Recent progress and future prospects for mechanized harvesting of fruit crops with shaking systems

Mechanized harvesting technologies with shaking systems for fruit industry have been widely investigated and significantly developed over the past several decades which were presented by a large amount of literature.This paper reviews the research and development progress of mechanized harvesting of fruits systematically with a focus on the theoretical study,fruit crop variety,shaking system categories,abscission chemical agents,and their actual applications.Based on the comprehensive review,mechanized harvesting systems for different fruit crops appear multifarious shaking modes with various vibratory mechanisms and structural dimensions.Major advantages in the development of fruit mechanical harvesting with effective vibratory patterns and catching frames provide a series of economic and agronomic benefits,such as reducing labor costs,promoting standardized planting,and increasing productivity.However,fruit injury and tree damage are the main reasons why mechanical shaking systems are rarely used for fresh fruit harvesting because of tenderness and frangibility of the fruit crops.Therefore,more efforts should be concentrated on the innovative shake-and-catch system with suitable frequency and amplitude to achieve low fruit damage or even nondestructive harvesting for fresh fruit market.This overview summarized the advantages and bottlenecks of these shaking systems for fruit harvesting and proposed the challenges and some constructive prospective viewpoints aimed at the major issues of mechanical harvesting techniques.In addition,employing sorting technologies to classify the postharvest fruits provide a new direction for the further development of mechanized harvesting in high-value fruit crops,as well as bring more benefits to growers and increase their interest in equipment investment on the mechanical shaking harvester for the fruit industry.

Applications of CRISPR/Cas genome editing in economically important fruit crops:recent advances and future directions

Fruit crops,consist of climacteric and non-climacteric fruits,are the major sources of nutrients and fiber for human diet.Since 2013,CRISPR/Cas(Clustered Regularly Interspersed Short Palindromic Repeats and CRISPR-Associated Protein)genome editing system has been widely employed in different plants,leading to unprecedented progress in the genetic improvement of many agronomically important fruit crops.Here,we summarize latest advancements in CRISPR/Cas genome editing of fruit crops,including efforts to decipher the mechanisms behind plant development and plant immunity,We also highlight the potential challenges and improvements in the application of genome editing tools to fruit crops,including optimizing the expression of CRISPR/Cas cassette,improving the delivery efficiency of CRISPR/Cas reagents,increasing the specificity of genome editing,and optimizing the transformation and regeneration system.In addition,we propose the perspectives on the application of genome editing in crop breeding especially in fruit crops and highlight the potential challenges.It is worth noting that efforts to manipulate fruit crops with genome editing systems are urgently needed for fruit crops breeding and demonstration.

Recent advances in fruit crop genomics

In recent years,dramatic progress has been made in the genomics of fruit crops.The publication of a dozen fruit crop genomes represents a milestone for both functional genomics and breeding programs in fruit crops.Rapid advances in high-throughput sequencing technology have revolutionized the manner and scale of genomics in fruit crops.Research on fruit crops is encompassing a wide range of biological questions which are unique and cannot be addressed in a model plant such as Arabidopsis.This review summarizes recent achievements of research on the genome,transcriptome,proteome,miRNAs and epigenome of fruit crops.

不同节位修剪对‘夏黑’葡萄二次花芽分化及果实品质的影响

为研究‘促早+避雨’栽培模式下,不同节位修剪对葡萄二次成花及二次果果实品质的影响,以7 a生‘夏黑’葡萄为材料,分析留5芽、留7芽和留9芽(简称5芽、7芽、9芽)修剪对葡萄萌芽率、成花率、单果质量、穗重、可溶性固形物含量等指标的影响。结果表明:3种不同修剪方式对葡萄二次萌芽率和成花率均产生了一定影响。其中,5芽修剪萌芽率和成花率最高,9芽修剪则较低。在单果质量和穗重方面,5芽修剪二次果穗重最大,但不同节位修剪并未对单果质量和果形指数产生显著影响。5芽和7芽修剪二次果可溶性固形物含量显著高于9芽修剪,5芽修剪二次果可滴定酸含量则显著低于9芽修剪,5芽修剪二次果葡萄糖和果糖含量均显著高于9芽修剪,但不同节位修剪均未对蔗糖和花色苷含量产生较大影响。综上所述,3种修剪方法中留5芽修剪最适宜于‘夏黑’葡萄一年两熟栽培,其次为留7芽修剪,留9芽修剪则不太适宜。

园艺作物果实β-半乳糖苷酶研究进展

β-半乳糖苷酶属于糖苷水解酶GH35家族,参与了植物不同生长阶段细胞壁的合成与修饰,尤其对肉质水果发育和成熟过程中多糖的裂解具有重要作用。文章概述了β-半乳糖苷酶的蛋白功能、不同亚型、亚细胞定位和活性规律,重点阐述了该基因家族在园艺作物果实质地变化中的作用及相关研究进展。

