A MADS-box gene,CiMADS9,was cloned from the male flowers of Carya illinoinensis by rapid amplification of cDNA ends. The gene was 1 077 bp with a 768 bp open reading frame encoding 255 amino acids. Multiple sequence c...A MADS-box gene,CiMADS9,was cloned from the male flowers of Carya illinoinensis by rapid amplification of cDNA ends. The gene was 1 077 bp with a 768 bp open reading frame encoding 255 amino acids. Multiple sequence comparisons revealed that Ci MADS9 is a typical MIKC-type MADS-box gene with a MADS-box domain and a K semi-conserved region. Phylogenetic analysis indicated that CiMADS9 belongs to the AGL15 group of the MADS-box gene family. Quantitative reverse transcription polymerase chain reaction analysis indicated that the expression levels in reproductive organs(i.e.,flowers and young fruits) were considerably higher than in vegetative tissues(i.e.,leaves and branches). The highest expression levels were observed in male flowers. An overexpression vector for CiMADS9 was constructed and the gene was inserted into the Arabidopsis thaliana genome. CiMADS9 expression was confirmed in all transgenic lines. Compared with wild-type plants,transgenic A. thaliana plants overexpressing CiMADS9 exhibited delayed flowering and an increased number of leaves.展开更多
A collection representing the native range of pecan was planted at the US DA-ARS Southeastern Fruit and Tree Nut Research Station,Byron,GA.The collection(867 trees)is a valuable genetic resource for characterizing imp...A collection representing the native range of pecan was planted at the US DA-ARS Southeastern Fruit and Tree Nut Research Station,Byron,GA.The collection(867 trees)is a valuable genetic resource for characterizing important horticultural traits.Canopy density during leaf fall is important as the seasonal canopy dynamics provides insights to environmental cues and breeding potential of germplasm.The ability of visual raters to estimate canopy density on a subset of the provenance collection(76 trees)as an indicator of leaf shed during autumn along with image analysis values was explored.Mean canopy density using the image analysis software was less compared to visual estimates(11.9%vs 18.4%,respectively).At higher canopy densities,the raters overestimated foliage density,but overall agreement between raters and measured values was good(ρc=0.849 to 0.915),and inter-rater reliability was high(R^(2)=0.910 to 0.953).The provenance from Missouri(MOL),the northernmost provenance,had the lowest canopy density in November,and results show that the higher the latitude of the provenance,the lower the canopy density.Based on regression,the source provenance latitude explained 0.609 of the variation using image analysis,and0.551 to 0.640 when based on the rater estimates of canopy density.Visual assessment of pecan canopy density due to late season leaf fall for comparing pecan genotypes provides accurate and reliable estimates and could be used in future studies of the whole provenance collection.展开更多
The purpose of this study was to analyze the effect of Zn nutritional status on the content of pigments, nonstructural carbohydrates, foliage proteins and amino acids of the pecan tree, as possible bioindicators of Zn...The purpose of this study was to analyze the effect of Zn nutritional status on the content of pigments, nonstructural carbohydrates, foliage proteins and amino acids of the pecan tree, as possible bioindicators of Zn deficiency. The experimental design was completely random with three Zn nutritional statuses: Normal, Intermediate and Deficient, being selected considering visual symptomatology. On all three nutritional statuses, the concentration of photosynthetic pigments was determined as well as of total soluble proteins and amino acids. Obtained results indicate that Zn deficient nutritional status was characterized by minimum photosynthetic pigment, protein concentrations, maximum amino acid and nonstructural carbohydrate concentrations. While the normal Zn nutritional status presented maximum photosynthetic pigments, proteins concentrations, minimum amino acids and carbohydrate concentrations. On the other hand, intermediate Zn nutritional status was characterized by a medium level between the other two Zn nutritional statuses. Finally, we stress the fact that pigments, proteins, amino acids and nonstructural carbohydrates may be good physiological indicators related to Zn nutritional status on pecan trees.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(Wangenh.)K.Koch.]is a deciduous tree whose fruits(nuts)are of high economic value and offer excellent nutritional benefits.However,soils high in sulphates can limit its growth and development...Pecan[Carya illinoinensis(Wangenh.)K.Koch.]is a deciduous tree whose fruits(nuts)are of high economic value and offer excellent nutritional benefits.However,soils high in sulphates can limit its growth and development.Working with 5-year-old trees of‘Western Schley’pecan grown in soils high in sulphates,the levels of proline and oxidative metabolism were recorded in the leaflets.Results showed that different levels of visible leaflet damage(‘sufficiency’,‘low’,‘moderate’or‘severe’)were associated with different levels of leaflet sulphates(mg kg^(−1)):‘sufficiency’(≤40),‘low’(41–60),‘moderate’(61–80)and‘severe’(80–100).‘Severe’sulphate damage was associated with significant reductions in chlorophyll(TChl)(17.04μg g^(−1)),relative water content(RWC)(50%)and leaf area(LA),and with increases in the concentrations of total carotenoids(TC)and proline(Prl).Increases were also observed in the activities of the oxidative metabolism enzymes:superoxide dismutase(SOD)(1.82 units min^(−1) g^(−1)),catalase(CAT)(2.86μmol H_(2)O_(2) min^(−1) g^(−1))and antioxidant capacity(AC)(87%DPPH inhibition).However,guaiacol peroxidase(GP)showed a reduction(2.97 nmol GSH min^(−1) g^(−1)).An inverse relationship was found between the sulphate concentration in the leaflets with respect to the evaluated parameters of TChl,TC,RWC,LA,AC,and GP.Proline synthesis and antioxidant enzymatic activity indicate salt stress in pecan leaflets in orchards irrigated with deep-well water high in sulphates.展开更多
