Isolation, cloning and sequencing of AFLP markers related to disease-resistance traits in Fenneropenaeus chinensis

Amplified fragment length polymorphisms (AFLP) technique was used to analyze the fingerprint- ing of four successive generations of Fenneropenaeus chinensis to reveal their disease-resistance traits. Some loci showed quite different genetic frequencies due to artificial selection, which implied that these fragments were putative markers related to the disease-resistance trait. We developed a simple and effective method to fur- ther characterize these AFLP fragments. Specific AFLP bands were cut directly from polyacrylamide gels, re-amplified, cloned and sequenced. Eight putative genetic markers were sequenced and their sizes ranged from 63 to 209 bp. The sequences were submitted to dbGSS (database of Genome Sequence Survey); and the BLAST analysis showed low similarity to the function genes, indicating these markers were tightly linked to a dis- ease-resistance trait but were not functional genes.

Rearing in intermediate salinity enhances immunity and disease-resistance of turbot (Scophthalmus maximus L.)

Studies were conducted to investigate the non-specific immune responses and disease-resistance of juvenile turbot Scophthalmus maximus,cultured at four different salinities（8,20,32 and 40） . Three concentrations（3.75 × 10 7,3.75 × 10 8 and 3.75 × 10 9 CFU/ml） of Vibrio anguillarum suspension were employed at each salinity to determine the 4-day LD 50 . The serum lysozyme activity,the alternative complement pathway activity（ACH50） and the phagocytosis percentage of head kidney in turbot were tested at 24,48 and 72 h post-challenge of V. anguillarum（1.1 × 10 8 CFU/ml,0.1 ml） ,respectively,to evaluate the non-specific immune responses at the selected rearing salinities. Fish reared at salinity 20 had the lowest mortality,namely,the highest 4-day LD 50 value（8.88 ± 0.17） . Besides,the lysozyme activity,ACH50 and the phagocytosis of turbot were the highest at the salinity 20,but with the lowest at the salinity 40 treatment regardless of sampling time. In addition,the non-specific immune activities kept increasing within 72 h post-challenge of V. anguillarum,except that the lysozyme activity increased from 24 to 48 h,and then decreased from 48 to 72 h at 40 significantly. These results together indicate that rearing in intermediate salinity（20） was able to enhance the immunity and disease-resistance of turbot.

Yield Characteristics of a New High-quality Disease-resistant Wheat Variety Chuanmai 618

[Objectives]The paper was to analyze the yield characteristics of a new high-quality disease-resistant wheat variety Chuanmai 618.[Methods]The yield characteristics of Chuanmai 618 were analyzed using the AMMI model and GGE biplot based on data from a 2-year regional test and a 1-year production test.[Results]The analysis of the AMMI model for the 2-year regional test indicated that Chuanmai 618 had a moderate yield and good stability.During the production test,Chuanmai 618 had an average yield of 450.52 kg/666.7 m^(2),an effective spike of 235700 spike/666.7 m^(2),a 1000-seed weight of 47.93 g,and a kernel number per spike of 47.28.The AMMI analysis sequencing graph showed that the varieties were ranked in the following order:Zhongkemai 1816>Chuanmai 618>Shumai 1958>Chuanyu 42>Mianmai 367>Xikemai 5518.According to the GE analysis,Chuanmai 618 had comparative advantages.[Conclusions]The new wheat variety Chuanmai 618 is a high-quality disease-resistant variety with good yield and stability.

