Australian Journal of Experimental Agriculture, 199 1,31,407-13
Evaluation of F1 hybrids incorporating the rin
(ripening inhibitor) gene to improve the storage life
and fruit quality of fresh market tomatoes
(Lycopersicon esculentum Mill.)
V: Q. NguyenA, W. J. AshcroftB, K. H. JonesC a n d W. B. McGlassonDE
* NSW Agriculture & Fisheries, Horticultural Research & Advisory Station, P.O. Box 581, Gosford, N.S.W. 2250, Australia.
Department of Agriculture & Rural Affairs, Institute for Irrigation and Salinity Research, Private Bag, Tatura, Vic. 3616, Australia.
c NSW Agriculture & Fisheries, Horticultural Research & Advisory Station, P.O. Box 1087, Griffith, N.S.W. 2680, Australia.
D CSIRO Division of Horticulture, North Ryde, N.S.W. 2113, Australia.
E Present address: Faculty of Horticulture, University of Western Sydney, Hawkesbury, Richmond, N.S.W. 2753, Australia.
B
Summary. Four new F1 hybrids which incorporate the
ripening inhibitor (rin) tomato mutation were compared
with standard commercial tomato cultivars, including
Flora-Dade, for the fresh market in New South Wales
and Victoria.
The rin gene, in the heterozygous condition, delayed
the start of ripening by a few days, increased the
interval between breaker and full ripe from 5 to 7 days
compared with commercial cultivars, and increased the
storage life of ripe fruits from 28 to 40 days at 20°C.
There were no significant differences between the level
of red colour developed by the rin hybrids and reference
tomatoes; however, the rin hybrid fruits took 4 days
longer to reach full red colour. The fruits of rin hybrid
were as firm as the reference tomatoes when picked at
breaker and stored at 20°C for 6 days. However, rin
hybrid fruits were significantly (P<0.05) firmer than
those of reference tomatoes when harvested at a full
ripe stage.
Of the 4 rin hybrids tested, HRAS 87-70, which
showed the most promise, was released in February
1990 as 'Red Centre'.
Introduction
In 1986-87, about 266000 t of fresh market tomatoes,
valued at $A115 million, were produced in Australia
(Newell 1989). Of those, about 2200 t were sent to overseas
markets, particularly Hong Kong (Chen and Zee 1987),
Singapore, New Caledonia and New Zealand (Newel1
1989). Tomatoes taste better when fruits ripen on the plant
(Bisogni et al. 1976; Hobson 1988), and Australian
consumers frequently complain that fresh market tomatoes
lack flavour, especially when picked at the green-mature to
early colour stages (McGlasson 1989) to ensure sufficient
storage life for transport and retailing during winter.
Although the present commercial cultivars normally keep
well, their storage life is barely long enough to enable
picking at an early colour stage for distant markets. The
best estimate of storage life of current commercial cultivars
such as Flora-Dade, when harvested at an early colour stage
(stage 2, breaker) (McGlasson and Beattie 1985) and stored
under refrigeration at 13OC, is about 28 days. For export,
some tomatoes are sent by air but cost is high and space is
limited.
Studies in the U.K. (Hobson 1967), Israel (Mmahi et al.
1975: Frenkel and Garrison 1976: Koueliovitch et al.
1979), the U.S.A. (Tigchelaar et al. 19%) and Australia
(McGlasson et al. 1983) have shown that the fruits of F,
hybrids heterozygous for the nor (non-ripening), rin
(ripening inhibitor), Nr (never ripe) and gr (green ripe)
genes ripen later and may have a shelf life several times
longer than fruits of normal inbred lines. Of those, fruit
of rin hybrids showed less inhibition of ripening than
fruit of nor, Nr and gr hybrids but did not suffer from
serious colour deficiencies when fully ripe
(Kopeliovitch et al. 1979).
Since rin hybrid fruits ripen and soften more slowly
than present commercial cultivars, it may be possible to
harvest the fruit at a more advanced colour stage without
loss of quality. Commercial cultivars should have a long
storage life, good eating quality and high yields of largeand medium-sized fruit, which are smooth, nearly round,
firm and red when ripe. This paper reports the final
results (1987-88 and 1988-89 seasons) of a breeding
program from 1985 to 1989, in which 4 F1 hybrids
heterozygous for the rin gene were screened, selected
and evaluated against commercial cultivars. Trellis and
.
