陆地棉86-1(G.hirsutum L.)与辣根棉(G. armourianum Kearn.)种间杂种及其利用的研究

陆地棉品种86-1 G.hirsutum L.×辣根棉C.armourianum Kearn.F_1染色体2n=3x=39,平均染色体构型为14.051+12.45Ⅱ+0.01Ⅲ。F_1直接与陆地棉回交,得到的BC_1F_1是一株混倍体(mixploid),其染色体为54—67个,其中2n=65的整倍体(euploid)只占15.7％,非整倍体(aneuploid)占82.8％,平均2n=61,平均染色体构型为7.741+25.83Ⅱ+0.45Ⅲ+0.06Ⅳ+0V+0.01Ⅵ。又以BC_1F_1为母本,与陆地棉二次回交,BC_2F_1苗期夭折;而以陆地棉为母本、BC_1F_1为父本回交的BC_2F_1生长健壮,有些辣根棉性状继续传递。通过多年选育已获得一些结铃性强、中长绒纤维高品质、高衣分的新材料。

陆地棉（G．hirsutumL．）茎尖分生组织培养及其在基因导入上的应用

陆地棉栽培品种的种子无菌发芽１～３天。将萌动种子的顶端分生组织培养在无激素或附加低浓度激素ＭＳ基本培养基上，直接再生完整小植株。从顶端分生组织到再生植株所需的最短培养时间约１０天。顶端分生组织供体种芽的萌芽天数及其所连接的胚轴长度对植株再生频率有明显影响，但与品种的关系较小，不同品种均能获得再生植株。应用基因枪轰击法将ＣＰＴⅠ基因和ＮＰＴⅡ基因的重组质粒导入到棉花茎尖分生组织，培养获得卡那霉素抗性株。

Introgression of Gossypium klotzschianum Genome into Cultivated Cotton,G.hirsutum

Exotic Gossypium germplasm is a rich source of useful agronomic traits for improvement programs of cultivated cotton.Efficient use of genetic variation available in the wild relatives depends

Genetic Variations and Cultivar Purity within the G. <i>hirsutum</i>Cultivars via RAPD Marker

To assess genetic variation within a cultivar, four commercial varieties with five individual G. hirsutum genotypes and their bulk were assayed with selected forty 10-mer RAPDs per cultivar via PCR. CIM-473 cultivar showed amplification of 321 bands in total per primer with an average of 8 bands. A range of similarity i.e.;80% - 100% within the cultivar has been observed for minimum and maximum respectively. CIM-448 showed amplification of 300 bands in total per primer with an average of 7.5 bands. Maximum similarity of 95% and minimum similarity of 84% was observed within the cultivar. In CIM-1100 the total numbers of fragments amplified are 304, with the average of 7.6 bands per primer and are 12% - 20% polymorphic. Similarly, in NIAB-78 the total numbers of fragments amplified were 310, with the average of 7.7 bands per primer. The reliability of RAPD technique for finding genetic resemblances is indicated by the mentioned results. Numerous groups within 5 individual genotypes bulk among 4 cultivars of G. hirsutum L. have been through cluster analysis which was by the unweighted pair group method of arithmetic means (UPGMA). Dendrograms have been used for showing cultivar relationship.

Genomic Differentiation Between Gossypium barbadense and G.hirsutum

Sea Island cotton(Gossypium barbadense L.) has superior fiber quality properties,while Upland cotton(G.hirsutum L.) is characterized by its high yield.Although these two species are

Mapping of QTL for Fiber Length Using Interspecific Gossypium hirsutum × G.barbadense F_2 Population

Cotton occupies a pre-eminent place among cash crops as it guides the destiny of a large section of the farming community as well as that of a flourishing textile industry.As the yarn manufacturing industry has undergone a technological revolution,more emphasis is given to quality of the raw

Genome wide identification and characterization of light-harvesting Chloro a/b binding(LHC)genes reveals their potential role in enhancing drought tolerance in Gossypium hirsutum

Background: Cotton is an important commercial crop for being a valuable source of natural fiber.Its production has undergone a sharp decline because of abiotic stresses,etc.Drought is one of the major abiotic stress causing significant yield losses in cotton.However,plants have evolved self-defense mechanisms to cope abiotic factors like drought,salt,cold,etc.The evolution of stress responsive transcription factors such as the trihelix,a nodule-inception-like protein(NLP),and the late embryogenesis abundant proteins have shown positive response in the resistance improvement to several abiotic stresses.Results: Genome wide identification and characterization of the effects of Light-Harvesting Chloro a/b binding(LHC)genes were carried out in cotton under drought stress conditions.A hundred and nine proteins encoded by the LHC genes were found in the cotton genome,with 55,27,and 27 genes found to be distributed in Gossypium hirsutum,G.arboreum,and G.raimondii,respectively.The proteins encoded by the genes were unevenly distributed on various chromosomes.The Ka/Ks(Non-synonymous substitution rate/Synonymous substitution rate)values were less than one,an indication of negative selection of the gene family.Differential expressions of genes showed that majority of the genes are being highly upregulated in the roots as compared with leaves and stem tissues.Most genes were found to be highly expressed in MR-85,a relative drought tolerant germplasm.Conclusion: The results provide proofs of the possible role of the LHC genes in improving drought stress tolerance,and can be explored by cotton breeders in releasing a more drought tolerant cotton varieties.