不同处理对大棚草莓连作土壤理化性质和果实品质的影响

为了探讨不同处理对大棚草莓连作土壤和果实品质的影响,以未处理为对照(CK),研究了甜玉米轮作、棉隆消毒、生物炭利用、菌渣混土等7个不同修复技术对处理后土壤理化性质、植株生长、果实品质、产量的影响。结果表明:甜玉米轮作处理(T1)土壤含水量、容重最高,EC值最低,养分含量除了全氮、全钾、碱解氮、有效锌外最低,盐分离子含量均低于CK;小麦秸秆炭处理(T3)土壤含水量、容重较低,EC值最高,pH值高于CK,有机质、全磷、有效磷、有效铜、有效锌含量最高,盐分离子含量除了F-和Cl-外均高于CK;T1草莓植株生长指标高于CK,单果重、单株产量高,果实硬度大,可溶性固形物含量高,糖酸比、固酸比最高。综上所述,T3可有效改善土壤板结和酸化,减少养分损失;T1土壤保水性好,养分利用率高,可消耗部分过多养分,减轻土壤富营养化,减缓连作土壤次生盐渍化,促进植株健康生长,提高果实品质和产量。

轮作与配施有机肥对菠萝生长、果实品质及产量的影响

通过田间试验,研究轮作与配施有机肥对菠萝生长、果实品质与产量的影响。结果表明:与菠萝连作(PP)处理相比,菠萝连作配施生物有机肥(PPB)、菠萝-甘蔗轮作(PS)、菠萝-甘蔗轮作配施生物有机肥(PSB)处理可显著促进菠萝生长、提高果实产量和品质。在植株生长方面,PPB、PS及PSB处理对叶长、叶宽及叶片数有显著的促进作用;在果实外观方面,果实纵径、横径、果眼数、果肉厚度、果肉厚度/果心直径比显著增加,而顶芽高与果心直径显著下降;在果实品质方面,可溶性固形物、维生素C及可溶性糖含量显著提高,可滴定酸含量明显降低;在产量方面,平均单果质量分别显著增加32.61%、51.09%和71.74%,总产量分别显著增加14.74%、34.58%和48.28%。此外,PSB处理的产量、果实性状及品质指标显著高于PPB处理,且优于PS处理。建议当地发展菠萝时,可在菠萝-甘蔗轮作基础上,适当配施生物有机肥。

不同土壤处理对重茬地苹果幼树生长结果的影响

重茬栽培存在重茬障碍问题,严重影响苹果幼树的生长发育。作者研究不同土壤处理对重茬地苹果幼树生长结果的影响。结果表明,不同土壤处理均有较好效果,明显提高果树成活率、促进树体生长发育、提高果实产量和品质。其中,多菌灵+菌肥、棉隆熏蒸+菌肥、客土3个处理的效果最好,可在实际生产中推广应用。

Branched Secondary Alcohol Ethoxylate, Ammonium Thiosulfate, Calcium Polysulfides-Thiosulfate, and Fish Oil Effects on Blossom Thinning, Fruit Set and Quality of Peaches and Nectarines

Total crop load has an inverse relationship with fruit size, while larger fruit size is often demanded by the peach and nectarine markets. Hand-thinning is extremely expensive, and thus, crop load adjustment, using blossom thinners is a crucial practice to ensure production of commercially acceptable fruit size and yield efficiency in stone fruit. In this study, the influence of branched secondary alcohol ethoxylate (Tergitol TMN-6) and/or ammonium thiosulfate (ATS), Crocker Fish Oil (FO), and a mixture of calcium polysulfides and thiosulfate (lime sulfur) on fruit set and quality attributes in peaches (Prunus persica) and nectarines (P. persica var. nectarina) were studied. All blossom thinners reduced fruit set in “Summer Lady” peach in both 2016 and 2017. Fruit sets in “Summer Lady” peach trees with a double application of Tergitol TMN-6 at the rate of 7.5 or 10 mL ·L¯1, each rate applied at 40% and 80% bloom, were lower than those receiving the same rates of this chemical only at 80% bloom, but they were similar to those receiving a single Tergitol TMN-6 spray at 15 mL·L¯1 at 80% or 100% bloom. “Summer Lady” peach trees receiving FO at 20 mL·L¯1 plus lime sulfur at 25 mL·L¯1, once at 40% bloom and again at 80% bloom had lower fruit set as compared to Untreated Control but the fruit set was higher than those with any Tergitol-TMN-6 spray. Tergitol TMN-6 at 12 m·L¯1 at 100% bloom or 10 mL·L¯1 all stages of bloom reduced fruit set in “Zee Lady” and “Snow Giant” peaches. In “Snow Giant” peach, trees receiving Tergitol TMN-6 at all concentrations and blossom stages had significantly higher fruit weight as compared to the trees of Un-treated Control. Applications of Tergitol TMN-6 at all concentrations at 80% bloom reduced fruit set in “Red Globe” and “Elberta” peaches in Utah. ATS and FO slightly reduced fruit set in peaches but they were less effective than Tergitol TMN-6 in all cases. Overall, it is concluded that efficacy of blossom thinners depends on the rate of thinners, temperature, cultivar and stage of bloom development.

