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Current State of Horticultural Research in Taiwan, Republic of China
Min-Tze Wul1 and Shui-Ho Cheng2
1Specialist, Horticulture Division, Council of Agriculture,Republic
of China
2Chief, Horticulture Division, Council of Agriculture,
Republic of China
|
 Taiwan is located
between latitudes 21°18' N and 25°18' N, with the Tropic of
Cancer running through the central part of the island. It has both
tropical and subtropical climates, which allows plenty of horticultural
crops to be produced commercially.
For the past four
decades, horticultural industry in Taiwan has grown up rapidly due
to the economic growth and increased population. In 1996, the area
planted to fruit trees, vegetables and ornamental plants was 230,000
ha, 177,000 ha and 9,970 ha respectively. The production value for
fruit, vegetable and ornamental crops was 2.06, 1.29 and 0.3 billion
US dollars, which accounted for 33.5 %, 20.9 % and 4.9 % of total
crop production value respectively.
The government
has made efforts on upgrading the research level of horticultural
crops in the past years, including increased research budgets, training
of research staffs, and strengthening of the international cooperation.
The major research organizations involved in the horticultural researches
and major research crops will be described as follows.
Major research organizations
1- Taiwan Agricultural Research Institute
Established in 1895, Taiwan Agricultural Research Institute has been
the oldest agricultural research organization in Taiwan. There are
five research laboratories in the Department of Horticulure, including
fruit crops, vegetable crops, ornamental plants, postharvest handling
and processing, and biotechnology. The major activities are aimed
at breeding new varieties and developing new techniques for horticultural
crops in Taiwan. Up to date, two pears, one peach, one cucumber and
one potato varieties have been released. Also many new lines of vegetable,
fruit and flower are tested regionally. They can be released in the
near future.
At present, major research projects conducted in the department are:
( 1 ) Breeding of cucumber, melon, spongy gourd, watermelon, yard
long bean, broccoli, spinach, amaranthus, hot pepper, and radish.
The breeding goals are heat tolerance, disease resistance (particularly
viruses, downy mildew, powdery mildew, fusarium wilt and gummy stem
blight in several cucurbit crops, viruses in radish, pepper and yard
long bean), high yield, good quality and wide adaptability.
( 2 ) Breeding of pear, loquat, plum, peach, and table grape. The
breeding goals are low chilling requirement and better quality.
( 3 ) Breeding of Anthurium, Gladiolus, Lilium, Hippeastrum, Zantedeschia,
ornamental Prunus. The breeding goals are to develop new flower varieties
for the local market.
( 4 ) Development of cultivation techniques such as waxing of pear
graft which can save labor, sprinkling water in loquat orchard to
reduce hot wind injury, and vegetable production under protective
facilities. Studies on producing virus free bulbous flower and off-season
production of Oncidium cut flower are also conducted.
( 5 ) On postharvest handling, several techniques for exporting litchi,
Chrysanthemum, Gladiolus and Oncidium cut flowers have been developed
and commercially applied. Cold storage of loquat, garlic bulb, major
cut flowers, and controlled atmosphere storage of cabbage have been
studied.
( 6 ) Researches on fruit and vegetable processing are conducted at
Chiayi and Fengshan stations. These include Improvement of the manufacturing
methods of fruit juice, dried fruits, vegetable pickles, fermentated
fruits and vegetables.
( 7 ) Biotechnology researches are aimed at enhancing the breeding
efficience. From anther culture, some haploid plants of Brassica
oieracea have been produced. A partial linkage map based on RAPD
markers has been established in melon. Some transgenic melon and watermelon
have been produced by using the virus coat protein genes of CMV, ZYMV
and PRSV-W.
All the work are conducted by 19 researchers and their assistants.
Among them, eight have Ph.D. degree and eleven have MS degree. Research
budgets are mainly supported by Taiwan Provincial Department of Agriculture
and Forestry, and Council of Agriculture.
The department also cooperates with other research organisations including
National Taiwan University and National Chung Hsing University on
the breeding program and exchange of material for biotechnology research.
2 - Chiayi Agricultural Experiment Station
Administratively, Chiayi Agricultural Experiment Station belongs to
Taiwan Agricultural Research Institute. Founded in 1918, the station
has aimed at germplasm collection, conservation, breeding and management
of subtropical and tropical fruits. Collection, evaluation and management
of indigenous ornemental plants have also been conducted in recent
years. The most important achèvements include release of 10
pineapple varieties and the extension of citrus virus-free budlines.
Currently, the major projects conducted in the station are
( 1 ) Collection and conservation, propagation and characterization
of subtropical and tropical fruits. 800 accessions, belonging to 49
families, 111 genera and 200 species, are maintained in the field.
( 2 ) Improvement of citrus cultivars which consists of introduction,
crossbreeding, mutation, and propagation of healthy trees by shoot-tip
grafting and heat therapy.
