Temperate Fruit Production Research Articles

EuAP2a, a key gene that regulates flowering time in peach (Prunus persica) by modulating Thermo-responsive transcription programming

Abstract Frequent spring frost damage threatens temperate fruit production, and the breeding of late-flowering cultivars is an effective strategy for preventing such damage, but the lack of specific genes and markers and a lack of understanding of the mechanisms make it difficult. We examined a Late-Flowering Peach (LFP) germplasm and found that its floral buds require a longer chilling period to release from their dormancy and a longer warming period to bloom than the control cultivar, two key characteristics associated with flowering time. We discovered that a 983-bp deletion in euAP2a, an APETALA2 (AP2)-related gene with known roles in regulating floral organ identity and flowering time, was primarily responsible for late flowering in LFP. This deletion disrupts an miR172 binding site, resulting in a gain-of-function mutation in euAP2a. Transcriptomic analyses revealed that at different stages of floral development, two chilling-responsive modules and four warm-responsive modules, comprising approximately 600 genes, were sequentially activated, forming a unique transcription programming. Furthermore, we found that euAP2a was transiently downregulated during the activation of these thermal-responsive modules at various stages. However, the loss of such transient, stage-specific downregulation of euAP2a caused by the deletion of miR172 binding sites resulted in the deactivation or delay of these modules in the LFP flower buds, suggesting that euAP2a acts as a transcription repressor to control floral developmental pace in peaches by modulating the thermo-responsive transcription programming. The findings shed light on the mechanisms behind late flowering in deciduous fruit trees, which is instrumental for breeding frost-tolerant cultivars.

Review on status of temperate fruit production: In case opportunities and challenges of temperate fruit production

Review on status of temperate fruit production: In case opportunities and challenges of temperate fruit production

Warm winters challenge the cultivation of temperate species in South America\u2014a spatial analysis of chill accumulation

Winter chill accumulation plays a crucial role in determining the moment of bud burst in temperate fruit and nut trees, and insufficient chill can greatly limit yield potentials. To assess future cultivation options for such species in South America, we estimated winter chill through a spatial analysis. We used historical data (1980–2017) from 158 weather stations to calibrate a weather generator and produce temperature data for 10 historical and 60 future scenarios. We computed Safe Winter Chill (SWC, corresponding to the 10th quantile of a chill distribution) for the period 1980–2017 and for all historical and future weather scenarios and developed a framework to interpolate SWC for the continent using the Kriging method. To improve the interpolation, we applied a 3D correction model based on two co-variables (means of daily temperature extremes in July). Our results suggest important chill declines in southern Brazil and central Chile. By 2050 under the global warming scenario RCP4.5 (Representative Concentration Pathway), absolute SWC in these regions may reach a median of 18.7 and 39.6 Chill Portions (CP), respectively. Projections are most alarming for a strong global warming scenario (RCP8.5). In southern South America, adequate SWC levels of about 60 CP may be expected even under the RCP8.5 scenario. Our results highlight the need for climate change adaptation measures to secure temperate fruit production in important growing regions of South America. The procedure we developed may help farmers and practitioners across South America estimate future SWC to adapt their orchards to future challenges.

Ethylene-Mediated Modulation of Bud Phenology, Cold Hardiness, and Hormone Biosynthesis in Peach (Prunus persica).

Spring frosts exacerbated by global climate change have become a constant threat to temperate fruit production. Delaying the bloom date by plant growth regulators (PGRs) has been proposed as a practical frost avoidance strategy. Ethephon is an ethylene-releasing PGR found to delay bloom in several fruit species, yet its use is often coupled with harmful effects, limiting its applicability in commercial tree fruit production. Little information is available regarding the mechanisms by which ethephon influences blooming and bud dormancy. This study investigated the effects of fall-applied ethephon on bud phenology, cold hardiness, and hormonal balance throughout the bud dormancy cycle in peach. Our findings concluded that ethephon could alter several significant aspects of peach bud physiology, including accelerated leaf fall, extended chilling accumulation period, increased heat requirements, improved cold hardiness, and delayed bloom date. Ethephon effects on these traits were primarily dependent on its concentration and application timing, with a high concentration (500 ppm) and an early application timing (10% leaf fall) being the most effective. Endogenous ethylene levels were induced significantly in the buds when ethephon was applied at 10% versus 90% leaf fall, indicating that leaves are essential for ethephon uptake. The hormonal analysis of buds at regular intervals of chilling hours (CH) and growing degree hours (GDH) also indicated that ethephon might exert its effects through an abscisic acid (ABA)-independent way in dormant buds. Instead, our data signifies the role of jasmonic acid (JA) in mediating budburst and bloom in peach, which also appears to be influenced by ethephon treatment. Overall, this research presents a new perspective in interpreting horticultural traits in the light of biochemical and molecular data and sheds light on the potential role of JA in bud dormancy, which deserves further attention in future studies that aim at mitigating spring frosts.

