Analysis on the Composition and Structure of Branches of Two Kinds of Tree Shapes in Korla Fragrant Pear

ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distribution characteristics of various branches in each cubic lattice by using the canopy cellular method. ResultThe results showed that： The total number of scaffold branches of evacuation layered tree shape was 97, which mainly distributed in the lower layer and middle part of the canopy; the total number of scaffold branches of open-center tree shape was 94, which mainly distributed in the lower layer and middle part of the canopy. The total number of annual branches of evacuation layered tree shape was 3 920, which mainly distributed in the middle layer and outer part of the canopy; and the total number of annual branches of the open-center tree shape was 3 183, which mainly distributed in middle layer and outer part of the canopy. The total number of perennial branches of evacuation layered tree shape was 2 184, which mainly distributed in lower layer and outer part of the canopy; the total number of perennial branches of open-center tree shape was 1 444, which mainly distributed in middle layer and outer part of the canopy. ConclusionThe total number and the distribution positions of scaffold branches in the canopy of each tree shape were basically the same. The total numbers of annual branches of the two kinds of tree shapes were different, but the distribution positions were basically the same. The total numbers and the distribution positions of perennial branches in the canopy of the two kinds of tree shapes were different.

Analysis on Differences in Photosynthetic Characteristics of Korla Fragrant Pear among Different Planting Densities

[Objective] The aim of this study was to explore the differences in photosynthetic characteristics of Korla fragrant pear among different planting densities,providing a basis for the improvement of fruit yield and quality of Korla fragrant pear in production. [Method] The net photosynthetic rates, photoresponse curves and CO2 response curves of Korla fragrant pear under six different planting densities were determined using Li-6400 XT portable photosynthesis system. [Result] There were significant differences in photosynthetic parameters of Korla fragrant pear among six different planting densities. The net photosynthetic rate of Korla fragrant pear was highest under the planting density of 4.0 m × 6.0 m. At the planting density of4.0 m×6.0 m, when the light intensity reached 1 800 μmol/（m^2·s）, the net photosynthetic rate of Korla fragrant pear reached the peak [19.326 μmol/（m^2·s）], and the apparent quantum yield, carboxylation efficiency and dark respiration rate all reached the maximum values; at the planting density of 6.0 m ×7.0 m, Korla fragrant pear showed lower light compensation point and CO2 compensation point, but higher light saturation point. At the planting density of 3.0 m ×5.0 m, Korla fragrant pear had higher light saturation point. [Conclusion] Among the six different planting densities,Korla fragrant pear with planting density of 4.0 m ×6.0 m showed the highest net photosynthetic rate. It suggested that Korla fragrant pear, at the planting density of4.0 m ×6.0 m, had stronger utilization capacity for low light and low-concentration CO2. Therefore, the Korla fragrant pear with the planting density of 4.0 m ×6.0 m has the highest photosynthesis efficiency, and the planting density of 4.0 m ×6.0 m is the most ideal planting density for Korla fragrant pear.

Effects of Regulated Deficit Irrigation on Twig Water Potential of Korla Fragrant Pear

With 7-year-old Korla fragrant pear trees as the experimental material, different root-zone irrigation patterns were arranged to study the effects of soil moisture on twig water potential of Korla fragrant pear trees at different growth stages. The results showed that under the condition of regulated deficit irrigation, the diurnal dynamics of twig water potential of Korla fragrant pear trees was V shaped at different growth stages, and the twig water potential of Korla fragrant pear trees reached the minimum during 14：00-16：00. At different growth stages, the twig water potential of Korla fragrant pear trees under drought stress was significantly lower than that of pear trees irrigated normally. Under both drought stress and normal irrigation, the diurnal variation of twig water potential of Korla fragrant pear trees during the flowering period was most gentle, that during the fruit-setting and mature periods showed some ups and downs, and that during the fruit enlargement period was greater. Under the experimental conditions, the twig water potential of Korla fragrant pear trees was positively correlated with soil moisture content, and the functional relationships between them at different growth stages were studied by regression analysis. In addition, the limits of twig water potential and soil moisture content for normal growth of Korla fragrant pear trees at different growth stages were determined.

