Temperate Fruit Crops Research Articles

GENETIC CONSERVATION, CHARACTERIZATION AND UTILIZATION OF WILD RELATIVES OF FRUIT AND NUT CROPS AT THE USDA GERMPLASM REPOSITORY IN DAVIS, CALIFORNIA

The National Clonal Germplasm Repository (NCGR) in Davis is one among the nine repositories in the National Plant Germplasm System, USDA-ARS, that is responsible for conservation of clonally propagated woody perennial subtropical and temperate fruit and nut crop germplasm. Currently the repository holds over 6500 accessions of germplasm of Actinidia (kiwi fruit), Diospyros (persimmon), Ficus (fig), Juglans (walnuts), Morus (mulberry), Olea (olive), Pistacia (pistachio), Prunus (stonefruits and almond), Punica (pomegranate), Vitis (grape), and other minor genera. Wild relatives are widely represented in these collections with about 91% of the taxa and 43% of the total accessions representing the wild gene pools. Research at the repository is mainly focused on genetic characterization of germplasm using molecular markers and morphological traits to quantify and describe genetic structure and differentiation within and among species and gene pools. Promoting the use of crop wild relatives (CWR) germplasm in genetic improvement of tree fruit and nut crops is our top priority. Presently, at the Davis repository, we are extensively utilizing Prunus and Juglans wild relatives for developing improved rootstocks with resistance to biotic and abiotic stresses. We will review and discuss the results of ongoing programs highlighting the importance of different CWRs as donors of genes for resistance to major soil borne diseases such as crown gall, Phytophthora rots, and nematodes in the rootstock improvement programs. Breeding for drought tolerance is another major thrust for which we are screening CWR germplasm to identify novel sources of drought tolerance to infuse into ongoing rootstock breeding programs.

Assessment of microbial biomass and enzyme activities in soil under temperate fruit crops in north western himalayan region

Microbial communities are important for the functioning of the ecosystem, both in relation to direct interactions with the plants and with regard to nutrient and organic matter recycling. A study in field condition was undertaken in Kashmir valley to reveal the effect of various temperate fruit crops viz. apricot, peach, plum and cherry along with a control (no-plantation) on microbial biomass carbon (MBC), nitrogen (MBN), phosphorus (MBP) and dehydrogenase, phosphomonoesterase (acid and alkaline) and urease activities in soil at two different depths (0-20 and 21-40 cm). All the fruit crops showed a sharp decline in microbial biomass and enzyme activities with the increase in soil depth. Each of the four fruit crops showed significant (p<0.05) impact on MBC over the control and the maximum MBC was recorded in plum (1000 mg kg-1) and the lowest value was observed in control (457 mg kg-1), at the surface layer. Since there is a relationship between MBC and MBN, the similar trend was also observed in MBN as in case of MBC. For MBP, fruit crops showed any significant effect neither on surface soil, nor on subsurface soil layer over control. At the surface layer, unlike microbial biomass the highest dehydrogenase activity was observed in peach (318 mg TPF g soil-1 h-1) and the lowest value (166 mg TPF g soil-1 h-1) was attained at control plot. Maximum alkaline phosphomonoesterase activity was observed in peach (381 mg PNP g soil-1 h-1), although for acid phosphomonoesterase the highest value recorded in apricot (306 mg PNP g soil-1 hr-1), at surface soil. A significant positive correlation (p <0.01) was observed amongst MBC, MBN and MBP. Both the phosphomonoesterase activities were significantly (p <0.05) correlated with MBP in soil. It can be concluded that the influence of the studied fruit crops on the soil was not uniform, in terms of the measured parameters.

Knowledge and adoption of improved grape cultivation practices in Haryana, India

Grape (Vitis vinifera L.) is a temperate fruit crop and also cultivated under tropical and sub-tropical regions of the world. India is fast emerging as one of the major grape growing countries in the world. The grape is one of the important fruit crops of Haryana. It occupies an area of 1157 ha. An investigation was carried out in Hisar district of Haryana on the knowledge and adoption of improved cultivation practices. Hisar district was selected purposively because it has maximum production and area under grape cultivation in Haryana. Hisar district consisted of six blocks and from among them, four blocks were selected. A sample of 100 farmers was selected proportionate to the area and production of these four blocks by using proportionate random sampling technique. A well structured interview schedule was used for data collection and collected data were analyzed by using appropriate statistical tools. Study revealed that majority of the respondents were having moderate level of knowledge about recommended/improved practices of grape cultivation. Among the different grape cultivation practices, respondents possessed highest knowledge about selection of site and cultivar. It was also found that a maximum number of respondents belonged to medium adopters category. Adoption level of grape growers increased with the increase in their education, land holding, socio-economic status, source of information and risk orientation.