( 3 ) Improvement of pineapple cultivars by means of cross-breeding
and clonal selection for developing table use varieties .
( 4 ) The effects of different planting density, plastic shelter,
nutrient, and cultural practice on fruit quality in mango are studied.
( 5 ) Lychee breeding for different maturing time through selection
of seedlings from open and controlled pollination.
( 6 ) Improvement of avocado varieties by means of introduction, open
pollination and seedling selection for high quality and yield, and
resistance to Phytothora root rot dise ase.
( 7 ) Evaluation of flowers and ornamental plants, includes collection
and acclamation of indigenous ornamental plants for in-house use,production
of large ornamental nursury plants, and improvement of media and water
management techniques for pot plants.
( 8 ) Composition analysis, utilization and processing of fruits have
been studied.
All the work are conducted by 10 researchers and their assistants.
The research budgets are mainly supported by Taiwan Provincial Department
of Agriculture and Forestry, and Council of Agriculture.
3 - Fengshan Tropical Horticultural Experiment Station
Like Chiayi Agricultural
Experiment Station, Fengshan Tropical Horticultural Experiment Station
also belongs to Taiwan Agricultural Research Institute administratively.
Established in 1940, the station consists of four departments-tropical
fruit crops, vegetable crops, plant protection, ultilization and management.
There are 30 researchers and 58 technicians in the station.The research
budgets totalled about 4.5 million US dollars every year which are
mainly supported by Taiwan Provincial Department of Agriculture and
Forestry, and Council of Agriculture.
The station has
been outstanding in breeding of several tropical fruits. Major accomplishments
include release of papaya Tainung No.1, No2, No.3, No.5, mango Tainung
No.l, No.2, carambola Tainung No.l, and passionfruit Tainung No.1.
For vegetable breeding,Chinese mustard Tainung No.l and onion Tainung
Selection No.3 were released.
Currently, the
major projects conducted are :
(1 ) Breeding of Mango (Mangifera indica L.) : Select different
varieties with dwarf, good flavor, fiberiess, fruit weight among 40Og
to 800 g, red skin, anthracnose resistance, suitability for storage
and transportation, early maturation.
( 2 ) Breeding of papaya (Carica papaya L.) for ring-spot virus
resistance ( or tolerance) and superior horticultural trait to enhance
fruit quality and quantity.
( 3 ) Regional yield trial of promising seedling lines of lychee (Litchichinensis;
Sonn) : Select early maturity, high quality varieties suitable
for regional needs.
( 4 ) Varietal Improvement of Guava (Psidium Guajava L.): Select
seedless, red flesh, good taste, Li-ku-bin resistant varieties for
the local fresh market.
( 5 ) Varietal Improvement and field test of Wax-apple ( Syzygiumsamarangense
Merrill et L.M. Perry ) : Through introduction, selection and
cross-breeding, varieties with good shape and colorness are the breeding
( 6 ) Breeding of sugar apple ( Annona Spp. Select varieties
with high fruitset, high quality, long shelf life and non-cracking
characters.
( 7 ) Varietal improvement and field test of Indian jujube (Zizyphusmauritiana
L.) Select varieties with spureless and powdery mildew resistance.
( 8 ) Establish a high density planting system and mechanical pruning
method for Yu-Her Pao lychee to lower the production cost.
( 9 ) Organic farming of Tropical fruit tree-Guava : To evaluate the
effect of organic fertilizer, microorganisms application and non-chemical
pest and disease control methods on fruit quality, quantity, soil
chemical, physical, biological properties.
( 10 ) Breeding for heat tolerance and virus resistance of mustard,
fusarium wilt resistance of bitter gourd, and heat tolerance and high
quality of pakchoi.
( 11 ) Improve the production technologies for onion and garlic, and
establish the hydroponic culture techniques for short-term leaf vegetables.
goals.
( 12 ) For tropical flower crops, mass propagation and flowering regulation
of bromeliads and improved production techniques of foliage plants
and Dendrobium orchid had been developed. An indigenous plant, Ficusvaccinoides,
was also developed as a new ornemental plant recently.
4 - Taichung District Agricultural Improvement Station (DAIS)
Taichung District
Agricultural Improvement Station was founded in 1902. The station
consists of one branch station,three technical divisions and three
adminstrative offices. There are 16 researchers and 30 techniciens
involved in horticultural research. Research budgets are mainly supported
by the Taiwan Provincial Government and Council of Agriculture. The
station is well equipped with facilities such as laboratories, greenhouse,
postharvest storage rooms,and approximately 50 hectares of land for
field experiment.
