LIBRO-CONGRESO-CITRUS

S18
overfruiting and temperature during growth periods. However, few researchers strongly assumed that it
was caused by scion rooting of ‘Shiranuhi’. So, this study was carried out to find out relationships between
reduction of flower and scion rooting, discriminance methods and the ecology of scion root of ‘Shiranuhi’
in Korea. From our results, when we conducted the DNA analysis, fourteen trees in less bloomed twenty
trees was proved as tree with the scion rooting of ‘Shiranuhi’ and this results was firstly identified in Korea.
Scion root of ‘Shiranuhi’ is tended to be 30% thicker and more vigorous in root growth than in the case
of trifoliate orange. Scion root of ‘Shiranuhi’ was usually observed in a deeply planted tree, and xylem of
‘Shiranuhi’ root indicated more white color than a case of trifoliata orange. ‘Shiranuhi’ tree by scion rooting
was more vigorous but less flowering than trees grafted onto trifoliata orange. When we used F2/R15, F4/
R15 and F5/R15 primer for discriminance of ‘Shiranuhi’ root and trifoliate root, it was possible for us to
discriminate scion roots of ‘Shiranuhi’.
S18P24
Effects of scion root on flowering, fruit quality and yield of ‘Shiranuhi’ mandarin hybrid in plastic
film house in Korea
Moon Y.E 1 , Kang S.B. 2 , Han S.G. 2 , Ko S.W. 2 , Chae C.W. 2 , Lee D.H. 3 and Choi Y.H. 2
1 Agricultural Research Center for Climate Change, National Institute of Horticultural & Herbal Science. R.D.A., Korea, Republic of KR;
2 Citrus Research Station, National Institute of Horticultural & Herbal Science. R.D.A., Korea, Republic of, KR; and 3 Planning Coordination
Division, National Institute of Horticultural & Herbal Science. R.D.A., Korea, Republic of, KR. yimoon@korea.kr
Most of citrus is usually propagated by grafting, and trifoliate orange (Poncirus trifoliata) is widely used as
rootstock of satsuma mandarin since it has dwarf and cold hardness in Korea. ‘Shiranuhi’ mandarin [(Citrus
unshiu × Citrus sinensis) × Citrus reticulata)] mainly needs trifoliate orange (P. trifoliata) as its rootstock.
However, recently, scion root was observed in ‘Shiranuhi’ mandarin trees grafted onto the trifoliate orange.
This study was carried out to find out effects of outbreak of scion root on the fruit quality, flowering and
yield of ‘Shiranuhi’ mandarin in Korea. For the experiment, we selected three farmers who have outbreak
of scion root in their ‘Shiranuhi’ mandarin orchards and surveyed the difference of growth and fruit quality
of ‘Shiranuhi’ mandarin between scion root and rootstock root (trifoliate orange root). In our experiment,
fruit size and weight of scion root of ‘Shiranuhi’ mandarin were smaller than rootstock root. Flesh ratio,
also, showed decrease in scion root of ‘Shiranuhi’. Moreover, flowering was severely decreased in scion
root trees than normal trees. Among survey of 174 ‘Shiranuhi’ mandarin trees, 160 trees were proved to be
scion root, and they had less flowering. Yields of scion root (18.2 kg) decreased 30% compared to rootstock
root (25.9 kg). However, there was no difference on the TSS, acidity and soluble solid-acid ratio between
scion root tree and rootstock root tree. From the results, we concluded that scion root had negative
influence on flowering, fruit size and the yields of ‘Shrinanuhi’ mandarin. Therefore, we suggest finding
a solution to improve flowering, fruit size and fruit quality in ‘Shiranuhi’ mandarin which has outbreak of
scion root.
S18P25
Evaluation on drought resistance traits of citrus rootstock seedlings based on multivariate statistics
Xu X.B., Yang Y.L., Gu Q.Q., Huang C.H. and Qu X.Y.
College of Agronomy,Jiangxi Agricultural University (JAU), P.R.China. xiaobiaoxu@hotmail.com
The drought resistance of nine citrus rootstocks was comprehensively evaluated by determining the
physiological indexes such as relative water content (RWC), the activity of superoxide dismutase (SOD),
catalase (CAT), peroxidase (POD), malondialdehyde (MDA), proline (Pro) and soluble sugar content (SSC)
under artificial controlling water condition by taking the seedlings of nine citrus rootstocks from the local
citrus rootstock resources of Jiangxi province in China, named ‘Sanhu Red’ tangerine (Citrus reticulata),
‘Choupi’ mandarin (Citrus aurantium), ‘Sanhu’ hybrid mandarin (C. reticulata × C. aurantium), ‘Chongyi’ wild
tangerine (C. reticulata), ‘Citrumelo’ (Citrus grandis × Poncirus trifoliata), ‘Trifoliate orange’ (P. trifoliata),
‘Goutou’ orange (C. aurantium), ‘Carrizo’ citrange (Citrus sinensis x P. trifoliata), ‘Sour’ pummelo (C. grandis)
as tested materials through the analysis of principal components and subordinate function values. The results
336 - VALENCIA CONFERENCE CENTER, 18th-23rd NOVEMBER 2012