อิทธิพลของตนตอชนิดตางๆตอผลผลิตและคุณภาพมะเขือสม
Influence of Different Rootstocks for Grafting on Yield and Quality of Currant Tomato
(Lycopersicon pimpinellifolium Jusl)
บุญสง เอกพงษ1 และจํานง สมกุล2
Boonsong Ekpong1 and Chamnong Somkul2
บทคัดยอ
ทําการตอยอดมะเขือสมอายุ 20 วันหลังเพาะกลา บนตนตอมะเขือและมะเขือเทศ 5 พันธุที่มีอายุ
แตกตางกัน 3 ระยะ พบวา อัตราการรอดตายมะเขือสมที่ตอบนตนตอมะเขือเทศสูงกวามะเขือสมตอบนตนตอ
มะเขือที่อายุเดียวกันกับมะเขือสม และเมื่อทําการตอยอดบนตนตอที่มีอายุเทากับ 26 และ 29 วัน มะเขือสม
บนตนตอทุกชนิดมีอัตราการรอดตาย 100 % ผลผลิตมะเขือสมบนตนตอใหผลผลิตสูงกวามะเขือสมที่ไมมี
การตอยอดซึ่งสัมพันธกับการเกิดโรค โดยมะเขือสมตอบนตนตอมะเขือยาวสีเขียวใหผลผลิตสูงสุด (5864 กก./ไร)
และมีเปอรเซนตการเกิดโรคนอยสุด (11.1%) จากการทดลองนี้จะเห็นไดวาตนตอมีผลโดยตรงตอผลผลิตและการ
เกิดโรคในการผลิตมะเขือสม
ABSTRACT
A local currant tomato variety at 20 days after sowing was grafted onto 5 cultivars of eggplant
and tomato rootstocks with 3 different ages. The result showed that survival rate of scion on tomato
rootstock was higher than on eggplant rootstock (20 days after sowing of rootstock). At 26 and 29
days after sowing of rootstock, all grafted plants survived 100%. In general, grafted plants produced
higher marketable yield than the control mainly due to less disease prevalence. The highest
marketable yield (5864 kg/rai) was currant tomato grafting on long green fruit eggplant rootstock with
the lowest of disease prevalence (11.1%). The study showed that rootstock influence on yield and
disease prevalence in the use of grafting applications in currant tomato production.
Key Words: Lycopersicon pimpinellifolium Jusl, Ralstonia solanacearum, rootstock, scion.
B Ekpong: boonsong@agri.ubu.ac.th
INTRODUCTION
Lycopersicon originated in the Indies highlands of Ecuador to Chile, although only two have
edible fruit: Lycopersicon esculentum Mill (common tomato) and Lycopersicon pimpinellifolium Jusl
(sometimes cultivated under the name of currant tomato) (Benton Jones, 1999). Currant tomato is
essentially wild, changed slightly by domestication. Vines are long indeterminate with an open growth
habit. Fruits are the size of a berry, 1/2" to 3/4" in diameter. Flavor is intense, sweet and piquant.
Diversification in consumer trends has encouraged cultivation of currant tomatoes in addition to
1
ภาควิชาพืชสวน คณะเกษตรศาสตร มหาวิทยาลับอุบลราชธานี
Department of Horticulture, Ubon Ratchathani University, Ubon Ratchathani. 34190.
2
ศูนยวิจัยพืชผักเขตรอน มหาวิทยาลัยเกษตรศาสตร วิทยาเขตกําแพงแสน จังหวัดนครปฐม 73140
Tropical Vegetable Research Center, Kasetsart University. Kamphaeng Saen Campus, Nakhon Pathom Province. 73140
ordinary table tomatoes (Anonymous. 2000). Especially, in North-East Thailand, currant tomatoes are
suited as ingredient in papaya salad.
Currant tomatoes, like common tomatoes, are difficult to grow during the hot-wet season.