Implications of Changing Climate on Productivity of Temperate Fruit Crops with Special Reference to Apple

Winter chill is essential for most of the plants that fall dormant in the winter in order to avoid frost damage and do not resume growth until a certain amount of winter chill has accumulated for fulfilling their chilling requirement. Climate change is likely to affect chilling requirement of temperate fruit crops significantly and therefore, the opportunity to meet this requirement will be reduced as the climate becomes warmer. Increase in average global temperature would move the existing plant species and varieties to new latitudinal belts with favourable climates. It is, therefore, possible that crops that are used to be productive in one area may no longer be so or the other way round. The resultant of these climate changes are clearly apparent in the shifting of apple cultivation from lower elevations to higher altitudes in India. Insufficient chilling greatly influences flower initiation and fruit colouration along with deterioration in fruit texture and taste. Further, the lack of proper chilling is also posing serious problems like scab disease, premature leaf fall and infestation of red spider mite in apple. High temperature and moisture stress is increasing sunburn and cracking in apple, apricots and cherries in the higher altitudes. Insufficient chilling reduces pollination, fruit set and ultimately the yield in walnuts, pistachio and peaches. Advanced flowering has been found in olive, apple and pear. Reduced flower size and pedicel lengths were observed in cherry due to less chilling. The studies regarding impact of climate change on fruit crops is meagre primarily due to lack of data, appropriate modeling and government policies. Development of low chill cultivars with greater tolerance to stresses, use of GIS to match varieties with the projected suitable production locations, development of suitable dormancy and chilling models, altering orchard microclimate and use of rest breaking chemicals are the viable approaches that can be adopted to yield reliable results on regional scale.

OVERVIEW OF TEMPERATE FRUITS IN NORTH EASTERN HIMALAYA: SITUATION AND CHALLENGES

The North Eastern Region of India is one of the richest reservoir of genetic variability and diversity of different horticultural crops that exists in plant type, morphological and physiological variations, reactions to diseases and pests, adaptability and distribution. The region spreads over an area of 2,620,230 km2 (8% of country’s geographical area) and consists of eight states. The region presents most diverse conditions for fruit growing in terms of slopes, altitudes, agro-climatic conditions and soil types etc. The altitudinal differences coupled with varied physiography contributes to great climatic variations in NE India, from near tropical to sub-alpine and sub-tropical climate. The soil of the region is rich in organic matter and is acidic to strongly acidic in reaction. The widely diverse agro-climatic conditions along with other physiographic conditions have led to immense variability among fruit crops in the region. According to National Horticulture Board, the area, production and productivity of fruit crops in the region in 2010-2011 were 412,000 ha, 3,432,100 t and 8.33 t/ha, respectively. Apart from major subtropical fruits like citrus, pineapple and banana, many temperate fruits like apple, peach, plum, strawberry, passion fruit and kiwifruit are grown in this region. Besides, major fruit species, the region is a treasure trove for many underutilized temperate fruit crops such as Persea americana, Pyrus pashia, P. indica, Prunus nepalensis, P. jenkinsii, P. avium, P. cerasus, P. serotina, Rubus ellipticus, etc. Many of these fruits are rich in nutrients and medicinal properties and have immense potential to contribute location specific food production, as they are well adapted to existing and adverse environmental conditions. Apart from providing diversification of the food base, different indigenous fruit species produce at different times of the years, ensure year round supply of nutrition. Furthermore, these crops have long been a traditional part of cropping systems. Utilization of bio resources through conventional and biotechnological interventions, development of agro-ecological zone specific farming system involving underutilized fruit crops, infrastructural development including processing, storage, transport and marketing, export oriented production programmes and border trade involving high value fruit crops and prevention of genetic erosion in non-traditional fruit species would boost fruit production in the region.