In the past years,through
the joint efforts of the staffs of the station, the research work
has been very productive and fruitful. A heat tolerant tomato variety
"Taichung Asveg No.4" had been developed and released in 1989. It
has an outstanding performance with regard to yield, resistance to
disease, firmness of fruit, and heat tol erance. The research on grapes
was directed to develop the technique of regulating the flowering
time so that 2-3 crops a year was possible. An outstanding technique
of topgrafting temperate pears onto tropical pears has been developed
to produce temperate pears in the tropical Lowlands of Taiwan. This
method enabled growers to produce fruits 40-50 days earlier than normal
harvesting time. The DRF hydroponic system developed by the station
for vegetable culture under tropical condition has been adopted by
growers for commercial production.
5 - Tainan District Agricultural Improvement Station(DAIS)
Established in
1923, Tainan District Agricultural Improvement Station is aimed at
conducting agricultural researches to promote agricultural production
for the one-third of total farmers in Taiwan. Tainan DAIS has made
significant contributions in the production of vegetables including
processing tomatoes, asparagus, and other processing vegetables. Up
to date, the station has released two onion, three tomato and asparagus,
and five muskmelon varieites. In addition to breeding effort, the
station has devoted to the researches on reducing production costs
such as the use of PE-sheet tunnel culture for muskmelon and green
asparagus, and mechanical harvest of processing tomato.
At present, major
projects conducted in Tainan DAIS are
(1) lmprovement of cultural techniques for mango, muskmelon, cherry
tomatoes, ornemental plants and tropical bulb flowers (curcuma).
(2)Breeding of muskmelon, cherry tomatoes, lotus, asparagus and cabbage.
The breeding goals are disease r esistance, heat tolerance and higher
quality.
(3)The extention of indigenous vegetables Including Solanum nigrum,
S. photeinocarpum, Amaranth and Madeira Vine.
(4)Development of culture techniques using simple structure: e.g.
various types and color of nets used for low tent and tunnel cover
to produce leaf vegetables in summer ; Application of degradable plastics
as mulching film to reduce production cost.
(5)Organic production of horticulturai crops. Application of EM (effective
micro-organism) on the production of leaf and fruit vegetables. The
Potzu branch station of Tainan DAIS had established an integrated
organic production system for sweet corn.
(6)To establish virus-free nurseries for garlic and bamboo shoot,
and a plug system for seedling production of vegetables and bedding
plants.
(7)Studies on post-harvest physiology of horticultural crops: Improve
shelf-life of leaf vegetables by pre-cooling systems.
All the work are
conducted by 20 researchers and their helpers (project assistants
and field workers). Among them, fourteen have MS degree. Research
budgets are mainly supported by the Taiwan provincial government and
the Council of Agriculture. The station is also well equiped with
chemical analytic instruments such as GC, HPLC, GC-mass and environmental
control spaces such as greenhouse, post-harvest storage room.
Tainan DAIS also
cooperates with other research organisations including AVRDC (Asian
Vegetable Research and Development Center) on the breeding of processing
and cherry tomatoes and Kaohsiung Medicine College on evaluating the
medicine effect of indigenous vegetables.
6 - Taiwan Banana Resarch Institute
Taiwan banana
industry is composed of about 8,000 small producers, each averaging
0.5-1.0 ha of banana orchard. Banana is the leading fruit for export.
About 45% of banana production was for export to the Japanese market,
and 55% for local consomption. In the last decade, a great research
effort has enabled Taiwan banana to survive in the increasingly comp
etitive international market.
Taiwan Banana
Research Institute was founded in 1970. There are six research groups
focusing on breeding, pest and disease controi, cultural practice,
tissue culture, soil and nutrition, and postharvest physiology and
handling. The instituts also conducts numerous technical service programs
to the banana growers including propagation of disease-free mericlonal
plantlets, disease forecasting, production forecasting, and education
and extension, etc. There are 6 senior researchers and 35 techniciens
working on the following major research projects: Breeding for r esistance
to Fusarium wilt, breeding for high yielding cultivars, pest
management, nutritional problem and ripening disorders, application
of tissue culture technology, and development of corporated farming
system. All research projects are financially supported by Council
of Agriculture, and Department of Forestry and Agriculture of Taiwan
Provincial Government, while overhead expenses come from interest
of foundation fund, service charge collected from export banana, and
banana production income from exp erimental farm. The Fruit Cooperative
supports most budget needed for conducting technical service programs.
The instituts
is equipped with greenhouses, insect-proof stock nursery, ripening
rooms, and a commercial tissue culture laboratory.
As a member of
the Asian and Pacific Network, International Network for the Improvement
of Banana and Plantain (INIBAP), the instituts actively participâtes
in the international research activities, and provides banana tissue
culture training course at international level. At national level,
the instituts works in close coop eration with National Taiwan University
and National Chung-Hsin University on several research projects.
7 - Taiwan Sugar Research Institute ( TSRI )
Taiwan Sugar Corporation
is a state enterprise under the ministry of Economic Affairs of the
Republic of China. In 1988, the Department of Horticulture was founded
at Taiwan Sugar Research Institute to conduct a series of research
and development programs. So far the Department has performed admirably
and won a very good reputation both at home and abroad. There are
116 Phalaenopsis hybrids have been registered at British Royal Horticulture
Society using TAISUCO ( Taiwan Sugar Corporation ) as an acronym,
and 53 hybrid varieties have been released to the market. A patented
environmental cooling system has been developed for producing off-season
flowering of Phalaenopsis.
