Budding is an important grafting technique to asexually propagate pecan(Carya illinoinensis(Wangenh.)K.Koch).To determine factors that might hamper success-ful budding of the species,a representative easy-to-survive c...Budding is an important grafting technique to asexually propagate pecan(Carya illinoinensis(Wangenh.)K.Koch).To determine factors that might hamper success-ful budding of the species,a representative easy-to-survive cultivar‘Pawnee’and a typical difficult-to-survive culti-var‘Jinhua’were used for comprehensive analysis.Mor-phological observation showed that cells surrounding the secretory cells or sieve tube had collapsed in‘Jinhua’but not in‘Pawnee’during grafting.‘Jinhua’might suffer more hypoxia stress than‘Pawnee’as‘Jinhua’had higher catalase,superoxide dismutase,polyphenol oxidase,pyruvate decar-boxylase(PDC),alcohol dehydrogenase(ADH)activities during grafting and contained greater levels of hydrogen per-oxide 12 days after grafting(DAG).Transcriptions of PDC and ADH were also up-regulated significantly in‘Jinhua’whereas they were not significantly affected in‘Pawnee’.Phenylalanine ammonia-lyase activities of‘Jinhua’were consistently lower than that of‘Pawnee’.Initial phenol con-tents were similar between the two cultivars.Graft-promot-ing substances,including soluble sugar,soluble protein,and gibberellin(GA)were incompletely recovered in‘Jinhua’12 DAG while fully restored in‘Pawnee’.Increased levels of trans-zeatin riboside in‘Jinhua’were much smaller than in‘Pawnee’3 DAG.The contents of indole-3-acetic acid were similar,and the dynamics of abscisic acid were the same between the two genotypes.Results suggest that hypoxia stress and shortages of sugar,protein,GA,and cytokinin during the healing process might be key factors limiting successful budding of pecan.The degree of scion-rootstock compatibility and the content of phenols might be excluded as constraints for successful budding.展开更多
Euplatypus segnis is an insect pest of economic importance in pecan (Carya illinoensis) trees grown at Parras, General Cepeda and Torreón Coahuila, Mexico. The objectives in this study-were to identify the fungal...Euplatypus segnis is an insect pest of economic importance in pecan (Carya illinoensis) trees grown at Parras, General Cepeda and Torreón Coahuila, Mexico. The objectives in this study-were to identify the fungal strains associated to ambrosia borer body and diseased pecan wood and determine their pathogenicity. The results showed that the associated fungi to Euplatypus segnis and damaging the pecan wood were identified as: Helminthosporium sp., Aspergillus sp., Penicillium sp., Phoma sp., Ascochyta sp., Phaecylomices sp., Umbeliopsis sp., Torula sp., Fusarium solani, Alternaria alternata, Fusarum oxysporum, and Lasiodiplodia theobromae. The pathogenicity tests on healthy 3 year old pecan trees cv. western using Fusarium oxysporum, Fusarium solani, Alternaria alternata and Lasiodiplodia theobromae suspension conidia shown die back tree branches after 84 days inoculation. The insect in combination with the fungal invasion eventually cause the death of trees. Additionally, the insect contributes to the spread of fungi in pecan nut orchards.展开更多
The pecan nut is considered one of the most important dried fruits in the world by its classification as healthy food. The nutritional balance in the harvest is crucial for its impact on the production, quality and co...The pecan nut is considered one of the most important dried fruits in the world by its classification as healthy food. The nutritional balance in the harvest is crucial for its impact on the production, quality and content of bioactive compounds. This research was carried out in the city of Aldama, Chihuahua (Mexico), where doses of mineral and organic fertilization were tested in L25 Taguchi structure with 6 factors and 5 levels by factor: nitrogen (N) 0 - 240 kg·ha-1, phosphate (P2O5) 0 - 120 kg·ha-1, potassium (K2O) 0 - 100 kg·ha-1, calcium (CaO) 0 - 400 kg·ha-1, liquid humus 0 - 3600 L·ha-1 and solid humus 0 - 8000 kg·ha-1. An average yield of 2.2 t·ha-1 was obtained;145 nuts per kilogram, 60% of the edible part of the nut. The total phenolic content was 225.9 mg gallic acid g-1 and the antioxidant capacity was 180.9 mg Trolox g-1. It is concluded that the factor with the greatest impact on yield, quality and antioxidant capacity in pecan nut was nitrogen. It was also found that the combination of mineral and organic fertilization helps to maintain the production and quality ranges of the nut. In turn, these factors contribute to the increase in the phenolic strength and antioxidant capacity. The optimal fertilization dosis to obtain the maximum levels in production of 3.2 t·ha-1;decrease the number of nuts per kilogram to 135, increase the percentage of the edible part of the nut to 61.8%, the increase in the total phenolic content to 318.6 mg of gallic acid g-1 and in the antioxidant capacity with 187.2 mg of Trolox g-1, was 184 kg·ha-1 of N, 107.4 kg·ha-1 of P2O5, 50 kg·ha-1 of K2O y 2777 L·ha-1 of liquid humus. Finally, the mineral fertilization complemented with organic fertilization is considered a good fertilization strategy for pecan trees and its possible benefits to health and the environment.展开更多
