Polyploidization is a key pathway for species formation and genetic innovation; approximately 70% of angiosperms have undergone at least one whole-genome duplication event during their evolutionary history. To determine the genetic and phenotypic stability of artificially induced autotetraploids across generations, this study utilized a colchicine-induced autotetraploid of Gossypium herbaceum as experimental material and conducted systematic comparative analyses of morphological, cytological, and molecular marker characteristics in the S3 and S4 generations. The results showed that, compared with the 2 & times;, seed weight in the S3 generation increased by 59.4% (to 89.22 mg), and in the S4 generation increased by 65.0% (to 92.40 mg), while there was no significant difference in fiber length. The leaf area of tetraploids decreased significantly during the flower-bell stage. Observation of pollen mother cell meiosis revealed that the proportions of normal tetrads in the S3 and S4 generations were 73.80% and 81.80%, respectively, and the proportions of normal pollen grains were 79.60% and 80.60%, respectively. Cytological stability was markedly improved in the S4 generation. A total of 34 alleles were amplified by SSR molecular marker analysis, of which 23 (67.60%) were polymorphic. The primers NBRI_G1015 and NAU1164 exhibited the highest polymorphism rates, at 87.50% and 83.30%, respectively. The average genetic diversity index (He) was 0.1411, indicating a highly inbred genetic background. The banding patterns of S3 and S4 are highly consistent, with strong signal intensity; not only do they amplify bands consistent with those of diploids, but they also exhibit specific new bands and band deletions. In summary, this autotetraploid material exhibits stable morphological advantages and genetic uniformity. As generations progress, its meiotic behavior and genetic structure tend to stabilize. The S4 generation exhibits greater cytological stability and genetic uniformity than the S3 generation, making it a highly promising new germplasm resource for cotton polyploid breeding.

Background: Information on the autopolyploid of Gossypium herbaceum remains limited until now. Previously, the autotetraploid of G. herbaceum was successfully generated via colchicine-induced chromosome doubling from the diploid cultivar 'Hongxing' in our lab. Methods: To investigate the drought stress response mechanism of this tetraploid, the autotetraploid S4 was used as the experimental material. The plants were subjected to drought stress during the flowering stage, followed by measurements of physiological and biochemical indicators and transcriptomic sequencing analysis. Results: Under drought stress, MDA content increased, and cell membranes sustained oxidative damage. Photosynthetic parameters, such as net photosynthetic rate (Pn), were significantly suppressed, while the activity of osmotic regulators and key antioxidant enzymes increased significantly. After rehydration, all of the above physiological indicators showed varying degrees of recovery. Transcriptome analysis revealed that, when comparing the treatment group with the control group, a total of 5530 differentially expressed genes (DEGs) were identified, with 2714 up-regulated and 2816 down-regulated. Furthermore, this study investigated the drought resistance mechanism involving the interaction between the MAPK signaling pathway and other metabolic pathways in the autotetraploid. Nine drought-resistant genes, including MAPK3, bHLH47, GaRbohD, RIBA1, PIP1-3, RCA1, RbohD, CYP707A and HSP70, were selected and analyzed using real-time quantitative PCR; the results were generally consistent with the transcriptomic data. Conclusions: These findings substantially enhance our understanding of the molecular mechanisms underlying drought responses in autotetraploids. This novel autotetraploid genotype expands the available cotton germplasm resources and is expected to hold significant value for research on polyploidy evolution.

The molecular mechanism of cleistogamy in foxtail millet was analyzed. We found that changes of cell wall components caused the abnormal development of the lodicule. Outcrossing between cultivated crops and their associated wild species may result in the loss of favorable agricultural traits in the progeny or the drift of genetically modified (GM) organisms in future generations. In this study, we found a cleistogamy mutant with an abnormal development of the lodicules. The lodicules were sampled when the florets just to bloom for RNA-seq analysis. Our results showed that, compared with the wild type, the mutant had more enriched pathways related to cell wall synthesis or decomposition. Staining of the lodicule cell wall showed that the mutant had relatively lower amounts of callose and cellulose than the wild type. The content of pectin methylation in the lodicule cell wall of the mutant was lower than that of the wild type. In summary, we analyzed the causes of cleistogamy phenotype in foxtail millet. Transcriptome data analysis revealed that this was probably caused by dysplasia of the lodicule cell wall. Cytochemical staining and immunofluorescence tests showed that the changes of the components in the cell wall caused the abnormal development of the lodicule. Overall, this study sheds light on the potential molecular mechanism of cleistogamy of foxtail millet and provides a theoretical basis for subsequent research.

