Expression changes of stress-induced peroxidase (swpa2 and swpa4) and storage root-specific sporamin (spo-A and spo-B) genes were examined using qRT-PCR after treatment with wounding and bacterial pathogens on leaves of sweetpotato (Ipomoea batatas) plants. As a result of examining the expression change in the wounding treatment condition for 48 hours after treatment, which is a representative physical stress, the expression of all genes increased after 12 hours of wounding treatment, but the expression pattern of each gene group showed distinct differences thereafter. Expression levels of swpa2 and swpa4 strongly increased up to 36 or 48 hours after wounding treatment, whereas spo-A and spo-B expression levels strongly decreased after 24 or 36 hours after wounding treatment. Peroxidase and sporamin genes are involved in the early response after wounding treatment and, in particular, the peroxidase swpa2 and swpa4 genes are also involved in the late response after wounding treatment. Gene expression analysis after infection with P. chrysanthemi, which causes softness in sweetpotato, showed that the swpa2 and swpa4 genes were weakly induced after 8 hours and then strongly induced after 20 hours during pathogen infection. Expression of the spo-A gene was weakly induced in the pathogen-treated group after 20 hours, whereas spo-B showed an expression pattern similar to that of the peroxidase genes. The above results indicate that expression of the stress-induced peroxidase gene used in this study is induced not only by abiotic stress but also by biological stress caused by bacterial pathogen invasion and that peroxidase plays an important function in the initial defense response.

중국 동북부지역 랴오닝성의 단둥(40°07'N 124°23'E)과 지린성의 궁주링(43°30'N 124°49') 및 룽징(42°46'N 129°26'E)에서 2020년과 2021년 벼 재배기간 중에 성페로몬트랩으로 이화명나방(Chilo suppressalis)(나비목: 포충나방과)의 성충 발생 시기를 조사하였다. 1화기 성충은 5월 중순부터 7월 하순 사이, 2화기 성충은 7월 중순부터 9월 중순 사이에 발생하여 세 지역 모두 연중 2회 성충 발생양상이 뚜렷하게 확인되었 다. 위도가 높은 지역에서 발생시기가 더 늦었다. 각 지역에서 관찰된 1화기 발생 시기를 기준으로 발생 시기 모델링을 통해 2화기 발생 시기를 추 정하고 관찰된 시기와 비교하였다. 네 개의 선행연구 자료로부터 성충, 알, 유충, 용 발육단계의 온도의존 생명현상(발육속도, 발육완성분포, 생존 율, 성충 노화율, 총산란수, 산란완성분포, 성충 생존완성분포) 모델들을 수집하거나 작성하였고, 이들을 선행 연구에 따라 단독으로 사용하거나 혼합하여 곤충 발생 시기 추정 소프트웨어인 PopModel에서 결합하였다. 모델링 결과에서 유충 발육기간이 짧게 관찰된 선행연구 자료를 기반으 로 하여 구성된 모형들이 2화기 성충 발생 시기를 더 근접하게 추정하였다. 2021년에는 단둥과 룽징에서 성충 조사 시기에 맞추어 이화명나방에 의 한 벼 피해주율의 변화를 조사하였다. 피해주율은 벼 재배기간 중 누적되어 2번의 증가시기가 뚜렷하게 나타났고, 이화명나방의 각 세대 유충에 의 해 발생한 것으로 추정되었다.

남부지역에서 고구마 바이러스 무병묘의 정식시기 및 재배 기간에 따른 괴근 수량 및 씨고구마 생산량을 조사한 결과는 다음과 같다. 1. 바이러스 무병묘 정식시기에 따라 씨고구마로 사용하기에 알맞은 100~300 g 크기의 괴근 생산량은 6월 중순 정식 재배에서 ‘신율미’ 2,364 kg/10a, ‘풍원미’ 2,625 kg/10a 수준이었다. 2. 바이러스 무병묘를 7월 상순에 정식하여 재배하여도 씨고구마로 사용하기에 알맞은 100~300 g 크기의 괴근 수량은 ‘신율미’ 2,043, ‘진홍미’ 1,799, ‘다호미’ 1,390, ‘풍원미’ 1,985 kg/10a 정도가 생산되었다. 3. 고구마 바이러스 무병묘 정식 후 110일, 120일, 그리고 130 일 재배 시 씨고구마 수량은 ‘풍원미’ 1,605, 1,907, 1,834 kg/ 10a, ‘호감미’ 1,816, 1,771, 2,137 kg/10a 수준으로 생산되었다. 4. 수확 전 채취한 고구마 잎에서 SPLCV, SPFMV, SPVG, SPLV 등 4종 바이러스 이병 정도를 검정한 결과 정식시기, 재배기간 등 품종에 따라 약간 차이는 있으나 낮게 검출되어 다음해 씨고구마 종자로 문제가 없다고 판단하였다. 5. 바이러스 무병묘 대량 증식에는 시설과 노력이 많이 소요되고 증식량이 적어 면적 확대에 어려움이 있기 때문에 무병씨고구마를 생산하면 면적 확대에 유리하다. 무병묘가 소량 일 경우는 계속 증식하면서 7월 상순까지 본밭에 정식하여도 씨고구마 생산이 가능하였다. 금후에는 무병묘로 생산한 연차 간 씨고구마에 대해 품종별 수량과 품질 평가 후 씨고구마의 적정 갱신 주기를 설정하고자 한다.

