Heat-induced softening of apple fruit varies markedly among cultivars; however, the biochemical factors underlying these differences remain incompletely understood. This study investigated the relationship between cell wall modifications and thermal flesh breakdown in three apple cultivars (‘Bramley’s Seedling’, ‘Fuji’, and ‘Toki’). Fruit flesh samples were heated under controlled conditions and analyzed for changes in texture properties, cell structure, cell wall composition, and molar mass distribution. Heating increased water-soluble pectin in all cultivars, with a markedly greater increase in ‘Bramley’s Seedling’, indicating pronounced pectin solubilization during thermal treatment. A pronounced shift from high- to low-molar-weight polymers in the Na2CO3-soluble fraction was also observed only in ‘Bramley’s Seedling’, suggesting extensive depolymerization of the Na2CO3-soluble pectic polymers. A decrease in hemicellulose and cellulose content following heating was observed exclusively in ‘Bramley’s Seedling’. Consistently, this cultivar exhibited significantly lower gumminess and chewiness compared with the other cultivars. Beyond compositional changes, ‘Bramley’s Seedling’ exhibited severe tissue disintegration and distinctive rheological behavior indicative of extensive cell rupture. In contrast, ‘Fuji’ and ‘Toki’ retained relatively stable cell wall structures and maintained tissue integrity after heating. These findings suggest that cultivar-dependent disassembly of cell wall polysaccharides, particularly pectin depolymerization and solubilization, is strongly associated with heat-induced tissue breakdown.

This study was conducted to investigate the effects of root zone temperature (RZT) on the growth of medicinal crop seedlings. Seed tubers of Codonopsis lanceolata and seeds of Rehmannia glutinosa were sown and, following germination or sprouting, transplanted into seedling boxes with controlled RZTs. Four chillers were installed to regulate the RZT, and temperature-controlled water was circulated continuously through five irrigation tubes embedded within the root media to maintain RZTs of 9 °C, 12 °C, 15 °C, and 18 °C. Seedlings were grown under these conditions, and growth parameters were measured 34 days after sowing for Rehmannia glutinosa and 47 days for Codonopsis lanceolata. In both species, increasing the RZT from 9 °C to 18 °C resulted in a linear or exponential increase in shoot height, leaf length, leaf width, shoot fresh and dry weights, root length, and root fresh and dry weights. Furthermore, higher RZTs led to increased tissue nutrient content and decreased nutrient concentrations in the root medium. Most of the analyzed nutrient elements showed significant trends of linear or quadratic regression. Based on these results, it is recommended to maintain the RZT at or above 18 °C to promote optimal seedling growth of Rehmannia glutinosa and Codonopsis lanceolata. Considering the growing need for standardized medicinal crop seedlings suitable for mechanical transplanting, these findings can serve as a foundation for controlled seedling production systems.

Apple russeting, characterized by the formation of corky tissue on the fruit surface, is a major cause of external quality deterioration in fresh-market apples. This study examined interannual variation in russet coverage in the russet-prone cultivar ‘Scilate’ (Malus domestica ‘Scilate’, marketed as ‘Envy’) over three consecutive growing seasons (2021–2023) and evaluated the relationships between russet development, post-bloom meteorological conditions, and gibberellin (GA₄+₇) plus 6-benzyladenine (6-BA) application. Marked interannual differences were observed in rough russet coverage, whereas smooth russet showed relatively stable proportions across years. Meteorological conditions varied substantially among years after full bloom, particularly with respect to temperature, humidity, precipitation, rainfall duration, and surface wetness. Period-wise correlation analysis revealed that the strength and direction of associations between rough russet coverage and meteorological variables differed depending on post-bloom stage. The strongest correlations were consistently observed during 21–30 days after full bloom (DAFB), when precipitation, rainfall duration, relative humidity, and dew index showed clear positive relationships with rough russet coverage. In contrast, correlations were weak or inconsistent during later post-bloom periods. Application of GA₄+₇ + 6-BA during early fruit development significantly reduced rough russet coverage while promoting fruit enlargement. The most pronounced suppression was observed at 18 mg·L⁻¹, whereas higher concentrations were associated with reduced soluble solids content and fruit firmness, indicating a trade-off between external appearance and internal fruit quality. Overall, these results indicate that humid and wet microclimatic conditions during 21–30 DAFB are closely associated with rough russet development in ‘Scilate’ apples and that appropriately timed GA₄+₇ + 6-BA application can effectively mitigate russet formation under such conditions. This study provides practical guidance for managing russet-prone cultivars in environments characterized by high rainfall and surface wetness during early fruit development.

