Agriculture Reference
In-Depth Information
the lines that will be used in hybrid development, it is expected that in
process of the gene recombination we will get the most favorable nutritive
contents ratio—especially antioxidants, with a particular emphasis on a
lycopene (ZDRAVKOVIC et al., 2002a, 2003c, 2007).
Late blight, which is caused by the fungus
Phytophtora infestans
,
emerges in tomato crops almost every year and causes considerable eco-
nomic damages. Fungicide control of this parasite is not always effective
and satisfactorily. The solution to this problem is in growing less sensitive
or more resistant tomato varieties or hybrids. The research on tomato re-
sistance to
Phytophtora infestans
is very complex due to high variability
of the pathogen physiological races. Tomato genotypes that are the carriers
of Ph-2 gene of resistance to this parasite were crossed with tomato gen-
otypes with good production characteristics (yield and fruit quality) but
more susceptible to this parasite. Successfully were selected tomato lines
and hybrids that expressed a higher level of resistance than their parents
(MIJATOVIC et al., 2007; ZDRAVKOVIC et al., 2004).
Special projects were launched aimed to the effect of partial drying
part of a root (PRD-treatment) on the growth of tomato plant, photosyn-
thesis, transpiration, water potential, peroxidase activation of the cell wall,
yield, sugar contents, lycopene contents, mineral contents and dry mat-
ter content. This treatment causes the increase of peroxidase activity and
sugar contents in mature tomato fruits (STIKIC et al., 2003).
Tomato fruit fi rmness can be achieved by entering a gene for de-
layed maturation (rin, nor, alc) in the selection of tomatoes. Therefore,
the process stops the ripening on a certain level of maturity. As a result
of interrupted maturation process, satisfactory fruit fi rmness occurs, but
with slightly less sugar, lycopene, beta carotene, etc. (CVIKIC et al.,
2000, ZDRAVKOVIC et al. 2008). Breeding for this trait in this man-
ner are in opposite to the selection requirements for organic production.
Fruits with greater fi rmness can be selected by accumulating fi rmness
traits (ZDRAVKOVIC et al., 2007, 2008). Genotypes with “fruit fi rm-
ness” gene cause long shelf life of mature tomato. (ZDRAVKOVIC et
al., 2003, MARKOVIC et al., 2008).
Investigation of inheritance of yield and yield components in all plant
species and in tomato is very important. Gene expression effects nutri-
tional and quality characteristics and therefore the selection may lead to
