Pork cutting is a very important processing in promoting economic appreciation across the swine business chain.  The goal of this research is to determine the proportion and weight of meat cuts, as well as to analyze the effects of carcass weight, sex and breed composition on meat cuts.  Simultaneously, we investigate the correlation between meat cuts, carcass traits and meat quality traits.  To assess 17 meat cut traits, 12 carcass traits and 6 meat quality traits, we sample 2 012 pigs from four breeds, including Landrace (LD), Yorkshire (YK), Landrace Yorkshire (LY), and Duroc Landrace Yorkshire (DLY).  The results showed that carcass weight, sex and breed composition have significant effects on the weight and proportion of most meat cuts.  The proportion of cuts for muscle and bone decrease as carcass weight grows, whereas the proportion of cuts for fat increases.  Moreover, the thickness of four-point backfat was significantly increasing (P<0.001) with increase of carcass weights, indicating that large amount of intaking energy in the late finishing stage was used for fat deposition.  Besides, the proportion of Shoulder cut (SC) and Back fat (BF) in barrows was significantly higher (P<0.001) than that in sows, whereas the Leg cut (LC) showed the opposite trend.  The Loin (LO) proportion and Loin muscle area (LMA) of barrows were significantly lower (P<0.001), but the proportion of fat areas in the image (PFAI) and visual marbling score (VMS) were significantly higher (P<0.001) than those of sows, respectively.  In terms of breeds, LD had the longest straight carcass length, significantly longer (P<0.001) than the other three breeds, which partially explains why LD had the largest proportion of the Middle cut (MC).  Moreover, the proportion of SC in DLY was the highest.  Last but not least, the correlations between the proportions of most meat cuts, and also between meat cuts and meat quality or carcass traits were low or not significant (P>0.05).  The effects of carcass weight, sex and breed composition on the meat cuts, meat quality and carcass traits are breed and growth stage dependent.  It also reflects the asynchrony of the growth curve between different sexes.  Our results laid an important foundation for breeding pig carcass cuts and composition.

Several viroids in the genus Pospiviroid can infect tomato (Solanum lycopersicum) and cause severe diseases, posing a serious threat to tomato production.  For simultaneous detection of six tomato-infecting pospiviroids - columnea latent viroid (CLVd), pepper chat fruit viroid (PCFVd), potato spindle tuber viroid (PSTVd), tomato apical stunt viroid (TASVd), tomato chlorotic dwarf viroid (TCDVd), and tomato planta macho viroid (TPMVd), we developed a universal probe based on a highly conserved 61 nt long sequence shared among them.  Compared with their specific probes, the universal probe has a similar, though slightly reduced, detection sensitivity and has the advantages of simple and cost-effective preparation and simultaneous detection of the six pospiviroids.  In addition, the universal probe was used in dot-blot hybridization assays for a large-scale survey of viroid(s) in tomato plantings in China.  Only PSTVd was detected in a few greenhouse-planted tomato plants.  Sequence analysis revealed that these tomato PSTVd isolates may have been introduced from tomato seeds imported from abroad. 

