hUNGARiAN AGRicUltURAl RESEARch

around the peduncle. This
group contains also the
genotypes which raise the
flower buds on spurs so the
amount of the destroyed shoots
is imperceptible (functional
resistance).
2 Semi sensitive: the amount of
the destroyed flowers is less
than 20% of the total fruit set.
Most of the hybrids and
cultivars of the experimental
orchard belong to this group.
3 Sensitive: more than 20% of
the flowers are destroyed every
year. This level of symptoms
appears even if the blossoming
period is dry.
Table 1. Groups of Monilia resistance / susceptibility among different
apricot genotypes
(0) (1) (2) (3)
Totally resistance Tolerant Semi sensitive Sensitive
Hybrid 1/33
(P. cerasifera x Zard Nikitszkij Ceglédi óriás
P. armeniaca)
P. salicina
Methley
Results of the evaluation are
shown in Table 1 and Figure 1.
The next step of the study was
to determine the genetic background
of resistance and clarifying
the particular mechanisms of
infection. According to the widely
accepted explanation, the infection
process begins when conidia
enters the pistils through the
stigmata. The base of this theory is
rooted in the infection mechanism
of Monilia laxa in sour cherry
where stigmata is completely
destroyed following the penetration
of the pathogen. Accordingly,
we supposed that the key
of the resistance could be in the
pistils or in the secretum.
Observing flowers used in the
crosses carried out as the part of
the apricot breeding work going on
at the department, it was clearly
visible that emasculated and handpollinated
flowers did not show
any symptoms of the Monilia
Pannónia Konzervnij pozdnij Mari de Csanad
P. salicina
considering Magyarkajszi C.235 Harmat Mandulakajszi
Burbank
P. dasycarpa Venusz Konkurencia Goldrich
P. cerasifera 23/22 Gönci magyarkajszi Ceglédi arany Ceglédi bíborkajszi
Harcot
Orange red
Korai zamatos
Ceglédi Piroska
infection. The same opinion was
reported by Bulgarian breeders
(Tzonev and Yamaguchi, 1999).
According to their experiences the
pathogen cannot penetrate the
forced pollinated pistil of
emasculated flowers. Their hypothesis,
explaining this observation,
was that the pollinated pistils
produce protective substances,
which do not allow the infection
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Hybrid 1/33 P.cer.x P. a.
P. salicina 'Methley'
P.salicina 'Burbank'
P. dasycarpa
P.cerasifera (alany)
Zard
Magyar kajszi C.235
Pannónia
Gönci magyarkajszi
Venusz
Nikitszkij
Harmat
Konzervnij pozdnij
Konkurencia
Priuszadebnij rannij
Ceglédi arany
Ceglédi óriás
Mari de Csanad
Effekt
Mandulakajszi
Sungiant
Ceglédi bíborkajszi
Harcot
Baneasa 4/11
Orange red
Korai zamatos
Ceglédi Piroska
Mamaia
Goldrich
Marculesti 18/6
Aurora
Sulmona
Kecs-psar
Figure 1. Ranking of apricot cultivars considering their susceptibility to Monilia laxa
(Szigetcsép, 2004–2009).
The totally resistant cultivars got 0 and the most susceptible cultivars got 3.
18 Hungarian Agricultural Research 2009/3–4