Differences in Light Response Curve and CO_2 Response Curve of Korla Fragrant Pear Trees in Different Training Systems

[Objective] This study was conducted to evaluate three training systems for Korla fragrant pear trees by comparing the characteristic parameters of light response curve and CO2 response curve, and to provide some theoretical basis for improving the pruning techniques of Korla fragrant pear trees. [Method] The light response curve and CO2 response curve of the trees trained to three systems were measured by LI-6400 portable photosynthesis system. The SPAD value was measured using SPAD-502 chlorophyll meter, and specific leaf weight was calculated, to evaluate the effects of the three training systems. [Result] The CO2 response curves of the three training systems were basically in agreement with their light response curves, but there were some differences in their characteristic parameters. Among the three training systems, the maximum net photosynthetic rate, apparent quantum yield and light compensation point of espalier trained trees were the highest, while their light saturation point was the lowest. The CO2 saturation point of delayed-open central leader trained trees and open center trained trees were 1 752 and 1 665 μmol/mol, both of which were much higher than that of espalier trained trees. In addition, the carboxylation efficiency and photorespiration rate of espalier trained trees were both higher than those of delayed-open central leader trained trees and open center trained trees, while the CO2 compensation point of espalier trained trees was the lowest. The leaf SPAD value of espalier trained trees was the largest, followed by that of open center trained trees, and the leaf SPAD value of delayed-open central leader trained trees was the smallest. In addition, the leaf area and specific leaf weight of espalier trained trees were both the highest, followed by those of open center trained trees. [Conclusion] Among the training systems for Korla fragrant pear trees, the espalier training system had better ability to capture light, higher photosynthetic productivity and strongest adaptability to light environment, and open center training system takes the second place. On the contrary, delayed-open central leader training system has the weakest adaptability to light environment, but it can adapt to a higher CO2 concentration. In summary, for the training of Korla fragrant pear trees, espalier training system, which has the highest theoretical yield, is the best among the three training systems, and delayed-open central leader training system is the worst.

Transcriptome analysis to identify candidate genes related to chlorogenic acid biosynthesis during development of Korla fragrant pear in Xinjiang

Korla fragrant pear(KFP)with special fragrance is a unique cultivar in Xinjiang,China.In order to explore the biosynthesis molecular mechanism of chlorogenic acid(CGA)in KFP,the samples at different development periods were collected for transcriptome analysis.High performance liquid chromatography analysis showed that CGA contents of KFP at 88,118 and 163 days after full bloom were(20.96±1.84),(12.01±0.91)and(7.16±0.41)mg/100 g,respectively,and decreased with the fruit development.Pears from these typical 3 periods were selected for de novo transcriptome assemble and 68059 unigenes were assembled from 444037960 clean reads.One‘phenylpropanoid biosynthesis’pathway including 57 unigenes,11 PALs,1 PTAL,64CLs,9 C4Hs,25 HCTs and 5 C3’Hs related to CGA biosynthesis was determined.It was found that the expression levels of 11 differentially expressed genes including 1 PAL,2 C4Hs,34CLs and 5 HCTs were consistent with the change of CGA content.Quantitative polymerase chain reaction analysis further showed that 8 unigenes involved in CGA biosynthesis were consistent with the RNA-seq data.These findings will provide a comprehensive understanding and valuable information on the genetic engineering and molecular breeding in KFP.