Flooding, waterlogged soils, high temperature and diseases can significantly reduce yields (Black et
al., 2003). Takahashi (1984) reported that 68% of failure cases in Japanese vegetable production
under continuous cropping were caused by soil-borne diseases and nematodes. Since soil
sterilization can never be completed, grafting has become an essential technique for the production
of repeated crops of fruit-bearing vegetables grown in greenhouses. Bacterial wilt of tomato is
caused by the pathogen Ralstonia solanacearum (Hayward, 1991; Gonzalez and Summers, 1994; Ma
and Black, 1999). The bacterium invades and gradually blocks the vascular tissue, the food- and
water-conducting vessels just beneath the epidermis, causing complete destruction of the plant, and
severely limiting tomato yield. Disease resistant rootstocks are commonly used in grafting susceptible
scions (Vuruskan and Yanmaz, 1990; Marsic and Osvald, 2004). This method provides a way for the
continuous production of one crop in one preferred area. Grafting of tomato scions onto bacterial wilt
resistant eggplant rootstocks has been demonstrated at AVRDC to protect the plants from damage
caused by waterlogged soils and bacterial wilt (Black et al., 2003). The influence of grafting on the
yield of currant tomato has not been precisely studied as yet in Thailand. The aim of this research was
to examine the effects of different grafting rootstocks on the success of grafting and yield of currant
tomato.
MATERIALS AND METHODS
The experiment was conducted at the Faculty of Agriculture, Ubon Ratchathani University
(latitude: 15° 07' N, longitude 104° 54' E, 130 m asl), from September 2005 to April 2006. The site is
an upland sandy low humic soil (Roi-et soil series). Soil samples to 10 cm, taken at sowing in
December 2005, was acidic (pH 4.8), and low in organic matter (0.9 %), N (0.05%), P (11.0 ppm) and
K (18 ppm). Prior to cultivation, the site has been planted with tomato for 5 years.
Local currant tomato was used as scion and 3 eggplant varieties [long green (LG), long
purple (LP) and round purple (RP) fruit type], 2 varieties of common tomato tolerant to bacterial wilt
(TM 01 selected at Ubon Ratchathani University and CL-6046BC3F2-51-0-20-5-15-14-1 from AVRDC)
were used as rootstocks. The seeds of scion were sown on November 18, 2005 and the seeds of
rootstock were sown at 0, 6, 9 and 12 days earlier than those of the scion. Pin grafting, as described
by Lee et al. (1998), was applied on December 8, 2005 at four leaf stage (20 days after sowing), thus,
rootstocks had different ages of 20, 26, and 29 days, respectively. The grafting procedure is shown in
Figure 1.
Figure 1 Pin grafting procedure.
The grafted plants were allowed to heal and acclimatise in a plastic tunnel covered with 0.2
mm-thick, UV-resistant polyethylene sheet to maintain moisture that evaporates from a water-filled
floor pan. The chamber was covered with shade nets to reduce light penetration. The over-the-top
shade nets further reduced light penetration and allowed good air circulation to minimize heat buildup. The grafted plants were kept at 28-32ºC and with more than 85% relative humidity for five days of
healing, which promoted the survival rate. Some grafted seedlings wilted initially but became upright
within three days. Six days after grafting, the hardening process was started by peeling away the top
layer of shading nylon net material and the water drained out of the floor pan. The plastic-covered
door of the chamber was opened but the screen door was kept closed to prevent insect infestation.
These conditions were maintained for five days. The grafted plants were moved out the chamber and
placed into a screen-house for ten days for further development and hardening to make them suitable
for transplanting.
Successfully grafted plants (Figure 2) were planted on December 28, 2006 into plots where
bacterial wilt disease was known to occur in a previous crop. Plot size was 1.53 m x 5.0 m. Spacing
was 0.80 m between rows and 0.50 m between plants within the row. The experiment was laid out in
randomized complete block design with six treatments (scion-5 rootstock combinations and nongrafted plants) with three replicates. Normal cultural practices for the experiment were followed for
irrigation, fertilization and pesticide application. Harvest was made once per week when the fruits
reached the color breaking stage. Harvesting began on March 15, 2006 and continued until April 12,
2006.