Pecan(Carya illinoinensis)is a tree nut crop of worldwide economic importance that is rich in healthpromoting factors.However,pecan production and nut quality are greatly challenged by environmental stresses such as t...Pecan(Carya illinoinensis)is a tree nut crop of worldwide economic importance that is rich in healthpromoting factors.However,pecan production and nut quality are greatly challenged by environmental stresses such as the outbreak of severe fungal diseases.Here,we report a high-quality,chromosome-scale genome assembly of the controlled-cross pecan cultivar‘Pawnee’constructed by integrating Nanopore sequencing and Hi-C technologies.Phylogenetic and evolutionary analyses reveal two whole-genome duplication(WGD)events and two paleo-subgenomes in pecan and walnut.Time estimates suggest that the recent WGD event and considerable genome rearrangements in pecan and walnut account for expansions in genome size and chromosome number after the divergence from bayberry.The two paleo-subgenomes differ in size and protein-coding gene sets.They exhibit uneven ancient gene loss,asymmetrical distribution of transposable elements(especially LTR/Copia and LTR/Gypsy),and expansions in transcription factor families(such as the extreme pecan-specific expansion in the far-red impaired response 1 family),which are likely to reflect the long evolutionary history of species in the Juglandaceae.A whole-genome scan of resequencing data from 86 pecan scab-associated core accessions identified 47 chromosome regions containing 185 putative candidate genes.Significant changes were detected in the expression of candidate genes associated with the chitin response pathway under chitin treatment in the scab-resistant and scabsusceptible cultivars‘Excell’and‘Pawnee’.These findings enable us to identify key genes that may be important susceptibility factors for fungal diseases in pecan.The high-quality sequences are valuable resources for pecan breeders and will provide a foundation for the production and quality improvement of tree nut crops.展开更多
Although the development of the robot picking vision system is widely applied,it is very challenging for fruit detection in orchards with complex light and environment,especially for fruit colors similar to the backgr...Although the development of the robot picking vision system is widely applied,it is very challenging for fruit detection in orchards with complex light and environment,especially for fruit colors similar to the background.In recent,there are few studies on pecan fruit detection and location based on machine vision.In this study,an accurate and efficient pecan fruit detection method was proposed based on machine vision under natural pecan orchards.In order to solve the illumination problem,a light compensation algorithm was first utilized to process the collected samples,and then an improved Faster Region Convolutional Neural Network(Faster RCNN)with the Feature Pyramid Networks(FPN)was established to train the samples.Finally,the pecan number counting method was introduced to count the number of pecan.A total of 241 pecan images were tested,and comparison experiments were carried out.The mean average precision(mAP)of the proposed detection method was 95.932%,compared with the result without uneven illumination correction(UIC),which was increased by 0.849%,while the mAP of the Single Shot Detector(SSD)+FPN was 92.991%.In addition,the number of clusters was counted using the proposed method with an accuracy rate of 93.539%compared with the actual clusters.The results demonstrate that the proposed network has good robustness for pecan fruit detection in different illumination and various unstructured environments,and the experimental achievement has great potential for robot-picking visual systems.展开更多
基金funded by the National Natural Science Foundation of China(3190134732001350)+1 种基金the Central Government Demonstration Project of Forestry Science and Technology(su[2022]TG11)the Key Research and Development Plan of Jiangxi Province(20223BBF61014).