Study on the Stability of World Diversity of Cultured Species <i>G. hirsutum</i>L. to Salination

The paper presents the results of a study of salt tolerance in some different eco-geographical samples of the cotton germplasm collection of the Institute of Genetics and Experimental Biology of the Academy of Sciences of the Republic of Uzbekistan. According to the results obtained, the studied samples were divided into several groups depending on their salt tolerance. Salt tolerant and unstable samples were found in all studied ecological and geographical groups, but differed in the frequency of distribution.

Development of glyphosate-tolerant transgenic cotton plants harboring the G2-aroA gene

Given that glyphosate weed control is an effective strategy to reduce costs and improve economic outcomes of agricultural production in China,the development of glyphosate-resistant cotton holds great promise.Using an Agrobacterium-mediated transformation method,a new G2-aroA gene that encodes 5-enolpyruvylshikimate-3-phosphate synthase（EPSPS）was transformed into cotton cultivar K312.The transgenic cotton plants were regenerated from a callus tissue culture via kanamycin selection.Ten regenerated cotton plants were obtained and allowed to flower normally to produce fruit.The results from polymerase chain reaction（PCR）and Southern and Western blot analyses indicated that the target gene was integrated into the cotton chromosome and was expressed effectively at the protein level.The glyphosate tolerance analysis showed that the transgenic cotton had a high resistance to glyphosate.Further,even cotton treated with 45.0 mmol L^–1 of glyphosate was able to slowly grow,bloom and seed.The transgenic cotton may be used for cotton breeding research of glyphosate-tolerant cotton.

GhAlaRP, a cotton alanine rich protein gene, involves in fiber elongation process

Fiber length is one of the most important quality parameters of cotton fibers.Transcriptomic analyses of developing cotton fibers have identified genes preferentially expressing in fiber elongation stage,but few have been functionally characterized.Here,on the basis of confirmation of the preferential expression profile of GhAlaRP(Gh_A09G1166 and Gh_D09G1172),an alanine rich protein gene,in the rapid elongating fibers,we investigated the role of GhAlaRP in fiber development by generating transgenic cottons with an increased or decreased expression level of GhAlaRP.Our results showed that the fiber length was consistently significantly shorter in both the GhAlaRP-RNAi lines and the alarp mutant generated by genome editing than in the control YZ-1.GhAlaRP was localized on plasma membrane,nucleus and endoplasmic reticulum.The yeast two-hybrid assay and bimolecular fluorescence complementation assay showed that GhAlaRP co-expresses and interacts with GhAnnexin(Gh_D11G2184)and GhEXPA(Gh_A10G2323)that are involved in fiber elongation.Down-regulation of GhAlaRP co-suppressed the expression levels of GhAnnexin and GhEXPA.These results suggest a role of GhAlaRP in regulation of cotton fiber elongation,which could be achieved by regulating the functions of GhAnnexin and GhEXPA.

A genome-wide identification of the BLH gene family reveals BLH1 involved in cotton fiber development

Background:Cotton is the world’s largest and most important source of renewable natural fiber.BEL1-like homeodomain(BLH)genes are ubiquitous in plants and have been reported to contribute to plant development.However,there is no comprehensive characterization of this gene family in cotton.In this study,32,16,and 18 BLH genes were identified from the G.hirsutum,G.arboreum,and G.raimondii genome,respectively.In addition,we also studied the phylogenetic relationships,chromosomal location,gene structure,and gene expression patterns of the BLH genes.Results:The results indicated that these BLH proteins were divided into seven distinct groups by phylogenetic analysis.Among them,25 members were assigned to 15 chromosomes.Furthermore,gene structure,chromosomal location,conserved motifs,and expression level of BLH genes were investigated in G.hirsutum.Expression profiles analysis showed that four genes(GhBLH1_3,GhBLH1_4,GhBLH1_5,and GhBLH1_6)from BLH1 subfamily were highly expressed during the fiber cell elongation period.The expression levels of these genes were significantly induced by gibberellic acid and brassinosteroid,but not auxin.Exogenous application of gibberellic acid significantly enhanced GhBLH1_3,GhBLH1_4,and GhBLH1_5 transcripts.Expression levels of GhBLH1_3 and GhBLH1_4 genes were significantly increased under brassinosteroid treatment.Conclusions:The BLH gene family plays a very important role in many biological processes during plant growth and development.This study deepens our understanding of the role of the GhBLH1 gene involved in fiber development and will help us in breeding better cotton varieties in the future.

