Purpose: To develop a tool for measuring peripheral intravenous catheter insertion performance. Methods: This was a cross-sectional descriptive study. Initial items were generated using existing guidelines and tools, and 19 experts assessed content validity. Data were collected from a tertiary hospital in D city from January 17, 2018, to October 20, 2019. The data of 365 nurses were used for principal component analysis with orthogonal rotation. Concurrent validity was confirmed using Pearson’s correlation between the developed tool and the nursing career period. Reliability was confirmed after evaluating internal consistency. Results: Initially, 16 items were generated, but three items were deleted in content validation. A two-factor solution was preferred in exploratory factor analysis and explained 48.2% of the variance. The two factors were named “point of care” and “follow-up care,” respectively. The tool’s reliability is .87. Conclusion: The developed tool was valid and reliable. It is composed of 13 items and can be used quickly and easily. Therefore, it can be utilized for the education and training of novice nurses and the self-reflection of experienced nurses. In addition, it will be useful to review the catheterization process in common clinical settings.

본 연구는 병풀(Centella asiatica) 두 품종(‘자이언트 타이 거 케어’, ‘굿병풀’)의 생장 특성과 추출용매에 따른 항산화 활성 및 Triterpenoid 함량을 조사하기 위해 수행되었다. ‘자이언트 타이거 케어’와 ‘굿병풀’의 정식 후 생장 특성은 정식 41일 후 엽과 엽병의 길이 생장에서 ‘굿병풀’이 유의적으로 높았다. 하지만 이후 수확기(정식 104일 후)까지 생장속도는 유사하였다. 정식 후 104일에 수확한 ‘자이언트 타이거 케어’의 식물체 크기와 관련된 생장(엽면적, 엽병두께, 엽병 길이, 생체중)이 ‘굿병풀’보다 유의적으로 높았다. 냉수, 열수, 50% 에탄 올, 70% 에탄올 추출물의 자유라디컬 소거능과 환원능으로 평가된 항산화 활성과 총 페놀 함량은 두 품종에서 모두 70% 에탄올 추출물에서 높았다. 추출 용매별 Triterpenoid 함량을 분석한 결과, 두 품종의 주요 Triterpenoid는 Madecasoside 와 Asiaticoside로 확인되었다. 품종별 총 Triterpenoids 함량은 ‘자이언트 타이거 케어’의 50% 에탄올 추출물과 ‘굿병풀’ 의 70% 에탄올 추출물에서 가장 높았으며, ‘굿병풀’이 ‘자이언트 타이거 케어’보다 높았다. 하지만 정식 104일 후 수확량 은 ‘자이언트 타이거 케어’가 ‘굿병풀’보다 3배 많아, 동일한 재배 면적(3.3m2 ) 에서 생산 가능한 총 Triterpenoids 함량은 ‘자이언트 타이거 케어’가 2.459mg으로 ‘굿병풀’(1.103mg) 보다 약 2.2배 높았다. 따라서 항산화 활성이 가장 높고 단위면 적당 총 Triterpenoids 생산량이 높은 ‘자이언트 타이거 케어’ 를 재배하는 것이 경제적일 것으로 생각된다.

