Thoughts on Science and Technology Service in Provincial Agricultural Research Institutes under the New Normal:Taking Changli Institute of Pomology of Hebei Academy of Agriculture and Forestry Sciences as an Example

In the context of the new normal of high-quality agricultural development,it is necessary to accelerate the comprehensive connection of scientific and technological services of provincial agricultural research institutes and industries,and mobilize the enthusiasm of scientific and technological service personnel.Under the new normal,traditional service types are single,technology promotion and training are becoming narrower and narrower.This article analyzed the problems in scientific and technological services of provincial agricultural research institutes,including lack of comprehensive demonstration bases,not close cooperation between scientific and technological and the government and new business entities,and lack of incentive mechanism.Finally,it came up with some pertinent recommendations such as improving supporting mechanism construction,making classified evaluation,and changing the scientific and technological service concepts.

Evaluation of Cold Resistance and Semi-lethal Low Temperature(LT_(50))of Nine Pear Cultivars

[Objectives]To evaluate the cold resistance and semi-lethal temperature of pear cultivars,and provide a theoretical basis for the regional extension and breeding of cold-resistant pear cultivars.[Methods]Nine pear cultivars were used to study the changes in relative conductivity and cell injury rate of pear branches under low temperature stress,and the semi-lethal temperature(LT_(50))of pear branches was analyzed by fitting Logistic equation.[Results]The relative conductivity and cell injury rate of pear branches took on the trend of slow increase,rapid increase,and slow increase the decrease of treatment temperature.The LC_(50) of the nine pear cultivars were as follows:Nanguo pear-33.9℃,Wanyu-32.3℃,Red D Anjou-31.8℃,Jinfeng-31.3℃,Wujiuxiang-29.2℃,20 th Century Pear-29.1℃,Hanxiang-35.1℃,Yuluxiang-27.9℃ and Korla Fragrant Pear-29.2℃.[Conclusions]The semi-lethal temperature could reflect the cold resistance of pear trees,and Wanxiang had better cold resistance.The evaluation of cold resistance and semi-lethal temperature of pear cultivars can provide theoretical basis for regional extension and breeding of cold-resistant pear cultivars.

Advances in Molecular Regulatory Mechanisms of Fruit Trees under Low Temperature Stress

The most recent research findings on the tolerance of fruit trees to cold stress are reviewed from a molecular perspective,including the perception and transduction of low temperature calcium signaling,CBF-dependent molecular regulatory mechanisms,non-CBF-dependent molecular regulatory mechanisms,and so forth.The objective is to provide a reference basis for further improving the cold resistance of fruit trees and cultivating new varieties of hardy plants.

A method for Improving the Efficiency of Pear Tree Crossbreeding

In view of the short blooming period of pear tree crossbreeding and the complexity of pollination process, a method that can improve the efficiency of crossbreeding of pear trees was provided. Meanwhile, this method can also be applied to the study of pollen xenia effect, pollination tree selection and pure pollen collection in pear tree cultivation.

Control Techniques of Chinese Chestnut Yellow Crinkle

This paper initially delineates the symptoms,characteristics,and hazards associated with Chinese chestnut yellow crinkle,as well as the transmission and infection pathways of the disease.Additionally,it proposes the prevention and control strategies of the disease,including rigorous investigation and monitoring of the disease,enhanced monitoring of seedlings and scions,and integrated disease management techniques to promote the tree s health and vitality.These strategies serve to inform the prevention and control of Chinese chestnut yellow crinkle in production.

Study of Effects of Plant Growth Regulators on Fruit Quality of Table Grape

The effects of different treatments on the seedlessness and fruit quality of‘Miguang’table grape was studied by using plant growth regulators,gibberellin acid(GA 3)and forchlorfenuron(CPPU),under different concentrations and application time.The results showed that the effects of different treatments on the seedlessness and fruit quality were different.Seedless rate,cluster weight,berry weight,berry shape index,soluble solid content,total acid content,soluble solids to acidity ratio,pulling resistance,turgor pressure and flesh firmness without skin were comprehensively evaluated,as a result of which,the optimum treatment on‘Miguang’table grape was to apply with GA 320 mg/L+SM 200 mg/L at one week before bloom and GA 325 mg/L+CPPU 3 mg/L at two weeks after bloom.

