Kwang-Soo Cho

Expressing the sweet potato orange gene in transgenic potato improves drought tolerance and marketable tuber production

Potato (Solanum tuberosum L.) is generally considered to be sensitive to drought stress. Even short periods of water shortage can result in reduced tuber production and quality. We previously reported that transgenic potato plants expressing the sweet potato orange gene (IbOr) under the control of the stress-inducible SWPA2 promoter (referred to as SOR plants) showed increased tolerance to methyl viologen-mediated oxidative stress and high salinity, along with increased carotenoid contents. In this study, in an effort to improve the productivity and environmental stress tolerance of potato, we subjected transgenic potato plants expressing IbOr to water-deficient conditions in the greenhouse. The SOR plants exhibited increased tolerance to drought stress under greenhouse conditions. IbOr expression was associated with slightly negative phenotypes, including reduced tuber production. Controlling IbOr expression imparted the same degree of drought tolerance while ameliorating these negative phenotypic effects, leading to levels of tuber production similar to or better than those of wild-type plants under drought stress conditions. In particular, under drought stress, drought tolerance and the production of marketable tubers (over 80g) were improved in transgenic plants compared with non-transgenic plants. These results suggest that expressing the IbOr transgene can lead to significant gains in drought tolerance and tuber production in potato, thereby improving these agronomically important traits.

Potato breeding via protoplast fusion

Abstract Plant cells from which the cell walls have been enzymatically or mechanically removed are called protoplasts. The protoplasts are theoretically totipotent and can be used as sources of somatic cell fusion in practical breeding programs. Wild Solanum species have often been used as sources of important agricultural traits including diverse disease resistance. However, they cannot often be directly applied to breeding programs due to their sexual incom-patibility with S. tuberosum . Somatic hybridization via protoplast fusion is one of the ideal methods to overcome this limitation and to introgress certain traits into S. tuberosum . This technique has still widely been used in potato since the first fusion was reported in 1970s. Therefore, this review highlights general perspectives of protoplast fusion and discusses the application of protoplast fusion in potato breeding. 서 론 원형질체(protoplast)는 세포벽을 기계적으로 또는 효소에 의해 제거한 식물세포를 말한다. 이론적으로 원형질체는 탈분화할 수 있는 능력을 가지며, 세포주기로 진입하여 반복적인 유사분열을 진행함으로써 증식 또는 다양한 기관으로 재분화 하는 등의 전형성능을 갖는다. 이러한 성질은 다양한 식물종을 대상으로 원형질체 융합을 이용한 실용적인 육종방법을 제공하며, 생식세포의 수정을 통해 이루어지는 접합자의 형성 전 또는 형성 후, 정상적인 접합자를 형성하는데 문제를 발생시키는 근연이종 식물체 간의 교잡능력 장벽을 피해 서로 다른 동형핵체(homokaryon) 또는 이핵접합체(heterokaryon)와 이형세포질 잡종(alloplasmic hybrids, cybrids)을 창출할 수 있는 기회를 제공한다. 4배체(2n=4x=48)인 재배종 감자(

Mining of microsatellite markers using next generation sequencing data and its application in genetic relationship analysis of tartary buckwheat (Fagopyrum tataricum Gaertn)

Fagopyrum genus is composed of about 20 species and among them two major species, common buckwheat (F. esculentum) and tartary buckwheat (F. tataricum). SSR markers are only reported in common buckwheat with lower numbers based on enriched repeat libraries and next-generation sequencing (NGS) is a cost-effective alternative. Here we report the development of new cDNA SSR (cSSR) markers characterized from transcriptome sequence data of F. esculentum and F. tataricum using NGS and these cSSR markers were applied for the validation of buckwheat germplasm. From the transcriptome sequences, a total of 8,360 and 6,518 putative cSSR markers were identified in common and tartary buckwheat, respectively, using SSR Locator. Among the cSSR markers, tetra-mer repeats are most abundant and occurred in rates of 54.9 and 37.3% in common and tartary buckwheat, respectively. To test the usefulness of newly developed cSSR markers with previously developed SSR markers based on the SSR motif enrichment library, in analysis of genetic relationship in tartary buckwheat, we selected five representative cSSR markers and applied to investigate the polymorphism of tartary buckwheat germplasm and found these markers can be applied in genetic diversity of germplasm with high polymorphism.

