Probabilistic Global Maximum Power Point Tracking Algorithm for Continuously Varying Partial Shading Conditions on Autonomous PV Systems

A photovoltaic (PV) string with multiple modules with bypass diodes frequently deployed on a variety of autonomous PV systems may present multiple power peaks under uneven shading. For optimal solar harvesting, there is a need for a control schema to force the PV string to operate at global maximum power point (GMPP). While a lot of tracking methods have been proposed in the literature, they are usually complex and do not fully take advantage of the available characteristics of the PV array. This work highlights how the voltage at operating point and the forward voltage of the bypass diode are considered to design a global maximum power point tracking (GMPPT) algorithm with a very limited global search phase called Fast GMPPT. This algorithm successfully tracks GMPP between 94% and 98% of the time under a theoretical evaluation. It is then compared against Perturb and Observe, Deterministic Particle Swarm Optimization, and Grey Wolf Optimization under a sequence of irradiance steps as well as a power-over-voltage characteristics profile that mimics the electrical characteristics of a PV string under varying partial shading conditions. Overall, the simulation with the sequence of irradiance steps shows that while Fast GMPPT does not have the best convergence time, it has an excellent convergence rate as well as causes the least amount of power loss during the global search phase. Experimental test under varying partial shading conditions shows that while the GMPPT proposal is simple and lightweight, it is very performant under a wide range of dynamically varying partial shading conditions and boasts the best energy efficiency (94.74%) out of the 4 tested algorithms.

Responses of photosynthetic characteristics and leaf senescence in summer maize to simultaneous stresses of waterlogging and shading

A field experiment was performed to investigate the physiological mechanism of the simultaneous stresses of waterlogging and shading on leaf photosynthetic and senescence during three growth stages of summer maize.The responses of leaf gas exchange parameters and antioxidant enzyme activities of the summer maize hybrids Denghai 605(DH605)to waterlogging(W),shading(S),and their combination(W+S)for 6 days at the third leaf stage(V3),the sixth leaf stage(V6),and the tasseling stage(VT)were recorded.Shading,waterlogging,and their combination disturbed the activities of protective enzymes and increased the contents of H2O2and O-2,accelerating leaf senescence and disordering photosynthetic characteristics.Under waterlogging,shading and their combination,leaf Pn,the photo-assimilates and grain yield was decreased.The greatest reduction for waterlogging and the combined stresses occurred at V3 and that for shading stress occurred at VT.The individual and combined stresses reduced the activities of protective enzymes and inhibited photosynthesis,reducing the accumulation of photosynthetic compounds and thereby yield.Waterlogging and the combined stresses at the V3 stage showed the greatest effect on leaf photosynthetic and senescence,followed by the V6 and VT stages.The greatest effect for shading stress occurred at VT,followed by the V6 and V3 stages,and the combined influence of shading and waterlogging was greater than that of either single stress.

Decreased panicle N application alleviates the negative effects of shading on rice grain yield and grain quality

Light deficiency is a growing abiotic stress in rice production.However,few studies focus on shading effects on grain yield and quality of rice in East China.It is also essential to investigate proper nitrogen(N)application strategies that can effectively alleviate the negative impacts of light deficiency on grain yield and quality in rice.A two-year field experiment was conducted to explore the effects of shading(non-shading and shading from heading to maturity)and panicle N application(NDP,decreased panicle N rate;NMP,medium panicle N rate;NIP,increased panicle N rate)treatments on rice yield-and quality-related characteristics.Compared with non-shading,shading resulted in a 9.5-14.8%yield loss(P<0.05),mainly due to lower filled-grain percentage and grain weight.NMP and NIP had higher(P<0.05)grain yield than NDP under non-shading,and no significant difference was observed in rice grain yield among NDP,NMP,and NIP under shading.Compared with NMP and NIP,NDP achieved less yield loss under shading because of the increased filled-grain percentage and grain weight.Shading reduced leaf photosynthetic rate after heading,as well as shoot biomass weight at maturity,shoot biomass accumulation from heading to maturity,and nonstructural carbohydrate(NSC)content in the stem at maturity(P<0.05).The harvest index and NSC remobilization reserve of NDP were increased under shading.Shading decreased(P<0.05)percentages of brown rice,milled rice,head rice,and amylose content while increasing(P<0.05)chalky rice percentage,chalky area,chalky degree,and grain protein.NMP demonstrated a better milling quality under non-shading,while NDP demonstrated under shading.NDP exhibited both lower chalky rice percentage,chalky area,and chalky degree under non-shading and shading,compared with NMP and NIP.NDP under shading decreased amylose content and breakdown but increased grain protein content and setback,contributing to similar overall palatability to non-shading.Our results suggested severe grain yield and quality penalty of rice when subjected to shading after heading.NDP improved NSC remobilization,harvest index,and sink-filling efficiency and alleviated yield loss under shading.Besides,NDP would maintain rice’s milling,appearance,and cooking and eating qualities under shading.Proper N management with a decreased panicle N rate could be adopted to mitigate the negative effects of shading on rice grain yield and quality.

