• Journal of agriculture & life science
• /
• v.43 no.6
• /
• pp.105-109
• /
• 2009

Kyungsan nursery complex which has a vast area for the production of various species of fruit tree stocks is in a high demand of virus-free saplings. Apple tree stocks, the most important products, urgently need more rapid and reliable viral diagnosis. In this study, a bead beater was tested because of convenience in dealing with large number of samples. Also, industrial glass bead abrasive (0.4 mm in diameter) at very low cost was used in a disposable way. For bead beater-aided RNA extraction from apple stem tissues, the guanidine thiocyanate method was confirmed to be very reliable. Silca membrane filter tube in connection to vacuum filtering device was strongly suggested for simplifying RNA capture and washing steps. Apple virus detection was confirmed by RT-PCR.

• Journal of agriculture & life science
• /
• v.44 no.5
• /
• pp.75-79
• /
• 2010

Apple, one of the most important fruit crops world-widely, is required for rapid, cost-effective and sensitive virus detection for its better productivity. RT-PCR is extensively employed for apple virus diagnosis, but the technique requires complete tissue homogenization which is time consuming and laborious. In this study, heating-based RNA extraction method was developed and proven to effectively work for stem tissues slightly better than for leaf tissues. In RT-PCR, almost identical results were generated from the use of RNA extracts from both tissues.

• Research in Plant Disease
• /
• v.19 no.4
• /
• pp.288-293
• /
• 2013

In worldwide, viral diseases of apple plants has caused the serious problems like reduced production and malformation of fruits. Also, the damages of apple plants by virus and/or viroid infection (Apple chlorotic leaf spot virus, Apple stem grooving virus, Apple mosaic virus, and Apple scar skin viroid) were reported in Korea. However there is few report about the protection approach against the infection by apple viruses. Therefore, this paper introduced the experimental protocol for the development of virus-free apple cultivars (Danhong, Hongan, Saenara, Summerdream). Apple plants were treated at $37^{\circ}C$ for 4 weeks and shoot tips were cultured in vitro. After heat treatment, the detection of apple viruses was performed by RT-PCR using virusspecific detection primers in new apple cultivars. With the heat treatments followed by in vitro shoot tip culture, the proportion of virus-free stocks of 'Danhong', 'Hongan', 'Saenara', and 'Summerdream' was 28%, 16%, 12%, and 12%, respectively. Taken together, this approach can be a good tool for production of virus-free apple stocks.

• Journal of Plant Biotechnology
• /
• v.46 no.3
• /
• pp.228-235
• /
• 2019

Apple (Malus pumila) is one of the most economically important fruits in Korea. but virus infection has decreased the sustainable production of apples and caused serious problems such as yield loss and poor fruit quality. Virus or viroid infection including apple chlorotic leaf spot virus (ACLSV), apple stem pitting virus (ASPV), apple stem grooving virus (ASGV), apple mosaic virus (ApMV) and apple scar skin viroid (ASSVd) have been also reported in Korea. In many cases, as apple gets infected with virus and viroid with no specific symptoms, the damage and symptoms caused by the viruses are not detected. In our research, viruses in the rootstock were eliminated for a virus-free apple dwarfing rootstock of M.9 and M.26. The virus elimination methods were apical meristem culture, thermotherapy ($37^{\circ}C$, 6 weeks) and chemotherapy($Ribavirin^{(R)}$). The detection of apple viruses was accomplished by Enzyme-linked Immuno-Sorbent Assay (ELlSA) and reverse transcription-polymerase chain reaction (RT-PCR). RT- PCR method was 10 ~ 30% more sensitive than the ELISA method. The efficiency of virus elimination was enhanced in apical meristem culture method. The acquisition rate of virus-free apple dwarfing rootstocks was 30 ~ 40% higher in apical meristem culture. After the meristem culturing of M.9, the infection ratio of ACLSV, ASPV and ASGV was 45%, 60% and 50%, respectively. In the apple dwarfing rootstock of M.26, the infection ratio of ACLSV, ASPV and ASGV was 40%, 55% and 55%, respectively. Based on this study, the best method for the production of virus-free apple dwarfing rootstocks was the apical meristem culture.

• Journal of Plant Biotechnology
• /
• v.44 no.4
• /
• pp.379-387
• /
• 2017

Various sizes (0.2 ~ 1.2 mm) and developmental stages (referred to as Stage 1 ~ 3) of apical and lateral meristems were excised, together or separately, directly from dormant buds of apple 'Hongro'. They were mixed infected by Apple scar skin viroid (ASSVd), Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV) and Apple stem grooving virus (ASGV), which are major viruses attacking apples. A total of 31 callus lines (> 10 mm in diameter) were obtained by culturing the explants on Murashige and Skoog (MS) medium supplemented with 3% sucrose, 3.0 mg/L benzyladenine (BA) and 0.1 mg/L indole-3-butyric acid (IBA), and they were subjected to RT-PCR analysis for virus detection. A high rate of virus elimination (expressed as the percentage of calli that did not amplify during RT-PCR, i.e., RT-PCR negative calli per total number of calli obtained) was achieved for ACLSV (100%), ASSVd (93.7%), and ASPV (93.7%), whereas it was only 25.8% for ASGV. ASPV was detected in the presence of 2 ~ 3 bracts. Simultaneous virus elimination of ASSVd, ASPV, ACLSV, and ASGV occurred during the meristem culture, in which the early stages of the dormant buds (Stage 1) were used, because ASGV was mostly eliminated during that stage. The results of the present study will be valuable for the production of virus-free apple trees.