Growth, quality, and yield characteristics of transgenic potato (Solanum tuberosum L.) overexpressing StMyb1R-1 under water deficit

Abstract This study was conducted to evaluate agronomic characteristics such as growth, quality, and yields of StMyb1R-1 transgenic potato and also to obtain the basic data for establishing assessment guidelines of transgenic potato. Three transgenic lines (Myb 1, Myb 2, and Myb 8) were cultivated under conventional irrigation, drought condition, and severe drought condition and were analyzed by com-paring with wild type, non-transgenic cv. Superior. Myb 2 showed a different flower color from wild type and Myb 1 had much bigger secondary leaflets than wild type. Myb 1 and Myb 2 showed higher P 2 O 5 content in both top and root zone and longer shaped tubers than wild type. In yield factors, transgenic lines had more tubers than wild type, however their yield decreases were severe because of the poor enlargement of tuber under water deficit condition. This tendency was noticeable in Myb 1 and Myb 2. In TR ratio, chlorophyll content, dry matter rate, and relative water content, there were no big differences between transgenic lines and wild type. Meanwhile, in phenotype, growth, quality, and yield factors, substantial equivalent was confirmed between Myb 8 and wild type. Then, Myb 8 showed the highest marketable tuber yield under conventional irrigation, while showed lower level than wild type under water deficit. Judged by this result, the enhancing drought-tolerance by

Recent advances in the applications of tissue culture and genetic transformation in potato

Potato is one of the most important crops in the world. Due to vegetative propagation of this crop, techniques of plant tissue culture and genetic transformation are often applied for potato researches and a lot of progress has been made in the breeding programs using these techniques during the last decades. In potato, there have been several trials to introduce GM potato varieties to the world market, but they so far failed due to the changed legislation and unwillingness of large processors to process GM potatoes. These issues are highly associated with the general acceptances of the public and other political decisions. In addition to these, there are still obstacles to overcome to achieve the development of commercial potato variety and several factors to improve horticulturally important traits. In this study, therefore, we reviewed recent advances and research status on tissue culture and genetic transformation in potato and discussed future perspective.

Chloroplast genome of the wild tuber-bearing diploid potato relative Solanum chacoense

Abstract Solanum chacoense is a wild tuber-bearing species belonging to Solanaceae family. The chloroplast genome of the species was completed by de novo assembly using a small amount of whole genome sequencing data. The genome is the circular DNA molecule with a length of 155,532 bp containing 159 predicted genes totally, including 105 protein-coding, 45 tRNA and eight rRNA genes. Maximum-likelihood phylogenetic analysis with 26 species in Solanaceae revealed that S. chacoense is the most closely grouped with S. commersonii.

Effect of Ridging System and Mulch Types on Growth, Yield, and Profitability of Potato ( Solanum tuberosum L.) in Spring Cropping

Received: 13 September 2016 / Revised: 20 September 2016 / Accepted: 26 September 2016 Copyright c 2016 The Korean Society of Environmental Agriculture This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ORCID

Salt tolerance and proline accumulation of potato (Solanum tuberosum L.) in vitro plants to NaCl treatment

