Open Field Trial of Genetically Modified Parthenocarpic Tomato: Seedlessness and Fruit Quality - Genetic Engineering: Recent Developments in Applications - page 153

The DefH9-RI-iaaM gene version is less efficiently translated and has a weaker
action in producing IAA than DefH9-iaaM, so its use avoids the malformation
of the fruit.
Parthenocarpy represents a useful trait in tomato fruit used for industrial pur-
pose as well. This because parthenocarpic fruits are usually either seedless or con-
tain significantly fewer seeds than non-parthenocarpic varieties. Manipulation of
fruit and seed quality, size and number has been recently included among the
third-generation traits of GM crop plants [11]. In the tomato sauce industry, seed
content is a problem and seeds are removed to obtain sauce of good quality. As far
as fruit quality concerns, parthenocarpy may also improve fruit quality through
increases in the solid soluble content of the fruit [12]. Productivity may also be
increased in some seasons because fruit set and fruit growth are less affected under
environmental conditions adverse for pollination and/or fertilization including
heavy rain, high humidity, hot and dry wind etc.
Processing tomatoes represent the greatest proportion of tomato production
(approximately 113 million tons in 2003 [FAO]). In this paper, data on agro-
nomic performance under open field conditions, technological and biochemical
characteristics of two DefH9-RI-iaaM UC 82 tomato lines are presented and
compared to untransformed control. We also included in our analysis a modern
F1 hybrid tomato, used by the processing industry, to determine the extent to
which biochemical and agronomical parameters vary between different non-GM
tomato lines. The data indicate that the use in the diet of fruits from a new line or
variety introduces much greater changes than the consumption of GM fruits in
comparison to its genetic background.
results
The field trial was performed in 2003. The mean air temperature from the first
week of June until the end of the growing season was unusually very high and
constantly above 25°C and 30°C average and maximum temperature, respectively
(Fig. 1).
Fruit production, as measured by marketable fruit yield, was highest in the
modern F1 tomato hybrid Allflesh (Table 1). The transgenic parthenocarpic lines
Ri4 and Ri5 gave a fruit yield similar to that of the untransformed control UC
82. However, one transgenic parthenocarpic line (Ri4) gave a marketable fruit
production that was not statistically different from all the other three genotypes
(Ri5, UC 82 and Allflesh).