Inheritance of downy mildew resistance in two interspecific crosses between Chinese wild grapes and European grapes

Research Note

Evaluation of agronomic traits in Chinese wild grapes and screening superior accessions for use in a breeding program

This study was conducted to evaluate 15 agronomic traits in 67 accessions of 13 Chinese wild Vitis species. The results have been used to screen superior accessions for grape breeding in the future. Chinese wild Vitis had high diversity in economic traits among the species, such as bud-burst date, blooming date, berry ripening date, bunch weights, berry weights, berry soluble solid contents, berry acid contents, and vine production. Bunch weights of 56 Chinese wild accessions and berry weights of 12 Chinese species (except V. davidii) were much smaller than those of the two European cultivars. In our 25-year of evaluation on disease resistance and economic qualities in this Chinese germplasm, we suggest that V. quinquangularis, V. amurensis, V. yeshanensis, V. romanetii, and certain accessions in V. liubanensis be the first potential materials chosen for breeding.

Comparison of resistance to powdery mildew and downy mildew in Chinese wild grapes

This research was performed under natural conditions in an effort to compare resistance within Chinese Vitis germplasm to powdery mildew and downy mildew. Sixty-six genotypes of 13 Chinese wild Vitis species were selected to evaluate disease resistance. Seven among these 13 species, V. amurensis, V. romanetii, V. piazezkii, V. davidii, V. davidii var. cyanocarpa, V. liubanensis, and V. bashanica showed resistance to powdery mildew. Three species, V. yeshanensis, V. davidii var. cyanocarpa, and V. pseudoreticulata exhibited resistance to downy mildew. Among 66 genotypes, 46 were resistant to powdery mildew, 28 were resistant to downy mildew and 19 genotypes had resistance to both diseases. Although more than half of the genotypes exhibited resistance to powdery mildew and a lesser number expressed resistance to downy mildew, resistance to both diseases in Chinese Vitis were significantly related (r = 0.395, df = 64, r0,01 = 0.325). Also, there is resistance variation regarding both diseases between the species and also, to a lesser degree, among the genotypes. The variation is not related to the geographic distribution of the germplasm. These variations should be considered when researchers collect the gemplasm on location, making every effort to obtain extensive genotypes for the breeding program.

Relatedness of resistance to anthracnose and to white rot in Chinese wild grapes

Resistance to anthracnose and to white rot in 56 accessions of 13 Chinese wild Vitis species, V. amurensis, V. quinquangularis, V. romanetii, V. adstricta, V. pseudoreticulata, V. piazezkii, V. davidii, V. davidii var. cyanocarpa, V. liubanensis, V. qinlingensis, V. bashanica, V. yeshanensis and V. hankockii was evaluated under natural conditions in 1996-1998. All 56 accessions and the 13 species showed resistance to anthracnose. All nine accessions of V. quinquangularis, and one accession each of V. romanetii, V. adstricta and V. pseudoreticulata exhibited susceptibility to white rot; the remaining 44 accessions (78.57 %) and the other 9 species presented resistant to grape white rot. Two V. vinifera cultivars (‘Cabernet Sauvignon’ and ‘Chardonnay’) were susceptible to anthracnose and highly susceptible to white rot. The r-value of susceptibility indices between anthracnose and white rot in the 56 accessions is insignificant. In Chinese wild grapes, the mechanisms for producing resistance to both diseases would be very different, but inheritance of resistance to these two diseases in a certain cross is somewhat related by molecular data.

A review of taxonomic research on Chinese wild grapes

The taxonomy of Chinese wild grapes can be traced back to the end of the 18th century. However, most research in this field was performed in the last three decades. On the basis of the data from the Chinese wild grape germplasm collected in the last 25 years at the College of Horticulture, Northwest A&F University, Yangling, Shaanxi, China, and publications by other scientists in China, we concluded there were 40 species, 1 subspecies, and 13 varieties of Chinese wild grapes. These were classified into 1 subgenus, 5 sections and 4 series according to FASONG WANG et al.’s systematics. The systematics on Chinese wild grapes is discussed in this paper.

The eco-geographic distribution of wild grape germplasm in China

Chinese wild Vitis species are mainly distributed in four major eco-geographic regions: (1) The Changbaishan Mountains and Xiaoxing’anling Mountains Region, (2) The Qinling Mountains Region, (3) The Mid-downstream Yangtze River Region and (4) The Guangxi Region. One, eighteen, thirty-two, and thirteen Vitis species have been found in these four regions, respectively. The Qinling Montains, the Bashan Montains, and the provinces of Jinagxi, Hubei, Hunan, and Guangxi have high Vitis diversity totaling over 30 species, indicating that these regions may be a major center of origin for Vitis. The range of distribution varies much among the species: Vitis pentagona, Vitis flexuosa, Vitis davidii, and Vitis wilsonae have a wide eco-geographic distribution; Vitis hancockii, Vitis bellula, and Vitis sinocinerea distribute more narrowly. The wild Vitis species of China are differentiated and adapted to local climates. We hope that this review familiarizes more researchers with the distribution of the wild grapes of China and will lead to more efficient collection and informed development of this germplasm.