Indaziflam is a preemergent herbicide widely used for the control of weeds in pecan(Carya illinoinensis)orchards in the southwestern region of the United States.Given the paucity of data regarding the effect of indazi...Indaziflam is a preemergent herbicide widely used for the control of weeds in pecan(Carya illinoinensis)orchards in the southwestern region of the United States.Given the paucity of data regarding the effect of indaziflam on the biochemical properties of soils supporting pecan production,this study was conducted to evaluate the effects of different application rates of indaziflam on soil microbial activity,diversity,and biochemical processes related to nitrogen(N)cycling.During two consecutive growing seasons(2015 and 2016),soil samples were obtained from experimental mesocosms consisting of soil-filled pots where pecan saplings were grown and treated with indaziflam applied at two different rates(25 and 50 g active ingredient(ai)ha^(-1),with the higher rate being slightly lower than the recommended field application rate of 73.1 g ai ha^(-1)).Soil samples were collected approximately one week before and one week after herbicide application for determination of soil microbial biomass and diversity,N mineralization,andβ-glucosaminidase activity.Soil samples collected from the control mesocosms without herbicide application were treated in the laboratory with two rates of indaziflam(75 and 150 g ai ha^(-1))to determine the immediate effect on microbial activity.No significant effect of herbicide treatment on soil respiration and microbial biomass was detected.The results showed a slight to moderate decrease in microbial diversity(7%in 2015 and 44%in 2016).However,decreasedβ-glucosaminidase activity with herbicide treatment was observed in soils from the mesocosms(33%)and soils treated with indaziflam in the laboratory(45%).The mineral N pool was generally dominated by ammonium after indaziflam application,which was consistent with the drastic decrease(75%)in nitrification activity measured in the laboratory experiment.The results of this study indicate that indaziflam,even when applied at higher than recommended rates,has limited effects on soil microbial activity,but may affect N cycling processes.展开更多
基金supported by grants from the National Natural Science Foundation of China(31200502,31401854)the Natural Science Foundation of Jiangsu Province(Grant No.BK20140760,BK20150552)
文摘A MADS-box gene,CiMADS9,was cloned from the male flowers of Carya illinoinensis by rapid amplification of cDNA ends. The gene was 1 077 bp with a 768 bp open reading frame encoding 255 amino acids. Multiple sequence comparisons revealed that Ci MADS9 is a typical MIKC-type MADS-box gene with a MADS-box domain and a K semi-conserved region. Phylogenetic analysis indicated that CiMADS9 belongs to the AGL15 group of the MADS-box gene family. Quantitative reverse transcription polymerase chain reaction analysis indicated that the expression levels in reproductive organs(i.e.,flowers and young fruits) were considerably higher than in vegetative tissues(i.e.,leaves and branches). The highest expression levels were observed in male flowers. An overexpression vector for CiMADS9 was constructed and the gene was inserted into the Arabidopsis thaliana genome. CiMADS9 expression was confirmed in all transgenic lines. Compared with wild-type plants,transgenic A. thaliana plants overexpressing CiMADS9 exhibited delayed flowering and an increased number of leaves.
基金supported by the USDA-ARS through CRIS project 6606-21220-014–00Dthe National Institute of Food and Agriculture–Specialty Crops Research Initiative grant 2016-51181-25408“Coordinated development of genetic tools for pecan”。
文摘A collection representing the native range of pecan was planted at the US DA-ARS Southeastern Fruit and Tree Nut Research Station,Byron,GA.The collection(867 trees)is a valuable genetic resource for characterizing important horticultural traits.Canopy density during leaf fall is important as the seasonal canopy dynamics provides insights to environmental cues and breeding potential of germplasm.The ability of visual raters to estimate canopy density on a subset of the provenance collection(76 trees)as an indicator of leaf shed during autumn along with image analysis values was explored.Mean canopy density using the image analysis software was less compared to visual estimates(11.9%vs 18.4%,respectively).At higher canopy densities,the raters overestimated foliage density,but overall agreement between raters and measured values was good(ρc=0.849 to 0.915),and inter-rater reliability was high(R^(2)=0.910 to 0.953).The provenance from Missouri(MOL),the northernmost provenance,had the lowest canopy density in November,and results show that the higher the latitude of the provenance,the lower the canopy density.Based on regression,the source provenance latitude explained 0.609 of the variation using image analysis,and0.551 to 0.640 when based on the rater estimates of canopy density.Visual assessment of pecan canopy density due to late season leaf fall for comparing pecan genotypes provides accurate and reliable estimates and could be used in future studies of the whole provenance collection.