This study investigated the effects of several fruit size factors on quality changes and the incidence of internal physiological disorders during the simulated export and distribution of 'Wonhwang' pears (Pyrus pyrifolia Nakai), the main early-season variety of Korean pear for export. Experiments were conducted on fruits packed (5 kg base) in four different grades of export standards at the Cheonan Pear Export Sorting Facility in 2023. All packaged fruits were stored at 1 degrees C for 30 days to simulate export transportation, followed by a simulated shelf life at 25 degrees C for 21 days. The soluble solids content did not vary by size, but the titratable acidity was lowest in the smallest fruit (Size 10) over the entire shelf lifetime. In addition, Size 10 fruits showed a higher respiration rate and greater ethylene production than fruits of other sizes. It was also found that the largest fruit (Size 7) and smallest fruit (Size 10) had lower levels of ethanol-insoluble substances than the medium-grade fruits of Sizes 8 and 9. The incidences of physiological disorders for fruits designated as Sizes 8 and 9 were lower in with regard to core browning and flesh browning compared to the largest fruit (Size 7) and smallest fruit (Size 10). Fruits of Size 8 and size 9 were judged to be the most suitable export standards for 'Wonhwang' pears.

‘Wonhwang’ pears are susceptible to the development of cortex and core browning after harvest. The effects of 1 μL L−1 1-methylcyclopropene (1-MCP) treatment on fruit quality, internal browning incidence, and targeted metabolites were evaluated in fruit stored at 25 °C for up to 30 d. Flesh firmness was higher in 1-MCP-treated fruit than in untreated fruit during storage; however, shrivelling increased in response to 1-MCP treatment. 1-MCP treatment delayed the changes in colour variables in core tissues but not in peel and cortex tissues, delayed cortex and core browning, and increased shrivelling. 1-MCP-treated fruit had higher sucrose, dehydroascorbic acid, alanine, threonine, and γ-aminobutyric acid contents and lower fructose and glucose contents than untreated fruit. The effects of 1-MCP on the physiological and metabolomic responses of fruit were detected using heatmap matrixes and by principal component analysis.

A better understanding of plant drought responses is essential to improve plant water use efficiency, productivity, and resilience to ever-changing climatic conditions. Here, we investigated the growth, morpho-anatomical, physiological, and biochemical responses of Quercus acutissima Carruth., Quercus serrata Murray, and Betula schmidtii Regel to progressive water-stress. Seedlings were subjected to well-watered (WW) and water-stressed (WS) conditions while regularly monitoring the soil volumetric water content, stem diameter (SD), height, biomass, stomatal conductance (gs), intercellular CO2 concentration (Ci), and leaf relative water content (RWC). We also investigated the variation in stomatal pore (SP) area, specific leaf area (SLA), root xylem vessel diameter (VD), and total soluble sugar (TSS) concentration between treatments. After 2 months, WS significantly suppressed SD growth of Q. acutissima and B. schmidtii but had no impact on Q. serrata. Total biomass significantly declined at WS-treated seedlings in all species. WS resulted in a smaller SLA than WW in all species. The SP of WS-treated seedlings of Q. acutissima and B. schmidtii significantly decreased, whereas it increased significantly with time in Q. serrata. Larger vessels (i.e., >100 to ≤ 130) were more frequent at WS for Q. acutissima and B. schmidtii, whereas smaller vessels (i.e., >40 to ≤ 90) were more frequent at WS than at WW for Q. serrata after 8 weeks. Tylosis was more frequent at WS than WW for Q. serrata and B. schmidtii at eighth week. WS seedlings showed lower gs, Ci, and RWC compared with WW-treated ones in Q. acutissima and B. schmidtii. TSS concentration was also higher at WS-treated seedlings in two Quercus species. Overall, principal component analysis (PCA) showed that SLA and SP are associated with WS seedlings of Q. serrata and B. schmidtii and the tylosis frequency, TSS, and VD are associated with WS seedlings of Q. acutissima. Therefore, water-stressed plants from all species responded positively to water stress with increasing experimental duration and stress intensity, and that is largely explained by morpho-anatomical traits and soluble sugar concentration. The present study should enhance our understanding of drought-induced tree growth and short-term tree-seedling responses to drought.

Watermelon (Citrullus lanatus) is an economically important fruit crop grown for consumption of its large edible fruit flesh. Pentatricopeptide-repeat (PPR) encoding genes, one of the large gene families in plants, are important RNA-binding proteins involved in the regulation of plant growth and development by influencing the expression of organellar mRNA transcripts. However, systematic information regarding the PPR gene family in watermelon remains largely unknown. In this comprehensive study, we identified and characterized a total of 422 C. lanatus PPR (ClaPPR) genes in the watermelon genome. Most ClaPPRs were intronless and were mapped across 12 chromosomes. Phylogenetic analysis showed that ClaPPR proteins could be divided into P and PLS subfamilies. Gene duplication analysis suggested that 11 pairs of segmentally duplicated genes existed. In-silico expression pattern analysis demonstrated that ClaPPRs may participate in the regulation of fruit development and ripening processes. Genotyping of 70 lines using 4 single nucleotide polymorphisms (SNPs) from 4 ClaPPRs resulted in match rates of over 0.87 for each validated SNPs in correlation with the unique phenotypes of flesh color, and could be used in differentiating red, yellow, or orange watermelons in breeding programs. Our results provide significant insights for a comprehensive understanding of PPR genes and recommend further studies on their roles in watermelon fruit growth and ripening, which could be utilized for cultivar development of watermelon.