본 연구는 식물공장에서 고흡수성 합성고분자(Super absorbent polymer; SAP)를 수경재배에서 배지로서의 활용가능성을 구명하고자 홍화 및 아마란스 새싹의 생육특성과 페놀함량 및 항산화도를 평가하였다. 대조구는 새싹 재배기(19 × 14 × 9cm, W × D × L)에 거즈를 깔고, 처리구에는 거즈 위에 SAP 를 추가하여 비교 분석하였다. 홍화 새싹 종자를 30°C의 증류수에 5시간 동안 침지한 뒤, 새싹 재배기에 파종 후 식물생장 상에서 재배하였다. 식물생장상의 내부 온도는 25 ± 1°C, 습도는 70 ± 4%로 유지되었고 광조건은 35 ± 6μmol·m -2 ·s -1 (광 주기 12h)로 설정하였다. 아마란스 새싹은 새싹 재배기에 파종 후 식물생장상 내부 온도 25 ± 2°C, 습도는 70 ± 5%, 광조건은 188 ± 10μmol·m -2 ·s -1 (광주기 16h)로 설정하였다. SAP 의 기본적인 특성으로 물리/화학적 분석과 홍화 및 아마란스의 발아율과 생육특성 및 기능성 물질을 분석하였다. 홍화는 발아율, 생육 및 기능성 물질에서 처리구와 대조구간 차이가 없었으나, 아마란스는 생육 측면에서는 대조구와 차이가 없었으나 발아율, 건물중, 페놀함량 및 항산화도에서 처리구가 각각 1.16배, 1.16배, 1.40배, 1.12배의 높은 결과를 보였다. 결과적으로, 이번 연구를 통해 식물공장에서 SAP을 활용한 새싹재배가 가능할 것으로 판단하였으며 추후 SAP가 식물 생리적으로 작용하는 연구가 필요할 것으로 사료된다.

본 연구는 적외선 열 영상 장치를 이용하여 2년생 ‘유미’ 복숭아나무의 토양수분 수준에 따른 엽온 및 CWSI를 분석하여 수분스트레스 측정 가능성을 검토하였다. 엽온은 대기온도와 유사한 일변화를 보이며 낮 시간대에는 대기온도보다 높은 양상을 보였다. 엽온은 전일(24시간) 기준으로 대기온도(r2 = 0.95), 일사량(r2 = 0.74), 상대습도(r2 = -0.88)와 모두 높은 상관계수를 나타났다. 또한 토양수분장력은 낮 시간대(11~16시)에 엽온(r2 = -0.57), 엽-대기온도차(r2 = -0.71), CWSI(r2 = -0.72)와 높은 부의상관을 나타냈다. CWSI와 엽온, 엽-대기온도차의 상관계수는 24시간 기준으로 매우 높았고(r2 = 0.90, r2 = 0.92), CWSI와 토양수분장력의 상관분석에서 24시간 기준으로는 상관관계가 낮았으나(r2 = -0.27), 낮 시간대(11~16시)에는 상관관계가 매우 높았다(r2 = -0.72). CWSI (y)와 토양수분장력(x)의 상관관계 결정계수(r2)는 11~12시간대에 가장 높았으며(r2 = 0.68), 이때 회귀식은 y = -0.0087x + 0.14로 조사되었다. 일반적인 토양수분스트레스 시점인 -50 kPa에 해당되는 CWSI는 0.575로 계산된다. 따라서 적외선 열 영상 장치를 이용한 엽온 및 CWSI는 토양수분장력에 대해 높은 상관계수를 나타낸 것으로 보아 복숭아나무의 수분스트레스 진단에 유용하게 활용할 수 있을 것으로 예상된다.

본 연구는 복숭아 주간부 동해 예방을 위한 피복재의 보온성을 평가하기 위해 백색부직포, 황색일반지, 방수패드로 만들어진 피복재의 물리적 특성 및 보온성을 평가하고 실제 겨울철 복숭아 주간부 보온효과를 구명하여 피복재로서의 이용가능성을 검토하기 위해 수행하였다. 세 피복재 중 2겹방수패드 처리가 보온율과 열저항성이 가장 우수하였다. 2겹방수패드 처리의 주간단열효과는 14.09oC 만큼 온도상승을 차단하였고, 야간보온효과는 7.23oC 만큼 온도하강을 차단하여 보온효과가 가장 우수함을 확인하였다. 따라서 방수패드 재질을 보온피복재로 개발·보급할 경우 복숭아 주간부 동해 피해를 경감시키는데 도움을 줄 수 있을 것으로 생각되었다.