Effects of Shading Degree on Storage Rate and Growth of Phoebe bournei Seedlings in Fields

In the research, four shading treatments were set, including the treatments with shading degrees at 0, 40%, 60% and 70%, in order to explore storage rate and seedling growth of annual Phoebe bournei. The results showed that the storage rate is growing upon shading degree. In the research, for example, storage rate reached the peak with the shading degree at 70%, and only 42.2% with shading degree at 0. In addition, seedling height and ground diameter showed extremely significant differences among treatments, and the treatment with shading degree at 60% was the best.

基于Shape-from-Shading的月球表面三维形状恢复算法研究

提出了一种基于Shape-from-Shading的月球表面三维形状恢复算法。首先分析了在太阳光照射下月球表面成像模型,建立了使用Lommel-Seeliger反射模型描述的反射图方程。然后用有限差分近似微分运算,将反射图方程所示的一阶变系数线性偏微分方程进行离散化处理,得到关于表面高度函数的代数方程。进而采用超松弛迭代法进行求解,获得月球表面三维高度函数值。最后使用合成图像和实际月球图像进行三维形状恢复仿真实验。实验结果表明提出的算法可以有效地恢复月球表面三维形状。

基于Shape from Shading的医学图像三维重建

通过对由医疗成像设备获取的二维灰度图像进行形状重建,得到的三维立体原型能帮助医学诊断人员确诊病情。介绍了Shape from Shading的实现原理和扫描电镜成像系统的简单构成,提出了一种基于线性逼近的用于解决SEM反射映射函数的实现方法,并将之应用于红血细胞的三维图像重构,得到的细胞图形非常接近其真实形状。

Effects of Shading Treatments on Growth of Asimina triloba(L.) Dunal Seedlings

[Objective]The study was conducted to investigate the effects of shading treatments on growth of Asimina triloba （L） Dunal seedlings and provided the theoretical basis for seedling production. [Method]70 day-old A. triloba seedlings had similar stem diameter and plant height and good growth vigour were taken as tested materials in 2005. 4 light gradient treatments which were the natural light with 100% light intensity, one-layer, two-layer and three-layer black shading network with the light transmittance rate of 50%, 25% and 12.5% were set up to study the effects of different shading treatments on growth of A. triloba. [ Result] With the shading treatments of one-layer and two-layer net, the plants of A. triloba seedlings grew rapidly. As the intensity of illumination decreased, the cetents of chlorophyll a （ Chl. a）, chlorophyll b （ Chl. b） and total chlorophyll increased at first and then reduced. At the same time the chlorophyll a/b value became smaller. Under natural light, the plants tended to consume more water and the soil temperature at 15：00 p. m was higher. There was a smaller difference among various treatments. [ Conclusion]The suitable shading treatment to the growth of A. triloba seedlings was under the light transmittance rate of 50% and height and stem diameter of trees increased fast. Chlorophyll a （ Chl. a）, chlorophyll b （ Chl. b） content in leaves of A. triloba seedlings were highest comparing with those in other conditions.

Estimation of Illuminant Direction and Albedo from Shading

Assuming uniform albedo and Lambertian surface for the imaging model, a new robust method for estimation of illuminant direction and albedo from shading is presented. If there is a singular point with maximum intensity in an image, the method use shading information of the singular point and its neighbors to estimate directly the elevation of illuminant direction, surface albedo, and the bias brightness. Some experiment results on synthetic images are given to illustrate the new approach is accurate and robust.

基于图象空间分布的Shading算法

本文首先介绍了基于局部光照模型的串行Shading算法，然后对设计分布式Shading算法所用到的动态任务分配、数据适应性任务分配、任务粒度等因素作了较为详细的论述，并给出了所设计的新的数据适应性任务划分算法，最后给出了所设计的分布式Shading算法的描述和实验结果.