Transcriptome-wide high-throughput deep m6A-seq reveals unique differential m6A methylation patterns between three organs in Arabidopsis thaliana

Proportion of two types of m6A distributing feature in mRNA. (DOC 30 kb

The two-component system CpxAR is required for the high potassium stress survival of Actinobacillus pleuropneumoniae

IntroductionActinobacillus pleuropneumoniae is an important respiratory pathogen, which can cause porcine contagious pleuropneumonia and lead to great economic losses to worldwide swine industry. High potassium is an adverse environment for bacteria, which is not conducive to providing turgor pressure for cell growth and division. Two-component system CpxAR is an important regulatory system of bacteria in response to environmental changes, which is involved in a variety of biological activities, such as antibiotic resistance, periplasmic protein folding, peptidoglycan metabolism and so on.MethodsHowever, little is known about the role of CpxAR in high potassium stress in A. pleuropneumoniae. Here, we showed that CpxAR is critical for cell division of A. pleuropneumoniae under high potassium (K+) stress.ResultsqRT-PCR analysis found that CpxAR positively regulated the cell division genes ftsEX. In addition, we also demonstrated that CpxR-P could directly bind the promoter region of the cell division gene ftsE by EMSA.DiscussionIn conclusion, our results described a mechanism where CpxAR adjusts A. pleuropneumoniae survival under high-K+ stress by upregulating the expression of the cell division proteins FtsE and FtsX. These findings are the first to directly demonstrate CpxAR-mediated high-K+ tolerance, and to investigate the detailed molecular mechanism

Molecular Genetic Features of Polyploidization and Aneuploidization Reveal Unique Patterns for Genome Duplication in Diploid Malus

Polyploidization results in genome duplication and is an important step in evolution and speciation. The Malus genome confirmed that this genus was derived through auto-polyploidization, yet the genetic and meiotic mechanisms for polyploidization, particularly for aneuploidization, are unclear in this genus or other woody perennials. In fact the contribution of aneuploidization remains poorly understood throughout Plantae. We add to this knowledge by characterization of eupolyploidization and aneuploidization in 27,542 F1 seedlings from seven diploid Malus populations using cytology and microsatellite markers. We provide the first evidence that aneuploidy exceeds eupolyploidy in the diploid crosses, suggesting aneuploidization is a leading cause of genome duplication. Gametes from diploid Malus had a unique combinational pattern; ova preserved euploidy exclusively, while spermatozoa presented both euploidy and aneuploidy. All non-reduced gametes were genetically heterozygous, indicating first-division restitution was the exclusive mode for Malus eupolyploidization and aneuploidization. Chromosome segregation pattern among aneuploids was non-uniform, however, certain chromosomes were associated for aneuploidization. This study is the first to provide molecular evidence for the contribution of heterozygous non-reduced gametes to fitness in polyploids and aneuploids. Aneuploidization can increase, while eupolyploidization may decrease genetic diversity in their newly established populations. Auto-triploidization is important for speciation in the extant Malus. The features of Malus polyploidization confer genetic stability and diversity, and present heterozygosity, heterosis and adaptability for evolutionary selection. A protocol using co-dominant markers was proposed for accelerating apple triploid breeding program. A path was postulated for evolution of numerically odd basic chromosomes. The model for Malus derivation was considerably revised. Impacts of aneuploidization on speciation and evolution, and potential applications of aneuploids and polyploids in breeding and genetics for other species were evaluated in depth. This study greatly improves our understanding of evolution, speciation, and adaptation of the Malus genus, and provides strategies to exploit polyploidization in other species

Prevalence of and risk factors for non-suicidal self-injury in rural China: Results from a nationwide survey in China

Background Non-suicidal self-injury (NSSI) is a highly prevalent and serious public health problem among adolescents worldwide. However, to date there were no studies assessing the prevalence of NSSI defined by suggested DSM-5 criteria among Chinese adolescents. We aimed to conduct a nationwide survey to explore the prevalence of and risk factors for NSSI among school-based adolescents in rural China. Methods A total sample of 15,623 adolescents in rural China were enrolled by using a multistage sampling method. Data was collected by self-report questionnaires including demographic characteristics, neglect, maltreatment, loneliness, resilience, social support and emotional management ability. NSSI was defined by suggested DSM-5 criteria, according to which the engagement in self-injury took place more than 5 times a year. Multinomial logistic regression models were used to estimate the association between risk factors and NSSI. Results There were 12.2% of adolescents (n = 1908) met the suggested DSM-5 criteria. Approximately 29% reported a history of NSSI at least once during the last year. Significant differences were found in several demographic factors including gender, ethnicity, grade, and family structure between adolescents with and without experiencing NSSI. The top three NSSI behaviors among adolescents with NSSI experience were hitting self, pinching, and pulling hair, with a prevalence rate of 16.7%, 14.1% and 11.2%, respectively. Female, Han ethnicity, fathers’ education level, neglect, maltreatment, loneliness, social support, suicidal behaviors and emotional management ability were significantly associated with NSSI by multivariate analysis. No significant relationship was found between resilience and risk of NSSI. Limitation The DSM-5 has proposed 6 groups of criteria for NSSI, we only used criteria on frequency given its more accepted feasibility and pragmatic application. Consequently, it may different from other prevalence that estimated by other criteria. Conclusion To the best of our knowledge, this is the first study reporting prevalence of NSSI defined by suggested DSM-5 criteria among adolescent in rural China. In comparison to finding from the similar samples of adolescents, Chinese rural adolescents seem to have a relative higher prevalence. The potential risk factors for NSSI include female, father's education, Han ethnicity, psychosocial factors and suicide behaviors. More evidence for further understanding of context of the occurrence, improving access to health care utilization, and identifying the role of psychosocial factors and family relationship, is needed for the prevention and management of NSSI.Published versio