복숭아 네 품종 ‘오도로끼’, ‘가납암백도’, ‘진미’, ‘장호원황 도’ 신초의 저온순화 및 탈순화 동안 시기별 내한성 변화는 전해질 누출률을 분석하여 나타냈다. 또한 내한성 결정 요인 을 분석하고자 SDS-PAGE를 이용하여 dehydrin 함량 변화를 확인하였으며, 그와 관련된 유전자 발현 분석은 quantitative real-time RT-PCR을 이용하여 수행하였다. 네 품종의 내한성 은 2012년 12월까지 꾸준히 증가하였으며 그 후 2013년 4월 까지 감소하였다. PpDhn1 유전자가 인코딩하는 60kDa의 dehydrin 단백질은 탈순화기(2013년 3-4월)에 비하여 저온순화 기(2012년11월-2013년 1월) 동안 높은 축적이 확인되었다. PpDhn1 유전자와 PpDhn3 유전자 발현양상은 복숭아 네 품 종에서 내한성 변화와 평행하게 나타난 반면, PpDhn2 유전자 는 뚜렷한 시기별 패턴을 나타내지 않았다.

Hand leaf thinning for improvement of fruit coloration and quality is one of the most labor-consuming works in Korean apple cultivation. The study was aimed at investigating whether foliar application of two chelate compounds (Cu-EDTA, Fe-EDTA) could defoliate effectively ‘Hongro’/M.9 apple leaves and enhance fruit coloration and quality. At 30 days before harvest, foliar spray with two chelate compounds defoliated significantly the apple leaves. Chelate treatments did not affect the leaf chlorophyll content. High concentration of chelates decreased drastically photosynthetic rate of true leaves, and then it stayed in low levels, whereas low levels of chelates reduced sharply the photosynthetic rate but it was gradually restored over time. Cu-EDTA regardless of its concentration triggered higher defoliation compared to Fe-EDTA. Consequently, higher defoliation improved light interception of fruits and accumulated more anthocyanin. Particularly, Cu-EDTA could target mainly fruit cluster leaves which affect directly light interception of the fruits, i.e. more selective defoliants compared to Fe-EDTA. However, 3% Cu-EDTA rather defoliated excessively, accompanying with reduction of fruit weight and soluble solids. Therefore, our results suggest that 1% Cu-EDTA which defoliates properly the fruit cluster leaves could improve coloration and quality of ‘Hongro’/M.9 apple fruits.

사과 ‘후지’/M.9 포트묘목 개발을 위해 질소시비농도에 따른 생장특성을 조사하고, 포트 우량묘목 생산에 적합한 질소시비 농도와 잎의 무기영양성분 함량 및 토양 화학성의 안정성을 확인하였다. 질소시비농도가 높아질수록 묘목의 생장은 증가되 었고, 특히 16 mM 처리가 수체 생장에 가장 좋았으며, 우량묘목 판단기준에 부합하였다. 32 mM 이상의 고농도는 오히려 생장 을 감소시켰다. 잎의 무기영양성분 함량은 8, 16 mM 처리구에서 기존 사과과원의 적정수준보다 높았고, 이러한 무기영양성분은 정식 후 수체 생장에 도움이 될 것으로 생각되었다. 토양 화학성 또한 8, 16 mM 처리구에서 안정적이었다. 따라서 수체 생육, 잎의 무기영양성분, 포트 내 토양화학성을 고려한 결과, 사과 ‘후지’/M.9 우량 포트묘목 생산을 위한 적정 질소시비량은 16 mM로 판단되었다.