DECIDUOUS FRUIT CROPS OF OMAN

Oman is located in the South Eastern part of the Arabian Peninsula. The climate is generally characterized by low rainfall (< 100 mm annually) and high temperature for most of the year. However, mountains in the northern part of the country (Hajar Mountains) reach an altitude of approximately 3,000 m a.s.l., where temperatures drops significantly to allow for the growth and cultivation of various temperate-zone fruit crops and other plants. Pomegranate is the most significant crop in this region, however, walnut, peach, apricot, fig, almond, apple and pear, also contribute significant income to the local inhabitants. Other crops of economic importance include roses and cold-climate vegetables. This paper presents an overview of the temperate fruit crops in Oman.

Genomics and Functional Genomics of Winter Low Temperature Tolerance in Temperate Fruit Crops

Winter low temperature tolerance is the result of genotype interaction with environmental cues influencing plant development and metabolic activity in preparation for sustained low temperatures and freezing conditions. In deciduous fruit trees the phenology of acclimation and dormancy processes are well documented and recent advances in functional genomic analyses are beginning to map the molecular mechanisms underlying the physiological and biochemical responses resulting from inductive short photoperiod and/or low temperatures. There are many commonalities between herbaceous annual plant acclimation and perennial plant acclimation; however, the ability to survive sustained periods of low temperature, extreme low temperatures and the presence of ice within tissues are not common in annual model plant systems. In addition, subzero temperature tolerance mechanisms vary with tissue type and age and seasonal and climatic conditions; thus, defining the phenotypes and underlying genetic control of these dynamic and complex quantitative traits is both time and land intensive. Rapidly increasing genomic sequences and databases of transcriptomic, proteomic and metabolomics data sets, coupled with existing mapping studies and new genotype by sequencing and single nucleotide polymorphism (SNP) marker analyses provide the opportunity to dissect winter survival and elucidate its genetic basis. This review explores recent genomic and functional genomic analyses that are contributing to a greater understanding of the molecular mechanisms regulating low temperature response and freezing tolerance in temperate woody plants. Developments are providing the opportunity to more quickly and precisely link responses to genes and gene variations underlying low temperature response and tolerance in temperate fruit crops.

Differential Transcriptional Profiles of Dormancy-Related Genes in Apple Buds

The production of temperate fruit crops depends on plant developmental processes, primarily the shift from the juvenile phase to the reproductive phase, dormancy transitions and flowering. Apple tree (Malus × domestica Borkh.) development is regulated by chilling temperatures, which are required for bud dormancy progression. The apple cultivar Castel Gala is a spontaneous mutation of "Gala Standard". "Castel Gala" is characterized by a 50 % decrease in the chilling requirement (CR) for dormancy release, which results in an earlier budbreak. This work explores the contrasting phenotypes of these cultivars using suppression subtractive hybridization (SSH). From 1,019 unigenes identified by SSH, we selected 28 candidate genes putatively associated with dormancy cycling. Reverse transcription-quantitative polymerase chain reaction was used to validate the differential expression profiles and to transcriptionally characterize these genes in three distinct apple cultivars ("Castel Gala", "Royal Gala" and "Fuji Standard") during a cycle comprising growth to dormancy. Of the 28 candidate genes analyzed, 17 confirmed the differences in expression predicted by SSH. Seasonal transcript accumulation during the winter was observed for several genes, with higher steady-state mRNA levels maintained longer in cultivars with a high CR. The transcription profiles suggest that these genes may be associated with dormancy establishment and maintenance. Of the 17 candidate genes, transcripts coding for dormancy-associated MADS-box (DAM), dehydrins, GAST1, LTI65, NAC, HTA8, HTA12 and RAP2.12-like proteins displayed major differences in gene expression between cultivars through the winter. These genes were therefore considered good candidates for key roles in the dormancy process in apple trees.

Chilling requirement for seed germination and phenological observations on peach cultivars

In subtropical climate areas, the models and methods proposed to evaluate the chilling requirement of temperate fruit crops often do not provide satisfactory results, thus calling for the development of alternative techniques. The aim of this study was to evaluate the correlations between some phonological traits and chilling requirement for seed germination of 18 peach cultivars and one nectarine cultivar. Two experiments were installed separately for the correlation studies. In experiment 1, the phenological traits were observed in the field, while in experiment 2, the chilling requirement for 50 and 100% seed germination of each cultivar was assessed. The number of days for beginning of bloom (r = 0.70**, 0.61**) and full bloom (r = 0.72**, 0.76**) were both significantly correlated with the number of chilling units for 50% and 100% germination of seeds. The number of days for beginning of budding and dormancy break were both significantly correlated with the number of chilling units for 50% and 100% germination (r = 0.48*, 0.50*, respectively). However, the same significant effect for these phenological traits was not found between chilling units and 50% germination of seeds, as well as between chilling units and harvest dates.