This study was carried out to obtain the basic quality characteristics, like moisture contents, hunter color value, total polyphenol, starch, amylose, and ash contents and pasting characteristics of sweet potato cultivars according to storage periods. Moisture contents of all the varieties decreased with long storage period, and were lower in dry type than tender and moist type sweet potato. Lightness(L value) of sweet potato flesh was decreased in Shinyulmi, Daeyumi, Shinhwangmi but other seven cultivars showed increasing trend. Redness(a value) was increased in Sinyulmi, Sinhwangmi, Sinjami and yellowness (b value) increased in Yeonjami only. The total polyphenol contents increased in Dahomi, Sinjami up to 4 months of storage and all other varieties showed decrease during storage period. The starch contents also decreased with storage period. The amylose contents showed different by the cultivars. The ash contents in all varieties ranged from 1.1 to 1.7%, and there was no difference among varieties and storage periods. There was no change in pasting temperature during storage periods. Peak viscosity, through viscosity, breakdown and final viscosity were different according to storage periods and cultivars. But setback tended to increase in all cultivars.

Sweet potato [Ipomoea batatas (L.) lam] plant is known to have the relatively tolerance soil moisture deficit compared to other upland crops. However, recently, it has been causing plant growth inhibition and decrease storage quality due to the drought during the growing season of sweetpotato in Korea. The response of root elongation, leaf and shoot growth of sweet potato plantlets, cultivated under different water potential conditions were observed. Six varieties, such as yellow fleshed (Jinhongmi), dark-yellow fleshed (Daeyumi), dark-orange fleshed (Juhwangmi), light-orange fleshed (Dahomi, Pungwonmi), and purple fleshed (Sinjami) were used in this experiment. Using the follow water osmotic potential (WOP) levels were 0 (control), -0.05, -0.1, -0.2, -0.3, -0.4, -0.5 MPa by polyethylene glycol (PEG). In in vitro culture condition, ‘Jinhongmi’ has been inhibited rooting number and number of leaves less than 2, although slightly low WOP of–0.05 and –0.1 MPa, and at –0.2 MPa. shoot was not growing. ‘Daeyumi’, Dahomi, and Juwhangmi’ produced 2 roots as a low WOP of –0.3 MPa. and at –0.2 MPa., it appeared 2 or 3 leaves. ‘Pungwonmi’ produced similar to root number 3.9 at –0.1 MPa compared to control, but root weight decreased 75% at - 0.1 MPa more than control. Root did not grow at – 0.2 MPa for ‘Sinjami’. In nursery bed culture condition, roots fresh weight, number of leaves, and shoot length were inhibited according to the decreases of water osmotic potential. In the case of leaf area, ‘Jinhongmi’ and ‘Daeyumi’ was a significantly difference to 8.4, 22.6 cm3 at –0.2 MPa compared to control, respectively. No difference were obsered for ‘Dahomi’ at -0.1 and –0.2 MPa. ‘Pungwonmi’ was decreased 86% at -0.1 MPa compared to the control. ‘Juhwangmi’ and ‘Sinjami’ was a significantly difference to 15.5, 3.6 cm3 at –0.1 MPa compared to control of 22.9, 16.8 cm3, respectively.

