DOI: 10.5061/dryad.hqbzkh1wh
title: Vascular network in the pericarp of tomato fruit and implications for fruit size, quality, and drought response

description: The importance of the vascular network for transporting water,
 carbohydrate, and nutrient for sustaining plant growth and development in
 the vegetative body of plants is well known. Nevertheless, the vascular
 network within a fruit is still inadequately
 understood. Here we characterized the vascular
 network in the fruit pericarp of ten tomato genotypes
 varying in fruit size from 20 to 287 g (fresh mass) and
 investigated its relation with typical hydraulic and anatomical traits
 under well-watered and water deficit conditions. We found that
 larger fruits had lower vein length density, accompanied by more
 xylem vessels within a vascular bundle and lower water uptake capacity per
 fresh mass. Vein length density was positively
 correlated with total soluble solids while negatively correlated with
 mesocarp cell size. This study highlights the association between
 hydraulic function of the fruit peripheral vascular network
 and fruit size, likely opening up a new research avenue for
 understanding fruit evolution, aiding in selection for drought-tolerant
 genotypes, and encouraging integration of fruit venation patterns into
 research.
description: # Vascular network in the pericarp of tomato fruit and implications for
 fruit size, quality, and drought response Dataset DOI:
 [10.5061/dryad.hqbzkh1wh](https://doi.org/10.5061/dryad.hqbzkh1wh) ##
 Description of the data and file structure We have submitted our raw data
 (RAW DATA.xlsx). The data was collected from the experiment which was
 performed in a solar greenhouse under natural daylight at Shiyanghe
 Experimental Station of China Agricultural University in Wuwei City, Gansu
 Province, Northwest China (N 37°52', E 10°50', and altitude
 1,581 m). This work was supported by research grants from the National
 Natural Science Foundation of China (51909263 and 52239002) and the
 National Key Research and Development Program of China
 (2022YFD1900500). Hao Li appreciated the funding from the China
 Scholarship Council (CSC202206350001) for supporting his study at INRAE in
 France. **Environmental/experimental conditions:**  Tomato seeds were
 germinated in a local seedling company, and seedlings were transplanted to
 pots (height 40.5 cm, bottom diameter 30.5 cm, and top diameter 38 cm)
 when 3-4 true leaves appeared. Each pot was filled with 18 kg air-dried,
 sieved, and evenly mixed sandy loam soil collected from local soil at a
 depth of 0-20 cm, with a mean dry bulk density of 1.41 g cm^-3^  and a
 soil field capacity of 28% m^3^ m^-3^. Small stones and fine sand
 were spread at the bottom of the pot as a filtration layer, and the soil
 surface was covered with vermiculite to reduce the scouring effect of
 irrigation on the surface soil. The date of anthesis of each flower was
 recorded, and the flowers on the first four tomato trusses on all tomato
 plants were manually fertilized, while the other flowers on trusses were
 left unfertilized. During the hand pollination process, each flower was
 gently shaken so that the anthers released their pollen onto the stigma
 within the same flower. In addition, a solution of p-chlorophenoxy acetic
 acid (10 mg kg^-1^) was applied to the flower, which was beneficial for
 pollination, fruit set, and fruit development. Fruit samples were taken
 from the artificially pollinated fruits in the first four trusses. ###
 Files and variables #### File: RAW_DATA.xlsx **Description:** In the
 RAW_DATA.xlsx file, there are 8 sheets, namely Table 1 and Fig
 2A-D; Fig2E-F, Fig6 and Fig. S4;  F4A-F, F6, F7 and Fig. S5; Fig4G-J and
 Fig. S6A-D; Fig4K-L Fig7 and Fig. S6E-F; Fig. S3; Fig. S5 and Fig.
 S7; Fig. 5 and Fig. S11. These correspond to the figures in the body of
 the text. In each sheet, the terms 'Genotypes' and
 'Treatments' have identical meanings.