408
V. Q. Nguyen et al.
on-ground cropping systems were included to enable
comparison of the performance of the new hybrids under
different climatic and cultural conditions.
Materials and methods
The experiments using the trellis culture system were
conducted on an alluvial, sandy clay loam at the
Hawkesbury Agricultural College (now the University of
Western Sydney, Hawkesbury) at Richmond, in the
Sydney metropolitan area, and at the Somersby research
farm of the Gosford Horticultural Research and
Advisory Station (yellow earth with sandy loam) on the
New South Wales central coast. The rin hybrids and
commercial cultivars were evaluated using the onground system (Sumeghy et al. 1983; Nguyen et al.
1988) at research farms at the Griffith Horticultural
Research and Advisory Station (Banna sand) in the
Murmmbidgee irrigation area and the Tatura Institute for
Irrigation and Salinity Research (Shepparton fine, sandy
loam) in the Goulburn Valley, Victoria.
Production of rin hybrids
In winter 1984, a rin mutant breeding line HRAS 81-85
was used as the male parent in crosses with a large
number of inbred cultivars made in a glasshouse at the
Hawkesbury Agricultural Research Unit, Richmond.
HRAS 81-85 is a code name for line 795054-1. Line
795054-1 is a fixed line, homozygous rin mutant bred at
the University of Florida, U.S.A. (J. W. Scott pers.
comm.). The screening of new rin hybrids began at the
Hawkesbury Agricultural College from 1984 to 1986
and then continued at Somersby. In the first 3 years
(1984-87), 10 plants of each new hybrid were screened
in unreplicated plots and selected on the basis of plant
height, total fruit yield, fruit firmness and total soluble
solids (TSS). In 1987-88, the 11 most promising rin
hybrids were evaluated at Somersby and 3 rin hybrids
were screened at the Tatura Institute for Irrigation and
Salinity Research. In 1988-89 the best 4 rin hybrids
were selected for the final test at Somersby. At Griffith
and Tatura, 1 rin hybrid, HRAS 87-70, showing the
greatest promise for both trellised and ground
production, was chosen for testing in 1988-89. At each
site, the entries were compared with the current
commercial standard cultivar, Flora-Dade.
Field techniques
Trellises. The trellis cropping system was used for
the Somersby experiments. The plants were transplanted
into raised beds in rows 1.7 m apart and with 0.5 m
between plants. Irrigation was by T-tape (emitters at
0.4 m intervals). Fertiliser was applied as a basal
dressing at the rate (kglha) of 60 N, 90 P and 60 K.
Three side-dressings of potassium nitrate and a
compound fertiliser (N, P and K at 15.5, 6.3 and 5.3%)
were applied at 2-week intervals from the first fruit
setting, to a total (kg/ha) of 60 N, 19 P and 74 K. Each
planting consisted of 4 randomised plots of 10 plants of
each entry. Fruit were harvested once a week over 8
weeks (1987-88) and 10 weeks (1988-89).
Measurements for firmness, TSS, titratable acidity and
sensory evaluation in 1987-88 were obtained only on
bulk samples of 15 fruit.
On-ground. The on-ground cropping system was
used for the experiments at Tatura (1987-88, 1988-89)
and Griffith (1988-89). The plants were grown on raised
beds in rows 1.5 m apart and with 0.4 m between plants.
Trickle irrigation lines with outlets 0.5 m apart were laid
0.1 m off-centre. Management practices for fertilising,
irrigation and pest control varied with location and were
based on local commercial management practices. Each
entry consisted of 10 plants. The trial at Tatura in
1987-88 consisted of unreplicated observation plots.
However, both trials at Tatura and Griffith in 1988-89
were replicated 3 times in a randomised complete block
design. Fruit were harvested 3 times at 2-week intervals
at Tatura and once a week for 4 weeks at Griffith.
Yield
Fruit were harvested at breaker, and fruit larger than
45 mm in diameter were divided into marketable and
unmarketable grades (Anon. 1977). Marketable fruit
were separated into standard market size-grades by
screening on the basis of fruit diameter (Somersby)
and/or fruit weight (Griffith). At Tatura, however, total
yield was measured and fruit size distribution was based
on fruit diameter.