Engineering disease-resistant plants with alternative translation efficiency by switching uORF types through CRISPR

Engineering disease-resistant plants can be a powerful solution to the issue of food security.However,it requires addressing two fundamental questions:what genes to express and how to control their expressions.To find a solution,we screen CRISPR-edited upstream open reading frame(uORF)variants in rice,aiming to optimize translational control of disease-related genes.By switching uORF types of the 5′-leader from Arabidopsis TBF1,we modulate the ribosome accessibility to the downstream firefly luciferase.We assume that by switching uORF types using CRISPR,we could generate uORF variants with alternative translation efficiency(CRISPR-aTrE-uORF).These variants,capable of boosting translation for resistance-associated genes and dampening it for susceptible ones,can help pinpoint previously unidentified genes with optimal expression levels.To test the assumption,we screened edited uORF variants and found that enhanced translational suppression of the plastic glutamine synthetase 2 can provide broad-spectrum disease resistance in rice with minimal fitness costs.This strategy,which involves modifying uORFs from none to some,or from some to none or different ones,demonstrates how translational agriculture can speed up the development of disease-resistant crops.This is vital for tackling the food security challenges we face due to growing populations and changing climates.

Control Effects of Combination of Plant Induced Resistant Agents against Tobacco Mosaic Virus (TMV)

[ Objective] The paper was explore the control effects of combination of plant induced resistant agents against tobacco mosaic vires （TMV）. [ Method ] The control effects of 6 different combinations of plant induced resistant agents against TMV of flue-cured tobacco cultivar HangDa were studied under the environ- ment of simulated disease nursery. [ Result] The combination of 2 induced agents polypeptide-agent and 3-acetonyl-3-hydroxyoxindole （AHO） had good control effect against TMV, which could obviously delay the incidence time of TMV in infected tobacco plants. With water and Duxiao as control, their average control effects against TMV of tobacco plants during field period reached 69.64% and 43.25% after transplanting for 70 d. They also showed significant superiority accord- ing to Duncan＇s test （p = 0.05 ） in the aspects of plant height and leaf number, and the growth and development condition of leaves was good. Tobacco seedlings carrying TMV virus had no direct correlation with whether the symptoms performed, the seedlings carrying virus would perform symptom only when the incidence condition was suitable. The peak period for the incidence of TMV in seedlings carrying virus was during 19 d after transplanting. Spraying effective agents during nursery stage and field period, as well as promoting quick growth at the initial stage of tobacco seedlings after transplanting were the key measures to control its inci- dence. [ Conclusion] The study provided theoretical basis for preparing the control measures against TMV.

家畜自然抗病力的遗传控制和培育(下)

四、家畜的自然抗病力及其研究方法研究家畜遗传性的自然抗病力,关键是要选择可靠的方法。主要涉及到如下几个步骤和所用的方法;即自然的接触病原体、评价抗病力和遗传分析,三者构成了研究的关键所在。接触病原体可以通过自然暴露或实验性对照接种。后者的优点是不仅能保证所有的实验动物都接触到病原体。

Advances in Cotton Breeding for Resistance to Fusarium and Verticillium Wilt in the Last Fifty Years in China

This review summarizes the main advances in cotton breeding for resistance to fusarium and verticillium wilt in the last fifty years in China. The topics discussed include main achievements, experiences, problems and countermeasures for solving.

The Resistance of Chinese Wild Vitis to Uncinula necator and its Inheritance in F_1 Generation

By natural field identification, the resistance of Chinese wild Vitis to Uncinula necator and its inheritance in F1 generation were studied with 35 clones of 9 Chinese wild Vitis species, 171 F1 individuals of 4 inter-species cross between Chinese wild Vitis and Vitis vinifera cultivars, and 16 individuals of self-pollinated Chinese wild Vitis. Results showed that the phenotypes of resistance to Uncinula necator in Chinese wild Vitis and its F1 generation were rich and diverse. Based on the segregation of resisitance to Uncinula necator in the progenies resulted from both interspecific hybridization and self-pollination, of Chinese native wild Vitis species and clones were controlled by poly genes showing dominant independent heredity. Minor resistant genes were also exist in Chinese wild susceptible Vitis species and clones.