The study was performed to investigate basic tree growth and fruit characteristics of ‘Nero’ black chokeberry (Aronia melanocarpa) depending on the different cultivation regions and altitudes in 2014, 2015. Tree growth and change of developmental stages of ‘Nero’ were similar regardless of meteorological environment of the four cultivation regions (Danyang, Okcheon, Yeongdong, and Geumsan) in 2014. Fruit characteristics of ‘Nero’ were significant differences in berry weight and anthocyanin content among the four orchards due to difference in cultivation techniques and relatively wide daily temperature range just before harvest, respectively. Tree growth and change of developmental stages of ‘Nero’ grown at the two orchards with different altitudes appeared to be similar during the successive years 2014 and 2015. Soluble solids content of the berries cultivated at low altitude (117 m) was higher than at high altitude (342 m). Acidity showed an inverse pattern with soluble solids content. Anthocyanin content increased progressively until at the middle of August, 2014-15 and then it decreased. Our results showed that black chokeberry is a species adaptive to the domestic environment as there were no differences in tree growth and change of developmental stages of ‘Nero’. Considering fruit quality of black chokeberry such as soluble solids content, acidity, and anthocyanin content, our results suggest that optimal harvest period of black chokeberry ‘Nero’ is August 8 to 19.

Effects of different soil water conditions on fruit characteristics were investigated in 5-year-old ‘Nero’ black chokeberry trees (Aronia melanocarpa). Three kinds of drought stresses, including low water deficit, severe water deficit, and very severe water deficit, due to decline of soil water decreased the fruit quality of weight of 10 berries, soluble solid content, and anthocyanin, compared with the control (consistent water supply) during the harvest period. After longer drought stress, supply of soil water could induce berry cracking because cell size of epidermis of fruits contracted, whereas cell size of sub-epidermis and flesh expanded. Thus periodic water supply using water supply facility is needed for yield and quality of ‘Nero’ black chokeberry fruits.

The objective of the study was to identify 52 Asian pear accessions, two primary pear species, and one reference pear Asian pear with 12 microsatellite markers to maintain pear germplasm collection. The number of alleles of 12 microsatellites detected ranged from eight at CH03d12 to 18 at CH01f07. Gene diversity ranged from 0.7053 at CH01d08 to 0.9224 at CH01f07. The lowest value of PIC was 0.6600 at CH01d08 and the highest was 0.9171 at CH01f07. A group consisting of ‘Ooharabeni,’ ‘Bartlett,’ and P. calleryana was out-grouped and served as a reference to determine the relationship among Asian pear accessions. Except for the out-group, 50 Asian pears were segregated into two groups. Group I was divided in two small groups. Each small group was characterized by P. bretschneideri and P. ussuriensis, respectively. Group II was characterized as P. pyrifolia, and the group was divided in four small groups. The eigenvalue, difference, proportion, and cumulative of six principal components based on PCA to 12 microsatellite. The eigenvalue of the first principal components was 5.5850. The proportion of the first principal component was 0.9308. The cumulative value of the first two principal components was 0.9801. Consequently, nearly all of the results were elucidated by the two principal components. The results from analysis of the standard set of microsatellites in this study may be used as basic materials for the management of Asian pear germplasm collections, and the data might be useful in the development of a core collection.

Proline has been shown to accumulate in plant under various type of stresses. In our previous study, changes in cold hardiness and proline content showed contrasting patterns during a constant deacclimation. This study was performed to investigate the proline accumulation and related gene expression in response to repeated deacclimation and reacclimation in peach cultivar ‘Daewol’. Proline content was analyzed using the ninhydrin method and related gene expressions were examined using quantitative real-time RT-PCR. Proline contents of ‘Daewol’ increased during the repeated deacclimation treatments. Interestingly, during the twice deacclimation, expressions of P5CS (Δ1-pyrroline-5-carboxylatesynthase) constantly decreased, whereas expressions of P5CR (Δ1-pyrroline-5-carboxylatereductase) increased. Expressions of OAT (ornithine-δ-aminotransferase) indicated up- and down- pattern in response to repeated deacclimation and reacclimation. Our results indicated that proline responds positively to higher temperature in the shoots of peach cultivar ‘Daewol’ and expressions of both P5CS and P5CR genes could show contrasting patterns during the deacclimation. Moreover, our results suggest that ornithine pathway could serve as an alternative pathway in proline synthesis process during deacclimation in peach.