Laboratory mutants of Sclerotinia sclerotiorum (Lib) de Bary, resistant to boscalid, have been extensively characterized.  However, the resistance situation in the lettuce field remains largely elusive.  In this study, among the 172 S. sclerotiorum isolates collected from asparagus lettuce field in Jiangsu Province, China, 132 isolates (76.74%) exhibited low-level resistance to boscalid (Bos^LR), with a discriminatory dose of 5 μg mL^–1.  In comparison to the boscalid-sensitive (Bos^S) isolates, most Bos^LR isolates demonstrated a slightly superior biological fitness, as evidenced by data on mycelial growth, sclerotium production and pathogenicity.  Moreover, most Bos^LR isolates showed comparable levels of oxalic acid (OA) accumulation, increased exopolysaccharide (EPS) content and reduced membrane permeability when compared to the Bos^S isolates.  Nevertheless, their responses to distinct stress factors diverged significantly.  Furthermore, the effectiveness of boscalid in controlling Bos^LR isolates on radish was diminished compared to its efficacy on Bos^S isolates.  Genetic mutations were identified in the SDH genes of Bos^LR isolates, revealing the existence of three resistant genotypes: I (A11V at SDHB, SDHB^A11V), II (Q38R at SDHC, SDHC^Q38R) and III (SDHB^A11V+SDHC^Q38R).  Importantly, no cross-resistance was observed between boscalid and other fungicides such as thifluzamide, pydiflumetofen, fluazinam, or tebuconazole.  Our molecular docking analysis indicated that the docking total score (DTS) of the type I resistant isolates (1.3993) was lower than that of the sensitive isolates (1.7499), implying a reduced affinity between SDHB and boscalid as a potential mechanism underlying the boscalid resistance in S. sclerotiorum.  These findings contribute to an enhanced comprehension of boscalid’s mode of action and furnish valuable insights into the management of boscalid resistance.

Increasing wheat yield is a long-term goal for wheat breeders around the world.  Exploiting elite genetic resources and dissecting the genetic basis of important agronomic traits in wheat are the necessary methods for high-yield wheat breeding.  This study evaluated nine crucial agronomic traits found in a natural population of 156 wheat varieties and 77 landraces from Sichuan, China in seven environments over two years.  The results of this investigation of agronomic traits showed that the landraces had more tillers and higher kernel numbers per spike (KNS), while the breeding varieties had higher thousand-kernel weight (TKW) and kernel weight per spike (KWS).  The generalized heritability (H²) values of the nine agronomic traits varied from 0.74 to 0.95.  Structure analysis suggested that the natural population could be divided into three groups using 43 198 single nucleotide polymorphism (SNP) markers from the wheat 55K SNP chip.  A total of 67 quantitative trait loci (QTLs) were identified by the genome-wide association study (GWAS) analysis based on the Q+K method of a mixed linear model.  Three important QTLs were analyzed in this study.  Four haplotypes of QFTN.sicau-7BL.1 for fertile tillers number (FTN), three haplotypes of QKNS.sicau-1AL.2 for KNS, and four haplotypes of QTKW.sicau-3BS.1 for TKW were detected.  FTN-Hap2, KNS-Hap1, and TKW-Hap2 were excellent haplotypes for each QTL based on the yield performance of 42 varieties in regional trials from 2002 to 2013.  The varieties with all three haplotypes showed the highest yield compared to those with either two haplotypes or one haplotype.  In addition, the KASP-AX-108866053 marker of QTL QKNS.sicau-1AL.2 was successfully distinguished between three haplotypes (or alleles) in 63 varieties based on the number of kernels per spike in regional trials between 2018 and 2021.  These genetic loci and reliable makers can be applied in marker-assisted selection or map-based gene cloning for the genetic improvement of wheat yield. 

Dopamine is a catecholamine and an anti-oxidant which functions in responses to stress and it interacts with plant hormones to mediate plant development.  At present, there are few studies on the functions of dopamine in apple.  This study developed a method for dopamine determination which was used to analyze dopamine in Malus germplasm, in order to clarify the tissue distribution, developmental changes, diurnal variations, and stress responses in apple trees.  First, the proposed method was verified.  The linear range of quantification was robust from 0.1 to 20 ng mL^–1.  The instrumental, inter-day precision, and sample repeatability relative standard deviations were 1.024, 5.607, and 7.237%, respectively.  The spiked recovery was greater than 100%, indicating the feasibility of the method and its suitability for the rapid analysis of dopamine in Malus.  Next, the dopamine content was measured in 322 Malus tissues.  The results showed that the dopamine level in Malus was low and the average dopamine content in leaf was higher than in peel and flesh.  The dopamine had a skewed distribution that deviated to the right in cultivars and wild accessions.  Finally, the tissue specificity, developmental changes, diurnal changes, and responses to stress were analyzed.  In cultivar ‘Pinova’ (Malus domestica), the dopamine concentration was the highest in leaf buds and lowest in flesh.  The dopamine contents in leaf and flesh decreased with the growth and development of cultivar ‘Liangxiang’ (Malus domestica).  The dopamine content of apple leaves was higher after either drought or salinity stress as compared to the control.  In this study, a dopamine detection method for apple was established based on HPLC-MS and shown to be a robust approach.  This study provides a framework for future research on elucidating the tissue distribution, developmental changes, diurnal variation, and stress responses of dopamine in apple trees.

