Advances in Molecular Regulatory Mechanisms of Fruit Trees under Low Temperature Stress

The most recent research findings on the tolerance of fruit trees to cold stress are reviewed from a molecular perspective,including the perception and transduction of low temperature calcium signaling,CBF-dependent molecular regulatory mechanisms,non-CBF-dependent molecular regulatory mechanisms,and so forth.The objective is to provide a reference basis for further improving the cold resistance of fruit trees and cultivating new varieties of hardy plants.

Overview of Relation between Mineral Nutrient Elements and Growth and Development of Fruit Trees

Mineral nutrition is the material basis for growth and development,yield and quality of fruit trees. It exerts a great effect on the growth and development,fruit quality,yield,and resistance of fruit trees. On the basis of reading a large number of references both at home and abroad,this paper elaborated the relationship between mineral nutrient elements and growth and fruit yield and quality of fruit trees,so as to make proper fertilizer mixing,balance the fertilizer application,promote growth and development of fruit trees,and increase the yield of fruit trees and improve the fruit quality.

Molecular Phylogeny of the “True Citrus Fruit Trees” Group (Aurantioideae, Rutaceae) as Inferred from Chloroplast DNA Sequence

The genus Citrus L. has a long controversial taxonomy history, and a well-resolved molecular phylogeny of the ＂true citrus fruit trees＂ group in the future will provide new information for advancing breeding techniques and developing better conservation strategies. In the present study, three cpDNA fragments （TrnL-TrnF, PsbH-PetB, and TrnS-TrnG） of 30 genotypes chosen from the six genera of the ＂true citrus fruit trees＂ group were analyzed. A molecular phylogenetic tree of the ＂true citrus fruit trees＂ group ＂~as reconstructed based on plastid DNA sequences. The results confirmed that the ＂true citrus fruit trees＂ group was monophyletic, and thereby the group was divided into genera as previously suggested based on morphological characters. The cpDNA data also suggested that Poncirus might be the first genus separated from the other five genera in the group. The genus Fortunella were of hybrid origin and Citrus might be as its putative paternal parent. The genera Microcitrus, Eremocitrus, and Clymenia were possibly monophyletic and their common ancestor might branch out from Citrus. Furthermore, the phylogenetic relationships within the Citrus genus were discussed.

Second Bloom of Fruit Trees and Preventive Measures

Second bloom of fruit trees refers to the flowering and fruit-bearing of fruit trees after autumn harvest, which seriously influences the yield and economic benefits of fruit trees. By analyzing the causes of second bloom, remedies are given to make scientific preventive measures and realize high-quality and high-yield cultivation of fruit trees.

Review of Research on Nutritional Physiological Mechanism and Nutritional Diagnosis of Magnesium in Fruit Trees

Magnesium is an essential nutrient element for the growth and development of fruit trees.It not only participates in photosynthesis of plants,but also promotes physiological and biochemical reactions such as carbohydrate and protein synthesis,enzyme activation,and reactive oxygen species(ROS)metabolism.Magnesium deficiency in fruit trees will directly influence the growth and development of trees and the improvement of fruit quality.This study mainly reviews the nutritional and physiological mechanism of magnesium in plants and the nutritional diagnosis of magnesium deficiency in fruit trees,in order to provide a theoretical basis for further research on magnesium nutrition in fruit trees,and accordingly provide a certain reference for the application of magnesium fertilizer.

Influence of Fruit Tree Types and Arrangements on Yield, Quality and Economic Returns of Cotton of Intercropping System in Southern Xinjiang

