Red Skin Color Research Articles

POMOLOGICAL AND CHEMICAL CHARACTERISTICS OF SWEET CHERRY CULTIVARS GROWN IN DALMATIA, CROATIA

Sweet cherry growing in Mediterranean area of Croatia has a long tradition because of the favourable ecological conditions. Four local cultivars ('Gomilicka', 'Rana Stonska', 'Stonska' and 'Tugarka') and five introduced cultivars ('Bigarreau Burlat', 'Garnet', 'Isabella', 'Summit' and 'Van') were evaluated for ripening time and fruit characteristics. To assess external and internal fruit quality, the following was investigated: fruit weight (g), fruit lenght, width and fruit thickness (mm), weight of pits (g), fruit pedicel length (mm), fruit soluble solids (%), fruit acid content (g/l) and fruit skin colour (L, C, H, CIELAB system). Large differences for particular quality attributes were found between cultivars. Fruit of 'Isabella' and 'Tugarka' had a mean weight >7.5 g, while those of 'Bigarreau Burlat' was less than 5 g. Fruit soluble solid content varied from 13.1% ('Tugarka') to 19.2% ('Van'), and total titrable acidity varied from 4.8 g/l ('Rana Stonska') to 9.3 g/l ('Van'). The 'Garnet' fruits had the highest L values (dark red skin colour). Chroma and hue angle had higher level for fruits of 'Summit', 'Isabella' and 'Garnet', and lover for the other cultivars.

A and MdMYB1 allele-specific markers controlling apple (Malus x domestica Borkh.) skin color and suitability for marker-assisted selection.

Pre-selection for fruit skin color at the seedling stage would be highly advantageous, with marker-assisted selection offering a potential method for apple pre-selection. A and MdMYB1 alleles are allele-specific DNA markers that are potentially associated with apple skin color, and co-segregate with the Rf and Rni loci, respectively. Here, we assessed the potential application of these 2 alleles for marker-assisted breeding across 30 diverse cultivars and 2 apple seedling progenies. The red skin color phenotype was usually associated with the MdMYB1-1 allele and A(1) allele, respectively, while the 2 molecular markers provided approximately 91% predictability in the 'Fuji' x 'Cripps Pink' and 'Fuji' x 'Gala' progenies. The results obtained from the 30 cultivars and 2 progenies were consistent for the 2 molecular markers. Hence, the results supported that Rf and Rni could be located in a gene cluster, or even correspond to alleles of the same gene. Our results are consistent with the hypothesis that red/yellow dimorphism is controlled by a monogenic system, with the presence of the red anthocyanin pigmentation being dominant. In addition, our results supported that the practical utilization of the 2 function markers to efficiently and accurately select red-skinned apple cultivars in apple scion breeding programs.

Effect of Citric Acid on Growth and Red Coloration of Red Porgy (Pagrus pagrus)

This study investigates the effect of dietary citric acid supplementation on the growth and red coloration of red porgy (Pagrus pagrus). Red porgy (~0.5 g) were fed one of four diets: (a) an unsupplemented control, (b) a diet containing astaxanthin at 0.06 g/kg, (c) a diet containing citric acid at 30 g/kg, or (d) a diet containing both astaxanthin at 0.06 g/kg and citric acid at 30 g/kg. After two months, fish reached ~6 g with no differences in growth between groups. Astaxanthin increased the total carotenoid concentration in the skin from 3.16 to 45.15 μg/g in fish fed the astaxanthin-supplemented diet and from 2.61 to 50.07 μg/g in fish fed the diet supplemented by both astaxanthin and citric acid, producing a distinctive red skin color. Diet composition did not affect the melanin concentration of the skin, which ranged 57.60-68.18 μg/g and did not differ between groups. Dietary supplementation of citric acid did not affect growth or coloration in red porgy, thus alternative means of administering citric acid should be sought, for example, adding citric acid to the rearing water or injecting it into the fish body.