Abstract In order to compare salt tolerance among potato cultivars (Solanum tuberosum L.), in vitro plants of each cultivar were cultured on the Murashige and Skoog’s medium containing different levels of NaCl (0, 75, 150, and 225 mM). The suitable level of NaCl for a comparison of the shoot and root growth between potato cultivars was 75mM. Shoot length and weight were better in ‘Dejima’, ‘Superior’, ‘Jayoung’, and ‘Haryeong’ than in other cultivars such as ‘Goun’ and ‘Atlantic’. Normal root growth was observed in ‘Seohong’, ‘Superior’, and ‘Haryeong’, while ‘Goun’, ‘Atlantic’, ‘Dejima’, ‘Jowon’, and ‘Chuback’ showed no root. Proline contents in all the cultivars increased as affected by NaCl levels, then the increase amount was fewer in the cultivars showed a better growth in both shoot and root than in others showed a poor growth. As a result of this study, ‘Superior’ and ‘Haryeong’ were determined as salt tolerant cultivars and therefore using these cultivars it would be possible to potato production at salt arable land such as reclaimed tidal.

The Correlation between Stem Characteristics and Its Resistance to Hail Damage in Potato Cultivars

BACKGROUND: Recently, weather disasters such as hail and typhoon occur frequently. These threaten the stable cultivation of potatoes. It is very important to cultivate potatoes with stable under unexpected weather disasters. This study was performed to investigate the correlation between mophological characteristics of potato stem and its resistance to hail damage in different potato cultivars. METHODS AND RESULTS: Hail fall occurred for 8 minutes on May 31, 2012 in the field of Highland Agriculture Research Center located in Jinbu-myeon Gangwon-do. Potato crop grown in the field was affected by hail due to which the stems of potato were broken. The percentage of broken stem of potato was investigated as the level of damage by hail. To determine the difference in the ratio of broken stem among the potato cultivars, physical characteristics of potato stem such as diameter and hardness were measured. To evaluate recovery phase after hail damage, ground coverage and yield were measured. The percentage of broken stem of cv. Goun and cv. Saebong were 30%, 26%, respectively, whereas it was 5% in the cv. Atlantic. Damage by hail was the lowest in cv. Atlantic. Diameter of the stem was 15 mm in cv. Atlantic, 13 mm in cv. Goun and 11 mm in cv. Saebong. The hardness of potato cultivars was measured which was 74 N in cv. Atlantic. 71 N in cv. Goun and 59 N in cv. Saebong. The ground coverage in cv. Atlantic was 79%, which was the highest followed by 73% in cv. Saebong and 56% in cv. Goun. The yield of cv. Atlantic was monitored at 90 days after planting which was 40 MT/ha and that of cv. Saebong was 36 MT/ha, whereas in cv. Goun, it was 30 MT/ha which was the lowest. CONCLUSION: The ratio of broken stem in cv. Atlantic was the lowest compared to cultivars. In the physical characteristics of stem, cv. Atlantic was the highest in value of diameter and hardness. Based on these results, it was considered that cv. Atlantic was resistant to hail damage compared to other cultivars.

Agronomic characteristics and field resistance to bacterial soft rot of transgenic potato overexpressing the soybean calmodulin 4 gene (SCaM4)

We performed in vitro assay and field trials to assess levels of changes in intrinsic properties and resistance against soft rot of the potato cv. Dejima upon the introduction of a soybean calmodulin 4 gene (SCaM4). Field trials with four lines overexpressing SCaM4 gene were conducted over two seasons, and harvested tubers were evaluated in bioassay for resistance to Pectobacterium carotovorum ssp. carotovorum. The SCaM4 transgenic potato lines inoculated with CFU/ml of P. carotovorum ssp. carotovorum showed enhanced resistance compared to control. Among the SCaM4 transgenic lines, the transgenic line SCaM4-4 exhibited the highest tolerance to soft rot in vitro assays, so did in field trials. In the field trial, the soft rot resistance of SCaM4-4 line was more than 5 times higher compared to that of control cultivar, Dejima. The major agronomic characteristics of the SCaM4 transgenic lines were not different from those of the nontransgenic `Dejima`. The result demonstrated that the transformation of a calmodulin 4 gene was a successful strategy in development of potato cultivar enhanced to soft rot.