Transgenic cotton expressing the Cry1Ac toxin from Bacillus thuringiensis has been planted widely in China since 1997, and reached 70% of the total cotton area in 2006. The results of monitoring the environmental impact of Bt cotton commercialization indicated that the target pests, cotton bollworm (Helicoverpa armigera) and pink bollworm (Pectinophora gossypiella), were effectively controlled while the mirids (Hemiptera: Miridae) evolved to be key pests in the cotton system. There were no significant changes in resistance gene frequency of field populations of cotton bollworm, but a shift toward increased tolerance was apparent in the area of intensive planting of Bt cotton, indicating that the potential risk of resistance of the target pest has become a major threat for sustainable planting of Bt cotton. Considering the factors associated with the evolution of resistance, risk management strategies are discussed in this paper.

The genetic diversity of 43 male sterile and low fertility Citrus accessions, as well as 13 fertile ones, were assessed using simple sequence repeat markers (SSRs). Thirty-five polymorphic alleles were generated from eight primers (on average 4.4 alleles per primer). Cluster analysis was performed via unweighted pair group method analysis (UPGMA) using the NTSYS-pc version 2.10. The results showed that the accessions could be classified into three groups: cultivars of mandarin were classified into group 1; those of sweet orange, grapefruit, ponkan or tangor into group 2; and Microcitrus with male sterile cytoplasm into group 3. Cluster analysis also revealed that Satsuma mandarin was more closely related to Bendiguangju mandarin than to Zaoju, Mankieh or Huangyan Bendizao tangerine. The present study on genetic diversity of male sterile and low fertility Citrus will provide useful information for further collection, preservation and utilization of this plant.

Endophytic bacteria isolated from Guangdong bamboo (Bambusa blumeana) plants were obtained under aerobic and anaerobic cultural conditions. Using the acetylene reduction assay (ARA), 40 strains were identified as diazotrophs. Diazotrophic isolates were grouped into five clusters (I, II, III, IV and V) by SDS-PAGE whole-cell protein patterns. The analysis of full-length 16S rDNA sequences of the representative strains of each group indicated that the endophytic diazotrophs showed great diversity and belonged to the genera Azospirillum (α-subclass of proteobacteria), Escherichia and Pseudomonas (γ-subclass of proteobacteria), and Aquaspirillum (β-subclass of proteobacteria).

Combining the long serial analysis of gene expression (LongSAGE) and the generation of longer cDNA fragments from serial analysis of gene expression tags for gene identification (GLGI) technique, a new strategy called modified GLGI (M-GLGI) was developed to isolate unknown 3′ expressed sequence tags (ESTs) and discover novel genes. A 17 bp LongSAGE tag was used as sense primer instead of a 10-base SAGE tag; PCR reaction was performed under an appropriate annealing temperature for each tag; universal DNA polymerase was used in PCR amplification instead of Pfu enzyme; a common cloning strategy using pMD-18T vector and Escherichia coli DH5α cells were used instead of a special vector and competent cells. Moreover, ESTs isolated by M-GLGI had 3′ ends with the polyadenylation signals and poly(dA) tails. This method is more sensitive for identifying genes expressed in low abundance than conventional EST sequencing.

This trial was aimed at investigating the effect of different doses of progesterone (P4) and types of vaginal bolts on new follicular wave induction, oestrus synchronization and superovulation in Holstein heifers. Results showed that the interval after prostaglandin F2α (PGF2α) application and oestrus occurrence between the sponge blot (SP) group (48.3 h) and the progestin release device (PRD) group (39 h) was significantly different (P<0.05). The average number of embryos obtained in the SP group (13.2) was significantly higher than that (8.7) in the PRD group (P<0.05). The same trend was observed for the number of usable embryos (5.7 and 3.3 for SP and PRD groups, respectively). The injection of 50 and 100 mg of P4 efficiently induced a new follicular wave, whereas no significant difference (P>0.05) was recorded on oestrus synchronization and superovulation between the two groups.

This research focused on the effect of distant hybridization to improve the flesh quality of offspring from Oreochromis aurea (♀)×Siniperca chuatsi (♂). The proportions of different tissues and percentages of nutrient components were compared between fish of the F3 generation and O. aurea and S. chuatsi. The results showed that the proportion of flesh in F3 hybrids was significantly lower than that in O. aurea. Crude lipid content was lower and crude protein content significantly higher in the F3 generation. Concentrations of four kinds of amino acids important for flavour (DAA) were higher in the F3 generation than in O. aurea, and the total DAA was significantly higher. Furthermore, the other amino acid contents and essential amino acid index of the F3 generation were intermediate between O. aurea and S. chuatsi. We conclude that some effects of hybridization have induced flesh quality improvement.