Estádio de maturação para o período ideal de colheita de maçãs 'Daiane' destinadas à armazenagem

Este trabalho foi realizado com o objetivo de identificar índices de maturação para o ponto ideal de colheita, de maçãs 'Daiane', destinadas a longos períodos de armazenamento. Maçãs foram colhidas semanalmente, em dois pomares comerciais, no período de 113 a 149 dias após a plena floração (DAPF), e armazenadas por 180 ou 240 dias a 0,7ºC, em atmosfera controlada. Medidas do estádio de maturação e da qualidade das maçãs foram realizadas um dia após a colheita e após a armazenagem. Atributos da aparência (cor vermelha) e sabor (relação açúcar/acidez) indicaram que a qualidade de maçãs 'Daiane', na colheita, é máxima quando colhidas 149 DAPF. No entanto, medidas da firmeza da polpa e da qualidade sensorial, realizadas após a armazenagem, indicaram que o período ideal de colheita de maçãs 'Daiane', destinadas a longos períodos de armazenagem, não deve estender-se além dos 136 DAPF. Maçãs 'Daiane' devem ser colhidas a partir de 121 DAPF para que mais da metade dos frutos tenham mais de 75% da superfície avermelhada. Desta maneira, o período ideal de colheita de maçãs 'Daiane', destinadas a longos períodos de armazenagem, ocorreu entre 121 e 136 DAPF no pomar 1, e entre 129 e 136 DAPF no pomar 2. No período ideal de colheita (121 a 136 DAPF), maçãs 'Daiane' apresentaram, um dia após a colheita, firmeza de 67 a 74 N, SS de 11,5 a 13 %, AT de 0,26% a 0,34%, índice de amido de 4,6 a 7,9 e índice de cor de fundo da epiderme de 2,6 a 4,0.

Amadurecimento e qualidade de ameixas 'Laetitia' tratadas com ácido salicílico e 1-metilciclopropeno

O objetivo deste trabalho foi avaliar o efeito da aplicação de ácido salicílico (AS), isoladamente e em combinação com o 1-metilciclopropeno (1-MCP), sobre o amadurecimento e a qualidade de ameixas 'Laetitia', armazenadas durante 40 dias, sob refrigeração (1 ± 0,1ºC / UR 92 ± 2%). Os tratamentos avaliados foram: controle; 1 mM de AS; 5 mM de AS; 10 mM de AS; e 5 mM de AS + 1-MCP (1 µL L-1). Nos frutos tratados com 10 mM de AS, verificou-se, após a saída da câmara, maior taxa de produção de etileno e incidência de manchas na epiderme, e, após três dias em condição ambiente, maior incidência de degenerescência de polpa. Em frutos tratados com 5 mM de AS, o 1-MCP proporcionou menor produção de etileno e menor incidência de degenerescência de polpa, maiores valores de atributos de textura, além de frutos menos vermelhos. O AS não apresenta efeito sobre a ocorrência de degenerescência da polpa e o amadurecimento de ameixas 'Laetitia', porém, provoca manchas na epiderme, em doses acima de 5 mM. Em frutos tratados com 5 mM de AS, a aplicação de 1-MCP atrasa o amadurecimento e mantém a qualidade da ameixa 'Laetitia'.