• 농업기술회보
• /
• v.48 no.4
• /
• pp.41-41
• /
• 2011

포도 주산지를 중심으로 문제가 되고 있는 꽃매미는 올해도 전국에 발생되어 농가에서는 각별한 주의가 요구되고 있다. 올해 농림수산식품부에서 조사한 발생면적은 7천여 ha로 전년보다 11% 정도 감소했지만, 발생지역은 10개 시도, 68개 시군으로 전년보다 20개 시군이 늘어나 확산추세에 있다.

• Journal of Plant Biotechnology
• /
• v.49 no.3
• /
• pp.222-229
• /
• 2022

Apples are the most grown fruit crops in the fruit industry of Korea. However, virus or viroid infection such as apple mosaic virus (ApMV), apple stem grooving capillovirus (ASGV), apple stem pitting virus (ASPV), apple chlorotic leaf spot virus (ACLSV), apple scar skin viroid (ASSVd) causes fruit yield reduction and poor fruit quality. Therefore, in this study, we examined to established an efficient virus-free system to eliminate the most infected ASGV virus in domestic apple orchard. We investigated that the shoot growth rate and the virus removal rate in ASGV infected potted apples that were treated with heat treatment in a growth chamber (constant temperature/humidity device) maintained at 36℃, 38℃ and 40℃ for 4 weeks. Here we found that the shoot growth rate was the highest in the heat treatment group (36℃) and the virus was removed in the middle and top of the shoot but not in the bottom. The virus was did not removed in the 38℃ and 40℃ heat treatment group in all section of shoots, and the heat treatment group (40℃) died after 4 weeks of heat treatment without growth of shoots. We performed in vivo shoot-tip grafting using the shoot-tip of potted apple heat-treated at 36 ℃, and we also investigated the viability and virus removal rate, which showed 94% viability and 20% virus removal rate. Collectively, our results suggest that it would be possible to produce the virus-free apple plants through heat treatment and shoot-tip grafting.

• Korean Journal of Plant Resources
• /
• v.37 no.4
• /
• pp.401-410
• /
• 2024

This study was undertaken to elucidate the effects of virus and viroid infections on the growth of trees and the attributes of fruit quality in 'Hongro' apples. Trials were initiated using virus-infected, viroid-infected, combined virus/viroid-infected, and uninfected apple trees in an experimental apple orchard at the National Institute of Horticultural and Herbal Science in 2019. The growth of each tree was measured annually and compared between virus-free and virus/viroid-infected trees. Fruits were harvested from all apple trees, and selected attributes of fruit quality, including yield, weight, firmness, titratable acidity, and anthocyanin content, were determined in September 2021-2022. The results revealed significant differences among virus-free trees and those infected with either virus, viroid, or a combination of virus and viroid. Infection with viral and viroid diseases led to reductions in tree height (14.0%), trunk area (23.1%), fruit yield (65.0%), fruit weight (34.4%), and anthocyanin content (39.8%), while increasing fruit firmness (33.2%) and titratable acidity (39.8%), respectively. We anticipate that our research findings will also be beneficial for apple virus and viroid disease control, as well as apple cultivation management.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.65 no.4
• /
• pp.496-507
• /
• 2020

Virus infections of apples result in lowered commercial qualities such as low sugar content, weakened tree vigor, and malformed fruits. An effective way to control viruses is to produce virus-free plants based on the development of an accurate and sensitive diagnostic method. In this study, real-time PCR assays based on SYBR Green I and TaqMan probes were developed for detecting ASGV, ASPV, and ApMV viruses. These methods can detect and quantify 10³ to 10¹¹ RNA copies/μL of each virus separately. Compared with methods with two different dyes, the SYBR Green I-based method was efficient for virus detection as well as for assay using the TaqMan probe. Field tests demonstrated that real-time PCR methods developed in this study were applicable to high-throughput diagnoses for virus research and plant quarantine.

• Research in Plant Disease
• /
• v.26 no.2
• /
• pp.95-102
• /
• 2020

The investigation of the infection rate of domestic apple orchards by four types of apple viruses (Apple chlorotic leaf spot virus [ACLSV], Apple stem pitting virus [ASPV], Apple stem grooving virus [ASGV], Apple mosaic virus [ApMV]) and one type of viroid (Apple scar skin viroid, ASSVd) found that most apple trees were infected with viruses and viroid at the rate of 97.3%. By region, the infection rate in Jeongseon stood at 98.8%, Danyang at 100%, Yesan at 100%, Jangsu at 89.1%, and Muju at 98.1%. By each virus and viroid, the infection rate of ASGV was the highest at 93.4%, followed by ASPV at 85.7%, ACLSV at 59.0%, ASSVd at 6.7%, and ApMV at the lowest 3.6%. In addition, 84.8% of the cases were infected with two or more types of viruses and viroid, nearly seven times the single type infection rate of 12.4%, and the cases infected with three viruses, ASPV, ACLSV, and ASGV accounted for 56.2%, more than the half the total number of trees investigated.