The Partnership of National Chung Hsing University (NCHU) and Vietnam Academy of Agricultural Sciences (VAAS)
As a leader in tropical and subtropical agricultural research, NCHU has contributed to agricultural development in developing countries in Asia, Africa, and Central America. In Taiwan, NCHU has been a major force of agricultural science and technology assistance. NCHU has chosen Southeast Asian partners for international cooperation and agricultural biotechnology transfer. In addition to assisting ASEAN to promote agricultural biotechnology, NCHU also views Southeast Asia and South Asia as the primary market for Taiwan's agricultural biotechnology. As the NCHU Vice President, Prof. Shyi-Dong Yeh has actively promoted agricultural cooperation with Vietnam and achieved remarkable results.
The Vietnam Academy of Agricultural Sciences (VAAS), which oversees 19 national agricultural research units and four agricultural universities partnered with NCHU, is the agricultural research hub in Vietnam. Every president of VAAS has been invited to NCHU, and agreements on academic cooperation are signed by both parties. Based on the close collaboration in the past, NCHU has chosen Vietnam as the partner for future collaboration. Funded by the Ministry of Science and Technology (MOST), Principal Investigator Shyi-Dong Yeh led the plan of VAAS-NCHU Agricultural Sciences and Technology Innovation Cooperation (VAAS-NCHU ASTIC), which was inaugurated on April 23, 2017, to follow the government's New Southbound Policy and to deepen our partnership with Vietnam. Organized by the Biotechnology Center in NCHU and the International Science and Technology Cooperation Center in VAAS, VAAS-NCHU ASTIC combines the strengths of the agricultural biotechnology industry and top talents in biofertilizer, biopesticides, soil-borne disease control, virus disease control, as well as food processing and functional food. Through the 19 agricultural science and technology research units under VAAS and the sister schools of NCHU. Through the help of 19 agricultural science and technology research units under VAAS and the sister schools of NCHU, we have established a platform for bilateral cooperation to promote scientific research, as well as talent exchange and cultivation. In addition, with the cooperation mode of VAAS in guiding agricultural biotechnology enterprises, we can encourage the export of agricultural technology and intellectual property to create innovative industries and markets in Vietnam.
After the first phase of the program ended in September 2019, we were fortunate to receive the second three-year grant from MOST to continue our goals based on the foundation we built. The second phase of the VAAS-NCHU ASTIC will continue our goals set in the first phase, with the following five tasks:
1. Work with the industry to cultivate passion fruit virus-free seedlings and promote passion fruit cultivation to boost the industry.
2. Cooperate with agricultural authorities in Vietnam to establish a production system for papaya seedlings and develop a vaccine for the Vietnamese papaya virus to create an emerging industry.
3. Control soil-borne diseases of coffee, black pepper, and banana with the biopharmaceuticals in Taiwan.
4. Partner with the industry and agricultural authorities to develop functional foods and assist Taiwanese products in applying for Vietnam's import license to reach the international market.
5. Promote academic exchange, staff training, and research cooperation.
The VAAS-NCHU ASTIC not only helps upgrade the agricultural biotechnology industry in Vietnam but also serves as a model for Taiwan to promote the export of agricultural biotechnology and to enter the international markets in ASEAN countries. The following introduces our progress and accomplishment in three areas, including "Assisting Vietnam in promoting the passion fruit industry", "Establishing a mass propagation system for virus-free passion fruit seedlings", "Taiwan-Vietnam cooperation in developing a mild vaccine for passion fruit virus", as well as other major achievements of our missions.
Assisting Vietnam in Promoting the Passion Fruit Industry
Vietnam is a long and narrow country with a subtropical climate in the Red River Delta in the North, similar to Taichung and Pingtung. In winter, the temperature is below 15℃ for two months, suitable for passion fruit growing. However, northern Vietnam has typhoons and encounters similar problems in Taiwan. The agricultural activities in northern Vietnam are concentrated on the Red River Delta, even its natural advantages are not as good as southern Vietnam's. However, Hanoi in the north is the capital city near China, so various agricultural products can be shipped to China without a hitch, which has huge market potential in the future. Compared to northern Vietnam, southern Vietnam is a tropical region where rice is harvested three times a year. Although there are no typhoons in southern Vietnam, the high temperature and humidity on the plains are not suitable for growing passion fruit. However, the hills here, which are 1,000 to 1,500 meters above sea level, have a temperature ranging between 20 to 30°C year-round, making it a suitable place for growing passion fruit. Therefore, Đắk Nông and Gia Lai provinces have become important areas of passion fruit cultivation in Vietnam.