文摘The purpose of this study was to analyze the effect of Zn nutritional status on the content of pigments, nonstructural carbohydrates, foliage proteins and amino acids of the pecan tree, as possible bioindicators of Zn deficiency. The experimental design was completely random with three Zn nutritional statuses: Normal, Intermediate and Deficient, being selected considering visual symptomatology. On all three nutritional statuses, the concentration of photosynthetic pigments was determined as well as of total soluble proteins and amino acids. Obtained results indicate that Zn deficient nutritional status was characterized by minimum photosynthetic pigment, protein concentrations, maximum amino acid and nonstructural carbohydrate concentrations. While the normal Zn nutritional status presented maximum photosynthetic pigments, proteins concentrations, minimum amino acids and carbohydrate concentrations. On the other hand, intermediate Zn nutritional status was characterized by a medium level between the other two Zn nutritional statuses. Finally, we stress the fact that pigments, proteins, amino acids and nonstructural carbohydrates may be good physiological indicators related to Zn nutritional status on pecan trees.
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.
文摘Pecan[Carya illinoinensis(Wangenh.)K.Koch.]is a deciduous tree whose fruits(nuts)are of high economic value and offer excellent nutritional benefits.However,soils high in sulphates can limit its growth and development.Working with 5-year-old trees of‘Western Schley’pecan grown in soils high in sulphates,the levels of proline and oxidative metabolism were recorded in the leaflets.Results showed that different levels of visible leaflet damage(‘sufficiency’,‘low’,‘moderate’or‘severe’)were associated with different levels of leaflet sulphates(mg kg^(−1)):‘sufficiency’(≤40),‘low’(41–60),‘moderate’(61–80)and‘severe’(80–100).‘Severe’sulphate damage was associated with significant reductions in chlorophyll(TChl)(17.04μg g^(−1)),relative water content(RWC)(50%)and leaf area(LA),and with increases in the concentrations of total carotenoids(TC)and proline(Prl).Increases were also observed in the activities of the oxidative metabolism enzymes:superoxide dismutase(SOD)(1.82 units min^(−1) g^(−1)),catalase(CAT)(2.86μmol H_(2)O_(2) min^(−1) g^(−1))and antioxidant capacity(AC)(87%DPPH inhibition).However,guaiacol peroxidase(GP)showed a reduction(2.97 nmol GSH min^(−1) g^(−1)).An inverse relationship was found between the sulphate concentration in the leaflets with respect to the evaluated parameters of TChl,TC,RWC,LA,AC,and GP.Proline synthesis and antioxidant enzymatic activity indicate salt stress in pecan leaflets in orchards irrigated with deep-well water high in sulphates.
文摘Indaziflam is a preemergent herbicide widely used for the control of weeds in pecan(Carya illinoinensis)orchards in the southwestern region of the United States.Given the paucity of data regarding the effect of indaziflam on the biochemical properties of soils supporting pecan production,this study was conducted to evaluate the effects of different application rates of indaziflam on soil microbial activity,diversity,and biochemical processes related to nitrogen(N)cycling.During two consecutive growing seasons(2015 and 2016),soil samples were obtained from experimental mesocosms consisting of soil-filled pots where pecan saplings were grown and treated with indaziflam applied at two different rates(25 and 50 g active ingredient(ai)ha^(-1),with the higher rate being slightly lower than the recommended field application rate of 73.1 g ai ha^(-1)).Soil samples were collected approximately one week before and one week after herbicide application for determination of soil microbial biomass and diversity,N mineralization,andβ-glucosaminidase activity.Soil samples collected from the control mesocosms without herbicide application were treated in the laboratory with two rates of indaziflam(75 and 150 g ai ha^(-1))to determine the immediate effect on microbial activity.No significant effect of herbicide treatment on soil respiration and microbial biomass was detected.The results showed a slight to moderate decrease in microbial diversity(7%in 2015 and 44%in 2016).However,decreasedβ-glucosaminidase activity with herbicide treatment was observed in soils from the mesocosms(33%)and soils treated with indaziflam in the laboratory(45%).The mineral N pool was generally dominated by ammonium after indaziflam application,which was consistent with the drastic decrease(75%)in nitrification activity measured in the laboratory experiment.The results of this study indicate that indaziflam,even when applied at higher than recommended rates,has limited effects on soil microbial activity,but may affect N cycling processes.