맛과 향이 좋은 촉성재배용 딸기 '대왕' 품종의 육성

'대왕' 품종은 농촌진흥청 국립원예특작과학원에서 2010년도 육성한 촉성재배용 신품종이다. 맛과 향이 우수하면서 경도가 강한 품종을 육성하기 위해 2006년 고당도 품종인 '매향'과 고당도 품종인 '원교3111호'를 교잡하여 육성하였다. '대왕' 품종의 주요 특성을 보면 초형이 직립형이고 초세는 매우 강하다. 화방당 꽃 수는 12-15개 정도로 적고 휴면타파를 위한 저온요구시간은 50-100시간 정도로 촉성재배용으로 적합한 품종이다. 과형은 원추형이고 과색은 연적색이며 평균과중은 16-17g 내외의 중대과형 품종이다. 과실의 당도는 <TEX>$11.1^{\circ}Brix$</TEX>, 산도는 0.39%로 당산비가 적절하여 식미가 좋으며 특히 과육 내 육질이 치밀하여 씹는 맛이 우수하다. 또한 경도가 <TEX>$18.2g{\cdot}mm^{-2}$</TEX>로 아키히메의 <TEX>$10.3g{\cdot}mm^{-2}$</TEX> 보다 <TEX>$7.9g{\cdot}mm^{-2}$</TEX>이 더 높아 봄철 늦게까지 수확이 가능하다. 그리고 상품과율은 대조품종인 '아키히메'보다 높았으나 전체적인 수량은 유의적인 차이를 보이지 않았다. 그러나 탄저병과 고온에 다소 약한 경향이 있다. A new cultivar 'Daewang' strawberry was developed by the National Institute of Horticultural & Herbal Science for forcing culture in 2010. The cultivar 'Daewang' was originated from the cross between 'Maehyang', a high firmness cultivar and 'Wongyo 3111', a high sugar content in 2006. The cultivar shows erect plant type, vigorous growth habit, early flower bud differentiation with 12-15 flowers per cluster from planting on healthy nursery. Fruits of 'Daewang' are conical type having a bright red skin color, and 16-17 g in an average weight. 'Daewang' is suitable for forcing culture as time required for dormancy breaking ranged between 50 and 100 hours. This cultivar has excellent taste for high sugar/acid ratio as sugar content of <TEX>$11.1^{\circ}Brix$</TEX>, acidity of 0.39% with abundant texture and can be harvested by late spring because the fruit firmness of 'Daewang' was <TEX>$18.2g{\cdot}mm^{-2}$</TEX> that was about <TEX>$7.9g{\cdot}mm^{-2}$</TEX> higher than <TEX>$10.3g{\cdot}mm^{-2}$</TEX> of 'Akihime' cultivar. But although total yield is not significantly different from 'Akihime' cultivar, its marketable yield is remarkably higher than that of 'Akihime' cultivar. Disease and pest resistance of 'Daewang' have a tendency to sensitive powdery mildew, anthracnose and spotted spider.

플럼코트 '하모니' 과실의 수확 후 품질에 미치는 저장온도 및 1-MCP 처리의 영향

본 실험은 자두와 살구의 종간잡종인 플럼코트 '하모니' 과실의 수확 후 적정저장 온도를 구명하고 에틸렌작용 억제제인 1-MCP 처리효과를 알아보기 위하여 수행되었다. 과실은 숙기를 3가지로 구분하여 수확 후 각각 0, 5, 10 및 <TEX>$20^{\circ}C$</TEX>의 온도에 저장하였고, 1-MCP(<TEX>$1{\mu}L{\cdot}L^{-1}$</TEX>) 처리는 <TEX>$10^{\circ}C$</TEX>에서 24시간 처리 후 <TEX>$10^{\circ}C$</TEX>에 저장하였다. 온도가 낮은 저장조건일수록 플럼코트 '하모니' 과실의 호흡량을 현저히 낮추었고 온도가 높을수록 호흡량의 증가와 함께 품질이 빨리 저하되었다. 저장온도 <TEX>$20^{\circ}C$</TEX>는 과실의 부패가 빠르게 촉진되어 유통조건으로 부적합하였다. 숙기에 따른 품질은 30-50% 정도의 붉은 착색 과실이 양호하였는데 특히, <TEX>$10^{\circ}C$</TEX>에 저장할 때, 식미가 가장 양호하였다. 1-MCP는 플럼코트 '하모니' 과실의 연화, 색도 변화, 산도 변화 등 전체적인 품질의 변화를 지연시키는데 효과적이었다. This study was conducted to investigate the optimum storage temperature and the effect of 1-methylcyclopropene (1-MCP) on the postharvest physiology and quality of plumcot (Prunus salicina Lindle. <TEX>${\times}$</TEX> Prunus armeniaca L.) 'Harmony' fruits. plumcot fruits were stored at 0, 5, 10, and <TEX>$20^{\circ}C$</TEX>, respectively, with three different ripeness stages grouped by skin color development. Furthermore, we treated <TEX>$1{\mu}L{\cdot}L^{-1}$</TEX> 1-MCP was treated at <TEX>$10^{\circ}C$</TEX> for 17 hours and stored at <TEX>$10^{\circ}C$</TEX> for 12 days to evaluate the effectiveness for better shelf-life. The results indicated that lower storage temperature than room temperature effectively reduced the respiration rate with delaying quality changes. While, the fruits showed worse fruit taste than the fruits stored at 10 and <TEX>$20^{\circ}C$</TEX>. Reversely, the fruits stored at <TEX>$20^{\circ}C$</TEX> showed more respiration rate and ethylene production. 1-MCP treatment effectively reduced the skin red color development, ethylene production, <TEX>$CO_2$</TEX> and softening of plumcot 'Harmony' fruits. Overall data indicated that the optimum harvest time and storage temperature could be 30-50% red color and near <TEX>$10^{\circ}C$</TEX>. Postharvest 1-MCP application at the level of <TEX>$1.0{\mu}L{\cdot}L^{-1}$</TEX> could maintain fruit quality well in plumcot fruits.