Spodoptera litura (Fabricius, 1775) is considered as a serious agricultural pest, which damaged to the many crops including sweet potato (Ipomoea batatas). We investigated weekly occurrence of the Spodoptera litura (Fabricius) using pheromone trap at six study fields of three regions, Jeonnam, Korea. A total of 41,895 individuals were collected from 18th July to 23th September in 2013; Yeongamgun was collected the highest individuals (17,519), and following the Muan-gun (12,709) and Haenamgun (11,667). The seasonal occurrence of S. Litura was increased from July to September, and peak occurrence timing was in late-September. There were a positive correlation between field area and number of individuals (P=0.02, r=0.89), and a negative correlation between field area and density (p=0.02, r=-0.89). As a PCA (principal component analysis) result, adults occurrence pattern were closely related to the temperature and relative humidity during larva stage.

The most common method of vegetative propagation of virus free plantlets is the use of shoots meristem culture in solid medium culture. This study was to investigate the effect on liquid medium culture for the growth of virus-free sweetpotato plantlets. Single-nodes derived from meristem culture of sweetpotato was examined in this experiment and three sweetpotato varieties ‘Singeonmi’, ‘Sinhwangmi’, and ‘Sinjami’ was used. The growth of plnatlets was greater in liquid medium culture than that of solid medium culture after longer incubation in 3 varieties. The total fresh weight of 5 week old plantlets after planting in solid culture were 2.17 g (‘Singeonmi’), 2.49 g (‘Sinhwangmi’), and 2.18 g (‘Sinjami’), but the fresh weight in liquid medium culture was 3.87, 3.88, and 3.35 g, respectively. Leaf number of ‘Singeonmi’ and ‘Sinjami’ plantlets after 5 weeks of liquid medium culture was 21.1 and 22.6, respectively and liquid medium culture showed 3 and 6.2 more leaf number than that of solid medium culture. Plant height of ‘Sinhwangmi’ and ‘Sinjami’ plantlets after 3 weeks of liquid medium culture was 4.1 cm and 3.4 cm, respectively, and liquid medium culture showed 1.1 cm longer stem length than solid medium. Overall, liquid medium culture of sweetpotato plantlets was more effective than solid medium in terms of leaf and stem growth.

수확과정에서 버려지고 있는 고구마 잎을 이용한 기능성 식품소재로서 활용가능성을 검토하고자, 밀가루 중량 대비 고구마 잎 분말을 2, 3, 5, 7%의 비율로 첨가하여 식빵을 제조 하고, 반죽 및 제빵 특성, 생리활성 및 기능성분 등을 조사하 였다. 반죽의 수분흡수량은 7% 첨가 시 가장 높았고, 반죽시 간은 유의적인 차이를 보이지 않았으며, 반죽의 저항도는 2~3% 첨가할 때가 가장 안정적이었다. 식빵의 수분 함량은 첨가량이 증가하여도 큰 차이를 보이지 않았고, 식빵의 내부색은 첨가량이 증가할수록 L값과 a값은 감소하였으나, b값은 증가하였다. 식빵의 부피와 비용적 및 굽기 손실률은 첨가량 이 증가할수록 감소하였으나, 항산화 활성과 총 폴리페놀, 루 테인 및 베타카로틴 함량은 증가하였다. 관능평가의 결과, 고 구마 잎 분말의 2~3% 첨가 시 맛과 색깔, 조직감, 입안에서의 씹힘성과 종합적인 기호도에서 가장 우수한 값을 얻었다. 이 상의 결과에서 고구마 잎 분말의 2~3% 첨가 시, 제빵 적성과 기능성, 상품성이 우수한 식빵을 제조할 수 있었다.