A yellow leaf curl disease with chlorotic and yellowish leaves, upward leaf curling and stunting symptoms was observed on tomato in Shantou city of Guangdong province. A virus isolate BS was obtained from a diseased tomato plant. The complete DNA-A sequence of the virus isolate BS was determined to be 2740 nucleotides long, with all the characteristic features of begomovirus genome organization. BS DNA-A encoded six potential open reading frames (ORFs), with two (AV1 and AV2) in virus sense and four (AC1, AC2, AC3 and AC4) in complementary sense, and contained an intergenic region of 269 nucleotides. The results of BLAST searches showed that BS DNA-A had higher sequence identity with reported begomoviruses in Asia than with those in America and Africa. Further sequence comparisons indicated that BS was most closely related to the isolate of Tomato leaf curl Taiwan virus (ToLCTWV-[Taiwan]) with a sequence identity of 97.7%. Nucleotide sequence identities of AV1, AV2, AC1, AC2, AC3, AC4 and intergenic region (IR) between BS and ToLCTWV-[Taiwan] were 98.6, 98.0, 98.0, 97.5, 96.3, 98.6 and 96.6%, respectively, while that of the six ORF-encoded proteins between BS and ToLCTWV-[Taiwan] were 97.7, 99.1, 97.5, 95.6, 91.8 and 99.0%, respectively. Phylogenetic analysis based on the DNA-A sequences has also indicated that BS is most closely related to ToLCTWV-[Taiwan], forming a branch with ToLCTWV-[Taiwan], Tomato leaf curl Guangdong virus and Tomato yellow leaf curl Guangdong virus. The above results demonstrate that BS is an isolate of ToLCTWV.

The spotted longbarbel catfish (Mystus guttatus) is a member of the family Bagridae and is mainly distributed in the Pearl River Valley and Nandujiang River of Hainan Island. It is one of the four most famous fishes in the history of Pearl River Valley. Nowadays, M. guttatus has become a potential target for aquaculture in China due to its high nutritional value, but its genetic background is still unknown. This study was carried out to estimate its population genetic diversity in Pearl River. The random amplified polymorphic DNA (RAPD) technique was performed on 30 samples, using 20 random primers of length 10 nucleotides. The results showed that each primer amplified 3–9 bands per sample. Twenty primers produced 3210 well-amplified DNA fragments with reproducible band patterns and the average number of amplified DNA fragments reached 107 in each individual. Broadly speaking, 48 (44.9%) of 107 loci were polymorphic. Only the S30 primer did not produce polymorphic loci. The genetic distance of individuals ranged from 0.0467 to 0.2804. The average genetic distance among the 30 individuals was 0.1526±0.037. Genetic data in this study could be useful in genetic resource assessment as well as in wild population conservation and exploitation of M. guttatus in the future.

Gene expression profiles between submergence rice (Oryza sativa ssp. indica) varieties, tolerant FR13A and sensitive IR39595-503-2-1-2, under submergence stress were identified using differential display reverse transcriptase-polymerase chain reaction (DDRT-PCR). A total of 1428 bands were amplified with 40 pairs of primers, of which 102 were significantly different between the two lines. The differential display ratio was 7.1%. Among 42 differential display bands derived from the submergence tolerant variety, the expression of seven fragments was confirmed by Northern blot analysis. The analysis of their sequences indicated that four of them showed high homology with genes related to a water stress response: genes encoding ATP-binding protein, isocitrate dehydrogenase, NADH dehydrogenase and terminal acetyltransferase, respectively. The remaining three fragments were novel cDNA fragments.