 **Genotypes:** Ten genotypes of tomato (*Solanum lycopersicum*) were used,
 which were Central Asia#1 (FCA), Barbosa (FBA), Choutaro#2 (FCH),
 Shifong#206 (PSF), Fongfan#64 (PFF), Fongza#33 (PFZ), Red Roman (PRR),
 Pink Angel (CPA), Fongbaoshi (CFB), Wanxi (CWX); **Treatments:** Two soil
 moisture treatments well-watered (control) and water deficit (water
 deficit), were applied to the tomato plants. Soil field capacity was
 maintained between 75-79% in the control plants. All plants were watered
 when soil field capacity of the plants under well-watered conditions
 approached 75%. The amount of water applied was reduced by 50% in the
 water deficit treatment, compared to the control at each watering. The
 variables in each sheet are defined as follows: **Table 1 and Fig 2A-D:**
 Fruit fresh mass (g): The mass of the whole mature tomato fruits at the
 red firm stage (g); Pericarp dry matter mass (g): Dry matter mass of
 pericarp of mature tomato fruits at the red firm stage (g); Pericarp water
 mass (g): Water mass of pericarp of mature tomato fruits at the red firm
 stage (g); Placenta dry matter mass (g): Dry matter mass of placenta of
 mature tomato fruits at the red firm stage (g); Placenta water mass (g):
 Water mass of placenta of mature tomato fruits at the red firm stage (g).
 **Fig2E-F, Fig6 and Fig. S4:** Fruit osmotic potential (MPa) :  Osmotic
 potential of pericarp samples from mature tomato fruits at the red firm
 stage (MPa) ; Total soluble solids (Brix): Total soluble solids of
 pericarp samples from mature tomato fruits at the red firm stage (Brix) .
 **F4A-F, F6, F7 and Fig. S5:** Total vein length (mm): Vein length,
 including primary and secondary vascular bundles, of tomato pericarp at
 the red firm stage (mm); Total primary vein length (mm): Vein length of
 primary vascular bundles of tomato pericarp at the red firm stage (mm);
 Pericarp area (mm^2^): The projected area of the fruit pericarp at the red
 firm stage (mm^2^); VLA on a per area basis (mm mm^-1^): Vein length
 density on a per fruit pericarp area basis (mm mm^-1^); Primary VLA on a
 per area basis (mm mm^-1^): Primary vein length density on a per
 fruit pericarp area basis (mm mm^-1^). **Fig4G-J and Fig. S6A-D:**
 Vascular bundle: Vascular bundle of tomato pericarp, including primary and
 secondary. The primary vascular bundles were defined as those running from
 the pedicel end to the stylar end in a carpel and the remaining vascular
 bundles were collectively grouped into secondary vascular bundles. Xylem
 vessel number: The number of the xylem vessel in the primary and secondary
 vascular bundle; vessel diameter (um): The diameter (um) of the xylem
 vessel in the primary and secondary vascular bundle; Theoretical hydraulic
 conductivity (kg m MPa^-1^ s^-1^): Theoretical hydraulic conductivity (kg
 m MPa^-1^ s^-1^) of the xylem vessel in the primary and secondary vascular
 bundle was calculated according to the Hagen-Poiseuille equation.
 **Fig4K-L Fig7 and Fig. S6E-F:** Mean cross-section cell size (mm^2^): 
 Mean cell size (mm^2^)  in fruit pericarp was determined by dividing the
 area of the rectangle by the number of cells contained therein; Cell layer
 number:  The number of cell layers on the exocarp included in the
 rectangular area was counted. A rectangle &gt; 1.5mm in width and pericarp
 thickness×80% in height, was drawn between the outer and the inner
 epidermis excluding the vascular bundles. The cells with 'null'
 represent the data is not available because the the sample images were
 partial damage. **Fig. S3:**  Stem water potentials at pre-dawn (MPa):
 Stem water potentials at pre-dawn (4:00-6:00 am) were determined on a
 typical sunny day in the middle of an irrigation cycle; Stem water
 potentials at midday (MPa): Stem water potentials at midday (12:00-14:00
 pm) were determined on a typical sunny day in the middle of an irrigation
 cycle. **Fig. S5 and Fig. S7**: Pericarp thickness at middle (mm):
 Pericarp thickness (mm) of the fruit at middle positions; Pericarp
 thickness at  proximal (mm): Pericarp thickness (mm) of the fruit at
 proximal positions; Pericarp thickness  at distal (mm) : Pericarp
 thickness (mm) of the fruit at distal  positions; Pericarp volume (cm^3^):
 Fruit pericarp volume was calculated by subtracting the volume of the
 space inside the pericarp from the volume of the whole fruit. The cells
 with 'null' represent the data is not available because the the
 sample images were partial damage. **Fig. 5 and Fig. S11**: Water uptake
 (g fruit^-1^): Accumulative water uptake on a per fruit basis  (g
 fruit^-1^) at different time (2h, 4h, 6h, 7h, 9h, 11h, 13h… ). ##
 Code/software no ## Access information Other publicly accessible locations
 of the data: * no Data was derived from the following sources: * no