Response of Leaf Tissue Structure to PP333 in Korla Fragrant Pear

[Objective] This study was performed to explore the effect of different concentrations of PP333 on leaf tissue structure of Korla fragrant pear and to lay the foundation for the cultivation and regulation of Korla fragrant pear. [Method] The leaf tissues treated with different concentrations of PP333 were dehydrated with al- cohol, embedded in paraffin and sliced into 10-μm slices. The thicknesses of leaf blade, upper epidermis, lower epidermis, palisade tissue and sponge tissue were measured, and the ratio of palisade to spongy layer thickness, cell tightness （CT） and cell looseness （CL） were calculated. [Result] The thickness of leaf blade, the ratio of palisade to sponge layer thickness and the thickness of palisade layer were all significantly increased after treatment with PP333. Treatment with 2 500 mg/L PP333 showed no obvious effect on the thickness of leaf epidermis, but increased the thicknesses of leaf blade and palisade tissue. Leaf CL was the highest in the treatment of 1 500 mg/L PP333. [Conclusion] PP333 can increase the leaf thickness, palisade tissue thickness and CT, reduce spongy tissue thickness and CL of Korla fragrant pear. Additionally, 1 500 mg/L was the optimal concentration for the application of PP333 to improve the cold resistance of Koda fragrant pear.

Response of Leaf Tissue Structure to Exogenous ABA in Korla Fragrant Pear

To study the effects of different concentrations of Abscisic Acid(ABA) on leaf tissue structure of Korla fragrant pear and lay the foundation for the cultivation and regulation of Korla fragrant pear. Using the paraffin section method, the leaf thickness, the epidermis thickness, the palisade tissue thickness and the sponge tissue thickness were measured; palisade spongy ratio, Cell Tightness(CT) and Cell Looseness(CL) were examined after treatments with exogenous ABA. Leaf thickness, leaf palisade spongy ratio and palisade tissue thickness increased significantly after exogenous ABA treatment compared with CK, while the effect on leaf epidermis was not obvious. The leaf thickness and palisade tissue thickness increased evidently after 70 mg · LABA treatment by 24.89% and 41.10%, respectively. The tissue structures of leaves were more compact, while CL was lower after 70 and 90 mg · LABA treatments. The effects of different concentrations of exogenous ABA could increase the leaf thickness, palisade tissue thickness of Korla fragrant pear and CT, reduced the thickness of spongy tissue and CL. Among those concentrations of exogenous ABA, the effect of spraying 70 mg · Lexogenous ABA was suitable for improving cold resistance of Korla fragrant pear.

Industrialization Development of Korla Fragrant Pear in Bayingolin Mongol Autonomous Prefecture,China

Based on the introduction of the natural and geographical conditions in Bayingolin Mongol Autonomous Prefecture in Xinjiang(Bazhou),development status of Korla Fragrant Pear is introduced from the two aspects of the production status and the storage and processing status of Korla Fragrant Pear.Among them,production status of Korla Fragrant Pear is analyzed from the aspects of the rapid growth of planting area and the stable growth of output.And the storage and processing status of Korla Fragrant Pear is introduced from the aspects of the development status of the storage industry the development status of processing industry,and the status of domestic and foreign marketing.Problems in the industrialization development of Korla Fragrant Pear in Bazhou are analyzed,such as the weak protection of brand and lack of external propaganda,the imperfect benefit affiliating mechanism between leading enterprises and peasant households,and the marketing network of Korla Fragrant Pear and single mode of marketing.Countermeasures for the acceleration of the industrialization development of Korla Fragrant Pear in Bazhou are put forward,such as making great effort at publicity,brand establishment and counterfeit prevention,cultivating leading enterprises,reducing market risk,implementing industrialization development,adopting various marketing forms and actively developing domestic and international markets.

Model for estimating the weight-loss ratio of damaged Korla fragrant pears

To predict the weight-loss ratio of Korla fragrant pears effectively,improve commodity value and study the variation laws of the weight-loss ratio of damaged fragrant pears during storage,this study predicted the weight-loss ratio of fragrant pears by utilizing the generalized regression neural network(GRNN),support vector regression(SVR),partial least squares regression(PLSR)and error back propagation neural network(BPNN).The prediction performances of GRNN,SVR,PLSR and BPNN models were compared comprehensively,and the optimal model was determined.In addition,the optimal prediction model was verified.The results show that weight-loss ratio of fragrant pears increases gradually with the extension of storage time.During storage,the weight-loss ratio of fragrant pears is positively related to the degree of damage.The trained GRNN,SVR,PLSR and BPNN models can be used to predict the weight-loss ratio of fragrant pears.The BPNN model is the most accurate in predicting the weight-loss ratio of damaged fragrant pears(R^(2)=0.9929;RMSE=0.2138).It has also been proved to have good predictive effect in production practice(R^(2)=0.9377,RMSE=0.7138).The research findings can provide references to predict the delivery quality and time of delivery of Korla fragrant pears.