Abiotic stress has been a great challenge to global food security. To reduce its effects, breeding crops for tolerance to abiotic stresses is a promising strategy. Broomcorn millet is cultivated in arid and semiarid areas with a high degree of abiotic stress tolerance. However, due to the lack of efficient genetic transformation methods for broomcorn millet, the characterization of genes related to abiotic stress tolerance lags behind that of other crop species. Therefore, establishing efficient in vitro regeneration and genetic transformation methods for broomcorn millet is essential. In this study, we used mature seeds of the sequenced variety ‘Longmi 4’ as explants and optimized its in vitro regeneration and genetic transformation methods. The optimal hormone concentrations for embryogenic callus induction medium were 2.5 mg/L 2,4-dichlorophenoxyacetic and 0.5 mg/L 6-benzylaminopurine. The optimal hormone concentrations for shoot regeneration medium were 2 mg/L 6-benzylaminopurine and 0.5 mg/L a-naphthaleneacetic acid. Additionally, the co-cultivation time was 3 days, and the optimal hygromycin concentration for putative transgenic callus selection was 20 mg/L. The transformation efficiency was 21.25

The role of the human microbiome in cancer has been extensively studied, focusing mainly on bacteria-host interactions and their impact on tumor development and treatment response. However, fungi, an immune-active component of the human microbiome, have received less attention regarding their roles in cancer. Recent studies have identified the widespread and specific colonization and distribution of fungi in multiple sites in patients across various cancer types. Importantly, host-fungal immune interactions significantly influence immune regulation within the tumor microenvironment. The rapid advancement of immune-checkpoint blockade (ICB)-based cancer immunotherapy creates an urgent need for effective biomarkers and synergistic therapeutic targets. Cancer-associated fungi and their associated antifungal immunity demonstrate significant potential and efficacy in enhancing cancer immunotherapy. This review summarizes and discusses the growing evidence of the functions and mechanisms of commensal and pathogenic cancer-associated fungi in cancer immunotherapy. Additionally, we emphasize the potential of fungi as predictive biomarkers and therapeutic targets in cancer immunotherapy.

In sorghum [ Sorghum bicolor (L.) Moench], combining ability and heterosis analysis are commonly used to evaluate superior parental lines and to screen for strongly heterotic hybrids, which helps in sorghum variety selection and breeding. In this context, combining ability and heterosis analysis were assessed using 14 restorer lines and seven cytoplasmic male sterile (CMS) lines in 2019 and 2020. The analysis of variance of all cross combinations had highly significant differences for all characters studied, which indicated a wide variation across the parents, lines, testers, and crosses. Combining ability analysis showed that the general combining ability (GCA) and specific combining ability (SCA) of the different parents were differed significantly among different traits. Most combinations with high SCA also showed high GCA in their parent lines. The heritability in the narrow sense of grain weight per panicle and grain yield was relatively low, indicating that the ability of these traits to be directly inherited by offspring was weak, that they were greatly affected by the environment. The better-parent heterosis for plant height, grain weight per panicle, panicle length, and 1000-grain weight was consistent with the order of mid-parent heterosis from strong to weak. The GCA effects of two lines 10480A, 3765A and three testers 0-30R, R111, and JY15R were significant for the majority of the agronomic traits including grain yield and might be used for improving the yield of grains in sorghum as parents of excellent specific combining ability. Seven strongly heterotic F 1 hybrids were screened; of these, hybrids 3765A × R111, 1102A × L2R, and 3765A × JY15R showed significant increases in seed iristectorigenin A content and will feature into the creation of new sorghum varieties rich in iristectorigenin A.