Physiological Basis of Photosynthetic Tolerance to Photooxidation and Shading in Rice

Thirty genotypes from rice germplasm were identified under photooxidation and shading condition and divided into four basic types : (1) cultivars tolerant to both photooxidation and shading, (2) cultivars tolerant to photooxidation but sensitive to shading, (3) cultivars tolerant to shading but sensitive to photooxidation, and (4) cultivars sensitive to photooxidation and shading. A comparative study of photosynthetic characteristics of a cultivar (cv. Wuyujing 3) that is tolerant and a cultivar (cv. Xiangxian) that is sensitive to both photoinhibition and shading showed that the photochemical efficiency of PSⅡ ( F v/F m ) and the content of PSⅡ_D1 protein in the tolerant cultivar “Wuyujing 3” decreased less under photoinhibition conditions as compared with “Xiangxian”. Under photooxidation conditions, superoxide dismutase was induced rapidly to a higher level and the active oxygen O - built up to a lower level in “Wuyujing 3” than in “Xiangxian”. At the same time, the photosynthetic rate decreased by 23% in “Wuyujing 3” vs. 64% in “Xiangxian”. Shading (20% natural light) during the booting stage caused only small decreases (7%-13%) in RuBisCO activity and the photosynthetic rate in “Wuyujing 3” but showed marked decreases (57%-64%) in “Xiangxian” which corresponded to the decreases in grain yield in the two cultivars (38% and 73%, respectively). The correlation analysis showed that the tolerance to photooxidation is mainly related to PSⅡ_D1 and that to shading is mainly related to RuBisCO activity. This study provided a simple and effective screening method and physiological basis for crop breeding in enhancing tolerance to both high and low radiation.

Slight shading after anthesis increases photosynthetic productivity and grain yield of winter wheat (Triticum aestivum L.) due to the delaying of leaf senescence

The solar radiation intensity and duration are continuously decreasing in the major wheat planting area of China. As a con- sequence, leaf senescence, photosynthesis, grain filling and thus wheat yield shall be affected by light deficiency. Therefore, two winter wheat （Triticum aestivum L.） cultivars, Tainong 18 （a large-spike cultivar） and Ji＇nan 17 （a multiple-spike cultivar）, were subjected to shading during anthesis and maturity under field condition in 2010-2011 and 2011-2012. Under the slight shading treatment （$1,88% of full sunshine）, leaf senescence was delayed, net photosynthesis rate （Po） and canopy apparent photosynthesis rate （CAP） were improved, and thus thousand-kernel weight （TKW） and grain yield were higher as compared with the control. However, mid and severe shading （S2 andS3, 67 and 35% of full sunshine, respectively） led to negative effects on these traits substantially. Moreover, superoxide dismutase （SOD）, peroxidase （POD） and cat- alase （CAT） activities in flag leaf were significantly greater under slight shading than those in other treatments, while the malondialdehyde （MDA） content was less than that under other treatments. In addition, the multiple-spike cultivar is more tolerant to shading than large-spike cultivar. In conclusion, slight shading after anthesis delayed leaf senescence, enhanced photosynthesis and grain filling, and thus resulted in higher grain yield.

Effects of Shading Treatment on the Growth of Bischofia javanica Seedlings

With annual Bischofia javanica seedlings as experimental material, the plasticity and comprehensive evaluation methods were employed to investigate the effects of different shading degrees （100% NS （natural sunshine）, 41.3% NS, 14.6% NS and 3.6% NS） on B. javanica seedlings growth, so as to obtain the shade toler- ance in B. javanica. The results showed that with the shading degree increasing, the seedling height increment, diameter increment, leaf area, fresh weights （above- ground part, underground part and whole plant） and dry weights （aboveground part, underground part and whole plant） of B. javanica seedlings all increased first and then decreased, and reached peak values under 41.3% NS, while the total root length, average root diameter, total surface area, total root volume and total root number all presented a decreasing trend. Also the comprehensive evaluation by subordinate function value method and plasticity analysis were carried out on these growth indexes. It was concluded that B. javanica seedlings have medium shade tol- erance from the comDrehensive analysis of growth indexes.