본 연구에서는 2년간 수원 밭작물 시험포장에서 단옥수수 품종인 고당옥과 구슬옥을 파종시기에 따른 생육 및 이삭 특성을 검토한 결과이다. 1. 고당옥과 구슬옥 모두 파종시기가 늦어질수록 파종에서 출사기까지의 일수가 짧아졌고, 출사에서 수확기간은 증가하였다. 2011년의 출사일수는 43 ~ 53일, 2012년은 44 ~ 54일이었고, 출사에서 수확까지는 2011년은 22 ~ 36일, 2012년에는 20 ~ 34일이었다. 2. 파종에서 출사기까지 생장온도일수(GDD)는 출사 후부터 수확기까지는 약 213 ~ 353oC 범위로 비슷하였으나 파종에서 수확까지의 GDD는 2011년(약 916 ~ 1,067oC)과 2012년(약 911 ~ 1,055oC) 모두 큰 차이가 없었다. 특히 8월 5일 파종에서 등숙기 중의 생장온도일수가 다른 파종시기에 비하여 크게 낮았는데 이는 등숙기의 기온이 상대적으로 낮은 것이 원인으로 판단된다. 3. 파종시기에 따른 생육특성을 보면 간장과 착수고는 파종시기가 늦어질수록 짧아졌으며 7월 말 파종 재배에서 유의하게 짧았으며, 경태는 파종시기가 늦어질수록 유의하게 얇아지는 경향을 보였다. 이삭직경은 고당옥은 4.37mm, 구슬옥은 4.43mm로 차이가 없으나 6월, 8월 파종보다 7월 파종구에서 두꺼운 것으로 나타났다. 4. 이삭무게는 두 품종 모두 6월, 8월 파종구 보다 7월 파종구에서 높고, 7월 25일 파종구를 보면 고당옥은 201g, 구슬옥은 140g으로 높았다. 2년간 단위면적당 이삭수량은 고당옥은 715kg/10a이고, 구슬옥은 677kg/10a이었다. 5. 파종시기에 따른 단옥수수 재배는 파종기가 늦을수록 생육이 지연되고 이삭수량이 감소되는 경향이 있고, 단옥수수 만식재배에 따른 최적 파종시기는 7월 20일 ~ 25일로서, 두 품종 모두 7월 25일에 이삭 수량성이 높은 것으로 나타났다. 7월 20 ~ 25일 파종 시 생육이 지연되고 이삭수량이 감소되는 단점 이 있지만 6월 말에 재배한 단옥수수 보다 습해의 피해가 적고, 수확적기가 짧고 전분축적 시간의 지연으로 수확시기를 연장할 수 있다는 장점이 될 수 있을 것으로 판단되어진다. 따라서 추후 단옥수수 만식재배 시 수량과 상품성 향상을 위한 최적 수확적기, 저장방법에 대한 연구가 이루어져야 할 것이다.

‘Pungwonmi’, a new sweetpotato variety, was developed for table use by Bioenergy Crop Research Institute, National Institute of Crop Science (NICS), RDA in 2014. This variety was derived from the cross between ‘Benisatsuma’ and ‘Luby3074’ in 2006. The seedling and line selections were performed from 2007 to 2009, and preliminary and advanced yield trials were carried out from 2010 to 2011. The regional yield trials were conducted at five locations from 2012 to 2014, and it was named as ‘Pungwonmi’. This variety has cordate leaf shape, and its leaves, stems, nodes, and petioles are green. Storage root of ‘Pungwonmi’ has an elliptical shape, red skin, and light orange flesh. ‘Pungwonmi’ was moderately resistant to fusarium wilt, and resistant to root-knot nematode. Dry matter content was 31.2%, and texture of steamed storage root was intermediate. Total sugar content of raw and steamed storage roots of ‘Pungwonmi’ was higher than that of ‘Yulmi’. β-carotene content of ‘Pungwonmi’ was 9.1 mg/100g DW. Yield of marketable storage root over 50 g of ‘Pungwonmi’ was 24.3 MT/ha under the early season culture, which was 46% higher than that of ‘Yulmi’. The number of marketable storage roots per plant was 2.8 and the average weight of marketable storage root was 156 g under the optimal and late season culture. Marketable storage root yield of ‘Pungwonmi’ was 24.1 MT/ha under the optimum and late season culture, which was 26% higher than that of ‘Yulmi’. (Registration No. 6428).

To obtain basic data on the effects of differences cultivation periods and methods on growth and development of sweet potato tuber. We investigated growth and development of six major cultivars showing different characteristics, such as dry type(Yulmi, YM; Jinhongmi, JHM), intermediate type(Pungwonmi, PWM; Hogammi, HGM), and purple type(Sinjami, SJM; Danjami, DJM). The average tuber weight of YM and JHM was 4.1 and 8.6 g respectively, 50 days after transplant. At 80 days, the weight of YM and JHM rapidly increased to 25.2 and 26.1 g, respectively. Finally, at 120 days, the weight of YM and JHM increased to 120.7 and 79.4 g, respectively. The average tuber weight of PWM and HGM was 13 and 3.3 g, respectively, 50 days after transplant. The development pattern of PWM showed a consistent increase in tuber weight during the cultivation period, an average weight of 104.2 g at 120 days. However, the tuber development pattern of HGM was different from that of PWM. The average tuber weight of HGM rapidly increased for 100 days after transplant and then showed no increase at 120 days. In case of purple type sweet potato, the average tuber weight of SJM consistently increased during the cultivation period, whereas DJM showed rapid increase in average tuber weight at 80 days after transplant. Korean consumers prefer small, round sweet potato approximately 100g in weight. Based on the results, YM, PWM and SJM are classified as early developing cultivars that can be harvested approximately 120 days after transplant. On the other hand, JHM, HGM, and DJM are classified as late developing cultivars that can be harvested approximately 130 days after transplant.