Vulnerability of Temperate Fruit Production to Climate Change: Adaptation and Mitigation Measures: A Review

Climate change refers to a statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer). As per United Nations Framework Convention on Climate Change (UNFCCC), change of climate is attributed directly or indirectly to human activity that alters the composition of global atmosphere and which is in addition to natural climate variability observed over comparable time period. The earth’s climate, although relatively stable over the past 10,000 years or so, has always been changing, mainly due to natural causes such as volcanic activity. However, since the second half of 20th century more rapid change has taken place, which has been attributed mainly due to human activities. Plausible climate change scenarios include higher temperatures, changes in precipitation, and higher atmospheric CO2 concentrations. Temperate region of the country, comprising mainly north-west and north east Himalayan region has witnesses a dramatic change in climate over the past 30 years, where adverse effect of climate change on temperate fruit production has been noticed. The carbon dioxide, methane, nitrous oxide, sulpherdioxide, etc. form greenhouse gas (GHG) pools in the atmosphere. Increase in the concentration of these gases is responsible for global climate change. According to Inter Governmental Panel on climate Change (IPCC), the climate is defined as the average weather, or more rigorously, as the statistical description of the weather in terms of the mean and variability of relevant quantities over periods of several decades (typically three decades as defined by Meteorological Organization). These quantities are most often surface variables such as temperature, precipitation, and wind, but in a wider sense the climate is the description of the state of the climate system. Global climate change and increasing climatic variability are recently considered a huge concern worldwide due to enormous emissions of greenhouse gases to the atmosphere and its more apparent effect on fruit crops because of its perennial nature. The changed climatic parameters affect the crop physiology, biochemistry, floral biology, biotic stresses like disease pest incidence, etc. and ultimately resulted to the reduction of yield and quality of fruit crops. So, it is big challenge to the scientists of the world. Mitigation is the most important measures to reduce the devastating effect of climate change.

Temperate fruits in the northern mountainous region: scientific results achieved and solutions for development in coming years

Perennial fruit crops generally and temperate fruits in particular make an important contribution to the sustainable development of the socio-economy in the northern mountainous region of Vietnam where the living standard of local farmers - 40% of whom are minorities from 30 groups - is still low (about 70% of the average of the country as a whole), though significant assistance has been made by the government and a slowly developed socio-economy has been recorded. It is obvious that proper temperate fruit production not only benefits local growers but also protects the environment in a significant way. Recent results concerning varietal selection and cultivation technologies for temperate fruits are summarized in this paper and some of the principal solutions, including proper planning, breeding programme enhancement, the establishing of production and value chains, and the training of skillful technicians and producers that is aimed at promoting production in the future, are also proposed.

Apples in action: Territoriality and land use politics of mountain agriculture in Taiwan

This essay outlines the symbolic and material transformation of mountain agriculture in Taiwan by tracing the historical trajectories of temperate fruit production, and of apple growing in particular. Specifically, we look at the area of Lishan, a major production centre for apples and other temperate fruits in Taiwan's Central Mountain Range in order to explore the relationship between the mountain agriculture and the politics of territorialisation. Focusing on the post‐war era, we argue that the development of mountain agriculture in Taiwan, and upland fruit growing in particular, has operated as a ‘more‐than‐human political technology’. The territory of Lishan is not just a passive geographical space, but engaged in a process of becoming, which re‐makes the mountain areas of Taiwan into ‘apple zones’ both spatially and socially. The spatial dimension centres on processes of political territorialisation, economic deterritorialisation and combined reterritorialisations whereby apple plantations have transformed the landscape from one focused on strategic politics to one embedded within development and market frameworks which entail their own particular forms of politics. The social dimensions are centred on the politics of forging connections among different elements circulating through the mountain areas of Taiwan, including apples, soldiers, transport infrastructures and agricultural policies.