Fruit quality assessment
Fruit sampling. During the peak harvest at each site,
15 fruit at colour stage 2 were taken from each replicate
of each experiment and stored at 200C for 6 days. The
firmness of the fruit was measured using a nondestructive compression meter (Sumeghy et al. 1983). A
longitudinal segment from each fruit of each replicate
was bulked, and the bulk sample from each replicate was
sealed in a polyethylene bag and frozen at -20°C for
later analysis of composition.
Fruit composition. The frozen samples of fruit were
thawed and macerated in a kitchen blender for about
3 min. The liquid was allowed to separate for a few
minutes so that juice, free of particulate matter, was
available for the determination of TSS (Atago N10 hand
refractometer) and titratable acidity (calculated from the
volume of 0.1 mol NaOHL required to raise the pH of
10 mL juice to 8.1).
Fruit colour, storage life and firmness offield-ripenedfiuit
Studies on fruit colour development, storage life and
firmness of field-ripened fruit were made only on the fruit
of Somersby trials. Fruit were harvested at colour stage 2,
dipped in calcium hypochlorite solution at pH 7.4
(1000 pg/g active chlorine) and stored at 20°C and
80-90% relative humidity at the Gosford Postharvest
IF1 rin hybrids and tomato quality
Laboratory. Four replicates of 5 fruit were used in these
experiments. Fruit colour and firmness were measured at
2-3 day intervals until the fruit started to rot. Surface
colour was determined with a spectrophotometer (Varian
Techtron UV-VIS model 635) standardised at 720 nm
wavelength and reading at 675 nm (b) and 540 nm (a)
wavelengths. Storage life was estimated on the basis of
the number of days required for two-thirds of a set of fruit
harvested at colour stage 2 to soften to a compression
value of 2.15 mm, which has been regarded as the
minimum acceptable firmness (Nguyen et al. 1988).
To determine the firmness of fruit allowed to ripen on
the plants, 5 fruit at colour stage 2 were tagged in each
replicate in the trellis planting. These fruit were picked
6 days later and firmness was measured immediately.
Mean temperatures in the field during the 6 days were
271170C (daylnight), with maximum and minimum
readings of 33 and 140C. Estimates of fruit colour, storage
life and firmness of fruit ripened on the plants, which
were made in 1988-89, were limited to Flora-Dade,
rin mutant HRAS 81-85 and F1 rin hybrid line HRAS
87-70, since previous experiments (1987-88) showed that
409
there were no significant differences in these attributes
among the series of F1 rin hybrids bred in this program.
Results
1987-88 experiments
A comparison of marketable yield at Somersby and
total yield at Tatura is shown in Table 1. At Somersby,
Flora-Dade had the highest yield but it was not
significantly (P>0.05) greater than line HRAS 87-70. At
Tatura, HRAS 87-68 and 87-70 both had much higher
yields than Flora-Dade (data not analysed). These 2
hybrids also produced a high proportion of the preferred
large- and medium-sized fruits, 83 and 86%,
respectively, compared with 72% for Flora-Dade (data
not presented). The firmness of all rin hybrids was
similar to or better than Flora-Dade, particularly at
Tatura. As expected, fruit of HRAS 81-85, the
homozygous rin line, were very firm. These fruit
remained firm for a very long time, increasing to only
1.13 mm compression by day 40 at 20°C. The storage
life of rin hybrids varied from 30 to 40 days based on the
time taken for fruit to become unacceptably soft. The
Table 1. Yield, firmness, chemical composition and storage life of tomatoes at Somersby, N.S.W., and
Tatura, Vic., in 1987-88
Measurements of firmness, total soluble solids (TSS), titratable acidity (TA) and storage life were obtained only
on a bulk sample of 15 fruits
Within columns for each planting, values followed by a common letter are not significantly different at P = 0.05
Entry
Marketable yield
Firmness
(compression, mm)
Trellises, Somersby*
1.27
0.72
Flora-Dade
KRAS 81-85 (rin)
rin Hybrid
HRAS 87-70
HRAS 85-1
HRAS 87-68
HRAS 88-17-8
HRAS 88-14-8
HRAS 88-15-8
HRAS 88-14-7
HRAS 88-16-7
HRAS 88-16-8
HRAS 88-15-7
HRAS 88-17-7
Flora-Dade
rin Hybrid
HRAS 87-68
HRAS 87-70
HRAS 85-1
TSS
(%)
TA
(m.e./100 rnL)
Storage
life (days)
3.0
4.6
6.1
3.6
28
>40
78.6C
125.6~
106.3~
71.1c
A Somersby trial: sowing, 8 Oct. 1987; transplanting, 6 Nov. 1987; harvesting, 11 Feb.-31 Mar. 1988 (8 picks).