Spatial distribution of air temperature and relative humidity in the greenhouse as affected by external shading in arid climates

The effect of external roof shading on the spatial distribution of air temperature and relative humidity in a greenhouse(Tin and RHin) was evaluated under the arid climatic conditions of Riyadh City, Saudi Arabia. Two identical, evaporatively-cooled, single-span greenhouses were used in the experiment. One greenhouse was externally shaded(Gs) using a movable black plastic net(30% transmissivity), and the other greenhouse was kept without shading(Gc). Strawberry plants were cultivated in both greenhouses. The results showed that the spatial distribution of the Tin and RHin was significantly affected by the outside solar radiation and evaporative cooling operation. The regression analysis showed that when the outside solar radiation intensity increased from 200 to 800 W m–2, the Tin increased by 4.5℃ in the Gc and 2℃in the Gs, while the RHin decreased by 15% in the Gc and 5% in the Gs, respectively. Compared with those in the Gc, more uniformity in the spatial distribution of the Tin and RHin was observed in the Gs. The difference between the maximum and minimum Tin of 6.4℃ and the RHin of 10% was lower in the Gs than those in the Gc during the early morning. Around 2℃ difference in the Tin was shown between the area closed to the exhausted fans and the area closed to the cooling pad with the external shading. In an evaporatively-cooled greenhouse in arid regions, the variation of the Tin and RHin in the vertical direction and along the sidewalls was much higher than that in the horizontal direction. The average variation of the Tin and RHin in the vertical direction was 5.2℃ and 10% in the Gc and 5.5℃ and 13% in the Gs, respectively. The external shading improved the spatial distribution of the Tin and RHin and improved the cooling efficiency of the evaporative cooling system by 12%, since the transmitted solar radiation and accumulated thermal energy in the greenhouse were significantly reduced.

Combined effect of shading time and nitrogen level on grain filling and grain quality in japonica super rice

There is limited information about the combined effect of shading time and nitrogen （N） on grain filling and quality of rice. Therefore, two japonica super rice cultivars, Nanjing 44 and Ningjing 3, were used to study the effect of shading time and N level on the characteristics of rice panicle and grain filling as well as the corresponding yield and quality. At a low N level （150 kg N ha^-1, 150N）, grain yield decreased （by 21.07-26.07%） under the treatment of 20 days of shading before heading （BH） compared with the no shading （NS） treatment. These decreases occurred because of shortened panicle length, decreased number of primary and secondary branches, as well as the grain number and weight per panicle. At 150N, in the treatment of 20 days of shading after heading （AH）, grain yield also decreased （by 9.46-10.60%） due to the lower grain weight per panicle. The interaction of shading and N level had a significant effect on the number of primary and secondary branches. A high level of N （300 kg N ha^-1, 300N） could offset the negative effect of shading on the number of secondary branches and grain weight per panicle, and consequently increased the grain yield in both shading treatments. In superior grains, compared with 150N NS, the time to reach 99% of the grain weight （T99） was shortened by 1.6 to 1.7 days, and the grain weight was decreased by 4.18-5.91% in 150N BH. In 150N AH, the grain weight was 13.39-13.92% lower than that in 150N NS due to the slow mean and the maximum grain-filling rate （GRmean and GRmax）. In inferior grains, grain weight and GRmean had a tendency of 150N NS〉150N BH〉150N AH. Under shaded conditions, 300N decreased the grain weight due to lower GReen both in superior and inferior grains. Compared with 150N NS, the milling and appearance qualities as well as eating and cooking quality were all decreased in 150N BH and 150N AH. Shading with the high level of 300N improved the milling quality and decreased the number of chalky rice kernels, but the eating and cooking quality was reduced with increased chalky area and overall chalkiness. Therefore, in the case of short term shading, appropriate N fertilizer could be used to improve the yield and milling quality of rice, but limited application of N fertilizer is recommended to achieve good eating and cooking quality of rice.

Study on New Nano Sun Shading Films

[Objective] The research developed a new kind of nano sun shading films that can be used in summer to maintain the appropriate indoor temperature for crops. [Method] The nano sun shading films were prepared by intercalation method. The films were characterized by XRD, TG, FA, UV-Vis-NIR and outdoor temperature test. [Result] Based on evaluation of cooling efficiency, a reduction 3-4 ℃ can be observed in newly developed nano sun shading films compared to control film. This film can control greenhouse light intensity effectively and decrease indoor tempera- ture, providing crops with appropriate growing temperature by reflecting most of in- frared light. Moreover, part of incident light can be converted to blue light and red light, which is beneficial to photosynthesis in plant. [Conclusion] Agricultural film is an important component to agriculture industry. Thus, agricultural film with improved properties and low cost has a broad application prospect.