Proline (Pro) accumulation is a common physiological reaction in response to abiotic stresses in many plants. Accumulation of Pro is believed to play the important role in protecting cellular components from dehydrating effects due to such stresses. The study was performed to investigate the relationship between cold hardiness and Pro content or expression of related genes in peach cultivars during a constant experimental deacclimation. Changes in cold hardiness were determined using electrolyte leakage method in the shoots of 10 peach cultivars (Prunus persica ‘Aikawanakajima’, ‘Chiyomaru’, ‘Daewol’, ‘Janghowon Hwangdo’, ‘Kiraranokiwami’, ‘Mihong’, ‘Misshong’, ‘Soomee’, ‘Suhong’, and ‘Sun Gold’). Pro content was analyzed using the ninhydrin method and related gene expressions were examined using quantitative real-time RT-PCR. While cold hardiness of 10 peach cultivars decreased, Pro contents of those increased during the deacclimation. Notably, at the same time, expression of P5CS (Δ1-pyrroline-5-carboxylatesynthase) decreased in 10 peach cultivars, whereas expressions of P5CR (Δ1-pyrroline-5-carboxylatereductase) and OAT (ornithine-δ-aminotransferase) increased. Our results demonstrate that Pro responds positively to higher temperature in the shoots of 10 peach cultivars and expression of both P5CS and P5CR genes could show contrasting patterns during the deacclimation. Furthermore, our results suggest that ornithine pathway, which has been suggested to be important during seedling development, could serve as an alternative pathway in Pro synthesis process during the deacclimation in peach.

In this study, we sought to identify primary pears species and Korean native pears, without the use of morphological characteristics. In addition, this study was to establish pear DNA fingerprinting data for Korean native pears using 12 microsatellite markers, and to accurately classify a database for management of the Korean pear collection. Forty two pear accessions (7 primary pears, 5 Asian pears, 29 Korean pears, and 2 reference pears) were analyzed with twelve primers covering whole pear genome. In the present study, all pear accessions were successfully classified along with their pedigrees, and the distribution of primary pears was parallel to those of the previous taxonomic results. Korean pears were divided into 3 groups. Group I was characterized by Pyrus calleryana, and included Korean pea pears. Group II was characterized by P. pyrifolia, and was classified into 2 small groups. The first small group comprised of ‘Najucheongbae’, ‘Sunchanggulimdolbae’, ‘Andongmookbae’, ‘Andongdangsilri’, and ‘Najucheongbae’ and was presumed to be cultivars of P. pyrifolia. The second small group consisted of ‘Cheongdangrori’ and ‘Pyeongchangsuhyangri’. These two accessions were assumed to be a hybrid of P. pyrifolia and the other cultivar. Group III was characterized by P. ussuriensis. ‘Goesanhwangbae’, ‘Andongcheongsilri’, ‘Gongjucheongsilri’, and ‘Yecheoncheongbae’ were assumed to be cultivars of P. ussuriensis. Contrary to ‘Ulreungdocheongbae A’, ‘Ulreungdocheongbae B’ was classified as belonging to the P. ussuriensis group. It is possible that this is a consequence of, P. ussuriensis genes being transferred into ‘Ulreungdocheongbae B’. The result of this research reaffirmed the efficiency of a standard set of microsatellite markers and provides data, which will be useful for developing a core collection of pears.