Colour Detection Thresholds in Faces and Colour Patches

Human facial skin colour reflects individuals' underlying health (Stephen et al 2011 Evolution & Human Behavior 32 216-227); and enhanced facial skin CIELab b* (yellowness), a* (redness), and L* (lightness) are perceived as healthy (also Stephen et al 2009a International Journal of Primatology 30 845-857). Here, we examine Malaysian Chinese participants' detection thresholds for CIELab L* (lightness), a* (redness), and b* (yellowness) colour changes in Asian, African, and Caucasian faces and skin coloured patches. Twelve face photos and three skin coloured patches were transformed to produce four pairs of images of each individual face and colour patch with different amounts of red, yellow, or lightness, from very subtle (deltaE = 1.2) to quite large differences (deltaE = 9.6). Participants were asked to decide which of sequentially displayed, paired same-face images or colour patches were lighter, redder, or yellower. Changes in facial redness, followed by changes in yellowness, were more easily discriminated than changes in luminance. However, visual sensitivity was not greater for redness and yellowness in nonface stimuli, suggesting red facial skin colour special salience. Participants were also significantly better at recognizing colour differences in own-race (Asian) and Caucasian faces than in African faces, suggesting the existence of cross-race effect in discriminating facial colours. Humans' colour vision may have been selected for skin colour signalling (Changizi et al 2006 Biology Letters 2 217-221), enabling individuals to perceive subtle changes in skin colour, reflecting health and emotional status.

적과 노력 절감용 촉성 딸기 '옥매' 품종 육성

A new strawberry cultivar (Fragaria ananassa Duch.) 'Okmae' was developed from a cross between 'Toyonoka' and 'Maehyang'. This cultivar has a good fruit quality and suitable number of flowers per cluster for labor saving in fruit thinning. 'Gyoengnam No. 1' was selected as an elite line with vigorous plant growth, higher soluble solids content and fruit firmness after examining its characteristics and productivity in forcing cultures from 2007 to 2009. Farmer's field trial of 'Gyoengnam No. 1' was conducted in 2010 and it was registered as 'Okmae' thereafter. The general characteristics of 'Okmae' are vigorous growth habit, erect plant type, less number of leaf and elliptic leaf shape. 'Okmae' has long peduncle and 9-10 flowers per flower cluster which need less labor for fruit thinning. Fruits of 'Okmae' are conical having a bright red and glossy skin color. Although 'Okmae' has a smaller average fruit number per plant of 21.9 than that of the control cultivars, it's possible to produce high yield because of greater fruit weight of 26.0 g. 'Okmae' showed a high soluble solids content of , low acidity of 0.37%, and high firmness of . It is sensitive to anthracnose and powery mildews, but high-quality strawberry can be harvested by using effective control measure.