The following measurements were recorded: (a) hypocotyl diameter at grafting, (b) number of
survival plants at transplanting date, (c) fruit yield (g plant-1), (d) total number of fruits plant-1, (e) fruit
diameter, (f) fruit quality, and (g) percentage of plants infested. Data were analyzed using analysis of
variance to examine treatment effects, and means were separated by Duncan's multiple range tests
at P≤0.05.
Figure 2 Successfully grafted plants.
RESULTS AND DISCUSSION
1. Stem diameter and survival rate of grafted plants
Hypocotyl diameter was measured and the results are presented in Table 1. The highest
diameter was recorded in UB 01 (2.7 mm) while eggplant (LG) had the smallest (1.8 mm). The
greatest difference in rootstock and scion diameters in grafting was that between LG, LP, RP and CT,
at -0.07 mm. The correlation between hypocotyl diameter and survival rate was highly significant
(r= 0.80).This result is similar to the findings of Oda et al., (1993 and 1994) in cucumber showing that
a smaller difference in hypocotyl diameter between rootstocks and scion may increase the chances
for vascular bundles of the scion and rootstock to come into contact and increase survival rate.
Higher survival rate was found in tomato rootstocks compared to that in eggplant at 20 days
of rootstock seedlings (Table 1). Thereafter, survival rate was not significant. This result showed that
there was no incompatibility between the rootstock and scion plants. It showed that hypocotyl
diameter might be the main factor for success in grafting. This confirmed the findings of Black et al.
(2003) that stem diameters of the rootstock and scion must be similar for successful grafting. In this
study, the seedlings of tomato rootstocks grew faster than eggplant rootstocks. For success in pin
grafting, seeds of tomato rootstock and scion should be sown on the same day while those of
eggplant rootstock should be sown 6 days before the scion seeds.
Table 1 Hypocotyl diameter and survival rate of grafted plants.
Rootstock
Diameter of hypocotyl and survival rate (%)
RHD- Survival 29
RHD- Survival
20 RHD- Survival 26
days SHD1 rate
days SHDa
rate days SHDa
rate
LG
0.13c -0.07 87b 0.17d
-0.03 100
0.18d -0.02 100
LP
0.13c -0.07 91b 0.18d
-0.02 100
0.20c
100
RP
0.13c -0.07 91b 0.20c
100
0.23b +0.03 100
TM01
0.19a -0.01 100a 0.25a
+0.05 100
0.27a +0.07 100
CL
0.17b -0.03 100a 0.21bc +0.01 100
0.25a +0.05 100
CT
0.2
0.2
0.2
F-test
**
**
**
**
C.V.(%)
6.7
4.7 4.9
8.2
Means in each column followed by the same letters are not significantly different by DMRT.
** Significant at probability level of 0.01; ns = not significant.
1
RHD: rootstock hypocotyl diameter, SHD: scion hypocotyl diameter
2. Yield and yield components
Plants grafted on different rootstocks differed significantly from non-grafted plants with
respect to number of fruits/plant, yield/plant and marketable yield/rai (Table 2).
Table 2 Effect of different rootstocks on yield, fruit characteristics and disease prevalence in tomato.
Plant
Fruit
Number Weight/ Yield/ Marketable pH TSS
Fruit
plant
yield
Rootstock
diameter
of
(°Brix) infested
(g)
(kg/rai)
(%)
(mm) fruits/plant (g)
LG
19.1
288.8cd
6.5
1649.3b 5864.1a 4.8 3.95
11.1
LP
19.2
228.3bc
7.3
1525.6b 4727.7ab 4.9 3.98
22.2
RP
19.3
306.5d
7.4
1705.2b 4168.1b 4.9 3.97
38.9
TM01
18.6
251.6cd
6.7
1785.4b 4364.3b 4.8 3.93
38.9
CL
18.6
198.2b
7.1
1396.7b 3414.0b 4.9 3.95
38.9
Un-grafted
18.4
71.7a
6.5
295.3a
98.4c 4.9 3.96
91.7
F-test
ns
**
ns
**
**
ns ns
C.V. (%)
4.5
17.2
14.3
20.9
23.6
2.1 3.2
Means in each column followed by the same letters are not significantly different by DMRT;
** Significant at probability level of 0.01; ns = not significant.
The maximum marketable yield was recorded in plants grafted on LG rootstock
(5864.1 kg/rai). The highest disease prevalence was recorded in non-grafted plants as compared to
other grafted ones with LG was having the highest resistance to bacterial wilt coming from the soil.