In 2016, a technology transfer agreement was signed between NCHU and Nafoods Group in Vietnam for the "detection of passion fruit viruses by specific nucleic acid primers and establishment of the virus-free passion fruit seedling propagation system", which gives the serum and the detection technology of six species of passion fruits as well as virus-free "Tainung 1" passion fruit seedlings to Nafoods for mass production. In 2018, we assisted Nafoods in setting up the "Nafoods-NCHU Plant Virus Certification Center" to ensure that the seedlings for grafting are virus-free, and helped them in testing the grafted seedlings. Established in 2018, the seedling farm of Nafoods in Quei Fang has six hectares of screen-house area that can produce up to 4 million virus-free seedlings every year, making it the largest passion fruit seedling farm in Asia. In the past, with the joint efforts of VAAS and Nafoods, NCHU has operated through ASTIC and increased the area of passion fruit cultivation from 1,500 hectares in 2016 to 12,000 hectares in 2020, making passion fruit cultivation an essential industry in Vietnam. These are significant accomplishments of ASTIC, which promotes the quick upgrade of Vietnam's agriculture. In addition, with the Ministry of Agriculture and Rural Development of Vietnam's poverty alleviation program, we have helped poor farmers in rural areas switch to passion fruit farming. It not only improved their income and livelihood but also eliminated the illegal opium poppy cultivation, which is another important contribution of our joint efforts with Vietnam.
Establishing a Mass Propagation System for Virus-free Passion Fruit Seedlings
1. NCHU's Establishment of the virus-free Passion Fruit Seedling
Passion fruit seedlings collected by Prof. Yeh's team from all over Taiwan were infected by papaya leaf curl virus (PLCV) and Euphorbia leaf curl virus (ELCV). Even the first "Tainung 1" passion fruit seedlings in the Fengshan Tropical Horticultural Experiment Branch of Agricultural Research Institute were also found to be infected with PLCV, and none of the passion fruit in Taiwan is virus-free. Luckily, we were able to find the virus-free plant tissue cultivated by Professor Yau-Shiang Yang from the Department of Horticulture in NCHU, which was now carefully put in an isolated greenhouse. All the virus-free seedlings propagated in Vietnam come from NCHU, and NCHU also provides free seedlings for businesses in Taiwan. Due to the growing area under cultivation in Vietnam, the number of exported seedlings from Taiwan has increased from 1 million to 6-8 million per year. Both Taiwan and Vietnam have benefited from this win-win strategy with our efforts.
2. Mass propagation of virus-free passion fruit seedlings in Vietnam after the technology transfer to Nafoods
With the virus-free seedlings and virus detection technology provided by NCHU, retired Prof. Woo-Nang Chang from the Department of Horticulture in NCHU and retired researcher Ying-Ta Lin established a mass propagation system for virus-free passion fruit seedlings. They developed the detection technology of passion fruit viruses in Vietnam. In 2016, NCHU signed an agreement with Nafoods to transfer the technology to Vietnam and assisted the company in establishing a seedling farm in Quei Fang, Nghệ An Province, near the Vietnam-Liao border. It is a large six-hectare farm with all seedlings growing in the screen-house, which opened in 2018 with the help of ASTIC. Now, Vietnam has the technology of specific nucleic acid primers to detect passion fruit viruses and the largest propagation farm in Asia, with a growing area under cultivation of passion fruit. Most passion fruits are juiced by Nafoods for export to Asia, Europe, and America, making Vietnam a major exporting country of passion fruit juice with its advantages of vast land resources and cheap labor. By 2020, the area under cultivation of passion fruit in Vietnam reached 12,000 hectares, ten times the size of six years ago, which greatly improved Vietnam's industries and farmers' income.
3. The isolation and detection of passion fruit viruses in Vietnam
With the growing production of passion fruit, problems are gradually emerging. The biggest problem for growing passion fruit is the "woodiness disease" caused by Potyvirus infection, transmitted by aphids. After infection, the branches of passion fruit would shrink, the leaves turn yellow with mosaic symptoms, and the passion fruit becomes deformed and stiff like wood. This disease spreads rapidly in Vietnam and has become the biggest killer of passion fruit production. Since the virus-free seedling has its limitations and the plants are not resistant to the virus, the disease has become the most important factor limiting passion fruit production in Vietnam and China.
After three years of investigation, research, isolation, and detection led by Prof. Yeh's team in NCHU, it was found that the most severe threat to production in Vietnam is Potyvirus, which is transmitted by aphids. Five virus isolates (DN1, DN4, NA1, GL1, and GL2) were collected from different areas of Vietnam, which were verified to be the cause of woodiness disease by back-inoculation to passion fruit. According to the analyses of coat protein (CP) and genomic sequences, GL1 is 98% related to East Asia Passiflora virus (EAPV) in Japan, and GL2 is 91% related to Telosma mosaic virus (TelMV) in Hainan, China. As for DN1, DN4, and NA1, they are related to an unidentified virus in Fuzhou, China, but the four isolates do not meet the threshold (76% nt identity of polyprotein) to be regarded as any of potyviral species. Thus, a new species name, Passiflora mottle virus (PaMoV), has been proposed by the International Committee on Taxonomy of Viruses.
A rabbit antiserum was produced against the CP of DN1, and it can distinguish PaMoV from TelMV and EAPV in western blotting and enzyme-linked immunosorbent assay (ELISA) without cross-reactions. Field surveys of 240 samples by ELISA and reverse transcription PCR found that passion fruit woodiness disease in Vietnam is caused mainly by PaMoV, followed by EAPV, mixed infection of PaMoV and EAPV, and rare cases of TelMV. In conclusion, protecting the passion fruit in Vietnam from infecting PaMoV and EAPV is our most important mission.