Seasonal changes in photochemistry, light use efficiency and net photosynthetic rates of wild blueberry (Vaccinium angustifoliumAit.)

Percival, D., Kaur, J., Hainstock, L. J. and Privé, J.-P. 2012. Seasonal changes in photochemistry, light use efficiency and net photosynthetic rates of wild blueberry (Vaccinium angustifolium Ait.). Can. J. Plant Sci. 92: 1135–1143. The seasonal variation of carotenoid concentration, chlorophyll a and b levels, dark- (Fv/Fm) and light-adapted (Fv′/Fm′) variable to maximal chlorophyll fluorescence (an indication of the quantum efficiency of PSII photochemistry) and net photosynthesis of the wild blueberry (Vaccinium angustifolium Ait.) was examined in the vegetative and cropping phases of production. Chlorophyll levels ranged from 2.0 to 12 µg cm−2and from 0.042 to 1.4 µg cm−2for chlorophyll a and b, respectively, were significantly lower in the cropping phase of production, and were also lower in the latter stages of the growing season. Similarly, carotenoid concentrations ranged from 0.67 to 4.1 µg cm−2and were lower in the cropping phase of production. However, carotenoid concentration and dark- and light-adapted variable to maximal chlorophyll fluorescence (Fv/Fm and Fv′/Fm′) decreased marketably at the mid-point of the growing season, presumably as a result of photoinhibition. Net photosynthetic values of upright stems ranged from 2.1 to 7.6 µmol m−2s−1, were substantially higher in the vegetative phase of production and also decreased significantly in the latter part of the growing season. Results from this investigation indicate that the wild blueberry has a relatively low photosynthetic rate, which may be prone to photoinhibition and limited carbohydrate supply (i.e., source) when compared with other temperate fruit crops.

Residual Effect of Pesticides used in Integrated Apple Production on Chrysoperlaexterna (Hagen) (Neuroptera: Chrysopidae) Larvae

Temperate fruit crops are an important economic activity for growers in southern Brazil. However, several pest species are associated to apple ( Malus domestica Borkh.) crops in Brazil. Pesticides are largely used to control them and one way to change this is to combine selective pesticides and predator insects. The goal of this research was to evaluate the effects of the abamectin, carbaryl, fenitrothion, methidathion, sulfur, and trichlorfon pesticides on the survival and stage length of larvae and pupae, adult oviposition from treated larvae, and hatched eggs of two Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) populations. The compounds were sprayed on glass plates in accordance with the International Organization for Biological Control (IOBC) recommendations. First- and second-instar larvae were exposed to pesticide residues. Carbaryl, fenitrothion, and methidathion caused 100% mortality of first- and second-instar larvae. Changes in the number of eggs laid by females from first- and second-instar larvae exposed to residues of abamectin and sulfur, or abamectin, sulfur, and trichlorfon, respectively, were not observed. Only abamectin reduced the number of hatched eggs laid by females in Bento Goncalves from treated first-instar larvae. Sulfur reduced the viability of C. externa eggs in Bento Goncalves and Vacaria females from treated second-instar larvae, whereas trichlorfon and abamectin reduced the viability of eggs in Vacaria females. In conclusion, carbaryl, fenitrothion and methidathion were harmful to C. externa. Trichlorfon was harmful to first-instar larvae and slightly harmful to second-instar larvae. Abamectin and sulfur were slightly harmful to first-instar larvae and harmless to second-instar larvae.

RECENT NPGS COORDINATED EXPEDITIONS IN THE TRANS-CAUCASUS REGION TO COLLECT WILD RELATIVES OF TEMPERATE FRUIT AND NUT CROPS

ISHS I International Symposium on Wild Relatives of Subtropical and Temperate Fruit and Nut Crops RECENT NPGS COORDINATED EXPEDITIONS IN THE TRANS-CAUCASUS REGION TO COLLECT WILD RELATIVES OF TEMPERATE FRUIT AND NUT CROPS

APPLICATION OF PROPICONAZOLE IN MANAGEMENT OF LAUREL WILT DISEASE IN AVOCADO (PERSEA AMERICANA MILL.) TREES

ISHS I International Symposium on Wild Relatives of Subtropical and Temperate Fruit and Nut Crops APPLICATION OF PROPICONAZOLE IN MANAGEMENT OF LAUREL WILT DISEASE IN AVOCADO (PERSEA AMERICANA MILL.) TREES