Genetic Diversity of Leaf Phenotypic Traits in Walnut Germplasm Resources

In order to reveal the genetic diversity and variation sources of leaf phenotypic traits in walnut,the coefficient of variation,Shannon-weaver index,phenotypic differentiation coefficient,and the correlation of 9 leaf phenotypic traits for 251 walnut germplasm resources from two walnut populations were analyzed.The results showed that the averages of the variation coefficients and Shannon-weaver indexes of the leaf phenotype traits were 17.45%and 1.86 respectively.The F values of most inter-population traits and all intra-population traits were highly significant,and the F values of inter-population leaf shape index,leaflet number,length and leaf length were very large.The averages of inter-population and intra-population differentiation coefficients were 9.15%and 90.85%respectively.The leaf size,leaf thickness,and leaflet number were highly correlated with trunk perimeters.According to the results of principal component analyses,the 9 traits can be simplified into four principal components,which represent leaf size,petiole,leaflet number and leaf shape,respectively.There were extensive variations and rich genetic diversities in leaf phenotypic traits of walnut,and the intra-population variation was the leading source of phenotypic trait variation.Leaf shape index,leaflet number,internode length and leaf length can be used for population classification.The size and thickness of leaves and the number of leaflets will affect the accumulation of nutrients in walnut tree,and then affect its trunk perimeter.

Analysis of Aroma Volatile Compounds in Fuji Apple Using SPME with Different Fiber Coatings

The aroma volatile compounds in Fuji apple were isolated by solid-phase microextraction( SPME),and detected by gas chromatography-mass spectrometry( GC-MS). The results showed that the optimal retention time of the heating up of capillary columns was 5 min. Of the seven fibers used in this work,DVB/CAR/PDMS was found to be the most suitable to extract the aroma volatile compounds in Fuji apple. A total number of 43 volatile compounds were identified according to their retention time on capillary columns and their mass spectra,including eleven esters,ten alcohols,ten aldehydes,seven alkenes,two anhydrides,one ketone,one phenol and one ether. This detection method will provide a new foundation for analysis of volatile compounds in apple were identified.

Control Effects of Different Fungicides on Pear Scab

[Objective] The paper was to select different fungicides for field efficacy test against pear scab in summer.[Method] Five treatments were designed in the test,including 10% difenoconazole WDG 6 000 times dilution,50% captan WP 600 times dilution,30% pyraclostrobin SC 2 000 times dilution,430 g/L tebuconazole 4 000 times dilution,and water(control).[Result] 10% Difenoconazole WDG 6 000 times dilution,50% captan WP 600 times dilution,30% pyraclostrobin SC 2 000 times dilution,430 g/L tebuconazole SC 4 000 times dilution had good control effects against pear scab,and the efficacies were 89.13%-93.51%.[Conclusion] The results will provide the theoretical basis for field control of pear scab in summer.

Optimization of Texture Determination of ‘Yali' by Texture Analyzer

[Objectives] This study was carried out to determine texture parameters for texture profile analysis （TPA）, and optimize the texture determination of ‘Yali’ by texture analyzer.[Methods] The traditional varieties of ‘Yali’ were taken as the materials, and texture parameters were determined at different compression rates and deformations at target.[Results] In the process of the TPA, the deformation at target had an extremely significant influence on 8 TPA texture parameters, namely, the hardness, cohesiveness, springiness, adhesiveness, gumminess, resilience, fracturability, and chewiness （ P ≤0.01）, while the compression rate had significant influence on the hardness and gumminess （ P ≤0.05）, had an extremely significant influence on fracturability （ P ≤0.01）, and had no significant influence on other 5 TPA parameters.[Conclusions] Taking the compression rate of 1 mm/s and 20% deformation at target as the experimental conditions for TPA could avoid the impact load of high speed on the tissue and objectively reflect the textural characteristics of ‘Yali’ pulp tissue.

GC-MS Analysis of Volatile Components in ‘Changping 8’ Apple Fruit

Solid-phase and micro-extraction combined with GC/MS(SPME-GC-MS) were employed to detect main aroma components in ‘Changping 8’ apple fruit. The results showed that, 29 kinds of compounds were identified from the aroma components in ‘Changping 8’ apple fruit, and they were aldehydes, alcohols, esters, ketones, etc. The main aroma components of apple fruits were acetic acid, hexyl ester, acetic acid, butyl ester,(E)-2-hexenal, 1-butanol, hexanal, and 1-hexanol.