Currently, there
are 19 researchers and 13 techniciens in the Department of Horticulture,TSRI.
The research budgets are mainly supported by Taiwan Sugar Corporation
which totalled about 1.5 million US dollars yearly. The research programs
are basically business oriented, the major projects conducted are
:
( 1 ) Breeding of Phalaenopsis : germplasm collection, clonal s election
and registration of new hybrids, crosses and seedling raising, studies
on genetics of flower color in Phalaenopsis equestris,identification
of RAPD markers linked to the red flower gene in Phalaenopsis equestris,study
on transgenic Phalaenopsis.
( 2 ) Researches of flower bulbs : breeding of Gladiolus and lily,
application of liquid shaking culture and RITA bioreator in cormlet
formation of Gladiolus,effect of planting media on the size of yearling
bulbs of lily, the fertilizations of Gladiolus and lily in a slate
calcareous alluvial soil,effect of storage duration on the germination
of Gladiolus flower bulbs.
Major Research Crops
1 - Citrus
Citrus germplasm
collection and conservation are conducted at Chiayi Agricultural Experiment
Station. There are 150 cultivars which were tested for regional adaptability.
Murcott, tangelos, satsumas, navels and grapefruits have been accepted
by the growers.
The Chiayi Agricultural
Experiment Station started nucellar lines breeding since 1976. Nucellar
seedlings of ponkan, tankan,and liu-cheng orange were raised by pollination
with trifoliate orange. Studies of nucellar embryogensis in vitro
have also been exploited. Tankan and ponkan plants obtained from nucelli
that had been cultured with Agrobacterium tumefaciens carrying
Ti plasmids for protein toxic to coleopteran pests and lepidopteran
pests. Some plants have already tested positively for the coleopteran
insecticide.
For breeding scion
cultivars with less seeds and resistance to citrus canker, tankan
( C. tankan , Matou-Wentan ( C. grandis ) and Kiyomi
( C. unshiu x C. sinensis ) were used as seed parents and pollinated
with sweet oranges and mandarins. Ten hybrids were selected and propagated
for further evaluations.
Citrus budwood
certification program began in 1982. The parent trees produced through
heat therapy and shoot-tip grafting were kept in screenhouse. The
trees have to be indexed free from Likubin ( Greening Tatter-leaf,
Tristeza, Exocortis, Psorosis and Xyloporosis.
Likubin is the
most destructive disease in Taiwan. For the rapid and precise indexing
of the disease, a sensitive and specific diagnostic DNA probe was
developed, which was just specific to Asian strain of greening and
didnot react with African one. Several cultural practices were proposed
to reduced the spread of Likubin according to the investigatîon
of its infection, including eradication of infected trees, spray of
insecticide to control its vector psillid in flushing season and replant
with healthy trees.
2 - Pineapple
The breeding objective
of pineapple in Taiwan has been set on developing varieties for table
use since the processing industry was declining in 1970. Tainung No.11
was released by Fenshan Tropical Horticultural Experiment Station
in 1986. Tainung No.13 and No.16 were bred by Chiayi Agricultural
Experiment Station in 1994 and 1995 respectively. These 3 varieties
are highly accepted by the domestic market.
For the improvement
of cultivation techniques, experiments on NPK fertilizers, mulching,
different planting density, and adjustment of production period had
been conducted intensively around 30 years ago. Currently, breeding
of varieties for table use is continuing and researches have been
focused on the cultivation improvement of the newly released varieties.
3 - Banana
Researches on
banana in Taiwan are mainly conducted by Taiwan Banana Research Institute.
The important works are :
( 1 ) Establishment of banana germplasm collection consisting of over
600 accessions, of which 450 belonging to the Asian and Pacific region
were transferred as a duplicate collection from the world banana genebank,
a coop erative project between the instituts and INIBAP. The passport
data for most accessions are available.
( 2 ) Breeding: Through somaclonal variation approach, the instituts
has succeeded in obtaining many useful somaclones derived from major
local cultivar "Pei-Chiao". These somaclones carry such desirable
characters as r esistance to Fusarium wilt and high yielding. The
release of a wiltresistant somaclone "Tai-Chiao No.l" for commercial
planting in 1990 has saved Taiwan banana industry from destruction
by Fusarium wilt, which should be regarded as a breakthrough in the
history of banana breeding. At present, field trials for some newly
developed wilt-resistant and a high yielding somaclone are in progresse
The instituts aiso released a semidwarf cultivar "Tai-Chiao No.2",
introduced from Central America, for commercial planting in 1992.