This study attempted to clarify the carrying-over effect of different nitrogen treatments applied to the main crop on the crop population growth and yield formation of ratoon rice under mechanized cultivation in Southeast China.  Based on the constant total nitrogen application amounts (225.00 kg ha^–1) in the main crop, an experiment with different ratios of basal and topdressing nitrogen fertilizer (the ratio of basal fertilizer:primary tillering fertilizer:secondary tillering fertilizer:booting fertilizer at 3:1:2:4 (N1), 3:2:1:4 (N2), 3:3:0:4 (N3), and 4:3:0:3 (N4), respectively, and a control without nitrogen treatment (N0)) was set up across two consecutive years in field using hybrid rice variety Yongyou 1540 as the test materials.  The results showed that the total tiller number and effective tillering percentage increased in the main crop under the N1 treatment, more nitrogen fertilizer applied in late growth stage of the main crop, and its effective tillering percentage of the main crop was the highest at up to 70.18%, which was 9.15% higher than that of conventional fertilization treatment (N4), more nitrogen fertilizer applied in early growth stage of the main crop.  The same tendency was observed in leaf area index (LAI) value of the main crop and its subsequent ratoon rice, which were 16.52 and 29.87% higher, respectively, in the N1 treatment than that in the N4 treatment at the full heading stage.  The same was true in the case of the transport rates of stem and sheath dry mater and the canopy light interception rates in both the main and its ratoon crops.  The transport rate of stem and sheath in main crop rice under N1 treatment increased by 50.57% compared with N4 treatment.  The canopy light interception rate of N1 treatment increased by 5.07% compared with N4 treatment at the full heading stage of the ratoon crop.  Therefore, the total actual yield was the highest in the main and its ratoon crops under N1 treatment, averaging 17 351.23 kg ha^–1 in two-year trials, which was 23.00% higher than that in the conventional fertilization treatment (N4).  The results showed that appropriate nitrogen treatment was able to produce a good crop stand in the main crop, which was essential for producing a good ratoon crop population and high yield especially under mechanized cultivation with low stubble height of the main crop.  The study suggested that shifting the proper nitrogen application amounts to the late growth stage of the main crop, such as N1 treatment, not only had a higher productive effect on ensuring the yield of the main crop, but also had a positive effect on the axillary bud sprouts from the stubbles for ratoon rice, resulting in an increased percentage of productive panicles and achieving the goal of one planting with two good harvests under the conditions of our study.

Grapevine (Vitis vinifera L.) is an economically important fruit crop in the world, and China ranks first in the production of grapes with approximately 15% of the world’s total yield.  However, diseases that cause the death of grapevine shoots pose a severe threat to the production of grapes.  In this study, the fungus Neopestalotiopsis eucalypti was identified as a causal pathogen of grapevine shoot rot based on the morphology of conidia and a phylogenetic analysis.  The phylogenetic analysis was performed with three isolates based on the combined sequence of internal transcribed spacer (ITS) region of ribosomal DNA, part of the translation elongation factor 1-alpha (Tef) and the β-tubulin (Tub2) genes.  The three isolates were all identified as N. eucalypti.  Pathogenicity tests of the three fungal isolates were conducted on grapevines shoots in vitro and in vivo.  The results showed that all three fungal isolates caused severe rot lesions on the inoculated grapevine shoots, and N. eucalypti was re-isolated from the inoculated grapevine shoots.  Therefore, N. eucalypti was confirmed as a causal agent of the grapevine shoot rot.  This is the first report of N. eucalypti causing grapevine shoot disease in China.