Effects of Shading at Different Stages After Anthesis on Maize Grain Weight and Quality at Cytology Level

The objective of the current study is to investigate the effects of different stages of shading after anthesis on grain weight and quality of maize at cytology level. The shading experiments were conducted in the field from 2005 to 2006, with a common maize cultivar （TY2） as the experimental material. Plants were given stress using horizontal shading net and the light intensity was reduced by 55%. Field-grown maize plants were shaded at 1-14 d （S1）, 15-28 d （$2）, and 29-42 d （$3） after pollination, respectively. Control plants （SO） were grown under natural light. Grain weight, quality, endosperm cell proliferation, cob sugar content, and grain pedicel vascular bundle cross section area were measured. The ultrastructural changes of endosperm ceils and endosperm transfer cells were observed after pollination. The result indicated that the grain weight, starch content, endosperm cell number, and volume were declined after shading. On the contrary, the proportion of embryo and endosperm, protein content, and fat content in grain increased. Shading treatments significantly delayed the development of the starch granules and remarkably reduced the endosperm filling status. Among the three treatments, the number of the grain endosperm was the least under shading stress at 1-14 d after pollination. However, the volume of starch granules and the substantiation of endosperm under shading treatment at 15-28 d after pollination were the worst. Compared with the control （natural sunlight without shading）, the soluble sugar of maize cob increased significantly, while there was no obvious change in vascular structure of small cluster stalk. The number of protein body in maize endosperm was influenced markedly by low light at different stages after pollination. Low light decreased the volume of the grain endosperm transfer and the cell wall extensions of the basal transfer ceils became thinner and shorter under shading treatment than those of the control. Furthermore, the degree of connection and the capacity of the nutrient transport were decreased and the mitochondrion number of the transfer cell was reduced after shading. The change in grain quality after shading was observed due to increase in the proportion of embryo and endosperm. The morphology and functions in endosperm transfer cell and the shortage of energy restricted the nutrient transport greatly with shading at different stages, suggesting that an impeded flux may be one of the important reasons for the reduction of maize grain weight of maize grain at later growth stage under low light condition.

Light shading improves the yield and quality of seed in oil-seed peony(Paeonia ostii Feng Dan)

Tree peony seed is unique for its super-high content of unsaturated fatty acid and is thus considered as an important source of woody oil. However, photosynthetic production is greatly reduced under high light intensity and air temperature during the seed filling period, which negatively affects seed yield and quality. The objective of this study was to determine if appropriate shading improves yield and quality of seed in oilseed peony. In this study, oilseed peony trees were shaded by different density polyethylene nets from four weeks after flowering to harvest stages to form light, moderate, and severe shadings, equivalent to about 80, 40, and 20% of full solar exposure, respectively. The effects of different shadings on some physiological parameters, yield and yield components, and nutritional composition of seed were examined. Averaged across two years, light shading increased the actual net photosynthetic rate（P_n） by 16.8%, the maximum net photosynthetic rate（P_（max）） by 81.4%, chlorophyll（Chl） content by 52.8%, auxin（IAA） content by 38.1%, and gibberellic acid（GA_3） content in leaves by 6.3%; it decreased the accumulation of H_2O_2 in leaves by 24.8%, malondialdehyde（MDA） by 22%, and endogenous abscisic acid（ABA） by 8.8%, indicating that leaf senescence in late season was considerably delayed. Light shading increased seed yield, and contents of crude fat and unsaturated fatty acids by 9.7, 5.6, and 9.6%, respectively, while moderate or severe shading significantly reduced all the three parameters. Light shading increased seed weight, but moderate or severe shading reduced seed weight or follicle density. The improved seed yield under light shading was mainly due to increased seed weight, while the reduced seed yield under moderate or severe shading was mainly attributed to reduce follicle density and seed weight. The improved seed weight and content of unsaturated fatty acids under light shading was possibly due to the delayed leaf senescence. The overall results indicated that light shading is beneficial to yield and quality parameters of seed in oilseed peony. Cultivating oilseed peony under a light shading environments such as partially closed forests would better increase total output and income per unit land area than that under full solar exposure.

