble solids (Figure 1).
The hybrids produced an average of 446 fruits
plant-1 and 33 fruits bunch-1. Although the number of
fruits did not differ, the productivity of the hybrids
from dwarf lines was 20% greater than that of the
commercial hybrid (Mascot) (Figure 1.c). This increase
in productivity is explained by differences in fruit weight.
Specically, the hybrids from dwarf lines produced fruits
that were 17% heavier than those of the commercial
hybrid (Mascot) (Figure 1.a).
Presumably, increases in fruit weight were
inuenced by the shortening of the internodes in the
hybrids from dwarf lines (Figure 1.f). The internodes of
these hybrids were, on average, 11% shorter than those
of the commercial hybrid (Mascot). Furthermore, shorter
internodes did not change the stem diameter of the hybrids,
which averaged 10.1 mm. Shorter internodes change the
capacity of the tomato plant to absorb light and perform
photosynthesis (Sarlikioti et al., 2011), thereby interfering
in the production of photoassimilates and consequently,
availability in sink regions. Therefore, it follows that
some of the photoassimilates that might have supported
internode growth or a stem diameter, instead supported
tomato growth. It is important to emphasize that not all
hybrids from dwarf lines showed shorter internodes,
higher fruit weight and higher productivity in relation to
the commercial hybrid (Mascot). This can be explained by
genetic factor, where some parents (female parents) have
lower productive potential, greater length of internodes and
varied diameter of fruits compared to control (Mascot).
In this sense, achieving better performance of hybrids
obtained by minitomato dwarf lines also depends of the
parental genetic potential.
Ciência e Agrotecnologia 41(1):15-21, Jan/Feb. 2017
18 FINZI, R. R. et al.
The internode length of tomato plants can also be
inuenced by temperature, the quantity and quality of the light
intercepted by the leaf (Chen et al., 2014), growth regulators
(Figueiredo et al., 2015), moisture stress (Sibomana; Aguyoh;
Opiyo, 2013), higher concentrations of atmospheric ozone
(Thwe et al., 2013), among others. Nevertheless, shorter
internodes caused by these factors hindered plant development,
which differs from the results found in the current study.
Gardner and Panthee (2012) and Panther and Gardner (2013a,
2013b) also observed shorter internodes in hybrids from dwarf
lines. According to these authors, one of the main advantages
of internode reduction for the growth of indeterminate mini-
tomatoes is plant compaction, which allows the use of shorter
plant supports. Furthermore, shorter indeterminate tomatoes
may also facilitate pruning and staking practices (Figueiredo
et al., 2015) and also facilitate harvesting.
Internode length also influenced the distance
between the rst bunch and the soil for hybrids from
dwarf lines. In general, the rst tomato bunch of hybrids
from dwarf lines was 30% closer to the soil than for the
commercial hybrid (Mascot) (Figura 1.b). The distance for
these hybrids varied from 18.0 to 27.6 cm.
Regarding the inuence of parent growth habit,
hybrid fruit obtained from the cross SDxA was, on average,
9% heavier than hybrid fruit from IxA and DxA. Hybrid
tomatoes from the IxA cross had internodes that were 7%
shorter, soluble solids that were 5% higher and 1 more bunch
per plant than hybrids from SDxA and DxA parentage.
Some reports show that small changes in the
expression levels, different allelic combinations or
mutations in growth habit genes can influence plant
performance (Krieger; Lippman; Zamir, 2010; Park et
al., 2014.). Thus, we can surmise that there were different
expressions in the growth habit genes of these hybrids,
especially in IxA versus DxA and SDxA, despite having
the same indeterminate growth habit.
Presumably, hybrids derived from IxA had
stronger gene expression related to reproductive
development to the detriment of vegetative development,
which explains the shorter internodes, greater numbers of
bunches and higher soluble solids in the fruit. The weight
of the fruit coming from SDxA parentage may have
been higher due to the expression of other genes linked
to owering (Krieger; Lippman; Zamir, 2010). Soluble
Figure 1: Agronomic performance of mini-tomato hybrids of dwarf lines where D: normal lines with determinate,
(SD) semi-determinateand (I) indeterminate growth habits; and (A) dwarf line. Means followed by distinct letters
dier by the Scott-Knott test at 0.05 signicance.
Agronomic performance of mini-tomato hybrids from dwarf lines 19
Ciência e Agrotecnologia 41(1):15-21, Jan/Feb. 2017
solid levels may have been affected not only indirectly
by plant morphology, but also directly by biochemical
mechanisms (Piotto and Peres, 2012).