The fact that the grafted plants produced better results than non-grafted ones when grown on
infested soils indicates the potential economic value for a grower of growing grafted plants (Vuruskan
and Yanmaz, 1990; Black et al., 2003). However, grafting had no significant effect on fruit diameter,
weight, pH, and percent of soluble solid. Considering lower disease prevalence and high yield,
eggplant (LG) could be considered as a good rootstock of currant tomato production.
CONCLUSION
Eggplant rootstock (LG) performed better for yield and yield components on currant tomato
than those of tomato rootstocks and non-grafted plants when grown on soil infested with bacterial wilt.
For success in pin grafting, tomato rootstock and scion seeds should be sown on the same day,
while eggplant rootstock seed should be sown 6 days before sowing of scion seeds.
ACKNOWLEDGEMENTS
We would like to thanks to the Office of Experimental Field and Central Laboratory, Faculty of
Agriculture, Ubon Ratchathani University, for providing all facilities used in this study. Ours thanks
also to Assoc. Prof. Dr. Tuantong Jutagate and Mr. Efren Altoveros for his support in statistical
analysis and reviewing this manuscript.
REFERENCES
Anonymous. 2000. Lycopersicon pimpinellifolium. Available source: http://www.ibiblio.org/pfaf/cgibin/arr_html?Lycopersicon+pimpinellifolium. October 11, 2006.
Black, L.L., D.L. Wu, J.F. Wang, T. Kalb, D. Abbass and J.H. Chen. 2003. Grafting tomatoes for
production in the hot-wet season. Available source:
http://www.avrdc.org/LC/tomato/grafting.pdf. October 11, 2006.
Benton Jones, J. Jr. 1999. Tomato plant culture in the field and greenhouse. CRC Press LLC. Florida
33431.
Gonzalez, W. G. and W. L. Summers. 1995. A Comparation of Pseudomonas solanacearumresistance Tomato Cultivars as Hybrid Parents. J. Amer. Hort. Sci. 120(6): 891-895.
Hayward, A. C. 1991. Biology and epidemiology of bacterial wilt caused by Pseudomonas
solanacearum. Annu. Rev. Phytopathol. 29: 65-78.
Lee, J.M., H.J. Bang, and H.S. Ham (1998). Grafting of vegetables. J. Japan. Soc. Hort. Sci. 67(6):
1098-1104.
Ma, C.M. and L.L. Black. 1999. Program II Year-round vegetable production systems. Available
source: http://www.avrdc.org/pdf/99proj4.pdf. October 11, 2006.
Marsic, N.K. and J. Osvald. 2004. The influence of grafting on yield of two tomato cultivars
(Lycopersicon esculentum Mill.) grown in a plastic house. Acta Agriculturae Slovenica. 83(2)
243 – 249.
Oda, M., K. Tsuji and H. Sasaki. 1993. Effect of hypocotyl morphology on survival rate and growth of
cucumber seedling grafted on Cucurbita spp. JARQ, 26: 259-263.
Oda, M., K. Tsuji, K. Ichimura and H. Sasaki. 1994. Factors affecting the survival of cucumber plants
grafted on pumpkin plants by horizontal grafting at the hypocotyls level. Bull. National
Research Institute for Vegetables, Ornamental Plants and Tea 9: 51-60.
Takahashi, K. 1984. Injury by continuous cropping in vegetables: various problems in the cultivation
using grafted plants. Yasaishikenjo Kenkyu Shiryo 18: 87-89.
Vuruskan, M.A. and R. Yanmaz. 1990. Effects of different grafting methods on the success of grafting
and yield of eggplant/tomato graft combination. Acta Horticulturae. 287: 405-409.