[Objective] The aim was to provide a theoretical basis for stable and highly effective intercropping arrangements and scientific management measures by selecting apple, pear, peach, apricot, walnut, jujube and other fruit trees to study their influence on yield, fiber quality and economic returns of intercropped cotton in southern Xinjiang. [Method] Based on major cropping pattern in production, randomized block design was adopted to explore growth indicators, canopy micrometeorological indicators, yield and fiber quality in key growth stage. [Result] Shading has a significant effect on cotton canopy micro-environment and canopy diameter is proportional to shading effect. According to comparisons of the same tree type, the change of canopy micro-environment was as follows： under canopyouter canopymiddle points and peachpearapplewalnutjujube for comparisons among different tree types. Canopy diameter is directly proportional to the number of tree branch and boll weight reductions and shading is the main cause of yield reduction. The canopy expansion is the major cause of decline of light intensity, temperature and humidity of cotton canopy. [Conclusion] Fruit trees, which will promote cotton yield,quality and canopy-environment, are as follows： jujube walnut apple pear peach trees. In practice, trees, which are small in canopy or well trimmed, are popular in production, such as jujube trees, to improve cotton yield and fiber quality.

Temperature Trends and Accumulation of Chill Hours, Chill Units, and Chill Portions in South Carolina

There is considerable concern about the potential impact of climate change on agriculture, such as the accumulation of chilling hours needed to break the dormancy of many perennial plants, like fruit trees. Therefore, this study aimed to determine if there had been a significant change in air temperatures and chill hours, chill units, and chill portion accumulation in South Carolina over the last two decades. Two decades of daily maximum (Tmax) and minimum (Tmin) air temperature records were obtained from weather stations in thirty-one counties in South Carolina. Hourly temperature data, reconstructed from the daily data, were used to calculate the daily and annual chill hours, chill units, and chill portions accumulation using four different chill models for each location and year. The chill models included the T(t) °C model, the 0°C °C model, the Utah model, and the Dynamic model. For each county, regression analyses were conducted to evaluate the historical trends. Despite year-to-year variability, the tendency was a statistically significant (α = 0.05) increase in air temperature, averaging 0.089°C per year for 20 out of 31 counties in South Carolina. The other 11 counties had no significant change in temperature. The average temperature increase in the 31 counties was 0.072°C per year. The temperature increase resulted in a decrease in annual chill accumulation during the fall to spring, averaging 17.7 chill hours, 8.6 chill hours, 17.0 chill units, and 0.40 chill portions per year calculated with the T(t) °C, 0°C °C, Utah, and Dynamic models, respectively. However, whether this decrease in chill values was statistically significant or not depended on the chill model used. This study did not investigate the cause of the observed historical trends in temperature and chill accumulation. Still, if the trends continue, they could significantly impact the future of the temperate fruit tree industry in the state.

The historical and current research progress on jujube–a superfruit for the future

Jujube(Ziziphus jujuba Mill.),or Chinese date,is the most important species of Rhamnaceae,a large cosmopolitan family,and is one of the oldest cultivated fruit trees in the world.It originates from the middle and lower reaches of the Yellow River,the‘mother river’of the Chinese people.It is distributed in at least 48 countries on all continents except Antarctica and is becoming increasingly important,especially in arid and semiarid marginal lands.Based on a systematic analysis of the unique characteristics of jujube,we suggest that it deserves to be recognized as a superfruit.We summarized historical research achievements from the past 3000 years and reviewed recent research advances since 1949 in seven fields,including genome sequencing and application,germplasm resources and systematic taxonomy,breeding and genetics,cultivation theory and techniques,pest control,postharvest physiology and techniques,and nutrition and processing.Based on the challenges facing the jujube industry,we discuss eight research aspects to be focused on in the future.

Improved observation of colonized roots reveals the regulation of arbuscule development and senescence by drought stress in the arbuscular mycorrhizae of citrus

Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to drought stress, remain unclear, which is mainly due to the difficulty in clearing and staining lignified roots with the conventional method. Here, we improved the observation of colonized roots of citrus plants with the sectioning method, which enabled the clear observation of AM fungal structures. Furthermore, we investigated the effects of one week of drought stress on arbuscule development and senescence with the sectioning method. Microscopy observations indicated that drought stress significantly decreased mycorrhizal colonization (F%and M%) although it did not affect plant growth performance. Fluorescence probes (WGA 488 and/or Nile red) revealed that drought stress inhibited arbuscule development by increasing the percentage of arbuscules at the early stage and decreasing the percentages of arbuscules at the midterm and mature stages. Meanwhile, drought stress accelerated arbuscule senescence, which was characterized by the increased accumulation of neutral lipids. Overall, the sectioning method developed in this study enables the in-depth investigation of arbuscule status, and drought stress can inhibit arbuscule development but accelerate arbuscule senescence in the colonized roots of citrus plants. This study paves the way to elaborately dissecting the arbuscule dynamics in the roots of fruit tree species in response to diverse abiotic stresses.