Levels of soluble solids in mini-tomatoes are
fundamental to the commercialization of the fruit. Thus,
high levels of soluble solids and high productivity are
two of the most important characteristics in hybrid mini-
tomatoes. In this regard, the hybrid UFU-1510 (IxA) stood
out from the rest with high productivity (2.2 kg plant-1)
and high soluble solids (8.0 ºBrix) (Table 1).
In tomato generally there is an inverse correlation
between productivity and soluble solids (Favati et al.,
2009), corroborating to the results found in this study
(r = -0.41) (Table 2). However, Preczenhak et al. (2014)
did not observe these results in minitomato genotypes,
justifying that the reduced fruit size and huge size of the
plant may be responsible for the positive relation between
productivity and soluble solids. The hybrid UFU-1510 was
the only one that maintained high productivity and soluble
solids in this study.
The increase in productivity was conrmed by
increases in fruit weight (r= 0.67). In addition, the number
of bunches (r= 0.25), diameter (r= 0.24) and number
of fruits (r= 0.58) also showed a positive correlation
with productivity. The internodes length had an inverse
correlation with the number of bunches (r= -0.44) and
number of fruits (r= -0.40) per plant, as well as a positive
correlation with the distance between the rst bunch
and the soil (r= 0.49), corroborating to the ndings of
this study.
Table 1: Agronomic performance of mini-tomato hybrids from dwarf lines where, D: normal lines with determinate,
(SD) semi-determinate and (I) indeterminate growth habit; and (A) dwarf. I: internode length (cm); TSS: total soluble
solids in fruit (ºBrix); DS: distance between rst bunch and the soil (cm); CPL: number of bunches plant-1; DI: stem
diameter (cm); FC: Number of fruits bunch-1; P: Productivity (kg plant-1); F: Fruits plant-1; FW: Fruit weight (g).
¹Means followed by distinct letters within a column dier by the Scott-Knott test at 0.05 signicance; ²KS, F: statistics of the
Kolmogorov-Smirnov and Levene tests, respectively; bold values indicate residuals with normal distributions and homogenous
variance at the 0.01 level of signicance.