ADVANCES IN PEACH AND NECTARINE BREEDING AT THE AGRICULTURAL RESEARCH COUNCIL OF SOUTH AFRICA

The Breeding and Evaluation unit of the Agricultural Research Council (ARC) Infruitec-Nietvoorbij uses conventional methods such as controlled crosses and recurrent mass selection to address the needs of the dessert and processing industries. The long-term objective is to breed a full range of high quality peach and nectarine cultivars ripening from very early (harvesting week 43) to very late (harvesting week 10) with the following attributes: a) Cold storage ability b) Desirable pomological attributes c) Adapted to diversity of SA climatic conditions d) Innovative cultivars During the period 2000 until 2007, 52 new yellow- and 21 white flesh peach selections, without blush for processing and 53 yellow flesh and 2 white flesh selections with full red skin colour aimed at the dessert industry, were identified. During the same period 124 full red and 23 yellow skin nectarine selections were identified. All these selections were promoted to the second phase of evaluation where budded trees are evaluated on different sites representative of the diversity of climatic conditions of the different fruit producing areas of South Africa. During this stage of evaluation fruit samples are evaluated for cold storage ability and/or processing potential. Five new peach cultivars and nine new nectarine cultivars have been released to the industry from 2000 until 2007. Three of the newly released nectarine cultivars have yellow skinned fruit with excellent drying characteristics and are marketed under the ColorburstTM trademark. During the 2006/2007 season 70.5% of the total peach cartons and 46% of the total nectarine cartons exported from South Africa were of cultivars developed by the ARC breeding program. It can be concluded that the breeding program has a substantial impact on the South African peach and nectarine industry in generating foreign income and keeping the industry competitive on the international markets.

Proteomic analysis of ‘Zaosu’ pear (Pyrus bretschneideri Rehd.) and its red skin bud mutation

BackgroundBreeding for strong red skin color is an important objective of the pear breeding program. There are few reports of proteome research in green skin pear and its red skin bud mutation. The manuscript at hand is one of the first studies dealing with 2D-PAGE-based analysis of pear fruits and leaves, establishing a suitable sample preparation and testing different 2D-PAGE protocols. Therefore, it may grant a basis for further studies on the pear proteome being the studies main goal. A proteomic analysis was conducted on leaves and fruits of ‘Zaosu’ pear (Pyrus bretschneideri Rehd.) and its red skin bud mutation in order to reveal their genetic differences in the protein level.ResultsIn the present study, the optimized two-dimensional (2-D) gel electrophoresis system of pear leaf and fruit was set up, and applied to analyze the leaves and fruit protein. The interesting peptide fragments were determined using 4800 Plus MALDI TOF/TOFTM Analyzer mass spectrometer, and the sequence obtained was blasted in NCBInr to identify the differentially-expressed protein. In the 1.5-fold differently-expressed proteins between ‘Zaosu’ pear and its mutant, 10 out of 35 proteins in fruit and 12 out of 24 ones in leaves were identified successfully. Among the 22 identified proteins, 7 protein spots were related to photosynthesis and energy metabolism; 4 were associated with environmental stress; 4 with disease defense; 2 with amino acid metabolism; 2 with cytoskeleton; 1 with antioxidant function; 1 with calcium metabolism; and 1 with unknown function. Moreover, related physiological index, such as chlorophyll content, Rubisco content and polyphone oxidase activity, were different between ‘Zaosu’ pear and its mutant.ConclusionA 2-D gel electrophoresis system of pear leaves and fruits was established, which was suitable for the analysis of proteome comparison. To the best of our knowledge, we have performed the first analysis of the proteomic changes in leaves and fruits of ‘Zaosu’ pear and its red skin bud mutation. Our study provides important information on the use of proteomic methods for studying protein regulation of ‘Zaosu’ pear and its red skin bud mutation.