文摘Budding is an important grafting technique to asexually propagate pecan(Carya illinoinensis(Wangenh.)K.Koch).To determine factors that might hamper success-ful budding of the species,a representative easy-to-survive cultivar‘Pawnee’and a typical difficult-to-survive culti-var‘Jinhua’were used for comprehensive analysis.Mor-phological observation showed that cells surrounding the secretory cells or sieve tube had collapsed in‘Jinhua’but not in‘Pawnee’during grafting.‘Jinhua’might suffer more hypoxia stress than‘Pawnee’as‘Jinhua’had higher catalase,superoxide dismutase,polyphenol oxidase,pyruvate decar-boxylase(PDC),alcohol dehydrogenase(ADH)activities during grafting and contained greater levels of hydrogen per-oxide 12 days after grafting(DAG).Transcriptions of PDC and ADH were also up-regulated significantly in‘Jinhua’whereas they were not significantly affected in‘Pawnee’.Phenylalanine ammonia-lyase activities of‘Jinhua’were consistently lower than that of‘Pawnee’.Initial phenol con-tents were similar between the two cultivars.Graft-promot-ing substances,including soluble sugar,soluble protein,and gibberellin(GA)were incompletely recovered in‘Jinhua’12 DAG while fully restored in‘Pawnee’.Increased levels of trans-zeatin riboside in‘Jinhua’were much smaller than in‘Pawnee’3 DAG.The contents of indole-3-acetic acid were similar,and the dynamics of abscisic acid were the same between the two genotypes.Results suggest that hypoxia stress and shortages of sugar,protein,GA,and cytokinin during the healing process might be key factors limiting successful budding of pecan.The degree of scion-rootstock compatibility and the content of phenols might be excluded as constraints for successful budding.
文摘Euplatypus segnis is an insect pest of economic importance in pecan (Carya illinoensis) trees grown at Parras, General Cepeda and Torreón Coahuila, Mexico. The objectives in this study-were to identify the fungal strains associated to ambrosia borer body and diseased pecan wood and determine their pathogenicity. The results showed that the associated fungi to Euplatypus segnis and damaging the pecan wood were identified as: Helminthosporium sp., Aspergillus sp., Penicillium sp., Phoma sp., Ascochyta sp., Phaecylomices sp., Umbeliopsis sp., Torula sp., Fusarium solani, Alternaria alternata, Fusarum oxysporum, and Lasiodiplodia theobromae. The pathogenicity tests on healthy 3 year old pecan trees cv. western using Fusarium oxysporum, Fusarium solani, Alternaria alternata and Lasiodiplodia theobromae suspension conidia shown die back tree branches after 84 days inoculation. The insect in combination with the fungal invasion eventually cause the death of trees. Additionally, the insect contributes to the spread of fungi in pecan nut orchards.
文摘The pecan nut is considered one of the most important dried fruits in the world by its classification as healthy food. The nutritional balance in the harvest is crucial for its impact on the production, quality and content of bioactive compounds. This research was carried out in the city of Aldama, Chihuahua (Mexico), where doses of mineral and organic fertilization were tested in L25 Taguchi structure with 6 factors and 5 levels by factor: nitrogen (N) 0 - 240 kg·ha-1, phosphate (P2O5) 0 - 120 kg·ha-1, potassium (K2O) 0 - 100 kg·ha-1, calcium (CaO) 0 - 400 kg·ha-1, liquid humus 0 - 3600 L·ha-1 and solid humus 0 - 8000 kg·ha-1. An average yield of 2.2 t·ha-1 was obtained;145 nuts per kilogram, 60% of the edible part of the nut. The total phenolic content was 225.9 mg gallic acid g-1 and the antioxidant capacity was 180.9 mg Trolox g-1. It is concluded that the factor with the greatest impact on yield, quality and antioxidant capacity in pecan nut was nitrogen. It was also found that the combination of mineral and organic fertilization helps to maintain the production and quality ranges of the nut. In turn, these factors contribute to the increase in the phenolic strength and antioxidant capacity. The optimal fertilization dosis to obtain the maximum levels in production of 3.2 t·ha-1;decrease the number of nuts per kilogram to 135, increase the percentage of the edible part of the nut to 61.8%, the increase in the total phenolic content to 318.6 mg of gallic acid g-1 and in the antioxidant capacity with 187.2 mg of Trolox g-1, was 184 kg·ha-1 of N, 107.4 kg·ha-1 of P2O5, 50 kg·ha-1 of K2O y 2777 L·ha-1 of liquid humus. Finally, the mineral fertilization complemented with organic fertilization is considered a good fertilization strategy for pecan trees and its possible benefits to health and the environment.