Hybrids Growth habit of
the parents I TSS DS BPL DI FB P F FW
UFU-1502 SDxA 7.9 a 7.1 c 23.9 c 13.3 b 9.9 a 29.1 a 2.0 b 384.6 b 10.5 a
UFU-1503 SDxA 8.0 a 7.1 c 23.3 c 13.8 b 10.1 a 31.8 a 2.4 a 435.3 b 10.9 a
UFU-1504 SDxA 6.9 b 6.7 d 18.0 d 13.8 b 10.2 a 36.5 a 2.5 a 500.0 a 10.2 a
UFU-1505 SDxA 7.8 a 7.3 c 22.1 c 13.9 b 10.8 a 31.1 a 2.0 a 431.8 b 9.4 b
UFU-1506 SDxA 7.9 a 7.0 c 27.6 b 14.5 a 10.7 a 30.4 a 2.3 a 438.8 b 10.3 a
UFU-1513 SDxA 7.3 b 7.5 b 19.8 d 13.4 b 10.2 a 32.4 a 2.0 b 427.0 b 9.4 b
UFU-1507 SDxA 7.5 a 7.2 c 24.5 c 13.3 b 10.4 a 33.3 a 2.3 a 441.8 b 10.5 a
UFU-1509 IxA 6.7 b 7.3 c 21.3 c 14.8 a 11.1 a 29.6 a 2.2 b 435.4 b 9.7 b
UFU-1510 IxA 6.7 b 8.0 a 21.4 c 15.1 a 10.8 a 33.1 a 2.2 a 498.6 a 8.9 c
UFU-1511 IxA 6.8 b 7.2 c 22.8 c 14.9 a 10.7 a 30.7 a 2.3 a 456.2 a 10.1 a
UFU-1512 IxA 7.4 b 7.1 c 19.5 d 14.4 a 10.5 a 31.7 a 2.2 a 453.3 a 9.6 b
UFU-1514 IxA 6.7 b 7.6 b 18.5 d 15.1 a 10.2 a 31.2 a 1.9 b 467.8 a 8.3 d
UFU-1516 DxA 7.3 b 6.8 d 22.1 c 13.4 b 10.7 a 34.5 a 2.3 a 459.4 a 10.0 a
UFU-1518 DxA 7.7 a 7.1 c 23.9 c 13.1 b 10.2 a 32.0 a 2.1 b 418.8 b 10.1 a
UFU-1519 DxA 7.2 b 6.6 d 22.7 c 12.8 b 10.1 a 35.5 a 2.0 b 450.9 a 8.8 c
UFU-1520 DxA 7.2 b 7.4 b 20.9 d 14.8 a 10.3 a 31.7 a 1.9 b 466.9 a 8.2 d
Mascot - 8.2 a 7.2 c 31.1 a 12.5 b 9.3 a 35.8 a 1.7 b 431.3 b 8.0 d
KS¹ 0.094 0.116 0.147 0.073 0.062 0.086 0.066 0.053 0.064
F (Levene)² 1.275 1.952 1.415 1.115 1.122 2.149 1.048 1.508 1.165
CV (%) 6.39 4.08 10.24 9.48 8.31 5.45 8.92 7.57 5.41
Ciência e Agrotecnologia 41(1):15-21, Jan/Feb. 2017
20 FINZI, R. R. et al.
The internodes lenght had no signicant correlation
with the fruit weight (r= 0.15), but it does not mean that these
variables are not related. The Pearson’s test measures only the
linear correlations. In this way, productivity had no signicant
direct correlation with internode length. However, shorter
internodes are correlated signicantly with the increase of
the number of fruits, which is correlated with productivity.
In general, the results found in this work indicated
greater effect in internodes shortening and genetic factor
as better hybrid’s performance. The exploitation of hybrids
from dwarf line (male parental) proved to be viable, which
could occur using this strategy in another cultures.
CONCLUSIONS
The growth habit of parents influences the
performance of hybrids from dwarf lines. Hybrids from
IxA parents have shorter internodes and consequently higher
content of soluble solids in the fruit and higher number of
bunches plant-1. Dwarf lines can be used to produce mini-
tomato hybrids with agronomic potential. In this way, UFU-
1510 (IxA) was selected as the most promising hybrid based
on productivity and total soluble solids.
REFERENCES
ABRAHÃO, C.; BÔAS, R. L. V.; BULL, L. T. Relação K:Ca:Mg na
solução nutritiva para a produção de minitomate cultivado
em substrato. Irriga. 19(2):214-224, 2014.
ALVARENGA, M. A. R. Tomate: Produção em campo, em casa-
de-vegetação e em hidroponia. Lavras: Editora UFLA,
2013. 455p.
BORÉM, A.; MIRANDA, G. V. Melhoramento de Plantas. Viçosa:
Editora UFV, 2009. 449p.
CHEN, T. W. et al. Quantication of the eects of architectural
traits on dry mass production and light interception of
tomato canopy under dierent temperature regimes using
a dynamic functional–structural plant model. Journal of
Experimental Botany. 65(22):6399–6410, 2014.
FAVATI, F. et al. Processing tomato quality as aected by
irrigation scheduling. Scientia Horticulturae. 122(4):562-
571, 2009.
FERREIRA, D. F. Sisvar: A computer statistical analysis system.
Ciência e Agrotecnologia. 35(6):1039-1042, 2011.
FIGUEIREDO, A. S. T. et al. Comportamento de plantas de
tomateiro indeterminado na presença de regulador de
crescimento. Revista Campo Digit@l. 10(1):31-40, 2015.
GARDNER, R. G.; PANTHEE, D. R. ‘Mountain Magic’: An early
blight and late blight-resistant specialty type F1 hybrid
tomato. Hortscience. 47(2):299-300, 2012.
GRAÇA, A. J. P. et al. Heterosis and combining ability of dual-
purpose tomato hybrids developed to meet family farmers’
needs in Brazil and Mozambique. Horticultura Brasileira.
33(3):339-344, 2015.
KRIEGER, U.; LIPPMAN, Z. B.; ZAMIR, D. The owering gene
SINGLE FLOWER TRUSS drives heterosis for yield in tomato.
Nature Genetics. 42(5):459-463, 2010.
MACIEL, G. M.; SILVA, E. C.; FERNANDES, M. A. R. Ocorrência de
nanismo em planta de tomateiro do tipo grape. Revista
Caatinga. 28(4):259-264, 2015.
Variables BPL DI FB TSS F P DS I
FW -0.06ns 0.23ns -0.16ns -0.41** -0.21ns 0.67** 0.22ns 0.15ns
I -0.44** -0.15ns 0.09ns -0.23ns -0.40*-0.17ns 0.49**
DS -0.17ns -0.13ns -0.43ns 0.35ns -0.28*-0.19ns
P0.25*0.24*0.20ns -0.33** 0.58**
F 0.40** 0.68ns 0.44** 0.37ns
TSS 0.40** 0.01ns -0.28*
FB -0.63** -0.19ns
DI 0.24*
** indicates signicance at 1%; ns indicates not signicant.
BPL: Number of bunches plant-1; DI: Stem diameter; FB: Average number of fruits bunch-1; TSS: Total soluble solids of the fruit; F: Average
fruits plant-1; P: Average productivity; DS: Distance between the rst bunch and the soil; I: Internode length; FW: Average fruit weight.