The Lc regulatory gene affects the formation of anthocyanin in plants. XY355 promoter, a petal-specific promoter, was obtained from the genome of rape (Brassica napus) by polymerase chain reaction (PCR). A plant expression vector, pXY60, was constructed, which contained the maize Lc regulatory gene under the control of the XY355 promoter. The vector was introduced into tobacco (Nicotiana tabacum) and petunia (Petunia hybrida) by an Agrobacterium tumefaciens-mediated method. The flower colour of some transgenic tobacco plants was changed from light red to deep red and that of some transgenic petunia plants had changed from white to light purple.

cDNA of the porcine small adipocyte factor 1 (SMAF1) gene was amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) with degenerate primers designed according to the conserved sequences between human and mouse genes. The cDNA (GenBank accession No. DQ191892) containing a complete encoding region was 256 bp in length, sharing 86 and 78% identity with that of human and mouse, respectively. Comparison of the deduced amino acid sequence between porcine SMAF1 and the human, mouse, cattle and rat protein showed that the amino acid similarity was 81, 67, 84 and 70%, respectively. The results of semi-quantitative RT-PCR showed that the porcine gene was expressed abundantly in adipose tissue, and at a significantly lower level in lean-type pigs (Large White pigs) than in lard-type pigs (Meishan pigs) at the age of 4 months (P<0.05). The results suggest that the porcine SMAF1 gene may have similar functions as in other species, that is, it may regulate adipogenesis and/or adipocyte function.

The black muntjac (Muntiacus crinifrons) is a critically endangered mammalian species, confined to a narrow region of south-eastern China. In the present study, the homogeneous ear fibroblast cells of a black muntjac were respectively cultured in Dulbecco's modified Eagle's medium (DMEM) (low glucose), DMEM (high glucose) and RPMI-1640. The population doubling time of subcultured cells was not significantly different between the three different media, but cell growth was greater in DMEM (low glucose). The interspecies embryos were reconstructed using the fibroblasts of black muntjac as donors and enucleated goat or rabbit oocytes as recipients and their blastocyst rates were 0 and 11.5%, respectively. The results demonstrated that the two cytoplasts could support reprogramming of the ear fibroblasts of black muntjac, but the developmental potential of the reconstructed embryos was different.

The isozymes of 10 enzymes connected with energy metabolism in Tegillarca granosa were analysed by vertical polyacrylamide gel electrophoresis. Esterase and α-amylase are enzymes related to energy intake, their activities were high in the digestive gland. Malate dehydrogenase, malic enzyme, isocitrate dehydrogenase, succinate dehydrogenase, alcohol dehydrogenase, lactate dehydrogenase, 6-phosphogluconate dehydrogenase (G-6-PDH) and adenosine triphosphatase (ATPase) are enzymes related to energy metabolism. The main energy supply of T. granosa comes from aerobic respiration; anaerobic metabolism and the pentose phosphate pathway take an auxiliary role in energy metabolism. The high activity of G-6-PDH in T. granosa might mean a considerable proportion of carbohydrates metabolized through this pathway. This reaction could provide abundant NADP for metabolism in T. granosa. Compared with other shellfish, T. granosa had lower activity of ATPase, which might have some relationship with the amnicolous life and low motility of this animal.

A complete chitin deacetylase (CDA) complementary DNA (cDNA) from Mucor racemosus was cloned and sequenced by reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification cDNA end (RACE) with gene special conserved primers. The cDNA sequence was submitted to GenBank (DQ538514). The complete cDNA with full-length of 1506 bp contained a 67 bp 5′-untranslated region, an open reading frame of 1344 bp and 95 bp 3′-untranslated region including tailing site AATAAA. The gene encoded a sequence of 448 amino acid residues and consisted of core nucleotides encoding a polysaccharide deacetylase domain covering 32% of the entire sequence. The CDA gene shared sequence homology with those of several fungi. The corresponding homology of the deduced amino acid sequences varied from 21 to 69%. Phylogenetic analysis according to the deduced amino acid sequences matched the classical fungi taxonomy. The three-dimensional structure of this protein was predicted. The protein had a whole CDA functional domain and a polysaccharide deacetylase domain.

An immuno-capture polymerase chain reaction (IC-PCR) method for detection of Acidovorax avenae subsp. citrulli (AAC), the causal organism of bacterial fruit blotch (BFB) of watermelon, was developed by combining the immunosorbent enrichment (ISE) method with classical PCR and comparing with the direct PCR and growth check methods. The results showed that all A. avenae subsp. citrulli strains tested have produced 360 bp specific fragments using IC-PCR and direct PCR methods, while other strains from 10 different genera showed negative PCR results. The minimum detection concentration was about 50–100 cfu/ml and 104 cfu/ml, respectively. The IC-PCR sensitivity was 100 times higher than that of direct PCR. The examination of seven batches of different melon seeds from the markets by IC-PCR showed that one cantaloupe, two honeydew melon and two watermelon seed varieties carried the pathogen, indicating that the IC-PCR is an accurate, sensitive, rapid and low-cost technique.