Characterization of a Novel RING-Type Ubiquitin E3 Ligase GhRING2 Differentially Expressed in Cotton Fiber

The ubiquitin-proteasome proteolysis pathway is responsible for the degradation of abnormal and short-lived proteins to regulate many important biochemical activities in eukaryotes. By employing affymetrix microarray analysis, we have identified a novel ubiquitin ligase E3 gene GhRING2 that is differentially expressed between two Gossypium hirsutum lines-Texas Marker-1 (TM-1) and Chromosome Substitution Line CS-B25. The CS-B25 line has chromosome 25 from G. barbadense substituted into TM-1. The complete nucleotide sequences of GhRING2 along with its 5’-flanking region were obtained by genomic walking. GhRING2 was highly expressed in elongating fiber, and GUS expression directed by the GhRING2 promoter was found in hypocotyls and young stems of transgenic Arabidopsis plants. Using a yeast two-hybrid assay GhRING2 was found to interact with a PROTODERMAL FACTOR1 (GhPDF1) protein. GhPDF1 was expressed preferentially in immature ovules and fiber initials, and the GhPDF1 gene had been suggested to play a role in cell fate determination and fiber development. Pull down and plasmid swap assays further confirmed the interaction between GhRING2 and GhPDF1. The expression and protein interaction data indicate that GhRING2 may be involved in the turnover of GhPDF1 and participation in the transition from initiation to elongation stages during fiber development. Our data strongly suggest that the ubiquitin-proteasome pathway may regulate cotton fiber growth and development. The nucleotide sequence data of GhRING2 in this article have been submitted to the Gen Bank Nucleotide Sequence Data Bases under the accession number BankIt 1,742,008 SeqKM 108,000.

Application of Gibberellic Acid on Diploid and Tetraploid Cotton Hybridization

Gibberellic acid growth regulator was used to develop interspecific hybrids between tetraploid and diploid species to increase the genetic variability in cotton.In order to retain bolls and seed set in triploid hybrids,emasculated flowers of two Gossypium hirsutum commercial varieties(Sahel and Sephid)

New red flower germplasm lines of cotton selected from hybrid of Gossypium hirsutum × G. bickii

By means of dropping GA3 (50 ppm) and NAA (40 ppm) on the hybrid boll-embryo culture in vitro, one F1 plant of G. hirsutum G. bickii was obtained; when F1 branches were grafted on upland cotton and then back-crossed with upland cotton under short-day and cooler-night condition, some BC1 seeds could be harvested. The characteristic segregation was very violent in early generation. Through 3 times of back-crossing and selecting, ten stable hybrid lines with the character of both male parent (viz. red petal-purple spot and strong fibre) and female par-ent (plant type, earliness, white fibre, lint length, etc. ) were established. These lines were assigned as HB red flow-er lines (HBRL). Transference of character of G. bickii to upland cotton was proved to be successful for the first time. These new germplasms may play an important role in both the genetic research and new cotton variety breeding.

STUDY ON THE INTERSPECIFIC HYBRID OF Gossypium hirsutum×G. bickii AND G. herbaceum×G. bickii

G. bickii an Australian wild species which belongs to G1 genome. It has many desirable charaeteristics, such as resistance to insects （due to its intense hairiness）, high gossypol stalk and gossypol-free seed, very useful for cotton breeding. However, due to difficulty of interspecific hybridization, transference of these characteristics has not yet been reported.

Breeding, introgression and inheritance of delayed gland morphogenesis trait from Gosspium bickii into upland cotton germplasm

A tri-specific hybrid with delayed pigment gland morphogenesis was obtained by crossing the amphi- diploid of (G. arboreum×G. bickii) F1 and an upland cotton germplasm with pigment gland genotype of Gl2Gl2gl3gl3. The tri-specific hybrid was a typical interspecific hybrid with high sterile, and the chromosome configuration at meiosis MI of PMC was 2n = 52 = 41.04Ⅰ+ 4.54Ⅱ + 0.57Ⅲ + 0.04. The crossover value of bivalent was 1.19. Two fertile plants with objective character were obtained in BC8 population by continuously backcrossing with Gl2Gl2gl3gl3 as recurrent parent to the tri-specific hybrid, and a new upland cotton germplasm, named ABH-0318, with delayed pigment gland morphogenesis trait was developed through selfing and screening. The pigment gland trait of ABH-0318 was stable, and there were almost no pigment glands observed in the dormant seeds, although there were a few pigment glands confined to cotyledon edges, and the gossypol content in the dormant seeds was 0.017% only, being a typical low gossypol cotton type. However, a large quantity of pigment glands emerged in cotyledons and other main organs of plant after seed germination, and the gossypol contents in the upper parts of the plant were similar to that of ordinary glanded cotton types. Genetic analysis demonstrated that the delayed pigment gland morphogenesis trait of this germplasm was controlled by the interaction of the genes located in two pig- ment gland loci, Gl2 and Gl3. Among them, the gene located in locus of Gl2, derived from G.bickii, was dominance to up- land cotton pigment gland alleles, Gl2 and gl2 , but was reces- sive epistatic to another glanded gene Gl3, which was named Gl2 temporarily. While the gene located in the locus of Gl3 b was a recessive gene come from upland cotton.