Advances in the production of temperate fruits in the tropics

The present study aimed to review the advances in the production of temperate fruits to determine future research directions that improve production in the tropics. Temperate fruits are no longer only produced in regions characterized by a cold winter period. These fruits are also produced in the sub-tropical and tropical regions characterized by mild winter or even the absence of chilling conditions often required by the tree to break dormancy. Currently, temperate fruit production is possible in certain regions of South America, Africa and Asia that are near to the Equator. However, temperate tree fruit production in tropical regions requires modified techniques to overcome dormancy and allow adequate flowering, growth and productivity. The main approaches taken are the development of cultivars with low chilling requirement, chemical induction of budbreak, interruption of irrigation during the winter period, defoliation, orchard densification, and double pruning. Breeding has become a key tool in the advancement of temperate fruit growing in the tropics, especially with the development of low chilling requirement cultivars.

Metabolomics analysis of 'Housui' Japanese pear flower buds during endodormancy reveals metabolic suppression by thermal fluctuation

Dormancy is a complex phenomenon that allows plants to survive the winter season. Studies of dormancy have recently attracted more attention due to the expansion of temperate fruit production in areas under mild winters and due to climate changes. This study aimed to identify and characterize the metabolic changes induced by chilling temperatures, as well as during thermal fluctuation conditions that simulate mild winter and/or climate change scenarios. To do this, we compared the metabolic profile of Japanese pear flower buds exposed to constant chilling at 6 °C and thermal fluctuations of 6 °C/18 °C (150 h/150 h) during endodormancy. We detected 91 metabolites by gas chromatography paired with time-of-flight mass spectrometry (GC-TOF-MS) that could be classified into eight groups: amino acids, amino acid derivatives, organic acids, sugars and polyols, fatty acids and sterols, phenol lipids, phenylpropanoids, and other compounds. Metabolomics analysis revealed that the level of several amino acids decreased during endodormancy. Sugar and polyol levels increased during endodormancy during constant chilling and might be associated with chilling stress tolerance and providing an energy supply for resuming growth. In contrast, thermal fluctuations produced low levels of metabolites related to the pentose phosphate pathway, energy production, and tricarboxylic acid (TCA) cycle in flower buds, which may be associated with failed endodormancy release. This metabolic profile contributes to our understanding of the biological mechanism of dormancy during chilling accumulation and clarifies the metabolic changes during mild winters and future climate change scenarios.

Impact of changes in climatic conditions on temperate fruit production of Himachal Pradesh

The study examined the impacts of changing climate on productivity of temperate fruit crops viz., plum, pear, peach and apricot in Himachal Pradesh based on climate information and farmers’ perception. Three study sites representing different elevations viz., Shimla, Kullu and Palampur were selected to relate the chill units with temperate fruit productivity. The climate element distribution over the period in each study site revealed an increase in the mean temperature to the tune of 0.050, 0.019 and 0.046 °C per year in Shimla, Palampur and Kullu respectively in the past 3 to 4 decade. The rate of decrease of rainfall per year during winter season was -9.86 mm in Shimla, -11.1 mm in Kullu and -8.6 mm in Palampur leading to a decrease in chill accrual. The chill units calculated using the UTAH model showed a decline of more than 4.97 chill units per year during December month, 0.64 units per year in January and 3.75 units per year in February month in past 26 year period in Shimla district. The decrease of 1.73, 1.84 and 1.65 chill units every year during December, January and February months were observed at Kullu. The decrease of chill units during December to February ranged from -2.8 to -12.8 per year in Palampur were also observed. The significance of the slope of chill units was worked out using Mann-Kendall trend test which indicated no significant trend for the December month for Kullu region and January and February months at Shimla. Significant decreasing trends in chill units for January to February months for Kullu, December month for Shimla and December to February months were observed at Palampur. The indications of changes in climate have also been supported by the farmers’ perception in Kullu, Kangra and Shimla districts accounting a reduction in snowfall with an increase in temperature in past 20 to 30 years affecting the chill accumulation. The temperate fruits pear, peach, plum and apricot showed significant increase in the production at the rate of 0.172, 0.064, 0.018 and 0.018 t/ha per year during the past two and half decade respectively. Thus, the decreasing trends in cumulative chill units due to increase in temperature and reduction in rainfall in all locations varied from sub temperate climate in mid hills to temperate in high hills did not affect the productivity of temperate fruits in Himachal Pradesh and a promising replacement for apple shifting region in the face of climate change.