Tatura trial: sowing, 25 Sept. 1987; transplanting,26 Oct. 1987; harvesting, 15 Feb.-15 Mar. 1988 (3 picks).
Total yield (tlha) from unreplicated observation trial.
V. Q.Nguyen et al.
410
Table 2. Characteristics of the test cultivars in 1988-89
experiments
Disease resistance: V, Verticillium dahlia strain 1;
F1, F2, Fusariurn oxysporum f. sp. lycopersici races 1 and 2;
N, nematodes; Tm, tobacco mosaic virus
EnW
Flora-Dade
Summit
Grosse Lisse
HRAS 81-85 (rin)
rin Hybrid
HRAS 85-1
HRAS 87-68
HRAS 87-70
HRAS 88-17-8
Flora-Dade
Summit
Goulburn
Arcadia
rin Hybrid
HRAS 87-70
Source
Disease
resistance
Trellises, Somersby
V, F1, F2
U.S.A.
V, F1, F2
U.S.A.
Aust.
Unknown
HRAsA Unknown
Fruit
shape
Pedicel
Entry
Globe
Globe
Globe
Globe
Jointless
Jointless
Jointed
Jointless
V, F1, N, Tm Oblate
HRAS
V, F1, F2
Globe
HRAS
V, F1,F2
Globe
HRAS
V, F1, F2, N
Globe
HRAS
On-ground, Griffith and Tatura
V, F1, F2
Globe
U.S.A.
V, F1, F2
Globe
U.S.A.
D A R A ~ V, F~
Globe
V, F1
Globe
DARA
Jointed
Jointless
Jointless
Jointless
HRAS
V, F1, F2
Globe
Table 3. Yield (tlha), firmness (compression, mm) and chemical
composition of tomatoes at Somersby and Griffith, N.S.W., and
Tatura, Vic., in 1988-89
TSS, total soluble solids; TA, titratable acidity
Within columns for each planting, values followed by a common letter
are not significantly different at P = 0.05
Jointless
Jointless
Jointed
Jointed
Jointless
A Gosford Horticultural Research and Advisory Station, N.S.W.
B Department of Agriculture and Rural Affairs, Mc.
softer fruit of Flora-Dade and HRAS 88-14-8 had shorter
storage lives (Table 1). TSS in the rin hybrid fruit ranged
from 4.0 to 4.9%, compared with 3.0% for Flora-Dade at
Somersby and 4.9% at Tatura. Titratable acidity ranged
from 5.4 to 6.8 m.e./100 mL for all entries at Somersby
but was lower at Tatura.
Based on yield, fruit firmness, chemical composition
and storage life, rin hybrids HRAS 87-70, 85-1, 87-68
and 88-17-8 were selected for further investigation
(Nguyen and McGlasson 1989). They were planted for
comparison with a number of reference cultivars for the
final trials in 1988-89 (Table 2).
1988-89 experiments
The plantings in 1988-89 at Somersby gave very
good yields (Table 3). HRAS 85-1 produced the highest
marketable yield, followed by Flora-Dade, Summit,
HRAS 87-67 and Grosse Lisse. HRAS 81-85 produced
the firmest fruit and Grosse Lisse the softest. There were
no significant (b0.05) differences in firmness among
the other entries. In the on-ground plantings at Griffith
and Tatura, HRAS 87-70 yielded 58 and 80 tlha, not
significantly different from the yields of Flora-Dade or
local cultivars Goulburn and Arcadia (Table 3). The
firmness of all entries at Griffith was similar to FloraDade, but at Tatura, Goulbum and HRAS 87-70 were
significantly firmer than the others. TSS values of most
entries were in the range 4.247%. However, rin hybrid
Flora-Dade
Summit
Grosse Lisse
HRAS 81-85
HRAS 85-1
HRAS 87-68
HRAS 87-70
HRAS 88-17-8
Marketable
yield (t/ha)
Firmness
(mm)
TSS
(%)
TA
(m.e./100 mL)
Trellises, somersbyA
88.7ab
0.96ii
4.51mno
Flora-Dade
Summit
Goulburn
Arcadia
HRAS 87-70
Flora-Dade
Summit
Goulburn
Arcadia
HRAS 87-70
* Somersby trial: sowing, 30 Sept. 1988; transplanting,9 Nov. 1988;
harvesting, 9 Feb.-12 Apr. 1989 (10 picks).