Distant hybridization and polyploidy is an important way for cotton germplasm innovation, and it may provide theoretical evidence and new materials by distantly hybridizing G. gossypioides with G. hirsutum and then chromosome doubling to use the excellent genes of G.gossypioides and to broaden the genetic diversity of G. hirsutum. In this study, we obtained allohexaploid cotton by synthesizing the female parent G. hirsutum with the male parent G. gossypioides, following with chromosome doubling by colchicine. And then we examined the morphology（leaf phenotype）, cytology（stomatal density, stomatal length, chloroplasts number in guard cell pairs, and pollen grain diameter）, and physiological and biochemical indexes（SOD, POD, CAT, soluble protein and chlorophyll fluorescence parameters of the hexaploid）. Three hexaploid plants were selected by flow cytometric identification. The statistical results of hexaploid, triploid and parental traits showed that there was not significant difference for the leaf shape index between hexaploid and G. hirsutum, indicating that the leaf shape of hexaploid was overall preferring to G. hirsutum, while the triploid distant hybrid was more inclined to paternal cotton G. gossypioides. The leaf area and stomatal length of hexaploid increased, and the number of chloroplasts in the guard cells significantly increased. The flower phenotypic traits of hexaploid were intermediate between two parents, but the pollen grain diameter of hexaploid was greater than the triploid, with the normal pollen grain ratio of 73.25% for hexaploid and of 51.13% for triploid, indicating the fertility recovering of hexaploid. The content of SOD, POD, CAT and soluble protein in hexaploid leaves were significantly greater than the other generations. There were significant differences in the initial fluorescence Fo,leaf variable fluorescence Fv, primary light energy conversion efficiency（Fv/Fm）, PS II potential photochemical efficiency（Fv/Fo）and open PS II capture excitation energy efficiency（Fm/Fo）between hexaploid and other generations. The overall results proved that the new germplasm of hexaploid between G. hirsutum and G. gossypioides were successfully synthesized by hybridization and chromosome doubling in our study, and it was tested that hexaploid has excellent performances superior to triploid especially in stress resistance and photosynthesis.

Sorghum bicolor (L.) is one of the oldest crops cultivated by human beings which has been used in food and wine making. To understand the genetic diversity of sorghum breeding resources and further guide molecular-marker-assisted breeding, six yield-related traits were analyzed for 214 sorghum germplasm from all over the world, and 2,811,016 single-nucleotide polymorphisms (SNPs) markers were produced by resequencing these germplasms. After controlling Q and K, QTLs were found to be related to the traits using three algorisms. Interestingly, an important QTL was found which may affect multiple traits in this study. It was the most likely candidate gene for the gene SORBI_3008G116500, which was a homolog of Arabidopsis thaliana gene-VIP5 found by analyzing the annotation of the gene in the LD block. The haplotype analysis showed that the SORBI_3008G116500hap3 was the elite haplotype, and it only existed in Chinese germplasms. The traits were proven to be more associated with the SNPs of the SORBI_3008G116500 promoter through gene association studies. Overall, the QTLs and the genes identified in this study would benefit molecular-assisted yield breeding in sorghum.

Abstract Background Heterosis has been widely used for breeding high-yield crops, changes crop breeding and agricultural production by increasing yield. Transcriptome profiles of sorghum spikes in hybrid Jinnuo 3 and its parents 10480A and L17R were performed by RNA sequencing technology at secondary branch and spikelet differentiation period. Results During above two differentiation period, there were 2,641 and 2,175 differentially expressed genes (DEGs) between Jinnuo 3 and 10480A, respectively. Meanwhile, there were 1,387 and 1,094 DEGs between Jinnuo 3 and L17R, respectively. These indicated that massive DEGs were existed between hybird and its parents, and a more similar expression pattern was presented between hybrid and male parent. Gene expression inheritance analysis showed that most of genes were expressed additively, suggesting that the complementary effect may play a foundation role in sorghum spike heterosis. Among non-additive expression genes, L17R-dominant genes were predominant, indicating that male parent may provide beneficial alleles with great contribution to heterosis. GO and KEGG analysis suggested that metabolic pathways, such as photosynthetic antenna protein, photosynthesis, carbon fixation in photosynthetic organisms, amino acid metabolism, glycolysis, and endoplasmic reticulum protein processing, would participate in yield heterosis formation in hybrid Jinnuo 3. Further analysis showed that photosynthesis-related genes PsbW, PsbR, Lhca2, Lhcb1 and LAX3, spike structure development-related genes MADS1, MADS7, MADS16 and MADS55, as well as stress resistance-related genes WRKY14, WRKY35, HSFB2C and HSP70, might play an important role in yield heterosis formation in hybrid Jinnuo 3. Conclusion Hybrids Jinnuo 3 increased yield by simultaneously increasing source (photosynthetic efficiency-related genes), library (spike development-related genes), and resistance (inresistance-related genes). This molecular mechanism could provide new clues for sorghum heterosis utilization and high-yield breeding.