Table 2: Pearson correlation coecients (r) between the agronomic performance variables of mini-tomato
hybrids.
Agronomic performance of mini-tomato hybrids from dwarf lines 21
Ciência e Agrotecnologia 41(1):15-21, Jan/Feb. 2017
MACIEL, G. M. et al. Potencial agronômico de híbridos de
minitomate com hábito de crescimento determinado e
indeterminado. Horticultura Brasileira. 34(1):133-137, 2016.
PANTHEE, D. R.; GARDNER, R. G. ‘Mountain Honey’ hybrid
grape tomato and its parent NC 6 grape breeding line.
Hortscience. 48(9):1192-1194, 2013a.
PANTHEE, D. R.; GARDNER, R. G. ‘Mountain Vineyard’ hybrid grape
tomato and its parents: NC 4 Grape and NC 5 Grape tomato
breeding lines. HortScience. 48(9):1189-1191, 2013b.
PARK, S. J. et al. Optimization of crop productivity in tomato
using induced mutations in the origen pathway. Nature
Genetics. 46(12):1337-1342, 2014.
PIOTTO, F. A.; PERES, L. E. P. Base genética do hábito de
crescimento e orescimento em tomateiro e sua importância
na agricultura. Ciência Rural. 42(11):1941-1946, 2012.
PRECZENHAK, A. P. et al. Caracterização agronômica de
genótipos de minitomate. Horticultura Brasileira.
32(2):348-356, 2014.
SARLIKIOTI, V. et al. How plant architecture affects light
absorption and photosynthesis in tomato: Towards an
ideotype for plant architecture using a functional–structural
plant model. Annals of Botany. 108(6):1065-1073, 2011.
SIBOMANA, I. C.; AGUYOH, J. N.; OPIYO, A. M. Water stress
affects growth and yield of container grown tomato
(Lycopersicon esculentum Mill) plants. Global journal of
Bioscience and Biotechnology. 2(4):461-466, 2013.
THWE, A. A. et al. Dynamic shoot and root growth at dierent
developmental stages of tomato (Solanum lycopersicum
Mill.) under acute ozone stress. Scientia Horticulturae.
150(1):317-325, 2013.
... The commercial check is characterized by indeterminate growth habits and Santa Cruz-type red fruits. UFU MC TOM1 used as the DP is a homozygous dwarf strain with indeterminate growth habits and oblong Minitomato-type fruits [8,9]. As the expression of the dwarf phenotype is recessive and monogenic [9], backcrossing was performed to transfer the recessive allele. ...
... The presence of reduced internodes resulting in compact tomato plants is a trend for new hybrids [8,20]. A dwarf parent was used in the combination for obtaining Minitomato hybrids, which resulted in hybrids with reduced internodes, and consequently, an increased number of clusters per linear meter of stem and enhanced productivity. ...
... In Minitomato, selected BC 2 genotypes should be used as the male parent to obtain normal hybrids with high yields [8]. Additionally, selected genotypes can provide hybrids with a broad spectrum of pest resistance [12] owing to high AS levels. ...
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... Future challenges in the sector include obtaining genotypes that are high yielding, resistant to pests and diseases, and show high fruit quality, thus requiring investments in innovation (Luz, Bittar, Oliveira, Nascimento, & Nogueira, 2016). The use of hybrid tomato plants has been the main strategy to achieve these objectives (Finzi, Maciel, Silva, Luz, & Borba, 2017a). ...
... The use of dwarf plants is important for the development of tomato hybrids. Hybrid tomato plants obtained from a dwarf parent (obtained through crossing a normal plant with a dwarf plant) develop notably short internodes, thereby achieving a high yield by increasing the number of clusters per linear meter of stem (Finzi et al., 2017a). One cluster more per stem leads to a yield gain. ...
... The dwarf line used by Finzi et al. (2017a) bears fruit that is incompatible for directly obtaining hybrids of the Santa Cruz tomato type, because it is small and oblong (Maciel, Silva, & Fernandes, 2015b). Finzi et al. (2020) performed the first backcross with a dwarf line mentioned aiming to obtain Salada type fruit. ...
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... Plant breeding has been an important strategy for increasing crop yield in a profitable and sustainable manner (Barbosa et al., 2011). In cherry/grape tomatoes, internode reduction through breeding with a dwarf parental line (Maciel et al., 2015) has led to promising results in obtaining hybrids with compact plant architectures and high yields (Finzi et al., 2017). Dwarf tomato plant populations have previously been cultured for round/salad-type tomatoes intended for in natura consumption , but similar dwarf plants have not yet been identified for the saladette/roma tomato segment. ...