The Physiology of Chilling Temperature Requirements for Dormancy Release and Bud-break in Temperate Fruit Trees Grown at Mild Winter Tropical Climate

It is studied that inadequate winter chilling may interfere with the normal processes of plant growth, reproductive development and subsequent yield. As much of the evidences behind these studies are subjective and region based, the available information was collated and evaluated to further investigate the impacts of winter chill that is currently an issue of fruit growers in mild winter areas. Though, the period of adequate low temperatures is insufficient in warmer regions to satisfy the chilling requirements of temperate fruit trees, this call up on many option for chill compensation; like planting low chill cultivars, use of dormancy breaking chemicals, forced defoliation, pruning and some other techniques as an alternative strategies. However, the diverse agro-climatic conditions due to major differences in altitude, rainfall as well as in slope characteristics showed the existence of different chilling temperature requirements across locations that favor many temperate fruit trees to grow: including apple, pear, grape, peach, nectarine, plum, cherry, walnut, almond and other fruit tree species. Temperate fruit production in mild winter areas now days increased rapidly and even more new industries are being developed in regions where none previously existed. To date, in tropical highlands, fruit productivity and quality have been gradually improved through introduction and selection of better adaptable varieties based on their chilling requirements. To supplement the present existing knowledge gap in relation to the cultivar-environment interactions, the use of chill models to quantify chill accumulation during winter months would help in classifying the environment (potential growing areas) according to the amount of chill hours existed in that location. Up to date, a number of valid methods were applied for quantification of chill accumulation in tropical and sub-tropical conditions showed varying results depending on the types of species, existing warm temperature and other climatic variables. The limitation in their predictive performance from region to region is due to their designing approaches that were primarily for temperate climate. This requires a model comparison for specific location, i.e. by using more than one model to avoid the potential mis­leading in calculation and chill estimation. Of the chill models tested to quantify the chill accumulation in the mild winter areas, the use of dynamic model gave good estimation that it nullifies the chilling reversal by high temperature. Also, the model of Positive Chill Units (PCU, or Positive Utah) is a competent under warm climate, next to the dynamic model. The Positive Utah model, an iteration of the original Utah, excludes the negation influence of high temperatures. The procedure for PCU is the same as for the original Utah model except that, when negative, the chill unit value is set equal to zero. Therefore, the accumulated chill units are equal to zero until the temperatures drop into the effective zone and positive chill units begin to accumulate. Though, for these areas with warm climate, using the 0 - 7.2 °C model is not recommended, because of its sensitivity to changes in temperatures that represent different weighing factors recorded for other models. Other important alternatives to these classical models include, the Growing Degree Hour Model (GDH), the Mean Temperature Model, Exponential temperature response functions and others are applied as independently, or in combination with classical chill models for a better chill estimation. Winter chill should be studied like other weather dependent processes because the present trends in chill decline across locations significantly affect fruit culture in areas with mild winter. Therefore, identifying the problems related with lack of insufficient winter chilling would help in designing possible strategies for the changing scenarios and understanding the current physiological responses of the plant against these changes.

World temperate fruit production: characteristics and challenges

In the last 30 years world population has increased 70% but per capita global fruit consumption is only 20% higher. Even though tropical and temperate fruit have similar contributions to the 50 kg/person/year of US consumption of fresh fruit, in the last 30 years this has been slightly greater for temperate fruit. Within fruit consumption, the largest expansion has been for organic fruit which increased more than 50% in the 2002-2006 period. The largest expansion of area planted in the 1996-2006 has been for kiwi (29%) and blueberries (20%), while apples (-24%) and sour cherries (-13%) have had the largest reductions. Nearly 50% of the total global volume of fruit is produced by 5 countries: China, USA, Brazil, Italy and Spain. The main producer (China) accounts for 23% of the total. While the main exporters are Spain, USA and Italy, the main importers are Germany, Russia and UK. Demands for the industry have evolved towards quality, food safety and traceability. The industry faces higher productions costs (labor, energy, agrichemicals). The retailers are moving towards consolidation while the customers are changing preferences (food for health). In this context there is greater pressure on growers, processors and retailers. Emerging issues are labor supply, climate change, water availability and sustainability. Recent developments in precision agriculture, molecular biology, phenomics, crop modelling and post harvest physiology should increase yields and quality, and reduce costs for temperate fruit production around the world.