본 연구는 ‘후지/M.9’와 ‘홍로/M.9’가 재식된 사과원에 바람이나 우박을 막기 위해 사용되는 망(구멍 크기 : 2×2mm)을 수관상부에 색상별로 백색과 청색을 나누어 설치한 후 햇빛의 차광정도 및 생육환경 차이 등에 따른 과실품질 변화를 조사하였다. ‘후지’ 사과의 경우 대기온도 34.8℃인 오후 2~3시경의 과실표면 온도를 측정한 결과, 무처리는 40.0℃로 가장 높았고, 청색 방풍망과 백색 방풍망 처리구는 각각 34.9℃, 36.6℃로 크게 낮았다. ‘홍로’에서는 무처리구가 44.2℃일 때, 청색 방풍망 처리구는 38.3℃, 백색 방풍망 처리구는 38.5℃를 기록하여 ‘후지’와 마찬가지로 온도 경감효과를 보였다. ‘후지’의 과피색차를 조사한 결과, 과피적색도(a*)는 무처리구가 16.5, 청색 방풍망 처리구는 18.0였으나, 백색 방풍망 처리구는 19.3으로 가장 높은 값을 보였다. ‘홍로’에서도 백색 방풍망 처리구가 적색도가 34.9로 무처리구 28.1에 비해 유의하게 높은 적색도 발현을 보였다. 일소피해 조사결과, ‘후지’에서 청색 방풍망 처리구 3.8%, 백색 방풍망 처리구 4.2%로 무처리구 9.4%에 비하여 크게 경감되었고, ‘홍로’의 경우는 청색 방풍망 처리구는 8.8%, 백색 방풍망 처리구는 12.4%로 무처리구 28.8%에 비하여 일소발생이 현저히 감소하였다. 이 같은 결과는 처리별 자외선 수치를 측정하였을 때 무처리 구간의 자외선 값에 비해 청색 방풍망 처리구에서 유의하게 낮아 방풍망 처리에 의한 자외선 차단 효과에 의한 것을 확인할 수 있었다.

This study was conducted to compare the effect of salicylic acid (SA), an ethylene biosynthesis inhibitor, and the 1-methylcyclopropene (1-MCP) fumigation, to prevent fruit quality deterioration and physiological disorders during the shelf-life of Korea’s leading export grape variety ‘Campbell Early’. The berries treated with SA after 1- MCP fumigation (1-MCP+SA) showed a higher firmness value and titratable acidity than single treatment of SA or 1-MCP. The rate of shattered berry was high as 41.7% for 100ppm ethephon spray, 40.8% for 25μM SA, and 38.2% for 1,000ppb 1-MCP, but showing only 18.7% when the SA was applied after 1-MCP fumigation. The ratio of short brushes less than 1mm was largest at 74.3% for ethephon treatment, while 1-MCP+SA treatment was found to have the longest brush length among all treatments, with a 2-4mm ratio of 22.8% and a 4-6mm ratio of 27.9%. The weight of rachis was found to be the lowest at 2.3g in the ethephon treatment, and the reduction of rachis weight loss per cluster by 1-MCP+SA treatment was evident. In addition, 1-MCP+SA treatment were effective in mitigating stem browning and berry decay during the 16-day storage period at 19oC in this cultivar, so it is believed that they can be used as a practical post-harvest treatment in grape exportation.

Precise and timely regulation of organ separation from the parent plant (abscission) is consequential to improvement of crop productivity as it influences both the timing of harvest and fruit quality. Abscission is tightly associated with plant fitness as unwanted organs (petals, sepals, filaments) are shed after fertilization while seeds, fruits, and leaves are cast off as means of reproductive success or in response to abiotic/biotic stresses. Floral organ abscission in Arabidopsis has been a useful model to elucidate the molecular mechanisms that underlie the separation processes, and multiple abscission signals associated with the activation and downstream pathways have been uncovered. Concomitantly, large-scale analyses of omics studies in diverse abscission systems of various plants have added valuable insights into the abscission process. The results suggest that there are common molecular events linked to the biosynthesis of a new extracellular matrix as well as cell wall disassembly. Comparative analysis between Arabidopsis and soybean abscission systems has revealed shared and yet disparate regulatory modules that affect the separation processes. In this review, we discuss our current understanding of the transcriptional regulation of abscission in several different plants that has improved on the previously proposed four-phased model of organ separation.