Construction of Technology System on Development and Repropagation in Vitro of Several Cultivars in Pear

It is the most available way to obtain self-rooted seedlings by tissue culture,which could breed de-virus seedlings with uniform traits and contribute to improve seedling quality.To construct a complete and efficient technology system,this test used stem with buds of 16 cultivars and super lines including Yali,Jingbaili,03-04-034,03-08-080 and so on as materials to study the best way for explant sampling time and position,sterilization time using HgCl 2 and hormone concentrations.The result indicated that the optimum technology system was that the middle parts of longest shoots before 20 d after full-blossom were sterilized for 8 min by 0.1%HgCl 2 and inoculated on the development medium MS+6-BA 0.5 mg/L+IBA 0.2 mg/L+saccharose 3%+agar 0.6%(pH=5.8),and then trans-inoculated into propagation medium MS+6-BA 1.0 mg/L+IBA 0.3 mg/L+saccharose 3%+agar 0.6%(pH=5.8).

Differential Gene Expression and Analysis inVenturia nashicola-inoculated and UninoculatedLeaves of the New Highly Resistant Germplasm03-04-034

The super line 03-04-034, which results from a cross between Pyrus bretchneideri cv Jingbaili and P.ussuriensis cv Yali, is highly resistant to pear scab.Specimens were inoculated with Venturia nashicola to generate a database of expressed sequence tags(ESTs) to be used as resources for transcripts induced in inoculated and uninoculated leaves. After performing subtractive suppression hybridization using cDNA of the inoculated and uninoculated leaves harvested 51 h after inoculation, 100 clones from the uninoculated and 100 clones from the inoculated cDNA library were selected and sequenced. BLASTN searches of each cDNA library against GenBank revealed eight unique sequences associated with the defense response, comprising four ESTs from the uninoculated cDNA library(ubiquitin extension protein, subtilisin-like protease, basic helix-loop-helix(bHLH) transcription factor and aspartic endopeptidase) and four ESTs from the inoculated cDNA library(S-adenosylmethionine synthase(SAMS), heat shock factor(HSF) domain class transcription factor, RNA-binding protein and polyphenol oxidase 5 precursor).Quantitative fluorescence real-time polymerase chain analysis revealed that the transcripts for SAMS and subtilisin-like protease were highly expressed in the incompatible interaction. The SAMS gene was more highly expressed in inoculated leaves than uninoculated leaves, while the reverse was true for subtilisin-like protease. The SAMS and subtilisin-like protease genes have been found to be associated with plant defense mechanisms. Further studies of greater detail are required to understand how these genes are expressed and regulated during infection with V.nashicola.

Analysis of Transfer Point of Grapholitha molesta Busck in Main Hosts in the Field

[Objective] The paper was to understand the selectivity and transitivity characteristics of Grapholitha molesta Busck in the course of host transfer.[Method] The damage time point of G.molesta was analyzed through sex pheromone trapping technique and reaction of resistance or susceptibility of different hosts.[Result] Along with the development of fruit tree organs,G.molesta appeared certain regular dynamics.During the flowering period of fruit trees,certain peaks of G.molesta were observed in pear orchard and peach orchard,and the average trap catches were182.8 and 208.6 moths,respectively.With the growth of new shoots,fruit expansion and ripening during the growth period of fruit trees,the trap catches and damage rate of peach trees were significantly higher than those of pear trees during new shoot stage,which were 151.8 and 118 moths,11.13% and 0.05%,respectively.There were significant differences in infected shoot rate.The trap catches in pear orchard reached the maximum at fruit ripening stage,which were 102.2,192.8,36 and 61.2 moths,respectively.There were significant difference in trap catches between pear orchard and peach orchard during fruit expansion stage and fruit ripening stage.[Conclusion] The study lays a foundation for accurately promoting effective prevention and control combining biological control and chemical control against G.molesta.