基金This work was supported by grants from the Natural Science Foundation of Zhejiang Province,China(grant no.Z20C160001)the State Key Laboratory of Subtropical Silviculture at Zhejiang A&F University(grant no.ZY20180202)the Research and Development Fund of Zhejiang A&F University(grant no.2018FR002).
文摘Pecan(Carya illinoinensis)is a tree nut crop of worldwide economic importance that is rich in healthpromoting factors.However,pecan production and nut quality are greatly challenged by environmental stresses such as the outbreak of severe fungal diseases.Here,we report a high-quality,chromosome-scale genome assembly of the controlled-cross pecan cultivar‘Pawnee’constructed by integrating Nanopore sequencing and Hi-C technologies.Phylogenetic and evolutionary analyses reveal two whole-genome duplication(WGD)events and two paleo-subgenomes in pecan and walnut.Time estimates suggest that the recent WGD event and considerable genome rearrangements in pecan and walnut account for expansions in genome size and chromosome number after the divergence from bayberry.The two paleo-subgenomes differ in size and protein-coding gene sets.They exhibit uneven ancient gene loss,asymmetrical distribution of transposable elements(especially LTR/Copia and LTR/Gypsy),and expansions in transcription factor families(such as the extreme pecan-specific expansion in the far-red impaired response 1 family),which are likely to reflect the long evolutionary history of species in the Juglandaceae.A whole-genome scan of resequencing data from 86 pecan scab-associated core accessions identified 47 chromosome regions containing 185 putative candidate genes.Significant changes were detected in the expression of candidate genes associated with the chitin response pathway under chitin treatment in the scab-resistant and scabsusceptible cultivars‘Excell’and‘Pawnee’.These findings enable us to identify key genes that may be important susceptibility factors for fungal diseases in pecan.The high-quality sequences are valuable resources for pecan breeders and will provide a foundation for the production and quality improvement of tree nut crops.
基金funded by the Forestry Science and Technology Innovation Fund Project of Hunan Province(Grant No.XLK202108-4)and the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Although the development of the robot picking vision system is widely applied,it is very challenging for fruit detection in orchards with complex light and environment,especially for fruit colors similar to the background.In recent,there are few studies on pecan fruit detection and location based on machine vision.In this study,an accurate and efficient pecan fruit detection method was proposed based on machine vision under natural pecan orchards.In order to solve the illumination problem,a light compensation algorithm was first utilized to process the collected samples,and then an improved Faster Region Convolutional Neural Network(Faster RCNN)with the Feature Pyramid Networks(FPN)was established to train the samples.Finally,the pecan number counting method was introduced to count the number of pecan.A total of 241 pecan images were tested,and comparison experiments were carried out.The mean average precision(mAP)of the proposed detection method was 95.932%,compared with the result without uneven illumination correction(UIC),which was increased by 0.849%,while the mAP of the Single Shot Detector(SSD)+FPN was 92.991%.In addition,the number of clusters was counted using the proposed method with an accuracy rate of 93.539%compared with the actual clusters.The results demonstrate that the proposed network has good robustness for pecan fruit detection in different illumination and various unstructured environments,and the experimental achievement has great potential for robot-picking visual systems.