Pediatric surgery triage: Problems and improvements

The Canadian Paediatric Triage and Acuity Scale (P-CTAS) is used and modified at hospitals as a triage tool for pediatric patients before they are seen in emergency rooms. Pediatric surgery patients account for very few of the many patients in emergency departments, but they should be triaged as emergency or urgent because they might be candidates for surgery. Problems with and improvements for triaging pediatric surgery patients using the P-CTAS were studied. This retrospective study evaluated all patients <16 years old who visited the emergency department of Kyorin University Hospital during an approximately 4 year period between 1 May 2005, and 11 February 2009. Pediatric surgery patients were divided into two groups to evaluate the efficiency of P-CTAS triage. Patients who needed emergency treatment were in group A, and the others were in group B. Most group A patients were level I, II, or III (97%, 111/114). In contrast, 60% (71/119) of group B patients were level IV or greater. Some problems with and suggestions for the P-CTAS were identified. Many patients with trauma were under 1 year of age, and many with a foreign body were under 2 years of age. Age categories should be added for patients with trauma or foreign body aspiration. Patients with abdominal pain, and without anal bleeding or vomiting who are >2 years old are triaged as level IV and they accounted for 12% of patients with possible intussusception in this study. A category of 'possible intussusception' should be made for level II. Most patients with acute scrotum, whether operated on or not, were level III. 'Red or purple color of scrotal skin' and/or 'within 6 h from onset' could be added to level II for patients with acute scrotum. P-CTAS worked well for pediatric surgery patients, and it needs to be modified and improved for such patients based on these results.

Release of three improved varieties for the expanded potato market in Kenya

Current potato varieties have not fully met the market demands of the rapidly expanding Kenyan potato industry. Newer varieties with tolerance to the major diseases, higher yields, better storability and processing qualities are therefore required. Through a collaborative research, six promising late blight tolerant clones initially from the International Potato Centre (CIP) were evaluated in National Performance Trials (NPT) in six potato growing regions. Three clones, namely: 393385.39, 393371.58 and 391691.96 were released by the National Variety Release Committee (NVRC) under the respective names of Sherekea, Kenya Mpya and Purple Gold. Sherekea had high yields (40-50T/ha), high tolerance to late blight and to major viruses, attractive red skin color, good storability, good cooking and processing qualities. Kenya Mpya had high yields (35-45 T/ha), high resistance to late blight, good chipping and mashing quality, short dormancy (75-90 days), early tuber bulking and early physiological maturity (90-105 days). Purple Gold had moderate to high yields, excellent crisping and good chipping, Table, cooking and mashing qualities, long dormancy and very good storability. The new varieties are expected to respond to various demands of the potato industry while increasing the varietal options available to the farmers.

Lipofuscin-Like Substance Involved in Pericarp Browning of Postharvest Litchi Fruit During Storage

Litchi (Litchi chinensis Sonn.) is a subtropical fruit of high commercial value in international trade. However, litchi fruit after harvest can rapidly lose their bright red skin color and turn brown with increasing storage time at ambient temperature. Postharvest browning of litchi fruit is mainly attributed to the degradation of anthocyanins and the oxidation of phenolics. In this study, the contents of lipofuscin-like substance in relation to the levels of anthocyanins and (-)- epicatechin, and browning index of litchi fruit during storage were investigated. In a storage period from 72 to 144 h, the relative content of lipofuscin-like substance increased by 51.1% while the contents of (-)-epicatechin and anthocyanins decreased by 41.2 and 98.1%, respectively, and the obvious accumulation of lipofuscin-like substance of pericarp tissue of litchi fruit was related to the reduced contents of anthocyanins and (-)-epicatechin. Furthermore, the increase in the con- tent of lipofuscin-like substance was significantly related to the increased browning index. It is suggested that lipofuscin- like substance could be one of the final products from the browning reaction of litchi fruit during storage.

