Abstract Tea is an economically important plant characterized by a large genome, high heterozygosity, and high species diversity. In this study, we assemble a 3.26-Gb high-quality chromosome-scale genome for the ‘Longjing 43’ cultivar of Camellia sinensis var. sinensis . Genomic resequencing of 139 tea accessions from around the world is used to investigate the evolution and phylogenetic relationships of tea accessions. We find that hybridization has increased the heterozygosity and wide-ranging gene flow among tea populations with the spread of tea cultivation. Population genetic and transcriptomic analyses reveal that during domestication, selection for disease resistance and flavor in C. sinensis var. sinensis populations has been stronger than that in C. sinensis var. assamica populations. This study provides resources for marker-assisted breeding of tea and sets the foundation for further research on tea genetics and evolution.
Nitric oxide (NO) and hydrogen peroxide (H2O2) are essential signaling molecules with key roles in auxin induced adventitious root formation in many plants. However, whether they are the sole determinants for adventitious root formation is worth further study. In this study, endogenous NO and H2O2 were monitored in tea cutting with or without indole-3-butyric acid (IBA) treatment by using the fluorescent probes diaminofluorescein diacetate (DAF-2DA) and 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA), respectively. The overproduction of NO and H2O2 was detected in the rooting parts of tea cuttings treated with or without IBA. But little NO and H2O2 was detected before the initiation phase of tea cuttings even with IBA treatment indicating that they might be not directly induced by IBA. Further carbon and nitrogen analysis found that the overproduction of NO and H2O2 were coincident with the consumption of soluble sugars and the assimilation of nitrogen. These results suggest that rooting phases should be taken into consideration with the hypothesis that auxin induces adventitious root formation via NO- and H2O2-dependent pathways and sink establishment might be a prerequisite for NO and H2O2 mediated adventitious root formation.
Abstract Selection signatures that contribute to phenotypic diversity, especially morphogenesis in pigs, remain to be further elucidated. To reveal the regulatory role of genetic variations in phenotypic differences between Eastern and Western pig breeds, we performed a systematic analysis based on seven high-quality de novo assembled genomes, 1,081 resequencing data representing 78 domestic breeds, 162 methylomes, and 162 transcriptomes of skeletal muscle from Tongcheng (Eastern) and Landrace (Western) pigs at 27 developmental stages. Selective sweep uncovers different genetic architectures behind divergent selection directions for the Eastern and Western breeds. Notably, two loci showed functional alterations by almost fixed missense mutations. By integrating time-course transcriptome and methylome, we revealed differences in developmental timing during myogenesis between Eastern and Western breeds. Genetic variants under artificial selection have critical regulatory effects on progression patterns of heterochronic genes like GHSR and BDH1 , by the interaction of local DNA methylation status, particularly during embryonic development. Altogether, our work not only provides valuable resources for understanding pig complex traits, but also contributes to human biomedical research.
In the 2006-2007,the xylem of root and stem of Pinus tabulaeformis,Pinus sylvestris,Picea meyeri,Picea wilsonii were soluted with the liquid of nitric acid-chromium acid and observated.The result:In the Pinus tabulaeformis and Pinus sylvestris,the vessel elements is exist,there is a pit or a perforation(or The compound bore hole ) on the horizontal wall of the vessel elements;In Picea meyeri,Picea wilsonii,the vessel were did not discover,only there is the bordered pit in the horizontal wall of the parts of the tracheids. It's the transfered type in the center of tracheid to vessel element probably.In addition,all of the four plants,there are fibertracheids and some tipycal fibers.
Despite the worldwide consumption and high economic importance of tea, the plant (Camellia sinensis) is not well studied in molecular biology. Under the few circumstances in which the plant is studied, C. sinensis flowers, which are important for reproduction and cross-breeding, receive less emphasis than investigation of its leaves or roots. Using high-throughput Illumina RNA sequencing, we analyzed a C. sinensis floral transcriptome, and 26.9 million clean reads were assembled into 75,531 unigenes averaging 402 bp. Among them, 50,792 (67.2%) unigenes were annotated with a BLAST search against the NCBI Non-Redundant (NR) database and 10,290 (16.67%) were detected that contained one or more simple sequence repeats (SSRs). From these SSR-containing sequences, 2,439 candidate SSR markers were developed and 720 were experimentally tested, validating 431 (59.9%) novel polymorphic SSR markers for C. sinensis. Then, a consensus SSR-based linkage map was constructed that covered 1,156.9 cM with 237 SSR markers distributed in 15 linkage groups. Both transcriptome information and the genetic map of C. sinensis presented here offer a valuable foundation for molecular biology investigations such as functional gene isolation, quantitative trait loci mapping, and marker-assisted selection breeding in this important species.
Induction on direct rooting of tea tissue culture microshoots with different levels of phytohormone was expermented in greenhouse.We screened out the optimum levels of hormone,analyzed the dynamics of the percentage of rooted seedlings under different hormone levels,and established the technology of direct rooting of tea microshoots in greenhouse.The results showed that the surviving rate of seedlings was 66.7%,the rooting rate was 60%,about 90% of those survived seedlings,the average amounts of root was 9.4,and the length was 3.64 cm at the 70th day after instantaneous dipping treatment of 100 mg/L IBA.This technology might be developed for commercial application of tea tissue culture procedure and the industrialized incubation of tea seedlings.
Objective
To study the incidence of chromosomal abnormalities in the umbilical cord blood, and analyze the number and structure and chromosome poly-morphism of the cord blood.
Methods
Umbilical cord blood was collected for lymphocyte culture, conventional G-banding and karyotype analysis.
Results
15 500 cases of umbilical cord blood samples were detected, of which 314 cases were abnormal karyotypes, the rate was 2.03%.Chromosomal inversions of children were 220, the percentage in population was 1.42%, the constituent ratio was 70.10%.Chromosomal translocations samples were 41, the percentage in population was 0.26%, the constituent ratio was 13.00%.Chromosome-derived samples were 14, the percentage in population was 0.09%, the constituent ratio was 4.51%.Children with 21-Down Syndrome samples were 12, the percentage in population was 0.08%, the constituent ratio was 3.80%.Children with displaced robertson were 11, the percentage in population was 0.08%, the constituent ratio was 3.50%.In sex chromosome abnormalities, 47, XXX were 5, 47, XXY were 7, 45, X were 4, the percentage in population was 0.10%, the constituent ratio was 5.10%.Children with chromosomal polymorphism were 317, the percentage in population was 2.04%.Compared with the other groups, the chromosomal inversions group′ proportion and constituent ratio were significantly different (χ2=11.53, 15.98; P 0.05), the incidence of abnormal natural of each group was closer.
Conclusions
Karyotype analysis of neonatal umbilical cord blood is a very useful to the insufficient prenatal diagnosis, and important for secondary prevention, fertility and clinical guidlines.
Key words:
Infant, newborn; Fetal blood; Karyotyping; Chromosome aberrations
The effect of different hormone on proliferation and growth of tea tissue culture seedlings were investigated,and an optimal culture medium of MS + BA 2.0 + NAA 0.1 + GA3 3.0 mg/L was screened out.On this optimal medium,the proliferation rate of tea cultured buds was 2.75 times after 30's incubation.And more than 20% of those buds could developed to seedlings higher than 5 cm.
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