... Greater difficulties arise in characterizing and analyzing the germplasm of dwarf tomato plants (Finzi, et al., 2017;Finzi et al., 2020), as they have considerably different morphologies than normal-sized tomatoes, which requires the refinement of methods and the use of new optimization techniques. Artificial neural networks (ANNs) have been used to obtain self-organizing maps (SOMs), which may be beneficial alternatives for the study of genetic dissimilarity in saladette type dwarf tomatoes. ...
... In order to conduct the introgression of genes of interest for different types of biotic stress and fruit nutritional quality, and promote higher productivity, research with dwarf tomato plants has been intensified (Maciel et al., 2015;Finzi et al., 2017;Finzi et al., 2020;Cavasin et al., 2021;Gomes et al., 2021;Oliveira et al., 2022). The use of dwarf plants has provided multiple advantages, and obtaining saladette/roma dwarf tomato populations is a promising technology for the future development of higher yielding hybrids, similar to that observed with cherry/ grape tomatoes (Finzi et al., 2017). ...
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... et al. /1678 PLANT BREEDING Article and the use of stimulants (Seleguine et al. 2016). In addition, there are reports of the benefits of reduction in internode space through plant breeding, resulting in more compact plants and, consequently, a larger number of tomato bunches per linear meter of stem/vine (Finzi et al. 2017a). Obtaining more compact plants that provide higher yield (Finzi et al. 2020) should be one of the aims of tomato plant breeding programs. ...
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... Tomato hybrids with short internodes and high yields have already been produced. Finzi et al. (2017a) obtained promising results using a dwarf line as a male parent to produce minitomato hybrids (phenotype of the hybrid is nearly to a non-dwarf plant). However, dwarf lines exhibit small and oblong fruits such as grape tomatoes Silva;Fernandes, 2015), precluding their direct use to obtain hybrids for the round tomato sector and makes important to develop dwarf lines with round fruits. ...
... The high soluble solid content is a desirable trait due to its association with sweeter flavored tomatoes, which are preferred by consumers Schwarzet al., 2013). Moreover, the short internodes of the dwarf populations are also beneficial because they result in more compact plants in hybrid combinations, with more clusters per linear meter of stem (Finzi et al., 2017a). ...
... It is important to highlight that the dwarf tomato populations are part of the first backcross with the recurrent parent. For the next phase of this study, we suggest performing another backcross and subsequently obtaining hybrid round tomatoes from dwarf lines similar to those breed by Finzi et al. (2017a) in mini-tomatoes. This makes it important to use different selection strategies to obtain superior dwarf populations, with genetic dissimilarity measures and selection indices proving to be promising alternatives. ...
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... Overall, performance per se is one of the main standards applied in the selection of superior tomato genotypes. For that matter, the univariate analysis using the Scott-Knott test of means (Scott and Knott, 1974) has been widely used by several authors (Araújo et al., 2016;Borba et al., 2017;Finzi et al., 2017;Maciel et al., 2018;Peixoto et al., 2018). Nevertheless, it is known that this type of selection can be inefficient, because it leads to a superior genotype in no more than one characteristic. ...
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Rhizoctonia root rot, caused by Rhizoctonia solani, is a common disease in areas intensively cultivated with melon (Cucumis melo) in the Northeastern Brazil. The objective of this study was to identify and characterize morphologically resistance sources of melon to R. solani. In the first trial, twenty-two melon accessions collected in the Northeastern Brazil were evaluated for their reaction to the isolate RS-21, in an experiment with the completely randomized design and five replications. The resistant accessions of the first experiment and 13 inbred lines of the ACP x AF -646 cross were evaluated for their reaction to the RS-22 and RS-23 isolates on a second trial carried out in a randomized design with five replications. The accessions T-A-08, T-A-09, T-A-19 and the line ACP-AF-06 were identified as sources of resistance. In both inoculation trials, seeds were planted in infested soil (50 mg of colonized rice grains/1.0 kg of soil). The evaluation of accessions was performed after 45 days, with a score scale from 0.0 to 4.0 to cluster genotypes in five classes. Resistance sources were characterized morphologically in an essay carried out in randomized block design with three replications. The characterization identified the T-A-08 and T-A-19 accessions as belonging to the botanical variety momordica and the T-A-09 accession and the ACP-AF-06 inbred line as belonging to the varieties acidulus and inodorus, respectively. Resistance sources may be used in future breeding programs aiming to obtain genotypes (inbred lines and hybrids) resistant to R. solani.
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