B Griffith trial: sowing, 14 Nov. 1988; transplanting, 12 Dec. 1988;
harvesting, 3 Mar.-17 Mar. 1989 (4 picks).
c Tatura trial: sowing, 5 Oct. 1988; transplanting, 22 Nov. 1988;
harvesting, 15 Feb.-15 Mar. 1989 (3 picks). Total yield was measured.
HRAS 88-17-8 at Somersby, together with Summit and
HRAS 87-70 at Griffith, had values of 5.0-5.5%.
The distribution of fruit size at Somersby showed that
Grosse Lisse, HRAS 87-68 and Flora-Dade produced
high proportions of small-sized fruit, while HRAS 85-1
had the highest percentage of large fruit (Fig. 1). Summit
and HRAS 81-85, 88-17-8 and 87-70 had an ideal size
range, comprising more than 85% medium- and largesized fruit (Beattie et al. 1983). At Griffith and Tatura,
Arcadia produced excessively high percentages of smallsized fruit. Flora-Dade, Summit and HRAS 87-70
produced more than 70% medium- and large-sized fruit.
The changes in surface colour of ripening fruit of both
Flora-Dade and rin hybrid HRAS 87-70 fitted a curve:
where C was the maximum level of colour and
A exp(-Bday) was the increment of colour per day
(Fig. 2). The daily increment of surface colour of rin
41 1
F1 rin hybrids and tomato quality
hybrid HRAS 87-70 [3.03exp(-0.3166 days)] was
slower than Flora-Dade [3.17 exp(-0.44 17 days)]. The
interval between colour stage 2 and full ripe (colour
stage 6) was about 7 days for rin hybrid fruit, compared
with 5 days for Flora-Dade. HRAS 87-70 reached
maximum red colour on day 17, compared with day 13
for Flora-Dade. The maximum red colour of
HRAS 87-70 (b/a = 0.23) was similar to that of
Flora-Dade. The surface colour of the rin mutant
HRAS 81-85 was not red but yellow, so its curve fitted
the model y = A exp(-Bday).
Estimates of storage life based on measurements of
4
Green 2 . 5 L
Days from breaker
Fig. 2. Colour development of fruit surface of tomatoes at Somersby
in 1988-89. Flora-Dade (e), Flrin HRAS 87-70 (A) and rin mutant
HRAS 81-85 (a). The scale of the horizontal axis has been changed
after day 10 because there was no significant difference in colour
development.
FD
S
H1
G
A
Entry
Fig. 1. Fruit size distribution of tomatoes at (a) Somersby (trellis),
(b) Griffith (on-ground) and (c) Tatura (on-ground) in 1988-89. The
solid, open and shaded areas of the bars represent the proportion of
large-, medium- and small-sized fruits, respectively. FD, Flora-Dade;
S, Summit; GL, Grosse Lisse; G , Goulburn; A, Arcadia;
HI, HRAS 87-70; H2,HRAS 81-85; H3, HRAS 85-1; H4, HRAS 87-68;
H5, HRAS 88-17-8.
Days from breaker
Fig. 3. The rate of softening of fruit of tomatoes at Somersby in
1988-89. Flora-Dade (a), F1 rin HRAS 87-70 (A) and rin mutant
HRAS 81-85 (m). Limiting firmness (horizontal broken line) was at
compression value of 2.15 mm, which has been regarded
as the
minimum acceptable firmness.
412
V. Q. Nguyen et al.
the rate of softening of tomatoes (Fig. 3) showed that a
quadratic model gave the best fit to the data for FloraDade and HRAS 87-70. HRAS 87-70 softened
(0.06 unitslday, accounting for 97% of variation) more
slowly than Flora-Dade (0.08 unitslday, accounting for
97% of variation). HRAS 87-70 also reached the
limiting firmness value (2.15 mm compression) on day
40, about 10 days later than Flora-Dade. A straight line
best fitted the data for rin mutant HRAS 81-85 and
accounted for 74% of the variation.
to current commercial cultivars. The high yield of
HRAS 85-1 at Somersby in 1988-89 was due mainly to
the high proportion of large-sized fruit. However, this
hybrid also produced a high proportion of cracking fruit
(25% total yield, data not presented), and its jointed
pedicel made it difficult to pick; it was, therefore,
undesirable. HRAS 87-68 produced good, marketable
yields and very attractive globe-shaped fruit. However,
this hybrid had a high proportion of small fruit.