Certain agricultural management practices are known to affect the soil microbial community structure; however, knowledge of the response of the fungal community structure to the long-term continuous cropping and rotation of soybean, maize and wheat in the same agroecosystem is limited.  We assessed the fungal abundance, composition and diversity among soybean rotation, maize rotation and wheat rotation systems and among long-term continuous cropping systems of soybean, maize and wheat as the effect of crop types on fungal community structure.  We compared these fungal parameters of same crop between long-term crop rotation and continuous cropping systems as the effect of cropping systems on fungal community structure.  The fungal abundance and composition were measured by quantitative real-time PCR and Illumina MiSeq sequencing.  The results revealed that long-term continuous soybean cropping increased the soil fungal abundance compared with soybean rotation, and the fungal abundance was decreased in long-term continuous maize cropping compared with maize rotation.  The long-term continuous soybean cropping also exhibited increased soil fungal diversity.  The variation in the fungal community structure among the three crops was greater than that between long-term continuous cropping and rotation cropping.  Mortierella, Guehomyces and Alternaria were the most important contributors to the dissimilarity of the fungal communities between the continuous cropping and rotation cropping of soybean, maize and wheat.  There were 11 potential pathogen and 11 potential biocontrol fungi identified, and the relative abundance of most of the potential pathogenic fungi increased during the long-term continuous cropping of all three crops.  The relative abundance of most biocontrol fungi increased in long-term continuous soybean cropping but decreased in long-term continuous maize and wheat cropping.  Our results indicate that the response of the soil fungal community structure to long-term continuous cropping varies based upon crop types.

Auxin signaling plays a significant role in the whole process of plant growth and development from embryogenesis to senescence. Auxin response factors (ARFs) are reported to regulate the expression of auxin response genes by binding to auxin response elements. ARF is the most critical transcription factor family which has been released in most species, but few reports in strawberry. In this study, the structure characterization of 12 FvARF genes in strawberry, their expression patterns at different development stages, different organizations, and different indole-3-acetic acid (IAA) treatments were analyzed. The expression of 12 FvARFs was found in all experiment tissues and showed almost the same trend during fruit development. All FvARFs respond to the treatment of IAA. Our study provides comprehensive information on ARF family in strawberry, including gene structures, chromosome locations, phylogenetic relationships and expression patterns. The information on FvARF genes paves the way for future research on strawberry ARF genes. Keywords:

The nonstructural protein 10 (nsp10) of porcine reproductive and respiratory syndrome virus (PRRSV) encodes for helicase which plays a vital role in viral replication.  In the present study, a truncated form of nsp10, termed nsp10a, was found in PRRSV-infected cells and the production of nsp10a was strain-specific.  Mass spectrometric analysis and deletion mutagenesis indicated that nsp10a may be short of about 70 amino acids in the N terminus of nsp10.  Further studies by rescuing recombinant viruses showed that the Glu-69 in nsp10 was the key amino acid for nsp10a production.  Finally, we demonstrated that nsp10a exerted little influence on the growth kinetics of PRRSV in vitro. 