‘Geonhwangmi’, a new sweetpotato variety, was developed for table use by Bioenergy Crop Research Institute, National Institute of Crop Science (NICS), and RDA in 2013. This variety was derived from the cross between ‘Singeonmi’ and ‘Mokpo34’ in 2005. The seedling and line selections were performed from 2006 to 2008, preliminary and advanced yield trials were carried out from 2009 to 2010. The regional yield trials were conducted at five locations from 2011 to 2013, and it was named as ‘Geonhwangmi’. This variety has five-lobed leaf, and its leaves, stems, and petioles are green. Storage root of ‘Geonhwangmi’ has an elliptical shape, red skin, and light orange flesh. ‘Geonhwangmi’ was moderately resistant to fusarium wilt, and resistant to root-knot nematode. Dry matter content was 29.4%, and texture of steamed storage root was intermediate. Sucrose content of steamed storage root of ‘Geonhwangmi’ was higher than that of ‘Yulmi’, and steamed storage root palatability of ‘Geonhwangmi’ was better than that of ‘Yulmi’. β-carotene content of ‘Geonhwangmi’ was 3.4 mg/100g DW, which was 7.8% of ‘Juhwangmi’. Yield of marketable storage root over 50 g of ‘Geonhwangmi’ was 23.0 MT/ha under the early seasonal cultivation, which was 39% higher than that of ‘Yulmi’. The number of marketable storage roots per plant was 2.6 and the average weight of marketable storage root was 151 g under the optimal and late seasonal cultivation. Marketable storage root yield of ‘Geonhwangmi’ was 24.2 MT/ha under the optimum and late seasonal cultivation, which was 45% higher than that of ‘Yulmi’. (Registration No. 5853).

To analysis of virus free sweetpotato effect, 5 virus free sweetpotato and virus normal sweetpotato varieties were planted in 5 different regions at 2010 year. The average yields of virus free sweetpotato are showed different results according to regions. Sinjami which cultivated at Iksan were increased maximum 68% compare to normal. However, Sinjami which cultivated in Hamyang were decreased yield 11% compare to normal. Analysis of tuber formation ratio of Sinjami, Yenhwangmi, Singeonmi which cultivated in Nonsan were decreased tuber number compare to normal. However, 3 varieties were all increased on Average storage root weight and yield of marketable storage root. In the results of analysis of marketable storage root according to cultivated regions and varieties, all varieties except Sinjami which cultivated in Hamyang were increased yield. Also, quality of virus free sweetpotato were enhanced 7 to 9 compare to virus infected sweet potato which showing average 3. Contents of starch between virus free and virus infected sweetpotato were not affected by virus. Virus free sweetpotato were more increased starch products according to increased total production yield. Also, Brix° (%) was not showing difference between virus free and virus infected sweetpotatoes. In this experiment, Virus free sweetpotato are enhanced production yields and quality. Therefore, we suggested that virus free sweetpotato is one of the methods to reduce damage by sweetpotato virus.

Storage root yield of sweetpotato was decreasing owing to continuous sweetpotato cropping, debasement of soil physical properties, increasing incidence of pest and disease. This study was conducted to evaluate the changes in physicochemical properties of the soil owing to subsoiling (subsoiling to 50 cm depth), and the effect on growth and yield of sweetpotato. The subsoiling treatments included subsoiling treated every year for two years, subsoiling in the first year, and no subsoiling control. The soil physical properties measured were bulk density, hardness, porosity, three phase. Bulk density, porosity, soild (%) of three phase were improved by subsoiling in topsoil and subsoil. Main vine length and vine yield in subsoiling soil were higher than those in no subsoiling soil, but those were not significantly different. Yield of marketable storage root in subsoiling soils treated every year for two years and treated in the first year was more increased 17% and 20% than no subsoiling soil, respectively. The number of marketable storage root per plant was also higher in subsoiling soils than no subsoiling soil, but it was not significantly different. Soluble solid contents and total free sugar contents of storage root of sweetpotato were not significantly different among the treatments. These results show that improving soil physical properties by subsoiling could promote high yield of marketable storage root in continuous sweetpotato cropping field.