Cloning and Sequence Analysis of Disease Resistance Gene Analogues from Three Wild Rice Species in Yunnan

Two sets of degenerate oligonucleotide primers were designed according to amino acid conserved regions of reported plant disease resistance genes which encode proteins that contain nucleotide-binding site and leucine-rich repeats(NBS-LRR), and the plant disease resistance genes which encode serine/threonine protein kinase(STK). By polymerase chain reaction(PCR), disease resistance gene analogues have been amplified from three wild rice species in Yunnan Province, China. The DIN A fragments from amplification have been cloned into the pGEM-T vector respectively. Sequencing of the DNA fragments indicated that 7 classes, 2 classes and 6 classes NBS-LRR disease resistance gene analogues from Oryza rufipogon Griff. , Oryza officinalis Wall. , and Oryza meyeriana Baill. were obtained respectively. The two representative fragments of TO12 from Oryza officinalis Wall, and TR19 from Oryza rufipogon Griff, belong to the same class and homology of their sequences are 100%. The result shows that the sequences of the same class disease resistance gene analogues have no difference among different species of wild rice. 5 classes STK disease resistance gene analogues were also obtained among which 4 classes from Oryza rufipogon Griff. , 1 class from Oryza officinalis Wall. By comparison analysis of amino acid sequences. we found that the obtained disease resistance gene analogues have very low identity(low to 25%) with the reported disease resistance gene L6, N, Bs2, Prf, Pto, Lr10 and Xa21 etc. The finding suggests that the obtained disease resistance gene analogues are analogues of putative disease resistance genes that have not been isolated so far.

10 Cultivars of the Rejuvenation Rose Group

On the basis of six-years’study (1986-1991) in the field of distant crossing, ten rose cultivars-elect of the to be established Rejuvenation Rose Group are recommended here for the first time. These cultivars have performed satisfactory ornamental characteristics and hardiness in Beijing.

Transcriptome analysis of the spleen of heterophils to lymphocytes ratio-selected chickens revealed their mechanism of differential resistance to Salmonella

Salmonella is one of the most common food-borne pathogens and its resistance in chicken can be improved through genetic selection.The heterophils/lymphocytes(H/L)ratio in the blood reflects the immune system status of chicken.We compared the genome data and spleen transcriptomes between the H/L ratio-selected and non-selected chickens,after Salmonella infection,aiming to identify the key genes participating in the antibacterial activity in the spleen.The results revealed that,the selected population had stronger(P<0.05)liver resistance to Salmonella typhimurium(ST)than the non-selected population.In the selected and non-selected lines,the identified differentiation genes encode proteins involved in biological processes or metabolic pathways that included the TGF-beta signaling pathway,FoxO signaling pathway,and Salmonella infection pathway.The results of the analysis of all identified differentially expressed genes(DEGs)of spleen revealed that the G protein-coupled receptor(GPCR)and insulin-like growth factor(IGF-I)signaling pathways were involved in the Salmonella infection pathway.Integrated analysis of DEGs and FST(fixation index),identified candidate genes involved in Salmonella infection pathway,such as GPR39,NTRK2,and ANXA1.The extensive genomic changes highlight the polygenic genetic of the immune response in these chicken populations.Numerous genes related to the immune performance are differentially expressed in the selected and non-selected lines and the selected lines has a higher resistance to Salmonella.

The tissue expression level of BPI gene in piglets from newborn to weaning and its relationship with Gram-negative bacterial infection

The bactericidal/permeability increasing protein (BPI) has an important function of nonspecific killing of Gram-negative bacteria. In this study, qPCR was used to detect the expression of the BPI gene in twelve tissues of Meishan piglets from birth to weaning. BPI gene overexpression, bacterial adhesions count and indirect immunofluorescence were applied to analyze the relationship between BPI gene expression and the infectivity of Escherichia coli and Salmonella. The results showed that the BPI gene was expressed highly in duodenum, jejunum and ileum (fold changes of relative expression levels were more than 10 000, 500 and 200, respectively). The expression of the BPI gene at 35 days of age was significantly higher (P<0.01) than that at all other days. Transcription of the BPI gene was up-regulated 2 401-fold in porcine intestinal epithelial (IPEC-J2) cells that were transfected with the BPI gene overexpression lentivirus (IPEC-J2-BPI), and significantly higher (P<0.01) than that in negative control cells (IPEC-J2-NC). Protein expression levels in IPEC-J2-BPI cells were also increased. When IPEC-J2 cells were incubated with E. coli and Salmonella, respectively, for 2, 4, 6, 8, 10 and 12 h, the number of bacterial adhesions in IPEC-J2-BPI cells was significantly less (P<0.05) than that in IPEC-J2-NC cells. The results of indirect immunofluorescence analysis showed that the number of bacterial adhesions in IPEC-J2-BPI cells was significantly less (P<0.01) than that in IPEC-J2-NC cells. These results demonstrated that the BPI gene might play an important role in regulating weaning stress especially intestinal-mediated immune response. Overexpression of the BPI gene at the cellular level could significantly enhance the anti-bactericidal ability against Gram-negative bacteria such as E. coli and Salmonella. This has important biological significance in piglet resistance to bacterial diarrhea.