Korea is a origin of three basic species, P. ussuriensis, P. pyrifolia and P. fauriei. Genetic relationship among Korean pear cultivars compared with their parents were also identified that they are closely related P. pyrifolia, P. ussuriensis and/or hybrid between two species. SSRs or Microsatellites are co-dominant and typically neutral inheritance showing high degree of polymorphism, large number of alleles per locus, abundance in genomes, and suitability for automation. SSR markers were developed in apple and pear where they were used for construction of genetic linkage maps, evaluation of the genetic diversity, cultivar identification, genotype identification, and in the determination of genetic relatedness. Many apple (Malus × domestica Borkh.) SSRs would be useful for genetic mapping in European and Asian pears in previous experiments and cross-species amplification was observed between apple and pear. The objectives of this study were to develop polymorphic SSR markers in ‘Whangkeumbae’ and ‘Minibae’, which were chosen as the representative cultivars of P. pyrifolia and P. ussuriensis in each among Korean pears, from ‘Golden Delicious’ genomic sequences generated by next generation sequencing technology and to evaluate the utility of the SSR markers based on ‘Golden Delicious’ sequences. Of 51 SSR markers, 18 were polymorphic in ‘Whangkeumbae’ and ‘Minibae’. The cross-species transportability of primers designed in ‘Golden Delicious’ sequences makes SSR markers more useful, given the current high level of investment in mapping the genomes of related Rosaceae.

Currently, the type of short insertions and deletions (InDels) polymorphisms are increasingly focused in genomic research. InDels have been known as a source of genetic markers that are widely spread across the genome. Genetic relationship among Korean pear cultivars compared with their parents was also identified that they are closely related P. pyrifolia, P. ussuriensis and/or hybrids between two species. Lack of genetic resources including molecular markers has made it difficult to study pears severely. Recently developed next generation sequencing (NGS) platforms offer opportunities for high-throughput and inexpensive genome sequencing and rapid marker development. The main goal of this study was to develop polymorphic InDel markers in ‘Whangkeumbae’ and ‘Minibae’, which were chosen as the representative cultivars of P. pyrifolia and P. ussuriensis × pyrifolia in each among Korean pears using genomic sequences generated by NGS technology. In this study, more than 18.6 Gbp and 15.8 Gbp sequences were obtained from NGS of ‘Whangkeumbae’ and ‘Minibae’, respectively. ‘Whangkeumbae’ contained 197,210 InDels and 197,272 InDels in ‘Minibae’. In InDels validations between ‘Whangkeumbae’ and ‘Minibae’, the number of polymorphic InDels were 149,338 and non-polymorphic InDels were 122,572. For InDel primer set designing, 11,308 of primers were designed from polymorphic InDels and 10,919 of InDel primers were recommended. The study shows that the utility of NGS technology to design amount of efficient InDels and the developed InDel primers will be used for genetic mapping, breeding by marker assisted selection (MAS) and QTL mapping of Korea native pear as well as further genetic studies.

Single nucleotide polymorphisms (SNPs) are the most frequent type among variations found in genomic regions and are valuable markers for genetic mapping, genetic diversity studies and association mapping in plants. There are three basic species known as Korean native which are Pyrus ussuriensis, P. pyrifolia, and P. fauriei. Genetic relationship among Korean pear cultivars compared with their parents was identified that they are closely related P. pyrifolia, P. ussuriensis and/or hybrids between two species. Lack of genetic resources, including molecular markers to study pears are very severe. Recently developed next generation sequencing (NGS) platforms offer opportunities for high-throughput and inexpensive genome sequencing and rapid marker development. The objective of this study was to develop polymorphic SNP markers in ‘Whangkeumbae’ and ‘Minibae’, which were chosen as the representative cultivars of P. pyrifolia and P. ussuriensis × pyrifolia in each among Korean pears, using genomic sequences generated by NGS technology. In this study, more than 18.6 Gbp and 15.8 Gbp sequences were obtained from NGS of ‘Whangkeumbae’ and ‘Minibae’, respectively. ‘Whangkeumbae’ and ‘Minibae’ contained 2,712,288 and 2,747,224 SNPs, respectively. In SNPs validations between ‘Whangkeumbae’ and ‘Minibae’, the number of polymorphic SNPs were 2,516,438 and non-polymorphic SNPs were 1,179,391. For HRM primer design, 2,125,479 HRM candidate primers were obtained from polymorphic SNPs and 343,731 SNP primers were developed. This study shows that the utility of NGS technology to discover efficiently a large number of SNPs and SNP primers can provide valuable information in the genome study of Pyrus spp.