Study on Curative Effect of Perforated Injection of Zinc-ammonia Complex on Rosette Disease of Fruit Tree

[ Objective ] The paper was to explore a kind of zinc preparation suitable for injection on trees with fast, efficient and safe cure effect on physiological disease of zinc deficiency. [Method] Taking three years old apple, pear, peach and grape trees as the materials, the author studied the absorption condition of these trees to six kinds of zinc substances and their security. The sealed curative effects of the injected zinc substances which were harmful and could be absorbed steadily by the fruit trees against rosette disease were studied. [ Result] The results of absorption condition and security experiments showed that only zinc-mmnonia complex could be absorbed steadily and safely throughout four seasons. When apple, pear, peach and grape trees affected by rosette disease were injected with zinc- ammonia complex, the leaves of those trees started to grow obviously after 10 d; the internodes of diseased branches elongated, the leaves turned bigger, and the ap- pearance of branches became normal after about 25 d. [ Conclusion] The curative effect of perforated injection of zinc-ammonia complex on fruit tree rosette disease was remarkable. The results also provided a new way for the cure of deficiency diseases of other trace elements.

Development of a Non-Pollution Orange Fruit Expert System Software Based on ASP.NET

Based on ASP.NET,a orange fruit tree fertilizer expert system software was developed.The system could simulate and decide an annual fertilization plan for young and mature trees in terms of geographical position and climate.This paper introduced the design conditions,framework,production,and deployment of the system.It exhibited characters of orange specialty and was a typical online agriculture expert system.The use of the system for orange fruit management could decrease production cost,guarantee orange quality and improve economical benefit at the same time.Farmer using the system saved N input by 41-238 g/plant,P2O5 input 3-24 g/plant,and K2O input 1-36 g/plant,and got higher yield by 6-17 kg/plant.

Growth simulation and yield prediction for perennial jujube fruit tree by integrating age into the WOFOST model

Mathematical models have been widely employed for the simulation of growth dynamics of annual crops,thereby performing yield prediction,but not for fruit tree species such as jujube tree(Zizyphus jujuba).The objectives of this study were to investigate the potential use of a modified WOFOST model for predicting jujube yield by introducing tree age as a key parameter.The model was established using data collected from dedicated field experiments performed in 2016-2018.Simulated growth dynamics of dry weights of leaves,stems,fruits,total biomass and leaf area index(LAI) agreed well with measured values,showing root mean square error(RMSE) values of 0.143,0.333,0.366,0.624 t ha^-1 and 0.19,and R2 values of 0.947,0.976,0.985,0.986 and 0.95,respectively.Simulated phenological development stages for emergence,anthesis and maturity were 2,3 and 3 days earlier than the observed values,respectively.In addition,in order to predict the yields of trees with different ages,the weight of new organs(initial buds and roots) in each growing season was introduced as the initial total dry weight(TDWI),which was calculated as averaged,fitted and optimized values of trees with the same age.The results showed the evolution of the simulated LAI and yields profiled in response to the changes in TDWI.The modelling performance was significantly improved when it considered TDWI integrated with tree age,showing good global(R2≥0.856,RMSE≤0.68 t ha^-1) and local accuracies(mean R2≥0.43,RMSE≤0.70 t ha^-1).Furthermore,the optimized TDWI exhibited the highest precision,with globally validated R2 of 0.891 and RMSE of 0.591 t ha^-1,and local mean R2 of 0.57 and RMSE of 0.66 t ha^-1,respectively.The proposed model was not only verified with the confidence to accurately predict yields of jujube,but it can also provide a fundamental strategy for simulating the growth of other fruit trees.