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.

不同滴灌带布设方式对苹果-大豆间作系统土壤化感物质与微生物的影响

为探究不同滴灌带布设方式对果农间作系统土壤酚酸类物质、酶活性和微生物分布特性影响,初步探明间作滴灌条件下,土壤酚酸类物质与土壤生物因子的相互关系。以晋西黄土区典型的苹果—大豆间作系统为研究对象,设置3种(L1、L2、L3)滴灌带间距,分析不同水分分布下土壤酚酸类物质、酶活性和微生物数量的空间分布变化,并在相关性基础上利用逐步回归模型,分析3个土壤因子之间的相互关系。结果表明:除苯甲酸和间苯三酚外,滴灌带间距对酚酸类物质分布影响显著(p<0.05),除过氧化氢酶外,滴灌带间距对酶活性、微生物数量分布有显著影响(p<0.05)。在垂直方向上,不同滴灌带布设方式使酚酸更多地分布在深层土壤,微生物数量和部分酶活性在L1、L2处理中随土层加深而先减后增;在水平方向上,不同滴灌带布设方式对土壤酚酸类物质、细菌和真菌分布影响与间作对照处理一致,随距树距离增加而增加。滴灌条件下,除对羟基苯甲酸外,酚酸类物质受脲酶、过氧化氢酶和放线菌的抑制作用显著,间作处理土壤酚酸总量较单作有所减少。L1处理土壤酶活性、微生物总量最高,L2处理土壤酚酸类物质累积量最低。其中L2处理在酚酸累积量最低的基础上,土壤酶活性也处于较高水平,因此,建议在果农间作系统中采用隔行大豆布设滴灌带模式,改善土壤微生态环境的同时可缓解化感物质的抑制作用。

不同负载量对金陵黄露桃产量和果实品质的影响

为探讨不同负载量对桃产量和果实品质的影响,以自然开心形树形的金陵黄露桃为试材进行了连续3年的试验。试验采用随机区组设计,设4个处理:T1,留果约150个/株;T2,留果约250个/株;T3,留果约300个/株;T4,留果约350个/株,单株重复,每处理重复6次。结果表明:T4处理产量较高,但单果重最低;T1处理产量最低,但单果重最高;T2处理产量相对较低,但单果重相对较高;T3处理产量相对较高,但单果重相对较低。T1处理果实可溶性固形物含量和糖酸比均较高。T2和T3处理果实内在品质均略低于T1处理。负载量对果实着色程度影响不显著。可见,盛果期金陵黄露桃负载量为每株约150个果实时(每667 m^(2)产量约1300 kg),产量较低,但可生产出较大果个的果实,品质较好;每株250~300个果实时(每667 m^(2)产量2000~2400 kg),可保证较高的产量和较大的果个。

Indigenous Fruit Trees of Tropical Africa: Status, Opportunity for Development and Biodiversity Management

Tropical fruit trees constitute important biological resources in the global agrobiodiversity context. Unlike the tropical fruit trees of American and Asian origin, indigenous fruit trees (IFT) of tropical Africa have scarcely achieved the status of international recognition in commodity markets and research arena outside Africa. This paper presented a critical review of the status of IFT in the Tropical African sub-regions (of West Africa, Central Africa, East Africa, Southern Africa and the Indian Ocean Islands) in relation to the introduced naturalised fruit trees from tropical America and Asia, threats to the diversity and sustainable use of IFT, analysis of the opportunities and challenges of developing IFT, as well as targets for crop improvement of the rich IFT of Tropical Africa. Domestication programme via relevant vegetative propagation techniques for priority IFT of the sub-regions was examined and advocated, in addition to the adoption of complementary conservation strategies, including Field GeneBanks in the management of the continent’s IFT diversity.

