Map-based cloning of q LP_(A01.1),a favorable allele from the Gossypium tomentosum chromosome segment line

Cotton is an important natural fiber crop worldwide which plays a vital role in our daily life.High yield is a constant goal of cotton breeding,and lint percentage(LP)is one of the important components of cotton fiber yield.A stable QTL controlling LP,qLP_(A01.1),was identified on chromosome A01 from Gossypium hirsutum introgressed lines with G.tomentosum chromosome segments in a previous study.To fine-map qLP_(A01.1),an F2 population with 986individuals was established by crossing G.hirsutum cultivar CCRI35 with the chromosome segment substitution line HT_390.A high-resolution genetic map including 47 loci and spanning 56.98 cM was constructed in the QTL region,and qLP_(A01.1)was ultimately mapped into an interval corresponding to an~80 kb genome region of chromosome A01in the reference genome,which contained six annotated genes.Transcriptome data and sequence analysis revealed that S-acyltransferase protein 24(GoPAT24)might be the target gene of qLP_(A01.1).This result provides the basis for cotton fiber yield improvement via marker-assisted selection(MAS)and further studies on the mechanism of cotton fiber development.

Transcriptome Analysis of Molecular Mechanisms Underlying Phenotypic Variation in Phaseolus vulgaris Mutant‘nts’

The phenotype of a common bean plant is often closely related to its yield,and the yield of plants with reduced height or poor stem development during growth is low.Mutants serve as an essential gene resource for common bean breeding genetic research.Although model plants and crops are studied to comprehend the molecular mechanisms and genetic basis of plant phenotypes,the molecular mechanism of phenotypic variation in common beans remains underexplored.We here used the mutant‘nts’as material for transcriptome sequencing analysis.This mutant was obtained through 60Co-γirradiation from the common bean variety‘A18’.Differentially expressed genes were mainly enriched in GO functional entries such as cell wall organization,auxin response and transcription factor activity.Metabolic pathways significantly enriched in KEGG analysis included plant hormone signal transduction pathways,phenylpropanoid biosynthesis pathways,and fructose and mannose metabolic pathways.AUX1(Phvul.001G241500),the gene responsible for auxin transport,may be the key gene for auxin content inhibition.In the plant hormone signal transduction pathway,AUX1 expression was downregulated and auxin transport across the membrane was blocked,resulting in stunted growth of the mutant‘nts’.The results provide important clues for revealing the molecular mechanism of‘nts’phenotype regulation in bean mutants and offer basic materials for breeding beneficial phenotypes of bean varieties.

Review of stopping power and Coulomb explosion for molecular ion in plasmas

We summarize our theoretical studies for stopping power of energetic heavy ion,diatomic molecular ions and small clusters penetrating through plasmas.As a relevant research field for the heavy ion inertial confinement fusion(HICF),we lay the emphasis on the dynamic po-larization and correlation effects of the constituent ion within the molecular ion and cluster for stopping power in order to disclose the role of the vicinage effect on the Coulomb explosion and energy deposition of molecules and clusters in plasma.On the other hand,as a promising scheme for ICF,both a strong laser field and an intense ion beam are used to irradiate a plasma target.So the influence of a strong laser field on stopping power is significant.We discussed a large range of laser and plasma parameters on the coulomb explosion and stopping power for correlated-ion cluster and C 60 cluster.Furthermore,in order to indicate the effects of different cluster types and sizes on the stopping power,a comparison is made for hydrogen and carbon clusters.In addition,the deflection of molecular axis for diatomic molecules during the Coulomb explosion is also given for the cases both in the presence of a laser field and laser free.Finally,a future experimental scheme is put forward to measure molecular ion stopping power in plasmas in Xi’an Jiaotong University of China.

Genetic mapping and identification of Lg^(f) loci controlling green fuzz in Upland cotton(Gossypium hirsutum L.)

Naturally colored cotton fiber is environment-friendly but has monotonous color and poor fiber quality.Identification of green fiber or fuzz genes would aid in investigating the biosynthesis of green pigments in cotton fibers. In this study, we established a mapping population and found that the Lg^(f) trait(white lint and green fuzz) from Gossypium hirsutum race latifolium is controlled by an incompletely dominant gene.The Lg^(f) locus was mapped to a 71-kb interval on chromosome 21 containing seven genes, including a transcription factor with similarity to Arabidopsis MYB9. Harboring 13 SNPs and a 4-bp insertion/deletion in its promoter, GhMYB9 was highly up-regulated in the critical period for green pigment development in fuzz. Virus-induced gene silencing of GhMYB9 in a green-fuzz accession of G. hirsutum race latifolium TX-41 conferred white or light green fuzz. These results suggest that GhMYB9 is an important contributor to green pigments in cotton fiber and shed light on the regulatory mechanism controlling green pigmentation.