Determination of the Geographical Origin of Fruits by Using 26S rDNA Fingerprinting of Yeast Communities by PCR-DGGE： An Application to Shea Tree Fruits

International trade intensifies the process of globalization which has extended to the entire planet and extends to the entire planet. In view of the difficulties of installing these documentary systems in developing countries, in particularly the countries of sub-Saharan Africa, the new strategies of traceability emerge. Among the new tools of tracing the products of vegetable origin, a ＂biological code bar＂ based on the analysis of the DNA of micro-organisms present on the fruits is an interesting tool. A molecular technique employing 26S rDNA profiles generated by PCR-DGGE was used to detect the variation in yeast community structures of Shea tree fruits （Vitellaria paradoxa） from Senegal, Ghana and Mali. When the 26S rDNA profiles were analyzed by image analysis and multivariate analysis, distinct microbial communities were detected on Shea tree fruits. The band profiles of yeasts from different countries were specific for each location and could be used as a bar code to discriminate the origin of the fruits. This method is a new traceability tool which provides fruit products with an unique biological bar code and makes it possible to trace back the fruits to their original location.

Method for the fruit tree recognition and navigation in complex environment of an agricultural robot

To realize the visual navigation of agricultural robots in the complex environment of orchards,this study proposed a method for fruit tree recognition and navigation based on YOLOv5.The YOLOv5s model was selected and trained to identify the trunks of the left and right rows of fruit trees;the quadratic curve was fitted to the bottom center of the fruit tree recognition box,and the identified fruit trees were divided into left and right columns by using the extreme value point of the quadratic curve to obtain the left and right rows of fruit trees;the straight-line equation of the left and right fruit tree rows was further solved,the median line of the two straight lines was taken as the expected navigation path of the robot,and the path tracing navigation experiment was carried out by using the improved LQR control algorithm.The experimental results show that under the guidance of the machine vision system and guided by the improved LQR control algorithm,the lateral error and heading error can converge quickly to the desired navigation path in the four initial states of[0 m,−0.34 rad],[0.10 m,0.34 rad],[0.15 m,0 rad]and[0.20 m,−0.34 rad].When the initial speed was 0.5 m/s,the average lateral error was 0.059 m and the average heading error was 0.2787 rad for the navigation trials in the four different initial states.Its average driving was 5.3 m into the steady state,the average value of steady state lateral error was 0.0102 m,the average value of steady state heading error was 0.0253 rad,and the average relative error of the robot driving along the desired navigation path was 4.6%.The results indicate that the navigation algorithm proposed in this study has good robustness,meets the operational requirements of robot autonomous navigation in orchard environment,and improves the reliability of robot driving in orchard.

果树在城市林业建设中的应用及展望

文章论述了果树在园林中应用的历史和现状,阐述了果树在城市林业建设中的特殊功能及应用前景,并提出了有关的应用建议。

落叶果树需冷量及其估算模型研究进展

落叶果树的需冷量得到满足,才能顺利完成自然休眠,进行下一个生长发育循环(尤其是正常开花结果),否则其他环境条件再适宜,果树也不萌芽开花,即使萌芽也不整齐,生长结果不良,达不到促成栽培的目的[1].因此,对落叶果树需冷量及其估算的研究至关重要,成为落叶果树设施栽培成败的关键.本文仅就需冷量估算模型进行介绍,以期为设施栽培和更完善的需冷量估算提供理论依据.……

Biogenic volatile organic compound emissions from leaves and fruits of apple and peach trees during fruit development