The common fig (Ficus carica L.) was one of the earliest horticultural crops to be domesticated.  A number of different viruses can infect fig trees including Fig mosaic virus (FMV) that has been detected in several commercial fig trees in Xinjiang, China.  However, the distribution of FMV and other fig-infecting viruses in China remains unknown.  In the present study, a sample from an ancient fig tree growing in Xinjiang was investigated by electron microscopy (EM) followed by PCR/RT-PCR, and FMV, Fig badnavirus 1 (FBV-1) and Fig leaf mottle-associated virus 1 (FLMaV-1) were detected.  Fig leaf samples (252) from commercial orchards across China were subjected to PCR/RT-PCR, and FMV, FBV-1 and Fig fleck-associated virus (FFkaV) were relatively abundant (44.4, 48.4 and 44%, respectively), while FLMaV-1 and Fig mild mottle-associated virus (FMMaV) were much scarcer (5.6 and 0.4%, respectively), and FLMaV-2, Fig cryptic virus (FCV), and Fig latent virus (FLV) were not detected.  The presence of disease-causing viruses in fig trees presents a significant challenge for fig producers in China.  This study may help to promote actions aimed at controlling fig viruses, especially FMV.

Genes controlling fruit appearance determine fruit shape and size.  In ethylmethane sulfonate (EMS)-mutagenized lines of Fragaria vesca accession Yellow Wonder (YW), two fruit shapes are observed: wild-type long fruit and mutated shortened fruit (sf).  In this study, we first characterized sf based on morphology, histology, cytology and physiology.  The sf was identified as a gibberellin (GA)-deficient mutant, and four complementary DNA (cDNA) libraries separately constructed from flower buds and small green fruits of YW and sf were sequenced to comparatively analyze transcriptome differences.  A total of 29 differentially expressed GA pathway genes were identified by comparisons between YW1 and sf1, and 28 differentially expressed GA pathway genes were identified between YW2 and sf 2.  In addition, the expression patterns of 45 differentially expressed genes were validated by quantificational real-time PCR (qRT-PCR), and the results were highly concordant with the RNA-Seq results.  This transcriptome analysis provides valuable information for understanding the molecular mechanisms of fruit development of strawberry.

The highbush blueberry (Vaccinium corymbosum), Duke, was used to construct a de novo transcriptome sequence library and to perform data statistical analysis.  Mega 4, CLC Sequence Viewer 6 software, and quantitative PCR were employed for bioinformatics and expression analyses of the basic helix-loop-helix (BHLH) transcription factors of the sequencing library.  The results showed that 28.38 gigabytes of valid data were obtained from transcriptome sequencing and were assembled into 108 033 unigenes.  Functional annotation showed that 32 244 unigenes were annotated into Clusters of Orthologous Groups (COG) and Gene Ontology (GO) databases, whereas the rest of the 75 789 unigenes had no matching information.  By using COG and GO classification tools, sequences with annotation information were divided into 25 and 52 categories, respectively, which involved transport and metabolism, transcriptional regulation, and signal transduction.  Analysis of the transcriptome library identified a total of 59 BHLH genes.  Sequence analysis revealed that 55 genes of that contained a complete BHLH domain.  Furthermore, phylogenetic analysis showed that BHLH genes of blueberry (Duke) could be divided into 13 sub-groups.  PCR results showed that 45 genes were expressed at various developmental stages of buds, stems, leaves, flowers, and fruits, suggesting that the function of BHLH was associated with the development of different tissues and organs of blueberry, Duke.  The present study would provided a foundation for further investigations on the classification and functions of the blueberry BHLH family.

Although the phosphate 1 (PHO1) gene family has been implicated in inorganic phosphate transport and homeostasis, the underlying mechanism of this gene in the strawberry has not yet been revealed.  In the present study, we analyzed the expression of the PHO1;H9 gene in the strawberry (Fragaria×ananassa), revealing the involvement of this gene in the regulation of phosphorus (P) content.  The coding sequence (CDS) of the PHO1;H9 gene, was isolated from the cultivated strawberry ‘Sachinoka’ and named as FaPHO1;H9.  The full-length CDS of this gene was 2 292 bp, encoding 763 amino acids, and the protein contained both SYG1/Pho81/XPR1 (SPX) and ERD1/ XPR1/SYG1 (EXS) domains, which were involved in phosphate (Pi) signaling.  Real-time reverse transcription-polymerase chain reaction (RT-PCR) data suggested that the level of FaPHO1;H9 expression was consistent with the P content in different organs, except for the petiole.  Particularly, its expression level was also correlated with P content in fruits of different developmental stages.  The expression of FaPHO1;H9 was also consistent with P content in leaves under different concentrations of P fertilizer application.  Furthermore, transgenic Arabidopsis lines were generated, and the P content in Arabidopsis plants over-expressing FaPHO1;H9 was significantly higher than that in wild-type plants.  Therefore, we proposed that FaPHO1;H9 functions in P transport.