( 3 ) Disease and pest control: The instituts identified the fungus
causing wilt of Cavendish bananas as a new race (race 4) of Fusarium
oxysporum f. sp. cubense. Integrated control measures were
successfully developed for major diseases and insects of banana occurring
in Taiwan - black Sigatoka, freckle disease, corm and stem borer,
and flower thrip, etc.
4 - Pear
(1 ) Germplasm
In Taiwan, pear's cultivars are cultivated mainly in the mountain
area (between 300 meters and 2,500 meters above sea level) where most
Japanese and Chinese cultivars are grown. Germplasm such as Hengshan
Pear, Golden Tread Pear and Japanese cultivars like 'Shinseiki' ,
'Housui' 'Shinko' are widely planted cultivars.
( 2 ) Breeding Program
Pear breeding program was started in 1976 by Taiwan Agricultural Research
Institute, 'Tainung No.l' and 'Tainung Nursery No.2'. which are low
chill required have been released. Both are progenies of 'Shinseiki'
x. 'Hengshan Pear'.
(3 ) Cultivation Techniques Improvement
In order to solve the problem of unsatisfied chilling requirement
of pear in lowland, a top-grafted technique has been developed. The
chilled flower bud scions of Japanese cultivars are grafted onto the
watershoots of Hengshan pear trees yearly. By this means, the temperate
pears can be produced under the subtropical condition.
5 - Grape
(1) Varieties
In the 5,000 ha
of vineyard in 1995, table grape constituted about 60% with Kyoho
as the leading variety. This was followed by the vinifera type
of Italia. The rest are the small acreage of cultivation of Himrod
Seedless, Red Italia, Muscat Bailey A, Niagara and Pioneer, etc. The
acreage for wine grape was about 2,000 ha, of which Golden Muscat
constituted the most, followed by Black Queen and Niagara. A low percentage
of these grapes are also used for juice making.
The important
varieties are cultivated in Taiwan as follows:
Kyoho (Ishiharawase
x Centennial)
Italia (Bicane x Muscat Hamburg)
Golden Muscat (Muscat Hamburg x Diamond)
Black Queen (Bailey x Golden Queen)
( 2 ) Techniques of Producing Multiple Harvests of Grapes
The subtropical
climate of Taiwan cannot provide a long enough period with cold enough
temp eratures (below 7°C) in winter to meet the chilling requirements
of grapevines, but the winter climate is cold enough to halt the growth
of grapevines. To avoid high temp erature and high humidity conditions,
and to solve the problem of over-production during the summer, the
following cutural practices for the regulation of the production season
have been developed: one crop a year (in summer or fall); two crops
a year (summer and winter crops, or fall and spring crops), and three
crops a year (summer, fall, and winter crops).
In order to force
the winter crop, a mature cutting is rooted in early spring and becomes
established as a new plant. After the flower buds have formed, the
pruning of the semi-hardwood is carried out. The new shoots emerge
and will later bear berries.
For the production
of the fall crop, the mature canes are pruned back in winter, leaving
2-3 buds per cane. With proper management of new shoots and flower
initiation, the young shoots can then be pruned again to promote flowering
and fruitset.
To produce two
crops a year, mature branches are pruned to 12-14 nodes in length
after the harvest of the first crop in summer or fall. Manual defoliation
is then carried out, or chemical d efoliants such as Dormex can be
applied to promote bud break and flowering. The second crop can then
be harvested in winter or in the following spring.
For the production
of three crops a year, a V-shaped frame is used to induce upright
growth in the grape canes for the first and second crop. The third
crop is forced on the horizontal trellis. The overlapping of fruit
development of two different crops makes it possible to harvest three
crops in ten months. The success of this technique depends on the
proper management of the canes, including the application of fertilizer,
pruning, pinching, and the use of plant growth regulators to retard
terminal growth. The appearance of leaf and shoot makes it possible
to judge very precisely the stage of branch development, and use this
as basic information for management.
6 - Wax apple
(1) Investigation of forcing culture methods by training, root pruning,
trunk girdling, waterlogging, drought, shading, chemical treatment,
etc. to produce off-season fruits. Traditionally, the production period
of wax apple in Taiwan was from June to October. By these forcing
culture techniques, the production period can be adjusted through
November to May of the next year. In addition, the quality of the
off-season fruits are much higher than the regular season fruits due
to the larger diff erences between day and night temp erature from
November to May in Taiwan.
(2 ) Diagnosis of plant nutrient requirements through mineral analysis
of leaf and soil for the purpose of improving quality of fruits.
7 - Papaya
Papaya (Carica papaya L.)was widely grown in southern part
of Taiwan but seriously infected by ring-spot virus disease which
made yield significantly reduced. Therefore, the researches have been
focused on breeding of ringspot virus resistant varieties. The breeding
methods include bulk s election of tolerant varieties, interspecific
hybridization among Carica species and use of embryo culture to rescue
the aborted embryoes of interspecific hybrid and transformation of
coat protein gene of papaya ringspot virus mediated by Agrobacterium
following liquid-phase wounding of embryogeneic tissues with caborundum.