CURRENT WORLD STATUS OF ORGANIC TEMPERATE FRUITS

Consumption of organic food has steadily increased in the primary markets of the European Union and North America. However, the statistical information base to describe this growth is either incomplete or inaccessible and sometimes inaccurate. In the USA, fruits and vegetables make up 40% of organic food sales, implying that the expanding overall market has also increased demand for organic temperate fruits such as apple, grape, and strawberry. Organic fruit in several European countries comprises over 5% of all fruit sales. Data on organic temperate fruit production have been compiled by FiBL and Washington State University. In 2006, there were at least 250,000 ha of organic temperate fruit (pome, stone, grapes, and berries) under production worldwide (fully converted plus in conversion). Expansion rates vary by the fruit type and geographic location. In Washington State, USA, a leading producer of apple, pear, and cherry, organic production will soon comprise 10% of all apple hectares. Over 5% of the grape hectares in Italy are under organic management. Major organic temperate fruit production is spread around the globe but often is most successful with semi-arid, dry summer climates due to reduced disease problems. Leading producers include Italy, Turkey, USA, France, Spain, Poland, and Germany, which together accounted for about three-quarters of the global organic temperate fruit hectares in 2006.

The Occurrence of Codling Moth in Low Latitude Countries: Validation of Pest Distribution Reports

Phytosanitary restrictions are increasingly a factor in the ability of U.S. tree fruit exporters to gain and maintain access to worldwide markets. Under international trade rules, these restrictions must be based on specific guidelines, including an assessment of whether the proposed quarantine pest is likely to establish and spread under the climatic conditions of the importing country. Given the interest in and growth of temperate fruit production in the tropics, countries in the region (such as Taiwan, Columbia, Indonesia, and Thailand) have begun to impose a range of quarantine restrictions aimed at preventing the introduction of temperate zone pests. Apples (Malus ×domestica) are regulated in certain tropical/subtropical countries, such as Taiwan, for the presence of codling moth (CM; Cydia pomonella) in spite of reports in the literature that the distribution of CM is theoretically limited by daylength and chilling requirements to temperate regions. This work provides background as to why CM has been identified as a potential pest of quarantine concern in some low latitude countries; describes an approach used to validate worldwide CM distribution reports, providing additional information to allow for the revision of CM distribution maps; and demonstrates how accurate information regarding pest species distribution reports can aid in establishing an argument of ecological nonadaptability in the pest risk analysis process. Currently, a report of CM in Peru remains the only account of this pest's presence in low latitude countries that could not be refuted by the approach described here.

The Occurrence of Codling Moth in Low Latitude Countries: Validation of Pest Distribution Reports

Phytosanitary restrictions are increasingly a factor in the ability of U.S. tree fruit exporters to gain and maintain access to worldwide markets. Under international trade rules, these restrictions must be based on specific guidelines, including an assessment of whether the proposed quarantine pest is likely to establish and spread under the climatic conditions of the importing country. Given the interest in and growth of temperate fruit production in the tropics, countries in the region (such as Taiwan, Columbia, Indonesia, and Thailand) have begun to impose a range of quarantine restrictions aimed at preventing the introduction of temperate zone pests. Apples (Malus ×domestica) are regulated in certain tropical/subtropical countries, such as Taiwan, for the presence of codling moth (CM; Cydia pomonella) in spite of reports in the literature that the distribution of CM is theoretically limited by daylength and chilling requirements to temperate regions. This work provides background as to why CM has been identified as a potential pest of quarantine concern in some low latitude countries; describes an approach used to validate worldwide CM distribution reports, providing additional information to allow for the revision of CM distribution maps; and demonstrates how accurate information regarding pest species distribution reports can aid in establishing an argument of ecological nonadaptability in the pest risk analysis process. Currently, a report of CM in Peru remains the only account of this pest's presence in low latitude countries that could not be refuted by the approach described here.

TEMPERATE FRUIT PRODUCTION IN INDIA

TEMPERATE FRUIT PRODUCTION IN INDIA