Comprehensive evaluation of Korla fragrant pears and optimization of plucking time during the harvest period

To optimize the harvest of Korla fragrant pears and to provide a theoretical basis for post-harvest processing,a total of 26 basic indices of Korla fragrant pears,including their morphology,quality,and softening age,were investigated.The harvest period ranged from August 22nd to October 6th,samples were collected every 5 d(totally 10 plucking days,indicated as H1-H10).The results indicated that changes in pectin content were the main causes of softening in fragrant pears.The scavenging of free radicals mainly occurred because of the collaborative effects of superoxide dismutase(SOD)and catalase(CAT).In the harvest periods H1-H3,the hardness,titratable acid(TA),chlorophyll content,density,and diameter of the stone cells,as well as the cellulose and hemicellulose content of the Korla fragrant pears were at their highest.During the periods H7-H10,the single-fruit weight,fruit horizontal and vertical diameter,color coordinates L,a*,b*,soluble-solids content(SSC),SOD activity,CAT activity,and water-soluble pectin were higher than in the other plucking periods.The highest vitamin C(VC)content and moderate values for a variety of indicators were observed during H3-H7.Variations in the Korla fragrant pears during H1-H3 mainly manifested through changes in softening-related parameters.During H3-H10,changes in the softening-related,aging-related,color-related,and quality indices had a dominant role.On this basis,some suggestions for the post-harvest processing of fragrant pears have been proposed.Fruit,during H1-H3,are suitable for transportation and storage;during H7-H10 are suitable for fresh-eating and further processing;and during H3-H7,exhibited moderate values for a variety of indicators and had the highest commercial value.This research provides a systematic evaluation of the characteristics of mature Korla fragrant pears during the harvest period and can form the basis for fruit quality control and processing of Korla fragrant pears.

Construction method of quantitative evaluation model for the maturity of Korla fragrant pear

The maturity variation laws of Korla fragrant pears were explored for a quantitative evaluation of harvest maturity to solve the reasonable matching between harvest maturity of Korla fragrant pears and market quality demands.Korla fragrant pears from different harvesting periods were chosen as the research objects.Some quality indexes were chosen as the evaluation indexes per industry standards,including hardness,soluble solid content(SSC),single-fruit weight,fruit longitudinal diameter,fruit equatorial diameter,pericarp color parameters(L*,a*,and b*),and titratable acid.Variation data of these quality indexes with accumulated temperature were collected.Scores of several quality indexes were gained through principal component analysis.A mathematical model of scores and accumulated temperatures was constructed.On this basis,a quantitative maturity model of Korla fragrant pears was constructed.Results demonstrate that SSC,single-fruit weight,fruit longitudinal diameter,fruit equatorial diameter,L*,a*,and b*are significantly and positively correlated with the accumulated temperature.Meanwhile,hardness and titratable acid showed significant negative correlations with the accumulated temperature.Relations between scores of principal components and accumulated temperature conform to the Sigmoidal model.The constructed quantitative maturity model of Korla fragrant pears can quantify the maturity of pears.Research conclusions can provide insight into the harvest periods,evaluate Korla fragrant pears’maturity,and lay a theoretical foundation for quantitative research on fruit maturity.