Biogenic volatile organic compounds(BVOCs)are widely involved in a variety of atmospheric chemical processes due to their high reactivity and species diversity.To date,however,research on BVOCs in agroecosystems,particularly fruit trees,remains scarce despite their large cultivation area and economic interest.BVOC emissions from different organs(leaf or fruit)of apple and peach trees were investigated throughout the stages of fruit development(FS,fruit swelling;FC,fruit coloration;FM,fruit maturity;and FP,fruit postharvest)using a proton-transfer-reaction mass spectrometer.Results indicated that methanol was the most abundant compound emitted by the leaf(apple tree leaf 492.5±47.9 ng/(g·hr),peach tree leaf 938.8±154.5 ng/(g·hr)),followed by acetic acid and green leaf volatiles.Beside the above three compounds,acetaldehyde had an important contribution to the emissions from the fruit.Overall,the total BVOCs(sum of eight compounds studied in this paper)emitted by both leaf and fruit gradually decreased along the fruit development,although the effect was significant only for the leaf.The leaf(2020.8±258.8 ng/(g·hr))was a stronger BVOC emitter than the fruit(146.0±45.7 ng/(g·hr))(P=0.006),and there were no significant differences in total BVOC emission rates between apple and peach trees.These findings contribute to our understanding on BVOC emissions from different plant organs and provide important insights into the variation of BVOC emissions across different fruit developmental stages.

Analysis of Meteorological Conditions during the Blossom Period of Apple and Peach in Haiyang City

Through observing the phenology of two kinds of fruit trees,apple and peach trees,during their flowering periods in the past seven years,the meteorological conditions in the flowering stages were analyzed and summarized in this paper.The late frost weather situation occurred in late April in Haiyang City also was elaborated in the paper.According to the data analysis,the terrain effect had induced a large temperature differences between north and south in April in Haiyang.Early flowering of fruit trees is as early as 5 to 8 days in the northern region than that in the southern region;accumulated temperature which was greater than or equal to 0 ℃ and the date of the temperature stably through a boundary,were the important meteorological indicators of the fruit trees' early flowering.The late frost in mid-late April is meteorological disasters of the fruit trees flowering period.The weather background of the occurred late frost,the disaster reasons and the measures for the prevention of late frost were proposed.

Economics of the plant species used in homestead agroforestry on an offshore Sandwip Island of Chittagong District, Bangladesh

This study was performed in five villages of Sandwip Upazila, Chittagong district with a view to identify the tree resources, utilization pattern and economic return of major fruit and timber tree species. Information collected from a total of 60 households ranging from marginal, small, medium and large categories. Number of plant species increased with the increase of homestead area. A total of 33 plant species were recorded from the homegarden, of which 19 were fruit and 14 were timber tree species. Considerable number of vegetables was also planted under the shade of the homestead trees. The investment analysis showed that average benefit-cost ratios were greater than one, net present values were positive and internal rate of returns were more than 10%. Long term investment on horticulture and timber tree species is highly profitable if species like Artocarpus heterophyllus, Cocos nucifera, Tectona grandis and Swietenia macrophylla are planted.

Treatments Comparison of Mineral and Bio Fertilizers in the Apple and Sour Cherry Organic Nursery

Maiden trees of apple cultivars ＇Topaz＇ and ＇Ariwa＇ grafted on M26 rootstock and of sour cherry cultivars ＇Debreceni Botermo and ＇Sabina＇ on mahaleb cherry （Prunus mahaleb L.） were fertilized with bioproducts such as： Fertigo-granulated manure, Micosat-microbial inoculum consisting of mycorrhizal fungi; Humus UP-an extract from vermicompost; Humus Active ＋ Aktywit PM-an extract from vermicomposts with PM （Positive Microorganism）; BioFeed Amin--a plant extract reinforced with amino acids; BioFeed Quality-a seaweed extract reinforced with humic and fulvic acids; Tytanit-titanium; Vinassa-molasses residue from yeast production; Florovit Eko-composed of many environmentally-friendly products. Control maidens were fertilized with mineral fertilizers containing mainly NPK. The maiden trees fertilized with the preparations Tytanit and Humus UP grew less vigorously and produced smaller increases in the length of lateral shoots than those fertilized with mineral fertilizers. On the other hand, bio preparations such as BF Amin, BF Quality, Micosat and Vinassa promoted tree branching and intensified the growth of lateral shoots, stimulating tree growth to a greater extent than the mineral fertilizers.