Pear (Pyrus spp.) is one of the most important temperate fruit species in the world. The identification of Pyrus spp. based on analysis and comparison of their phenotypes has been causing a number of synonyms and homonyms among Pyrus spp. For accurate identification, genotype analysis with molecular marker such as microsatellite is necessarily to use. However, It is difficult to share and compare of microsatellite profiles obtained among different laboratories because no effort has made to standardize equipment or protocols. A strategy for data comparison by dint of reference to the alleles detected in well-known cultivars will be helpful for co-work with laboratories and developing international databases. Thus the study was performed to compare results between laboratories of microsatellite DNA profiling for reproducibility and standardize allele scoring by defining reference alleles efficiently. In this study, ninety pear species including forty-four comparison Asian pears, six of comparison suspicious Asian pears and reference pears, seven basic pear species, and twenty-seven Korean native pear cultivars to development of a standard set of SSR reference alleles. Twelve primers covering most of pear genome were chosen, which are CH02b10, CH03g07, CH04e03, CH03d12, EMPc117, CH01f07a, EMPc11, CH01d09, GD147, CH01d08, CH05c06, and GD96 located in pear chromosome of 2, 3, 5, 6, 7, 10, 11, 12, 13, 15, 16, and 17 respectively. Genotyping was conducted with Fragment Analyzer. After genotyping, a set of defined standard alleles based on reference pear cultivars can facilitate data comparison among laboratories and will permit the improvement of a common international database.

Recent climate changes due to global warming are gradually introducing adverse circumstances for winter survival of temperate fruit trees. Particularly, late winter or early spring thaws followed by hard freezes can cause severe injury to deacclimated flower buds. Thus, the selection of later or slower deacclimating cultivars is needed to avoid frost injury in late winter or early spring. This study was performed to investigate relationship between cold hardiness and bud development under an experimental deacclimation condition for 10 Prunus persica cultivars (Aikawanakajima, Daewol, Izumi Hakuto, Janghowon Hwangdo, Kiraranokiwami, Mihong, Misshong, Soomee, Suhong, and Sun Gold). The rate of deacclimation was not correlated with hardiness before the deacclimation treatment. On the other hand, a strong positive correlation was found between cold hardiness and stage of bud opening.

Changes in cold hardiness were confirmed with relative electrolyte leakage (REL) method in the shoots of two peach cultivars (Prunus persica Janghowon Hwangdo and Odoroki) during cold acclimation and deacclimation. Changes in proline (Pro) content and related gene expressions were also analyzed. Particularly, transcript accumulations of P5CS and P5CR were examined using quantitative real-time RT-PCR. REL in the shoots of two peach cultivars was significantly different during the entire experimental period. Cold hardiness of two cultivars increased gradually to December 2012, and then decreased to April 2013, whereas Pro contents of ‘Janghowon Hwangdo’ and ‘Odoroki’ were reduced from the beginning of the experiment to February 2012 and then increased in the spring. Interestingly, P5CS gene encoding an enzyme, which catalyzes conversion from glutamic acid (Glu) into glutamic-γ-semialdehyde (GSA) in the first step of Pro pathway, showed the contrasting patterns with Pro contents of two cultivars. On the other hand, P5CR gene encoding an enzyme, which catalyzes conversion from Δ1-pyrroline-5-carboxylate(P5C)intoPro in the final step of Pro pathway, showed the similar patterns to Pro contents in two cultivars. Our results demonstrate that Pro responds negatively to low temperatures in the shoot of different peach cultivars, including the supplemental 10 peach cultivars, and expression of both P5CS and P5CR genes could show contrasting patterns from each other. Our results suggest that identification of both P5CS and P5CR genes are required necessarily for accurate analysis of Pro biosynthesis because Pro accumulation is affected more by expression of P5CR gene.