园艺作物果实苹果酸代谢与转运及其调控研究进展

番茄、苹果、梨、枣等园艺作物是典型的苹果酸型果实,其果实酸度主要取决于液泡中苹果酸的积累量。苹果酸不仅决定果实的风味品质,还可作为呼吸底物为植物体提供必需的物质和能量,在调节植物细胞渗透势、酸碱平衡、抗逆性等方面起着重要作用。苹果酸代谢途径比较复杂,涉及众多结构催化酶的参与,而苹果酸主要贮存于液泡中,从细胞质向液泡的跨膜运输和储存是复杂的生物学过程,需要多种转运蛋白、质子泵的参与。总结了苹果酸型果实酸度性状遗传研究、转运蛋白及质子泵在苹果酸跨膜转运中的作用,并将转录因子对苹果酸的代谢调控进行了概述,以深入理解苹果酸代谢调控网络,为园艺作物品质育种提供理论基础。

负载量对高接瑞香红苹果果实生长和品质的影响

【目的】通过探究负载量对苹果新品种瑞香红高接树的果实生长、果实品质以及经济效益的影响,为高接瑞香红苹果树的适宜负载量提供依据。【方法】以高接第5年的瑞香红苹果树为材料,应用干截面积法设计3种负载量处理,以最大负载量为对照,T1:3.0个·cm^(-2)TCSA(树干横截面积,trunk cross-sectional area);T2:2.0个·cm^(-2)TCSA;T3:1.3个·cm^(-2)TCSA;CK:4.3个·cm^(-2)TCSA,测定每种负载量下果实纵横径增长速率、果实外观与内在品质、果实香气物质含量,根据果实产量与分级标准预估每种负载量下的经济效益。【结果】随着负载量降低,果实生长速率、大型果所占比率、平均单果质量、翌年开花数量、果面a值,以及可溶性固形物、果糖、葡萄糖、香气物质含量均表现出增加趋势;果实的产量、硬度、蔗糖含量表现出降低趋势;果实的果形指数、果面L值、果面b值、可滴定酸含量无显著变化;预估经济效益先增高后降低。【结论】低负载量下果实生长速率较快,果实品质较好,但产量与经济效益较低;提高负载量虽然能增加产量,但会降低果实品质,综合来看,高接第5年的瑞香红苹果树以3.0个·cm^(-2)TCSA的负载量较为适宜。

三种胡麻生长模型对现蕾期和青果期干旱胁迫响应能力的比较

本研究利用不同胡麻品种、不同干旱程度的大田试验数据,检验、评估3种作物模型干旱胁迫效应算法的精确性,及其在现蕾期、青果期干旱胁迫处理下对胡麻蒸腾速率、气孔导度、叶面积指数及籽粒产量4个指标的模拟预测能力。模拟结果表明,干旱胁迫使胡麻蒸腾速率、气孔导度、叶面积指数和籽粒产量降低。3种作物模型干旱胁迫效应算法可以模拟出胡麻生理生化指标在各干旱处理下的变化趋势,但模拟效果不够理想。3种干旱胁迫效应算法均低估了籽粒产量。综合考虑,WOFOST模型干旱胁迫效应算法对籽粒产量、蒸腾速率的模拟效果最好,APSIM模型干旱胁迫效应算法对气孔导度的模拟效果最好,DSSAT模型干旱胁迫效应算法对叶面积指数的模拟效果最好。

微生态制剂改良土壤对凋萎病杨梅营养生长和果实品质的作用

凋萎病是近年来危害杨梅产业的主要病害,为研究微生态制剂对凋萎病杨梅营养生长和果实品质的影响,设置抗重茬微生态制剂、土壤调理剂、生物有机肥以及不同组合处理进行试验,常规管理为对照。结果表明,各处理均显著促进梢长、梢粗、叶长、叶宽,显著降低果实可滴定酸含量。其中抗重茬微生态制剂处理的梢长、梢粗和叶长分别比对照增加122.92%、19.80%和18.94%,果实可溶性固形物和总糖分别增加9.98%和19.04%,表现最优;生物有机肥处理的叶宽比对照增加15.99%,表现最优。土壤调理剂处理的果实可滴定酸含量比对照降低51.16%,为最低。综上所述,所有处理中单施用抗重茬微生态制剂的杨梅营养生长和果实品质最好,抗重茬微生态制剂值得在杨梅产业上大力推广用于改良凋萎病杨梅的营养生长和果实品质。

基于深度学习的苹果图像语义分割方法研究

针对现有语义分割方法存在分割速度慢、精度低等不足,通过结合MobileNet模块、深度可分离卷积DSC以及CBAM注意力机制,提出一种基于改进的DeepLabv3+网络的苹果图像分割方法,可用于苹果自动化采摘工作中苹果果实的定位。通过实验探究腐坏程度、腐坏位置、苹果品种以及复杂背景等因素对苹果图像语义分割性能的影响,同时验证该方法的鲁棒性。

水分胁迫对果树光合作用及同化代谢的影响研究进展

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