China is the largest potato producing country worldwide, with this crop representing the fourth largest staple food crop in China. However, the steady presence of Potato spindle tuber viroid (PSTVd) over the past five decades has a significant economic impact on potato production. To determine why PSTVd control measures have been ineffective in China, more than 1 000 seed potatoes collected between 2009 and 2014 were subjected to PSTVd detection at the Supervision and Testing Center for Virus-free Seed Potatoes Quality, Ministry of Agriculture, China. A high PSTVd infection rate (6.5%) was detected among these commercial seed potatoes. Some breeding lines of potato collected from 2012 to 2015 were also tested for PSTVd infection, revealing a high rate of PSTVd contamination in these potato propagation materials. Furthermore, comparison of the full-length sequences of 71 different Chinese PSTVd isolates revealed a total of 74 predominant PSTVd variants, which represented 42 different sequence variants of PSTVd. Comparative sequence analysis revealed 30 novel PSTVd sequence variants specific to China. Comprehensive phylogenetic analysis uncovered a close relationship between the Chinese PSTVd sequence variants and those isolated from Russia. It is worth noting that three intermediate strains and six mild strains were identified among these variants. These results have important implications for explaining the ineffective control of PSTVd in China and thus could serve as a basic reference for designing more effective measures to eliminate PSTVd from China in the future.

  Phenylalanine ammonia-lyase (PAL), the first enzyme of phenylpropanoid pathway, is always encoded by multigene families in plants. In this study, using genome-wide searches, 13 PAL genes in cucumber (CsPAL1–13) and 13 PALs in melon (CmPAL1–13) were identified. In the corresponding genomes, ten of these PAL genes were located in tandem in two clusters, while the others were widely dispersed in different chromosomes as a single copy. The protein sequences of CsPALs and CmPALs shared an overall high identity to each other. In our previous report, 12 PAL genes were identified in watermelon (ClPAL1–12). Thereby, a total of 38 cucurbit PAL members were included. Here, a comprehensive comparison of PAL gene families was performed among three cucurbit plants. The phylogenetic and syntenic analyses placed the cucurbit PALs as 11 CsPAL-CmPAL-ClPAL triples, of which ten triples were clustered into the dicot group, and the remaining one, CsPAL1-CmPAL8-ClPAL2, was grouped with gymnosperm PALs and might serve as an ancestor of cucurbit PALs. By comparing the syntenic relationships and gene structure of these PAL genes, the expansion of cucurbit PAL families might arise from a series of segmental and tandem duplications and intron insertion events. Furthermore, the expression profiling in different tissues suggested that different cucurbit PALs displayed divergent but overlapping expression profiles, and the CsPAL-CmPAL-ClPAL orthologs showed correlative expression patterns among three cucurbit plants. Taken together, this study provided an extensive description on the evolution and expression of cucurbit PAL gene families and might facilitate the further studies for elucidating the functions of PALs in cucurbit plants.