CONSERVATION, MULTIPLICATION AND UTILIZATION OF WOOD APPLE (FERONIA LIMONIA) - A SEMI-WILD FRUIT CROP IN WEST BENGAL (INDIA)

ISHS I International Symposium on Wild Relatives of Subtropical and Temperate Fruit and Nut Crops CONSERVATION, MULTIPLICATION AND UTILIZATION OF WOOD APPLE (FERONIA LIMONIA) - A SEMI-WILD FRUIT CROP IN WEST BENGAL (INDIA)

The fulfilment of chilling requirements and the adaptation of apricot ( Prunus armeniaca L.) in warm winter climates: An approach in Murcia (Spain) and the Western Cape (South Africa)

Different chilling requirements (CRs) are required for apricot ( Prunus armeniaca L.) cultivars to overcome dormancy. In a global climate change context, knowledge of these requirements is critical; producers must select the appropriate cultivars to avoid losses caused by an inadequate cultivar adaptation in a particular area. Important differences have been reported in the CRs of cultivars of temperate fruit crops that are cultivated in different climatic conditions. However, the lack of standardisation of protocols to calculate CRs hinders the comparison of the results obtained using different methodologies. This study was aimed at analysing adaptation in terms of the CR fulfilment of commercial apricot cultivars grown successfully in different climatic conditions. Apricot-growing locations with different latitudes and altitudes and cultivars with varying CRs were chosen. The plant material spanned the CR range for this species in South Africa and Spain. Three of the examined cultivars were tested simultaneously in both countries. The Utah, Dynamic and hours below 7 °C models for estimating CR were evaluated and compared. The cultivars examined displayed different CR ranges in Spain and South Africa. We concluded that CR differences higher than 50% can be found for clonal plant material grown successfully in different climatic conditions. This variation might be associated both with different temperatures and other factors such as latitude. No significant differences in heat requirements were found among cultivars in Spain, suggesting that this variable might not be cultivar-specific. Finally, the distribution of clonal plant material provides an excellent framework for studying the climatic adaptation of crops.

Evolution and perspective of the temperate fruit crops in São Paulo state, Brazil

This work was carried out to show the current situation of the temperate fruit crops in São Paulo state, Brazil, with an emphasis on grapes, peaches, apples, plums, nectarines and pears crops. Current economic data of crops, major growing regions, main cultivars produced, as well as the new technologies generated by research are presented. Regarding the grape crop, a decrease in the national production as well as in the major growing states was observed. The main grapes growing centers in São Paulo state are presented, highlighting its peculiarities regarding cultivars, cultural crop management and current researches. A trend has been observed toward increasing Niagara Rosada grape growing area rather than the fine table grape cultivars. It was also observed the adoption of cultural practices, aiming to increase productivity, to improve the fruits quality and to reduce manpower necessity. In terms of stone fruits, peaches are the most widely cultivated in São Paulo state, followed by plums and nectarines. Both for stone fruits crop and for apples and pears crops, statistics and comments are presented on the crops evolution as well as the current researches results and the requirements of these fruit crops in São Paulo state, Brazil.

Toxicological and ultrastructural analysis of the impact of pesticides used in temperate fruit crops on two populations of Chrysoperla externa (Neuroptera, Chrysopidae)

Avaliaram-se os efeitos de (g i.a. L-1) abamectina (0,02), carbaril (1,73), enxofre (4,8) fenitrotiona (0,75), metidationa (0,4) e triclorfom (1,5) sobre a sobrevivencia de larvas e pupas, na oviposicao de adultos e viabilidade de ovos de Chrysoperla externa de duas populacoes (Bento Goncalves e Vacaria, Rio Grande do Sul). Alteracoes morfologicas causadas por abamectina em ovos depositados por C. externa da populacao de Vacaria foram avaliadas por meio de analises ultra-estruturais. Os agrotoxicos foram aplicados sobre placas de vidro. Agua destilada foi utilizada como testemunha. Para avaliacao da mortalidade de larvas utilizou-se delineamento experimental inteiramente ao acaso, em esquema fatorial 2 x 7 (duas populacoes x sete tratamentos) e para avaliacao dos efeitos dos compostos sobre a capacidade de oviposicao e viabilidade de ovos utilizou-se esquema fatorial 2 x 4. Carbaril, fenitrotiona e metidationa causaram 100% de mortalidade das larvas. Abamectina reduziu a viabilidade de ovos de C. externa, provenientes de larvas de terceiro instar de ambas as populacoes; entretanto, apresentou toxicidade mais elevada sobre insetos de Vacaria. Analises ultra-estruturais evidenciaram que abamectina causou deformacoes na micropila e na superficie externa do corion de ovos de C. externa. Baseando-se no efeito total (E), carbaril, fenitrotiona e metidationa sao prejudiciais a C. externa; triclorfom e inocuo, enquanto abamectina e enxofre sao inocuos e levemente prejudiciais a larvas de terceiro instar oriundas de Bento Goncalves e Vacaria, respectivamente.