8 - Tomato
Researches on
tomato (Lycopersicon esculentum) in Taiwan have been mainly
conducted by AVRDC with the coop eration of several district agricultural
improvement stations. AVRDC maintains one of the world's largest collections
of tomato germplasm, totalling some 6944 accessions. Of this total,
more than 70% belong to Lycopersicon esculentum, and the rest
are wild species.
A step-by-step
incremental research approach was employed by AVRDC scientiste to
improve tomato adaptability to the tropics. This has been achieved
mainly by developing heat tolerant and disease-resistant lines. This
research program has successfully contributed to the development and
release of 92 tropical lines in 32 contes throughout the world. These
tomato lines possess heat tol erance, r esistance to diseases viz.
bacterial wilt, tomato mosaic virus, and nematode, and have good fruit
firmness and cracking resistance.
In cooperation
with the District Agricultural Improvement Stations, 5 AVRDC tomato
hybrids/varieties have been named and released to Taiwan's farmers.
These releases include two fresh market tomato hybrids, Taichung ASVEG
No.4 and Hualien ASVEG No.5- two processing tomato varieties, Tainan
S2 and Tainan S3; and one cherry tomato variety, Tainan ASVEG No.6.
The release of heat-tolerant tomatoes have resulted substantiel increases
in summer tomato production and significantly contributed to farmer's
incomes.
The goal of the
tomato improvement project is to develop tomato varieties/lines adapted
to summer production. Consequently, heat tol erance, resistance to
bacterial wilt, tomato yellow leaf curl virus, tomato mosaic virus,
and tomato fruitworm, as well as good horticultural characteristics
are important s election criteria and research activities. Currently,
major progresses were achieved towards introgression of late blight
resistance into tomato, and towards application of grafting technique
to overcome the two major constrains, ie., flooding and bacterial
wilt in summer tomato production. Progress was also made towards evaluation
of the effectiveness of gene constructs conditioning resistance to
cucumber mosaic virus, tospovirus, or fusarium wilt.
9 - Chinese cabbage
Researches on
Chinese cabbage have aiso been mainly ondule by AVRDC. AVRDC had collected
and is maintaining a total of 1522 accessions of Brassica germplasm.
Among these collections, more than 800 accessions belong to heading
Chinese cabbage (Brassica campestris spp pekinensis). Evaluation
of the AVRDC Chinese cabbage germplasm for heat tol erance and other
major traits required for the hot, humid areas has enabled the s election
of elite genetic stocks for breeding. Breeding high yielding, heat
tolerant cultivars with r esistance to major diseases such as soft
rot, downy mildew, and turnip mosaic virus is one of the mandates
of AVRDC.
Heat tol erance
in Chinese cabbage is inherited in a relatively simple fashion, thereby
rendering a straightforward genetic transfer. The genetic diversity
among the tropical, heat-tolerant gene pool was found to be narrow,
and to enrich such genetic base they were, therefore, a heterosis
breeding was attempted. A selected set of heat-tolerant stocks was
crossed with unrelated cultivars carrying disease r esistance. These
intercultivar populations were then subjected to repeated mass s election
cycles for heat tol erance and disease r esistance.
Yield improvement
in the new tropical Chinese cabbage cultivars developed at AVRDC has
been appreciable. VVhereas old local cultivars, previously grown by
farmers during the summer season in Taiwan, normally yield about 8-10
t/ha, 32-35 days after transplanting, the new hybrids and open-pollinated
varieties can produce three times (30 t/ha) as much in the same growth
period.
Some hybrids and
open-pollinated varieties from AVRDC have been officially released
in Taiwan, the Philippines, Japan, Indonesia, Thailand,Bangladesh
and China. In Taiwan, two hybrids, ASVEG No.1 and Tauyuan ASVEG No.2,
were released to the farmers. The performance of the improved heat-tolerant
Chinese cabbage has also been outstanding in other tropical countries.
Diamondback moth,
the Chinese cabbagels most serious insect, can now be satisfactorily
controlled with the artificial rearing and release of two parasitic
wasps and the bacterial pesticide Bacillus thuringiensis. Progress
was also made towards development of heat-tolerant cultivars with
higher levels of r esistance to mosaic virus and downy mildew, and
with elongated head conformation which is preferred by the consumers
in Taiwan.
10 - Fruit vegetable
The research of
fruit vegetables breeding was mainly focused on four different cucurbits,
including cucumber (Cucumis sativus), melon (cucumis melo),
loofah (Luffa spp.), and watermelon (Citruitus lanatus).
