conference schedule and program with abstracts - Horticulture ...

P-14
Morphological characteristics of cracking susceptible Korean table grapes, ‘Heukgoosul’
and ‘Tamnara’
I.-C. Son, S.-I. Oh, D. Kim*
Department of Horticultural Science, Chungbuk National University, Cheongju, Korea
*Corresponding author: dkpomo@chungbuk.ac.kr
Though ‘Heukgoosul’ (‘Golden Muscat’ x ‘Pione’) and ‘Tamnara’ (‘Campbell Early’ x ‘Himrod
Seedless’) are very promising new table cultivars bred in Korea, they have serious problems with
berry cracking. The growth characteristics and morphology of berries was investigated to
determine the factors affecting berry cracking among ‘Heukgoosul’, ‘Tamnara’, and cracking
resistant ‘Hongisul’ and the two major cultivars, ‘Campbell-Early’ and ‘Kyoho’. Cluster weight
was 457.3 g in ‘Heukgoosul’, 331.2 g in ‘Tamnara’ 321.8 g in ‘Hongisul’, 341.0 g in ‘Campbell-
Early’, and 506.1 g in ‘Kyoho’. Berry weight was 11.19, 7.57, 5.01, 5.61, and 11.30 g
respectively. The firmness of the pericarp, which influences berry cracking, was highest at 1.62
kg·Ø5mm -1 in ‘Hongisul’ compared with 1.39, and 1.38 kg·Ø5mm -1 of cracking susceptible
‘Heukgoosul’ and ‘Tamnara’ grapes. The berry splitting rate under critical turgor pressure was
over 70% in ‘Heukgoosul’, ‘Tamnara’, and ‘Kyoho’ in order of ‘Hongisul’ < ‘Campbell Early’ <
‘Kyoho’ < ‘Heukgoosul’ < ‘Tamnara’. Critical turgor pressure was highest of 13.2 atm in
‘Campbell Early’ and was lowest of 5.7 atm in ‘Tamnara’ grape. The length of the fruit stalk and
cap stem, which influences the denseness of berries in a cluster, were shortest at 159.5 and 6.25
mm in cracking susceptible ‘Heukguseul’. The breakdown of the stylar scar observed using SEM
was seen in ‘Heukgoosul’, ‘Tamnara’, and ‘Kyoho’. Those cracking susceptible three cultivars
also had irregular arrangement with larger cells in the transverse sectional structure of pericarp.
As a result of morphological observation, berry cracking in the ‘Heukgoosul’ grape was
influenced by the higher berry density in a cluster with shorter length of fruit stalks and cap
stems and in ‘Tamnara’ was associated with structural weakness of pericarp with lowest berry
firmness and critical turgor pressure.
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