PHYSICAL, SENSORY AND CONSUMER ANALYSIS OF EATING QUALITY AND APPEARANCE OF PEAR GENOTYPES AMONG SOUTH AFRICAN CONSUMERS

The Agricultural Research Council (ARC) Infruitec-Nietvoorbij, South Africa, aims to breed new European pear cultivars with a local as well as export market potential. They are focused on a range of blushed cultivars from early to late season that do not lose their red skin colour in high temperature conditions. Important eating quality characteristics that are used as selection criteria are high sugar content (sweet taste) and a strong pear flavour. We used descriptive sensory analysis, consumer preference and physical maturity measurements to determine the preference of pear appearance and taste among South African pear consumers. Our research showed that yellow, green and lightly coloured blushed pears were preferred and important sensory attributes were pear flavour, sweet taste, melting character, juiciness and a soft texture. Good flavour and texture are the most important positive attributes. Mealiness and hardness were the main negative attributes. Hence, it appears that the ARC breeding objectives are very well aligned with the preference of South African consumers. The findings were also consistent with international studies that indicated high pear flavour, sweetness, melting texture and juiciness as the most preferred sensory attributes in European pears. Therefore, preference studies can be conducted locally on new cultivars for the export market. Considering the preference for lighter red blush, breeders may find that new cultivars that accumulate more red pigment and are therefore less prone to colour loss may have a lower preference among consumers.

Differential Effects of Nitrogen Supply on Skin Pigmentation and Flesh Starch Breakdown of ‘Gala’ Apple

Apple maturity is often assessed by starch hydrolysis index, skin color, soluble solids, flesh firmness, and the rate of ethylene evolution. In red-fruited apple cultivars, the intensity and extent of coloration is an important consideration in determining the time of fruit harvest. Negative relationships have been found between tree nitrogen (N) status and fruit skin pigmentation, but how N affects flesh starch breakdown has not been examined in detail. The objective of this study was to determine how N supply affects flesh starch breakdown relative to skin color development. Seven-year-old ‘Gala’/M.26 trees were provided with four levels of N (8.8, 26.4, 52.7, and 105.4 g N per tree) in a modified Hoagland's solution. The effects of N supply on yield, fruit quality, and fruit maturation were evaluated. At harvest, fruit in the lowest N treatment was significantly smaller and had lower soluble solids but higher starch concentration, better color, and higher firmness than those grown at higher N supplies. Increasing N supply decreased both anthocyanin synthesis and chlorophyll degradation in fruit skin. Flesh starch concentration was higher at higher N supply at 38 days before harvest but was lower at higher N supply at harvest. Starch degradation was completed earlier during cold storage with increasing N supply. These results indicate that increasing N supply delays skin red color development but accelerates flesh starch degradation in ‘Gala’ apples. These differential effects of N supply should be taken into account when assessing fruit maturity for optimizing harvest time.

‘Victoria Red’ Grape

‘Victoria Red’ is the eighth grape cultivar (Vitis hybrid) developed by the University of Arkansas Division of Agriculture (Clark, 2010). This release is a cooperative endeavor with Texas A&M University and Tarkington Vineyard of Victoria, TX. The most significant characteristic of ‘Victoria Red’ is its disease resistance, vigor, and productivity in coastal Texas, an area of the United States with extremely high Pierce’s disease (Xylella fasitidiosa Wells et al.) pressure. It is a seeded grape with bright red skin color and large, attractive clusters. The skin is tender. This cultivar resists cracking at maturity resulting from rainfall. It has a neutral flavor. Winterhardiness is a limitation of the cultivar, because it routinely experienced cane and trunk injury in testing in west–central Arkansas. ‘Victoria Red’ is recommended primarily as a fresh-fruit cultivar for on-farm and local market sales in USDA hardiness zones 7b or warmer. Although resistance to Pierce’s disease has not been proved, it is recommended for trial in areas where this disease is prevalent.