Non-destructive detection of the fruit firmness of Korla fragrant pear based on electrical properties

In order to achieve the non-destructive detection of the firmness of Korla fragrant pear during the ripening period,the characteristic variables integrating the parallel equivalent inductance(Lp),quality factor(Q),parallel equivalent capacitance(Cp),dissipation factor(D),parallel equivalent resistance(Rp)and impedance(Z)were formulated through principal component analysis(PCA).Further,based on the characteristic variables,the models were established for predicting the firmness of Korla fragrant pear by using the generalized regression neural network(GRNN)and back-propagation neural network(BPNN).The results showed that firmness has significant correlations with the six electrical parameters.The first two principal components(PCs)were selected as the characteristic variables of the electrical parameters.GRNN exhibited the best performance in predicting firmness(R2=0.9628,RMSE=0.383).The results could provide important references for non-destructive detection of the quality of Korla fragrant pear.

Changes in Soil Organic Matter,Nitrogen and Phosphorus Contents during Decomposition of Pear Branches

[Objectives]To investigate the changes in soil organic matter,nitrogen and phosphorus content in the decomposition process of Korla fragrant pear branches by indoor mixed culture.[Methods]The branches of Korla fragrant pear in the orchard were collected and returned to the field for a period of 150 d for indoor mixed culture.[Results]Different ages of Korla fragrant pear branches have different effects on soil nutrient content during the simulated return to field decomposition process.Compared with the control in the same period,the treatment of returning to field reached a significant level(P<0.05).Compared with the control,the average values of organic matter,total nitrogen and available phosphorus content in treatment 1 and treatment 2 increased by 2.16 times and 1.93 times,61%and 59%,5.88 times and 6.88 times,respectively;compared with the control,the average increase performance of the alkaline hydrolysis nitrogen content of the two treatments was basically the same,and the treatment 2 was the best;compared with the control,the average total phosphorus content of treatment 1 and treatment 2 increased but not significantly.[Conclusions]The contents of soil organic matter,nitrogen and phosphorus were all increased during the decomposition of pear branches,and the overall improvement effect of 10-year-old trees was better than that of 5-year-old trees.Returning the pruned branches to the field can provide a reliable theoretical basis for solving the problem of organic fertilizer shortage in orchards,and also can ensure technical support for improving soil fertility and improving the rhizosphere micro-environment of pear trees.

梨火疫病抗性评价体系的建立及其种质资源抗性鉴定

【目的】利用梨幼果建立梨火疫病(Erwinia amylovora)抗性资源评价体系,筛选出对梨火疫病具有抗性的材料,为抗病育种提供技术支撑。【方法】以36个梨品种和41个库尔勒香梨杂交后代为材料,利用人工接种的方式对幼果期、膨大期和成熟期的果实进行接种试验,并根据接种后致病力的强弱,制定梨品种(种质)的抗性分级指标,综合评价77份种质资源的抗病水平。【结果】与梨果实膨大期和成熟期相比,接种幼果期果实更能准确评估梨品种(种质)的抗性水平;在接种24 h后,梨幼果开始显症;77个品种(种质)对梨火疫病的抗性水平差异显著,高感品种(种质)13个,感病品种(种质)11个,中感品种(种质)27个,抗病品种(种质)26个;供试品种(种质)对梨火疫病的抗性不高,其中只有33.77%的品种(种质)表现抗病性,66.23%的品种(种质)不同程度感病。【结论】本研究建立以梨果实的幼果期为接种时期,在接种24 h时开始观察发病情况的梨火疫病抗性资源评价体系;从供试品种(种质)筛选出的26份材料达到抗性水平,为培育新的抗性品种提供参考。

库尔勒香梨大疆T50无人机授粉参数优选与田间验证

为了提高库尔勒香梨无人机授粉作业的精确性,选用大疆T50无人机,采用三因素(作业速度、作业高度、667 m^(2)喷施量)三水平的正交试验,比较雾滴覆盖率、雾滴密度及雾滴沉积量的分布效果,筛选作业参数并进行了田间授粉效果的验证。结果表明:在环境风速不超过1.5 m/s的条件下,大疆T50无人机对纺锤形库尔勒香梨授粉的最佳作业参数为作业速度4 m/s、作业高度距离树顶4.5 m、667 m^(2)喷施量4L;田间授粉的花序坐果率为75.56%,花朵坐果率为32.87%。影响库尔勒香梨树冠上层雾滴效果的主要因素依次为667 m^(2)喷施量、作业高度、作业速度,影响树冠中层和下层雾滴效果的主要因素依次为667 m^(2)喷施量、作业速度、作业高度。