Analysis of Host Selectivity and Taxis of Grapholita molesta in Different Peach Varieties

[Objective]The paper was to preliminarily determine the susceptible varieties of Grapholita molesta(Busck)by analyzing trap catches of peach trees at different ripening stages,new shoot damage rate and fruit damage rate at different development stages.[Method]Three traps were hanged in peach orchard of the same variety,with the interval of 30 m.The traps were fixed on ventilated and shaded branches for regular and fixed-point monitoring.Three trees were randomly selected from each variety to investigate the damage fruit rate and new shoot damage rate at east,south,west and north directions of each tree,and the number of infected fruits and damaged new shoots was recorded.[Result]There were obvious differences in taxis selection of G.molesta to different peach varieties,and the trap catches in the same variety varied among different periods.The damage caused by G.molesta in the same variety over the same period was different among different organs.The catch peak of late ripening peach 03-46-78 appeared on August 11.In summer shoot period,the trap catches of late ripening peach 03-46-78 were extremely higher than those of other varieties,and the damage rate of late ripening peach Jinyuan was extremely higher than that of other varieties.In autumn shoot period,the average trap catches of late ripening peach 03-46-78 were significantly higher than those of other varieties,and the damage rate of late ripening peach Jinyuan was significantly higher than that of other varieties.The investigation and analysis of different ripening stages of peach fruits showed that the damage rate of late ripening variety Ruiguang 39 was significantly higher than that of other varieties in the ripening stage.The trap catches of late ripening peach 03-46-78 were significantly higher than those of other varieties in the young fruit stage.The trap catches of late ripening peach 03-46-78 had significant difference with those of other varieties during fruit expansion stage.The trap catches of late ripening peach 03-46-78 had significant difference with that of other varieties during fruit ripening stage.[Conclusion]With the development of new shoots and the ripening of fruits,G.molesta appears different dynamic regularities in different organs of various varieties.The time point that G.molesta transfers with the development of fruit tree organs should be grasped to deeply analyze the physical and chemical properties of fruit trees during the growth period,so as to find out reasonable and effective prevention and control techniques for fruit farmers.

Occurrence and Control of Pear Rust in Eastern Hebei Province

In recent years, pear rust sometimes occurs in eastern Hebei area, resulting in early defoliation, fruit abscission and loss of fruit commodity value. In this paper, the incidence symptoms, regularity and causes of pear rust are summarized, and the comprehensive prevention and control measures of pear rust in eastern Hebei are put forward.

Key Points of Prevention and Control Technology against Pear Powdery Mildew

Due to the lack of attention to the prevention and control of powdery mildew in pear orchard in autumn,the occurrence of pear powdery mildew is aggravating year by year,and it has become one of the main diseases of pear tree.In this paper,the symptom diagnosis,incidence regu-larity and prevention and control technology of pear powdery mildew are summarized,which will provide the reference for prevention and treatment of pear powdery mildew in production.

Occurrence and Integrated Control of Psylla chinensis in Eastern Hebei Province

The paper introduces the damage characteristics and occurrence regularity of Psylla chinensis in pear orchards in eastern Hebei Province,and summarizes the integrated prevention and control techniques of P.chinensis,in order to provide a reference for the prevention and control of P.chinensis in eastern Hebei Province.

The Changing Characteristics of Profile Distribution of Organic Nitrogen Components in Apple-pear Orchard Soil

In order to evaluate the effects of soil depth on the contents of soil organic nitrogen,organic nitrogen forms in apple-pear orchard soil profile were quantified using the method proposed by Bremner in 1965.The results indicated that in addition to the amino sugar-N,all the soil organic N components within the same soil layer in wasteland were more than those in apple-pear orchard soil;with the layer depth increasing,the contents of different organic nitrogen forms in apple-pear orchard soil and wasteland were decreased;and the proportion of each organic N component within total hydrolysable N was different,and the percentages of ammonia N and amino acid-N components within total hydrolysable N were higher,especially the percentage of ammonia N components within total hydrolysable N was the highest.

A Training System of Pear Trees for Simplified High-density Cultivation

In view of the deficiencies of training technologies during constructing pear orchards by modern simplified dense-planting cultivation with ordinary pear seedlings widely used in production,a simple and easy-to-operate training method was proposed,mainly including constructing fence nets,determining low main trunks,leaving buds at the northwest position,multiple bud removal,winding and notching,simplified branch supporting,and simplified branch pulling.