사과 표면의 온도 측정 결과, '후지' 품종에서 무처리 구가 44°C로 가장 높게 나왔으며, 미세살수 처리구가 35°C로 가장 낮아 사과의 표면온도를 직접적으로 낮추 는데 가장 효과적이었고, '홍로' 품종에서는 방풍망 처리 구가 무처리구에 비해 약 9°C의 온도하강 효과를 나타 내었다.조도 및 광량은 방풍망 처리구가 53.263lx로 무처리 구의 90.283lx에 비하여 유의하게 낮은 결과를 보였다. 그리고 오후 시간의 햇볕은 파장이 긴 적색광으로 과 실의 품온이 증가하고 광합성량이 증가되는 반면 과 실의 호흡량이 증가하여 색소 발현 및 저장양분의 축 적에 저해요인으로 작용하는 것으로 판단되었다. 또한, 방풍망을 이용한 차광으로 빛의 강도와 온도를 인위 적으로 낮추어 광포화점이 발생하지 않는 정도에서 충분한 채광시간과 효율적인 광합성작용을 유도 하는 것이 과실품질을 향상시킬 수 있는 방법으로 판단되 었다. '후지'와 '홍로'의 최대양자수율 Fv/Fm 값이 다 른 처리들보다 무처리구에서 0.74로 가장 낮은 것으 로 조사되었는데 이는 미세살수, 방풍망 처리구가 무 처리구에 비해 높은 광합성 효율을 나타내고 있음을 시사하였다.'후지'의 일소피해 조사결과 미세살수 처리구는 5%, 방풍망 처리구는 7%로 무처리구에 비하여 일소발생이 약 15% 경감되었고 '홍로'의 경우는 미세살수 처리구는 22%, 방풍망 처리구는 25%로 무처리구에 비하여 일소발 생이 약 7% 감소하였다. '홍로'의 일소피해 발생이 '후지' 에 비해서 높았던 이유는 '홍로'가 '후지'보다 비대 속도 가 빠르며 광을 받는 과실 표면의 면적이 상대적으로 컸기 때문으로 판단되었다.착색지수 중 적색도(a*)의 경우 '후지' 품종에서 무처 리구에 비하여 미세살수와 방풍망 처리구가 각각 26% 및 34%로 착색향상을 개선할 수 있었다. 이상의 결과를 종합하면, 사과 주요 품종에 대한 미세살수 및 방풍망 처리는 추후 기후변화로 인인 사과생육기 고온증상으로 발생할 수 있는 과실일소 및 착색불량 등 과실품질저해 요인을 저감할 수 있는 현장적용이 가능한 기술로 판단 되었고, 또한 이로 인한 상품성 증가로 농가 소득증대에 기여할 것으로 판단되었다.

본 연구는 우리나라 대표 수출 포도 품종인 ‘캠벨얼리’ 를 대상으로 에틸렌작용억제제인 1-methylcylopropene(1-MCP)과 에틸렌생합성 저해 효과를 지닌 salicylic acid(SA)를 단독 혹은 병행처리하여 과실의 저장 및 유 통환경에서 발생하는 탈립, 갈변 및 부패 등 생리장해의 발생과 과실 품질에 미치는 영향을 에틸렌 발생물질인 에테폰과 비교하여 검토하였다. 1-MCP 1,000ppb 훈증 처리 후 SA 25μM을 살포 처리하고 19°C에서 16일간 저장한 후 조사한 과립경도 및 산함량 수준은 단용처리 에 비하여 높게 나타났다. 탈립률은 100μL·L-1 에테폰 처 리구 41.7%, SA 처리구 40.8%, 1-MCP 처리구 38.2%로 나타났으나 1-MCP 처리 후 SA를 처리한 경우는 18.7% 로 탈립방지 효과가 월등하였다. 브러쉬의 길이를 측정 한 결과, 에테폰 처리구는 1mm 미만의 비율이 74.3%로 매우 높게 나타났던 반면, 1-MCP 처리 후 SA를 처리한 경우는 2-4mm의 비율이 22.8%, 4-6mm 비율이 27.9% 로 브러쉬 길이가 길게 조사되었다. 과축의 무게는 에테 폰 처리구에서 2.3g으로 가장 낮아 감모율의 증가에 미 치는 에틸렌의 영향과 1-MCP 및 SA의 감모 억제효과 를 확인할 수 있었다. 또한 1-MCP와 SA는 저장 중 ‘캠 벨얼리’ 포도의 줄기갈변 억제 및 부패 경감에 일부 효 과가 있음을 확인되어 추후 수출시 품질유지를 위한 기 술 적용이 가능할 것으로 판단되었다.