库尔勒香梨园土壤肥力空间变异特征与综合评价分析

为研究库尔勒香梨园土壤pH、盐分、速效养分以及微量元素空间分布特征,掌握香梨园综合肥力水平,以库尔勒市香梨种植区为研究区,选取具有代表性的50个库尔勒香梨园进行样点布设与土样采集。运用经典统计学和地统计学方法研究香梨园表层(0~40 cm)土壤养分指标和微量元素指标的空间变异性,探究香梨园土壤肥力状况。经典统计分析表明:pH的变异系数为0.02属于弱变异,电导率的变异系数为1.03表现为强变异,有机质、碱解氮、速效磷、速效钾、有效锰、有效铜、有效锌和有效铁的变异系数分别为0.37、0.53、0.99、0.59、0.45、0.25、0.24和0.48,为中等变异程度,研究区土壤综合肥力指数IFI值在0.37~0.80之间,平均值为0.58;地统计分析表明:土壤有机质、碱解氮和速效钾的块金系数大于75%,空间自相关性较弱;pH、电导率、速效磷、有效锰、有效铜、有效锌和有效铁的块金系数在25%~75%之间,这些指标具有中等强度的空间自相关性;库尔勒香梨园Ⅰ(优)、Ⅱ(良好)、Ⅲ(中等)、Ⅳ(较差)和Ⅴ(差)类土壤占比分别为2.72%、10.54%、61.80%、24.87%、和2.77%,土壤综合肥力在空间上呈现斑块状,肥力较好的Ⅰ级在北部零星分布、Ⅱ级斑块状分布在北部及西部,Ⅲ级主要分布在北部以及南部,肥力较差的Ⅳ、Ⅴ级主要集中在中部。总体上,库尔勒市香梨园土壤肥力为中等水平,土壤属性空间异质性比较强,其中有效锰、有效铁是制约土壤肥力的主要限制因子,果园有必要进行差异化管理,并应重视补充锰、铁微量元素肥,此外中部地区还要着重补充氮肥、磷肥和有机肥。

化肥配施有机液体肥对香梨产量、品质及土壤理化性质和细菌群落结构的影响

旨在探究化肥配施有机液体肥对香梨产量和质量、土壤理化性质以及细菌群落结构的影响。以单施化肥(CF)为对照,化肥全量配施有机液体肥(CF100OFL)及化肥减量20%配施有机液体肥(CF80OFL)两种处理,利用Illumina MiSeq平台对土壤细菌群落进行测序分析,同时测定香梨产量和品质以及土壤基本理化性质。结果表明,与CF相比,CF100OFL和CF800OFL处理显著增加香梨单果质量、可溶性固形物含量并降低可滴定酸的含量,CF100OFL和CF800OFL处理的土壤速效磷、速效钾和有机质含量较CF分别提高59.63%、38.52%、12.03%和7.48%、7.29%%、5.92%。同时,两者土壤细菌群落多样性指数(Chao1)分别提高26.91%和13.77%,也提高土壤变形菌门、拟杆菌门、棒状杆菌门以及浮霉菌门的相对丰度,降低放线菌门、酸杆菌门和硝化螺旋菌门的相对丰度。此外,化肥配施有机液体肥显著提高土壤过氧化氢酶、蔗糖酶和脲酶的活性。冗余分析及线性回归分析表明,速效磷、速效钾和土壤含水量是影响细菌群落的主要因子,速效磷、速效钾也是香梨单果质量和单株产量、可溶性固形物含量的主要影响因子。综合考虑产量、品质、土壤以及投入产出等因素,CF80OFL处理通过改变土壤微生物群落结构、提高微生物活性,可有效改善香梨园土壤质量,亦可增加香梨产量和品质。