Optimising quality-parameters of apple cv. ‘Pigeon’ by adjustment of nitrogen

To improve the productivity and quality of the apple cultivar ‘Pigeon’ the influence of 5 fertigation levels (14, 42, 70, 112, 224 mg N/l) and 3 widths of herbicide strip (0.2, 0.5, 1.0 m) were investigated on growth, yield and post-harvest quality/colour development of fruit. ‘Pigeon’ apples are picked when ca. 20% of the fruit skin has turned red, the fruit are then exposed to a sunning period on the orchard floor of 2–3 weeks to enhance red colour development (80% red skin); however the internal quality deteriorates during this period. Fruit drop occurs if fruit are left on the tree to develop colour. This study focused on how to reduce the length of the post-harvest sunning period to maximise both colour development and fruit quality. It was demonstrated that 14 mg N/l resulted in a low yield, small fruit, low vegetative growth, and low N content in leaf dry matter, but good fruit colour development. Excessive N fertigation (224 mg N/l) did not produce the significantly highest yield or the largest fruit, but it did enhance vegetative growth and resulted in less fruit colouration. N fertigation influenced optimal picking date; higher N fertigation delayed the time of picking, and increased the incidence of green fruit. Fruit from the high-N treatments required more days of post-harvest sunning to obtain the comparable red skin colour than fruit from the lower N-treatments. However, when all treatments were picked at ca. 20% fruit coloration it was not possible to reduce the length of post-harvest sunning period by N-supply. Most of the post-harvest colour development occurred within the first 6–9 days following harvest; colour developed on both sides but was enhanced on the shade side of the fruit. The shade side of the fruit had a greater potential for better red colour development than the blush side of the fruit. The content of soluble solids, fruit firmness and contents of minerals were not influenced by N-supply. The sunning period significantly reduced fruit firmness. Grass cover competed with the tree for N uptake with the narrow herbicide strip producing the smallest yield, the smallest vegetative growth and the reddest fruit. The wider the herbicide strip the lower the N fertigation necessary for optimal fruit production.

High temperature reduces apple fruit colour via modulation of the anthocyanin regulatory complex

The biosynthesis of anthocyanin in many plants is affected by environmental conditions. In apple (Malus × domestica Borkh.), concentrations of fruit anthocyanins are lower under hot climatic conditions. We examined the anthocyanin accumulation in the peel of maturing 'Mondial Gala' and 'Royal Gala' apples, grown in both temperate and hot climates, and using artificial heating of on-tree fruit. Heat caused a dramatic reduction of both peel anthocyanin concentration and transcripts of the genes of the anthocyanin biosynthetic pathway. Heating fruit rapidly reduced expression of the R2R3 MYB transcription factor (MYB10) responsible for coordinative regulation for red skin colour, as well as expression of other genes in the transcriptional activation complex. A single night of low temperatures is sufficient to elicit a large increase in transcription of MYB10 and consequently the biosynthetic pathway. Candidate genes that can repress anthocyanin biosynthesis did not appear to be responsible for reductions in anthocyanin content. We propose that temperature-induced regulation of anthocyanin biosynthesis is primarily caused by altered transcript levels of the activating anthocyanin regulatory complex.

Skin Color, Scab Sensitivity and Field Performance of Lines Derived from Spontaneous Chimeras of Red Norland Potato

On the Canadian prairies, consumers favor red-skinned potatoes (Solanum tuberosum), with Red Norland representing the most widely grown red-skinned cultivar. However, the skin color of Red Norland is not as red as desired, particularly after extended storage. In 2004 three Red Norland tubers which appeared to have zones of darker skin color were discovered. Plants were grown from sprouts taken from both the light and dark colored zones of these tubers. The change in skin color was stable through several generations of vegetative propagation; otherwise the plants and tubers were comparable to Red Norland. This suggests that the color change was due to a chimeral mutation in the epidermis. In field trials conducted in 2005 and 2006 over 30 lines derived from the chimeral tubers were assessed for skin color, yields, tuber conformation and sensitivity to common (Streptomyces scabies) and powdery scab (Spongospora subterranea). Lines with acceptable yield and tuber configuration as well as enhanced scab resistance and/or superior red skin color were evaluated in replicated trials conducted from 2007 to 2009. Several lines were identified that had superior red skin color relative to Red Norland. Several of the new lines also appeared more resistant to common scab than Red Norland. Yield potential of the selected lines was comparable to Red Norland and when adjusted for grade out due to excessive common scab, yields of several of the chimeral lines were superior to Red Norland. This study suggests that chimeras may represent a method for rapid, low cost improvement of skin color and common scab resistance of potato, while maintaining desirable agronomic characteristics.