HRAS 87-68 should be further investigated in dry, hot
weather in an on-ground cropping system, since this
hybrid performed well in the inland irrigation areas.
HRAS 88-17-8 was the only rin hybrid that had
consistently high TSS. However, its marketable yield
was relatively low and the plants are highly susceptible
to bacterial speck (Pseudomonas tomato), which is one
of the common diseases of the N.S.W. coastal area. Of
the 4 rin hybrids tested, HRAS 87-70 was the most
promising, with a high marketable yield of medium to
large fruit of attractive shape and appearance. It is a
semi-determinate type with a jointless pedicel and
resistance to Fusarium oxysporum f. sp. lycopersici races
1 and 2 and Verticillium dahlia strain 1. Informal
evaluation of sensory quality showed that rin hybrids
were at least as acceptable as standard commercial
cultivars (data not presented).
The characteristics of retention of firmness and a
longer storage life of rin hybrid fruit, whether harvested at
an early colour stage or allowed to ripen to a more
advanced stage on the plant before harvesting, should be
advantageous to the tomato industry. Overall it may be
expected that the sensory quality of commercially grown
tomatoes would be improved if all fruit were harvested at
a more advanced stage than at present. The longer storage
life of rin hybrids also facilitates sea freight to markets in
South East Asia.
Discussion
Our experiments c o n f i i previous reports (Murahi et al.
1975; Tigchelaar et al. 1978; Kopeliovitch et al. 1979)
that the presence of the rin gene in F1 hybrids delays the
ripening of fruit but allows satisfactory red colour
development (Fig. 2). The firmness of fruit of rin hybrids
that we examined was similar to that of current
commercial cultivars Flora-Dade and Summit (Tables 1
and 3). However, in the dry and hot weather conditions
that prevail inland at Tatura and Griffith, fruit of rin
hybrids were firmer than Flora-Dade or Summit and,
therefore, more desirable. The slower rates of softening
and consequent, longer storage life of rin hybrids enable
them to be harvested at either an early colour stage
(breaker) or even a more advanced colour without the risk
of fruit rapidly becoming too soft (Table 4). Bisogni et al.
(1976) reported that field-ripened tomatoes were judged
as better in overall quality and flavour than room-ripened
tomatoes. Hobson (1988) also indicated that tomatoes
taste better if they ripen fully on the plant. In Australia,
the retention of firmness and storage life of tomatoes is
important commercially because of the long distance from
producers to both domestic and overseas markets. A sea
freight service from Brisbane takes 9 days to Singapore
and 11 to Hong Kong. The commercial storage life of the
fruit for shipment must include the time from harvest to at
least a week after arrival at its overseas destination, to Availability of rin hybrid
permit orderly marketing while the fruit is in first-class
The rin hybrid HRAS 87-70 was officially released
condition. Tomatoes that are soft and have a shorter by NSW Agriculture & Fisheries in February 1990 under
storage life are less able to withstand these harvesting, the commercial name of 'Red Centre'. Small samples of
packaging and transport processes.
seed for research purposes may be obtained from the
The marketable yield of some rin hybrids was similar senior author.
Table 4. Firmness (compression, mm) of fruit of tomatoes picked
at breaker (colour stage 2) or when ripe (full colour)
Values followed by a common letter are not significantly
different at P = 0.05
Fruit picked at breaker,
stored 6 days at 20°C
Fruit picked when ripe
in field
0.96a
0.64b
0.98a
1.08~
0.70b
0.95a
Acknowledgments
We wish to thank Dr J. W. Scott, University of Florida
IFAS, U.S.A., for supply of homozygous rin line
(795054-1); Mr D. Smith, Mr T. Platt and
Mr K. Alagappan for competent and willing field
assistance; and Ms K. Woods for laboratory assistance.
Statistical analysis was provided by Ms L. Spohr,
Technical Officer (Scientific), and Mr B. Coote, Senior
Biometrician, Division of Rural and Resource
Economics, NSW Agriculture & Fisheries.
F, rin hybrids and tomato quality
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Received 18 July 1990, accepted 18 December 1990