库尔勒香梨开花前后花药细菌多样性分析

【目的】研究库尔勒香梨花药细菌的多样性,分析库尔勒香梨开花前后花药细菌变化,为新疆南疆梨树常见病害的防治提供菌种资源。【方法】采用平板涂布法分离和纯化香梨开花前后花药细菌,分析细菌多样性,并借助16S rDNA基因序列分析技术对其进行分子鉴定,确定其分类地位。【结果】香梨开花前后花药所携带的细菌种类具有多样性。对开花前后花药分离的菌株分别随机挑选9株和7株进行分子鉴定,筛选的9株开花前花药细菌全部归属于芽孢杆菌属,其中包括枯草芽孢杆菌、解淀粉芽孢杆菌和贝莱斯芽孢杆菌。筛选的7株开花后花药细菌除了有芽孢杆菌属细菌,也包括鞘氨醇杆菌属细菌,开花后花药细菌多样性大于开花前。【结论】开花前花药所携带的细菌其中有5株为枯草芽孢杆菌,2株为解淀粉芽孢杆菌,2株为贝莱斯芽孢杆菌。开花后花药所携带的细菌其中有3株为枯草芽孢杆菌,2株为解淀粉芽孢杆菌,1株为副炭疽芽孢杆菌,1株为多食鞘氨醇杆菌。

库尔勒香梨全产业链发展现状与对策建议

库尔勒香梨是新疆的优势林果产品。对近年来库尔勒市全力打造库尔勒香梨全产业链的成功经验进行了梳理与总结,对存在的问题进行了深入剖析,并针对性地提出了建设性建议。

基于多光谱图像角度融合测定库尔勒香梨理化指标

基于多光谱图像角度融合,提出了一种库尔勒香梨快速无损检测的方法。以库尔勒香梨为研究对象,应用多光谱成像采集系统,以10°为间隔,获取了相对方位角为10°~90°内的多光谱图像。使用ENVI5.1软件进行多光谱图像角度融合并提取感兴趣区域(ROI),获得多光谱数据。对光谱反射率、波段和相对方位角进行了皮尔逊相关性分析,发现波段和相对方位角都对光谱反射率呈极显著相关性,且相对方位角相关系数为0.1大于波段相关系数0.053,有必要在建模过程中加入相对方位角因素。采用标准正态变量变换(SNV)、均值中心化变换(MC)、卷积平滑处理(S_G)和归一化处理(Nor)等预处理方法,选用偏最小二乘回归(PLSR)建立全波段检测模型,通过校正集相关系数(R_(c))、预测集相关系数(R_(p))、校正集均方根误差(RMSEC)和预测集均方根误差(RMSEP)对模型的效果进行评价,对比探究特征角度下和角度融合下库尔勒香梨关键指标的模型检测效果。结果表明:采用角度融合处理后,所建立的PLSR和SVM模型预测效果都有显著提升。预测库尔勒香梨含水率最优模型为采用角度融合的偏最小二乘回归模型(AF-PLSR),其R_(c)为0.936, RMSEC为0.298,R_(p)为0.901, RMSEP为0.285;预测库尔勒香梨硬度和糖度的最优模型为以角度融合的支持向量机模型(AF-SVM),R_(c)分别为0.894、 0.905, RMSEC为0.527、 0.376;R_(p)为0.830、 0.901, RMSEP为0.532、 0.379。角度融合将不同角度下的光谱数据结合在一起,获得了比单一角度更加丰富的信息,得到了更加完善的光谱。所建立的检测模型精度更高。结果证明:基于多光谱图像角度融合技术预测库尔勒香梨的含水率、硬度和糖度是可行的。为提高多光谱无损检测精度和高光谱无损检测精度提供了一种新的思路。