Association between microsatellite markers and bovine tuberculosis in Chadian Zebu cattle

Bovine tuberculosis (BTB) is a considerable threat to livestock keepers and public health in many developing and underdeveloped countries. We investigated associations between 20 microsatellite markers and three phenotypes for BTB in a sample of the Chadian cattle population. The phenotypes measured were: 1) single intra-dermal comparative cervical tuberculin test (SICCT) performed on live animals, 2) presence of lesion post-slaughter, 3) a bacteriological tissue culture test for Mycobacterium bovis using the samples with observed lesions and 4) a predicted Bayesian model (BM) estimate of a true BTB disease status using all tested animals. All traits were recorded in binary form and as either 1 = presence or 0 = absence. A total of 224 animals for SICCT, lesion and BM traits and 96 animals with bacteriological culture test were genotyped. Generalised linear models were fitted to the binary BTB phenotypes that consisted of age (covariate), sex (2 levels), breed (2 levels) and markers (alleles: 5 - 14 levels) as explanatory variables and implemented in R using glm with a logit link function. The model was fitted for each marker, separately. Six out of 20 markers tested were significantly associated with at least one trait considered;these were ILSTS005, ILSTS006, TGLA227, BM2113 and CSRM66. Genomic regions around these markers may serve as a basis for further functional investigations. This is the first study to report association of microsatellite markers with bovine tuberculosis traits in African or Chadian cattle population.

Research Progresses of Eggplant Phomopsis Rot and Its Resistance Breeding

Eggplant phomopsis rot was summarized from the aspects of distribution and damage, pathogen identification and pathogenicity differentiation, and disease-resistant breeding. Furthermore, some existing problems and research directions in future was also discussed.

SSR Molecular Marker for Late Blight Resistance Gene in Tomato CLN2037

[Objectives] The research aimed to investigate the genetic rule of the disease resistance of tomato CLN2037,find molecular markers linked with disease-resistant genes and locate the disease-resistant genes. [Methods] BCr,BCs and F2 were constructed from tomato CLN2037 and susceptible cultivar T2-03,and their resistance to late blight was identified and analyzed by inoculating the disease in the seedling stage of tomatoes. The genetic linkage analysis was made based on the genetic linkage map constructed by ICu GI using group segregation method and 90 pairs of tomato SSR primers. [Results]The resistance of CLN2037 to late blight was controlled by a single recessive gene. The polymorphic bands amplified by primer DM0231 had a linkage relationship with resistance genes. The size of the polymorphism fragment was 226 bp with the genetic linkage distance of 2. 67 c M,and the disease resistance gene was localized on CCPB272-03741.[Conclusions]DM0231 could be used as a molecular marker for molecular breeding of tomato against late blight,which laid the foundation for further fine localization of late blight resistance genes.

A new way of creating new wheat germplasms resistant to wheat diseases

The improvement of wheat cultivar cannot be done without resistant germplasms. Distant hybridization has been a useful way in the creation of new. disease-resistant wheat germplasms. Using distant hybridization, the disease-resistant genes of the near genera of wheat can be transferred to the common wheat. However, the separation generation of distant hybrids is relatively long, and no effective approach has been developed to shorten this generation. It is very difficult to obtain stable wheat lines which have