A Preliminary Study on Insect Pollinators of Temperate Fruit Crops in Himachal Pradesh

INTRODUcnON Pollination is an ecological process that involves the transfer of pollen from the male to the female part of the flower with the help of abiotic and biotic pollen dispersal agents. It is an essential pre-requisite for fertilization and fruit/seed setting. If there is no pollination, there will be no fertilization and no fruits or seeds will be fonned (Free, 1993). Insects constitute one among the primary groups of pollinating agents (Free, 1993). Various insect groups, which are of prime significance in pollination of agricultural and horticultural crops mainly belong to the orders Hymenoptera (bees, ants and wasps), Diptera (ilies, mosquitoes, fungus gnats, midges etc.), Coleoptera (beetles and weevils), Lepidoptera (moths and butterflies), Thysanoptera (thrips), Hemiptera (bugs) and Neuroptera (lace wing flies).

Changes in fruit maturity indices along the harvest season in ‘Algerie’ loquat

Loquat is a subtropical fruit tree that presents an annual cycle reverse to that of the well-known temperate fruit crops. Loquat rests during summer, blooms in autumn, develops its fruit through winter and ripens them in early spring. Its unusual phenology allows growers to obtain high prices for its fruits, especially for early harvests. Although loquat is harvested based on skin colour, a minimum soluble solid content (TSS) of 10° Brix is often required for commercialization. However, we have noticed that the relationship between skin colour and eating quality seems to change along the season leading costumers to complain for the high acidity of the earliest fruits. In order to establish a reliable maturity index, we have evaluated the changes in different fruit maturation parameters along the harvest period in four consecutive seasons for ‘Algerie’ loquat. The results show that in samples collected with similar skin colour, TSS and, especially, fruit titratable acidity (TA) tend to decline as harvest season progresses. This makes fruit skin colour on its own not suitable as a harvest index to assure an adequate fruit quality under all circumstances. We propose instead to monitor continuously TSS and TSS/TA ratio along the season in order to fulfill consumer's expectations.

Insecticide resistance of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), in mainland China

In order to investigate the extent of resistance of oriental fruit fly, Bactrocera dorsalis (Hendel), which is a widespread pest throughout tropical, subtropical and temperate fruit crops, 25 populations of this insect were collected from 13 sites in mainland China in 2007 and 2008. In addition, resistant strains were established that showed increasing development of resistance. Compared with the susceptible strain, one population of B. dorsalis expressed high resistance (RR = 70.4-fold), 16 populations expressed medium resistance (11.5-fold < RR < 25.8-fold) and eight populations had low resistance or remained susceptible (1.4-fold < RR < 8.9-fold) to trichlorphon. As regards β-cypermethrin, one population showed high resistance (RR = 44.0-fold), nine populations expressed medium resistance (12.2-fold < RR < 28.4-fold), 14 populations expressed low or minor resistance (3.0-fold < RR < 9.7-fold) and one population remained susceptible (RR = 1.1-fold). As regards avermectin, five populations had developed high resistance (44.3-fold < RR < 104-fold), seven populations expressed medium resistance (11.4-fold < RR < 38.6-fold) and three populations expressed low or minor resistance (3.5-fold < RR < 5.6-fold). A continuous resistance selection in the laboratory strain showed that the resistance ratios to trichlorphon, β-cypermethrin and avermectin were 71.6-fold, 333-fold and 70.4-fold respectively. The data provided a comprehensive survey of insecticide resistance in Bactrocera dorsalis in mainland China. All results suggested that early resistance management programmes should be established for restoring the efficacy of pesticide-based control measures.