The subjects performed in these four cucurbits include germplasm
collection, screening, and breeding for disease r esistance. In the
past few years, 150 varieties of cucumber, 190 varieties of melo,
86 varieties of 'loofah, and 100 varieties of watermelon were collected
and preserved at Taiwan Agricultural Research Instituts. Screening
for viruses disease r esistance, two cucumber varietiesHei-pei-Ta-Kua
and Tai-Chung Mu-Kua, were released, which were highly resistant to
4 viruses such as CVM, ZYMV, PRV-W, and CGMMV. In melon, preliminary
data showed that Hei-Sa-Mi and New melon were resistant to CMV, while
B-63-3, Pl 180280 and Pl 414723 were resistant to PRV-W, and Pl 414723
was partial r esistance to ZYMV. In Luffa spp. the results
indicated that most varieties of L. cytindrica were resistant
to CMV, but susceptible to ZYMV, in contraste L. acutangula were
resistant to ZYMV, but susceptible to CMV. In watermelon, one variety
collected from Malawi was highly resistant to 3 viruses such as ZYMV,
PRV-W, and MVBMV. Studies on the inheritance of virus r esistance
in cucumber, it showed that the r esistance to ZYMV was controlled
by a single r ecessive gene, while PRV-W was controlled by a single
dominant gene. All of the collected varieties/lines were first investigated
for their horticultural characteristics, and tested for viruses r
esistance, then inbreeding for several generations, until the viruses
r esistance genes become homozygous. So far, some inbred lines with
viruses r esistance were released and some viruses r esistance hybrids
of cucumber, loofah were evaluated in regional trials. A new cucumber
hybrid was released to the farmers in 1994.
The research of
biotechnology in fruit vegetable crops was mainly focused on three
diff erent cucurbits, including melon (Cucumis meto), watermelon
(Citrutius vulgaris), and bitter gourd (Momordica charantia).
The subjects performed in these three cucurbits included genetic
linkage mapping using molecular markers in melon, gene transformation
in melon and watermelon, and gene cloning in bitter gourd. In the
past year, a partial linkage map for melon based on RAPD (random amplified
polymorphic DNA) markers has been established, which consists of 125
loci in 29 linkage groups, and totally covers 1348 centmorgans. The
constructed map may have covered 40 - 60 % of the genome in melon.
Some transgenic melon plants containing coat protein gene of cucumber
mosaic virus were produced in the laboratory and waiting for further
tests in the green house and field. Transformation of coat protein
genes of zucchini yellow mosaic virus and papaya ringspot virus in
watermelon and melon are also in proceeding, and some promising results
have been obtained. In bitter gourd, cloning of the ACC gene(s) from
the genome was conducted. To-date, some PCR derived DNA fragments
are ready for sequence study and gene identification.
11 - Leaf vegetable
Leaf vegetables
including Pai-tsai, mustard, water convolvulus, cabbage, Chinese cabbage,
spinach, lettuce, celery, and garland chrysanthemum are cultivated
in Taiwan. The total acreage of leaf vegetables is 37,000 hectare,
which is 26% of the acreage for the total vegetable production.
Two heat tolerant
Chinese cabbage varieties have been released by the coop eration between
District Agricultural Improvement Stations and AVRDC. One Pai-tsai
and one water convolvulus varieties have also been released. Those
varieties were developed for summer vegetable production.
The National
Plant Genetic Resource Center at Taiwan Agricultural Research Institute
(TARI) has collected 712 leaf vegetable varieties. AVRDC aiso collected
951 varieties from 1993 to 1995. The major breeding goals for leaf
vegetables are heat tol erance, disease r esistance and better quality.
Plastic houses
have been used to produce short-term leaf vegetables. These structures
can protect the vegetables from heavy rains in summer and cold streams
in winter. Biological control methods such as sex ph eromone and microbial
pesticide developed from indigenous Bacillus thurigiensis are
applied in the field. Modified atmosphère (MA) storage and
precooling proc edures have been applied to prolong the shelf-life
of leaf vegetables.
The research of
leaf vegetable breeding was mainly focused on four species, including
amaranth (Amaranthus tricolor L.) , spinach (Spinaciaoferacea
L.) , kale (Brassica oieracea L. Alboglabra group) , non-heading
Chinese cabbage (Brassica campestris L. ssp. Pekinensis var.
laxa Tsen et Lee). The subjects performed in these four leaf vegetables
include germplasm collection , screening , and breeding for heat tol
erance. In the past few years, 58 varieties of amaranth, 80 varieties
of non-heading chinese cabbage, 73 varieties of kale and 180 varieties
of spinach were collected in the germplasm of Taiwan Agricultural
Research Institute. In amaranth, one strain-Am2 which can be harvested
3 days earlier than ordinary one and has more than 30% yield. In non-heading
chinese cabbage and kale , heat tolerances and high self-incompatability
are the major characters for selection.