Effect of Shading on Gas Exchange of Cotton Leaves Under Conditions of Different Soil Water Contents

Effect of different shading levels (no-shading, 80% shading, and 40% shading) on photosynthetic and stomatal responses in cotton leaves were investigated under conditions of different soil water contents in summer midday. All cotton leaves exhibited similar basic responses to shading, including decreased net photosynthetic rates, a tendency to decrease in transpiration rates, and increased stomatal conductance and intercellular CO2 concentration. The leaf conductance of 80% shaded and 40% shaded plants increased by 28% and 16.7% compared with no-shaded plants at high water, respectively, but the net photosynthetic rates of 80% shaded and 40% shaded plants declined by 50% and 14.73%, respectively. Results showed that combined effect of soil moisture and shading on photosynthetic and stomatal responses in cotton leaves was very remarkable.

Effects of shading after pollination on kernel filling and physicochemical quality traits of waxy maize

Understanding the effects of shading after pollination on kernel filling and physicochemical properties of waxy maize could improve kernel quality.Experiments were conducted to investigate the effects of shading(30% and 50% light deprivation,taken plants without shading as control) on kernel weight,size,and physicochemical properties during kernel development in 2013 and 2014 using two waxy maize varieties(Suyunuo 5 and Yunuo 7).Results indicated that shading reduced kernel filling rate and decreased kernel size and weight,and the influence was large under severe light deprivation conditions.The large reduction in kernel weight and volume of Suyunuo 5 in response to shading indicated that it was more sensitive to shading than Yunuo 7.Starch content was reduced and protein content was increased by shading,especially under severe shading after 22 days after pollination(DAP).The iodine binding capacity of Yunuo 7 was not affected by shading at fresh and maturity stages but was gradually decreased by shading at the newly formed stage,while the values for Suyunuo 5were decreased at 7 and 40 DAP only by moderate shading and were similar among three treatments at 22 DAP.Severe shading decreased crystallinity at all kernel development stages,whereas moderate shading decreased crystallinity at fresh stage and increased it at mature stage for Suyunuo 5.Crystallinity in Yunuo 7 was increased by shading at 7 DAP and decreased by shading at 40 DAP,whereas the value at 22 DAP was increased by moderate shading and reduced by severe shading,respectively.The average gelatinization temperatures at different stages were decreased by shading and showed no difference between two shading levels.The retrogradation percentage at 7 DAP for both varieties was increased by shading.The value at 22 DAP was increased by moderate shading for Suyunuo 5 and decreased by severe shading for Yunuo 7,respectively.The retrogradation percentage at 40 DAP was decreased by shading treatments for Suyunuo 5 and reduced only by moderate shading for Yunuo 7.Peak viscosity was decreased by shading at fresh stage for Yunuo 7 and at maturity for Suyunuo 5.In conclusion,shading after pollination inhibited kernel filling of waxy maize and reduced paste viscosity quality,but kernel retrograde quality,crystallinity and starch iodine binding capacity in response to shading were dependent on stage and variety.

Transcriptome and co-expression network analyses provide insights into fruit shading that enhances carotenoid accumulation in pomelo(Citrus grandis)

Carotenoids are indispensable for human health,and citrus fruit are a crucial source of dietary carotenoids.Bagging,an important orchard practice to enhance fruit economic value,is widely used in many horticultural crops,including citrus fruit.The bagged‘Majiayou’pomelo(Citrus grandis)produces vivid deeper red pulp,a fantastic agronomic trait,but the underlying molecular regulatory mechanism remains largely unexplored.Here,the enhancement of carotenoids,especially lycopene,was confirmed by HPLC analysis of carotenoids in the pulp of bagged fruit and controls.qRT-PCR analysis of the 14 carotenoid pathway genes further revealed that upregulated PSY and downregulated CCD1 expression in bagged fruit could directly enhance the accumulation of carotenoids.In addition,RNA-seq analysis identified 311 differentially expressed genes(DEGs)in the bagged fruit and controls in five developmental stages.Weighted gene co-expression network analysis(WGCNA)identified 13 critical candidate genes among the DEGs,which are closely associated with lycopene accumulation.The underlying regulatory mechanism of these candidate genes on the transcription of carotenoid pathway genes in the bagged fruit was discussed.Considering that the candidate genes were involved in the corresponding metabolic pathways,the increase in sucrose content and decrease in ABA in bagged fruit were also identified,implying that these candidate genes may be indirectly related to carotenoid enhancement in pulp by regulating phytohormones,primary metabolism,and stress responses.The results provide new insights into the potential regulatory mechanism of lycopene enhancement in the pulp of bagged‘Majiayou’pomelo,facilitating breeding and orchard management efforts to improve the nutritional quality and esthetic value of citrus,and perhaps other fruit crops.