Effects of pigment glands and gossypol on somatic cell culture of upland cotton (Gos-sypium hirsutum L.)

The effects of pigment glands and gossypol on the somatic cell culture of upland cotton were studied, using the materials as follows: three pairs of glanded and gland less upland cotton near isogenic lines, TM-1, and Coker 312. The results showed that the pigment glands and gossypol contents in the explants had great inhibiting effect on the induction and growth of callus in somatic cell culture of upland cotton, and the induction rate of callus and the single callus weight of glandless cotton were much higher than those of their glanded near isogenic lines. It was easier to obtain regeneration plants from glandless cotton than from their glandednear isogenic lines. There was a significant inverse correlation between the gossypol contents in the explants and callus induction rate, with the correlation coefficient of -0.84. The vitro gossypol in the medium had some inhibiting effect on the induction and growth of callus, especially for the gland-less cotton. However, a certain concentration of vitro

Genomic insight into the divergence and adaptive potential of a forgotten landrace G.hirsutum L.purpurascens

Wild progenitors are an excellent source for strengthening the genetic basis and accumulation of desirable variation lost because of directional selection and adaptation in modern cultivars.Here,we re-evaluate a landrace of Gossypium hirsutum,formerly known as Gossypium purpurascens.Our study seeks to understand the genomic structure,variation,and breeding potential of this landrace,providing potential insights into the biogeographic history and genomic changes likely associated with domestication.A core set of accessions,including current varieties,obsolete accessions,G.purpurascens,and other geographical landraces,are subjected to genotyping along with multilocation phenotyping.Population fixation statistics suggests a marked differentiation between G.purpurascens and three other groups,emphasizing the divergent genomic behavior of G.purpurascens.Phylogenetic analysis establishes the primitive nature of G.purpurascens,identifying it as a vital source of functional variation,the inclusion of which in the upland cotton(cultivated G.hirsutum)gene pool may broaden the genetic basis of modern cultivars.Genome-wide association results indicate multiple loci associated with domestication regions corresponding to flowering and fiber quality.Moreover,the conserved nature of G.purpurascens can also provide insights into the evolutionary process of G.hirsutum.

The cytogenetics and fiber properties of an allohexaploid between Gossypium hirsutum and G.somalense

Cytogenetics and fiber properties were studied on the Gossypium hirsutumxG. somalense F2 hybrid and later generations. The cytological analyses of pollen mother cells (PMCs) were made at meiotic metaphase I. The results indicated that the hybrid was a new allohexaploid, its chromosome number determined as 2n=6x=78, and genome group as 2[(AD)1E2]. Chromosomal configurations of the hexaploid averaged 0.15Ⅰ+ 38.72Ⅱ + 0.1Ⅲ + 0.02Ⅳ per cell, 85.09% PMCs having 39 bivalents, and only 11.84% PMCs having 1 to 2 multivalents, indicating that heteroge-netic recombinations of chromosomes occurs between (AD)1 and E2, nevertheless, the frequency is lower. The hexaploids are self-fertile and the progenies remain the hexaploids, whose fibers are light brown and have higher strength by measurement of HVI 900 system. The fiber strength increases 42% than that of upland cotton variety. Therefore, it is possible for the hexaploid to be an important germplasm resource to improve fiber strength of cotton.

陆地棉×比克氏棉育成种质系的同工酶和RAPD分析

为了从分子水平上检验野生棉遗传特性向陆地棉转育的结果以及育成种质之间的遗传差异，通过等电聚焦电泳和RAPD技术，对来自科遗181陆地棉品系与野生比克氏棉杂交后代的6个遗传稳定的不同种质系及其亲本的过氧化物酶同工酶图谱和DNA指纹图谱进行了分析。结果如下：（1） 6个种质系的基本酶谱特征均倾向于陆地棉亲本，但在其中2个种质系的过氧化物酶图谱中，观察到各具有1条等电点值（PI）为4.85的野生亲本的特征带；（2） DNA指纹图谱的分析表明，不同种质系之间在基因组水平上具有高度的异质性。并且在OPO10和OPO11 2个引物的扩增图谱中观察到4个育成种质系具有野生比克氏棉亲本的特征带。