12 - Phalaenopsis
For breeding the
Phalaenopsis varieties with graceful flowers, varied periods
of flowering, and easy cultivation for the production of cut-flowers
and potted flowers, thirty-eight wild species and 1800 outstanding
clones have been collected as the parental materials for crossing
at Taiwan Sugar Research Institute. Techniques of chromosome doubling,
molecular marker, and gene transfer were being used in the support
of breeding. A system of meristem culture has been established for
the multiplication of promising clones. Media for germination and
survival of the Phalaenopsis seeds were developed. In order
to produce the high-quality Phalaenopsis and reduce its production
cost, the system to automatically control the greenhouse environment,
which favors growth and flower controlling was developed. The transport
benches between the greenhouse and the working station for potting
and repotting Phalaenopsis plants were also established. An
automatic moveable bench system equipped with a sprinker fertilisation
system was designed. Several kinds of media for growing the Phalaenopsis
including local and cost-saving materials such as the bagasse
trying to substituts the importing media, and their corresponding
management methods were studied. Methods and formula for lengthening
the vase life of cut-flowers of Phalaenopsis were developed.
Major diseases and insect pests on the Phalaenopsis were periodically
investigated and their corresponding precaution and controlling methods
were recommended. Effects of low temp erature on forcing of floral
initiation in the Phalaenopsis, and chilling injury on the
Phalaenopsis were studied.
13 - Chrysanthernum
Chrysanthemum
is the major cut flower calculated by harvested acreage, and also
the most important exported cut flower in Taiwan. There are more than
1,700 hectare are cultivated per year. Most of them are sold in domestic
market. More than 40 million stems were exported in 1991, but the
exportation reduced to less than 10 million stems in 1996 because
of the comp etition of Chrysanthemum from Okinawa.
Most of commercial
varieties were introduced from foreign countries, such as Japan, Netherlands,
and U.S. Some amateur breeders tried to do crossing from 30 years
ago. lt was no advantage because the market was limited and the idea
of "Royalty" was not respected meanwhile. In order to select varieties
which are suitable for the climate of Taiwan, the breeding program
was then conducted at Taichung District Agricultural Improvement Station.
The hybridization as well as mutation programs were tried.
Since most of
Chrysanthemum are grown in the open-field, the quality of cut flowers
is not stable especially in summer season. However, the quality can
be enhanced and production is more stabilized when Chrysanthemum is
cultivated under structure facility and shading. Growth regulators,
such as GA and retardant were tested to control the growth of plants.
Plug system with mechanized transplanting was introduced to save labor
cost. Postharvest handling was improved continuously to reach the
need of Japanese market. Integrated pests control is adapted in the
field and pest-resistant varieties is going to be developed through
biotechnology.
14 - Gradiolus
Gradiolus is the
second major cut flower in Taiwan. Productions for export as well
as local market are very important to this flower business. The current
varieties were introduced from Netherlands and then evaluated to select
proper varieties which is suitable to the climate of Taiwan. The breeding
program of gradiolus is conducted at Taiwan Sugar Research Institute.
In biotech research, the system of virus-indexed plants of gradiolus
was established. In cultural practices, researches on different resources
of potassium and phosphorons were examined to overcome the necrosis
of leaftip. Collection and s election for good varieties suitable
for different seasons were undertaken. The growth and flower quality
have been promoted by using the day-length control, night-break by
lighting, etc.
Researches on
physiology and dormancy of corms are conducted and effect of flooding
on the quality of cut-flower was determined. Rehydration and pr eservation
treatments could enhance quality and vase-life of cut gladiolus. The
organic-cultivation were studied for reducing the use of chemicals
and promote the growth of plants.
15 - Rose
Rose is one of
the three major cut-flowers in Taiwan. The quality of rose has been
improved by several researchers. Most of rose varieties were introduced
from foreign countries, such as Japan, Netherlands as well as U.S.
and then were selected for the climate of Taiwan and cultural practice
through many experiments. There is no breeding company of rose in
Taiwan, but some professional growers tried to select new varieties
through mutation or crossing.
Propagation by
cuttings was studied in Taichung DAIS for severai years. Some resuits
on the practical procedure of producing cuttings have been accepted
by farmers in Taiwan. Propagation by tissue culture was also tested,
especially for potted rose, but the economical evaluation is still
lacking.
Rose cultivated
under plastic houses is widely extended to farmers recently because
the quality of rose flowers produced is highly improved in comparison
with that in open field. A new culture method "bending pruning" was
developed in Taichung DAIS and extended to growers. Through the application
of "bending culture" technique, rose flowers have longer flower stem
than traditional prunîng method, and the flower quality is also
enhanced. The neck bent of cut-flower was also improved by using basket
with water during transportation. This practical procedure keeps the
flowers in good shape from field to auction market.
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Green - Seeds Co., Ltd.
81/10B Ho Van Hue Street, Phu Nhuan District, Ward 9, Ho Chi Minh City, Vietnam
Tel: +84 (8) 847 6901 - Fax: +84 (8) 844 1392 - Email: info@green-seeds.com
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