Organic manure application is an important measure for high yield and good quality vegetable production, whereas organic manure is also a main source of residual antibiotic in soils. A 3-yr experiment was conducted on a fluvo-aguic soil in Tianjin of northern China. The objective of this study was to investigate the effects of different fertilization patterns on yield of six-season vegetables with celery and tomato rotation, and dynamic change of tetracyclines residues in the soil during the sixth growing season (tomato season). The field experiment comprised six treatments depending on the proportion of nitrogen of each type of fertilizer: 4/4 CN (CN, nitrogen in chemical fertilizer), 3/4 CN+1/4 MN (MN, nitrogen in pig manure), 2/4 CN+2/4 MN, 1/4 CN+3/4 MN, 2/4 CN+1/4 MN+1/4 SN (SN, nitrogen in corn straw), and CF (conventional fertilization, the amounts of nitrogen application were 943 and 912 kg N ha–1 for celery and tomato season, respectively). In addition to CF treatment, the amount of nitrogen application in other treatments was greatly reduced and equal (450 and 450 kg N ha–1 for celery and tomato season, respectively). Results showed that the combined application of 3/4 CN+1/4 MN achieved the highest yield and economic benefit in the first four seasons, but addition of straw (2/4 CN+1/4 MN+1/4 SN treatment) performed better in the subsequent two seasons, and the average yields of 2/4 CN+1/4 MN+1/4 SN treatment were respectively higher by 9.9 and 12.8% than those of 4/4 CN treatment, and by 5.6 and 10.5% than those of CF treatment. The residual chlortetracycline (CTC) in manure-amended soil for three consecutive years increased along with the increase of applied amount of pig manure. Under the same amount of pig manure application, content of CTC in straw-amended soil was obviously decreased compared with no straw-amended soil (3/4 CN+1/4 MN treatment), and averagely decreased by 41.9% for four sampling periods in the sixth season. Addition of crop straw facilitated the degradation of CTC in manure-amended soil. As a whole, the conventional fertilization was not the desirable pattern based on yield, economic benefit and environment, the optimal fertilization pattern with the highest yield and profit and the least soil chlortetracycline residue was the treatment of 2/4 CN+1/4 MN+1/4 SN under this experimental condition.

Overestimation of nitrogen (N) uptake requirement is one of the driving forces of the overuse of N fertilization and the low efficiency of N use in China. In this study, we collected data from 1 844 site-years of rice (Oryza sativa L.) under various rotation cropping systems across the Yangtze River Valley. Selected treatments included without (N0 treatment) and with N application (N treatment) which were recommended by local technicians, with a wide grain range of 1.5–11.9 t ha–1. Across the 1 844 site-years, over 96% of the sites showed yield increase (relative yield>105%) with N fertilization, and the increase rates decreased from 78.9 to 16.2% within the lowest range <4.0 to the highest >6.5 t ha–1. To produce one ton of grain, the rice absorbed approximately 17.8 kg N in the N0 treatment and 20.4 kg N in the N treatment. The value of partial factor productivity by N (PFPN) reached a range of 35.2–51.4 kg grain kg–1 with N application under the current recommended N rate. Averaged recovery rate of N (REN) was above 36.0% in yields below 6.0 t ha–1 and lower than 31.7% in those above 6.0 t ha–1. Soil properties only affected yield increments within low rice yield levels (<5.5 t ha–1). There is a poor relationship between N application rates and indigenous nitrogen supply (INS). From these observations and considering the local INS, we concluded there was a great potential for improvement in regional grain yield and N efficiency.

One concern about the use of transgenic plants is their potential risk to natural enemies. In this study, using the eggs of the rice brown planthopper, Nilaparvata lugens, as a food source, we investigated the effects of Cry1Ab rice on the biological characteristics and functional response of an important predator Cyrtorhinus lividipennis. The results showed that the survival ability (adult emergence rate and egg hatching rate), development (egg duration, nymphal developmental duration), adult fresh weight, adult longevity and fecundity of C. lividipennis on Bt rice plants were not significantly different compared to those on non-Bt rice plants. Furthermore, two important parameters of functional response (instantaneous search rate and handling time) were not significantly affected by Bt rice. In conclusion, the tested Cry1Ab rice does not adversely impact the biological character and functional response of C. lividipennis.