[目的]多倍化是植物进化及新物种形成的重要途径,利用染色体加倍之后基因的剂量效应及多倍体优势,培育出综合性状优良的草棉同源四倍体新种质,有效拓宽棉花种质资源.[方法]以草棉同源多倍体后代S1和S2为材料,利用流式细胞仪鉴定倍性,对同源四倍体进行形态学、细胞学和生理生化指标鉴定.[结果]倍性鉴定表明,5株S1中有1株三倍体和4株四倍体,7株S2中有1株非整倍体和6株四倍体.在植株形态、叶片性状、花的表型、气孔性状等方面,S2较S1更稳定.细胞学鉴定结果表明,S2正常四分体(85.17％)和正常花粉粒(87.33％)的比例较S1都有所提高,说明同源四倍体减数分裂逐渐趋于正常.S2叶片中超氧化物歧化酶、过氧化物酶和过氧化氢酶的活性以及丙二醛、可溶性蛋白、可溶性糖、脯氨酸和叶绿素的含量均高于S1及其二倍体亲本.在结实率、种子大小和纤维长度方面,S2优于S1.[结论]通过染色体加倍成功合成了草棉同源四倍体新种质,S2较S1表现出更强的多倍体优势,且育性于S2代趋于稳定.

多倍化是物种形成及植物育种的重要途径.以实验室前期合成的草棉同源多倍体后代S1为材料,对其进行流式细胞术、形态学、细胞学和SRAP分子标记鉴定.流式细胞倍性鉴定表明,以二倍体的荧光峰值作为参照,8株后代中有5株三倍体和3株四倍体.形态学鉴定表明,二倍体表现为株高、茎细、叶薄、叶片较小、叶色翠绿、花朵较小,三倍体和四倍体则表现为植株矮小、茎秆粗壮、叶片增厚和皱缩、叶片较大、叶色浓绿、花朵较大.细胞学鉴定表明,随着倍性的增加,气孔密度呈下降趋势,而气孔长度、叶绿体数和花粉粒直径均呈上升趋势;二、三和四倍体草棉在花粉母细胞减数分裂过程中均出现正常和异常行为,包括单分体(0.17％,2.50％和2.17％)、二分体(0.33％,0.67％和0)、三分体(4.17％,10.00％和2.33％)、正常四分体(94.83％,54.00％和73.67％)、异常四分体(0.17％,0.33％和0.83％)和多分体(0.33％,32.50％和21.00％);异常多分体均不能形成正常花粉粒,所以三者的正常花粉粒所占比例分别为95.33％、58.83％和77.67％.SRAP分子标记鉴定表明,三倍体和四倍体不仅扩增出与二倍体完全一致的条带,还出现了条带的缺失与新的特异性条带,其中三倍体的遗传比例分别为80.81％、6.73％和12.46％,四倍体的遗传比例分别为76.59％、10.37％和13.04％,从分子水平证明了多倍体的真实性.

通过转录组测序筛选草棉同源多倍体与二倍体相比差异表达基因,为同源多倍体的表型变化及其染色体加倍过程中遗传物质的变化提供基因表达水平的依据.本研究以草棉二倍体(CK)和同源多倍体后代为材料,通过流式细胞仪鉴定出同源三倍体(T)和同源四倍体(M)植株,比较同源四倍体与二倍体的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、脯氨酸和可溶性蛋白含量生理指标,并进行转录组测序分析.草棉同源四倍体叶片的SOD、POD、CAT、脯氨酸和可溶性蛋白含量均显著高于二倍体.DESeq差异分析结果表明,CK vs T、T vs M、CK vs M分别有4166(2832个上调,1334个下调)、4037(1766个上调,2271个下调)、4184(2679个上调,1505个下调)个DEGs,有205个DEGs是不同倍性植株两两比较的3组间共同表达的.GO功能分析表明,DEGs在膜的固有成分、膜的组成部分、催化活性等途径差异显著.KEGG富集分析表明,DEGs在类黄酮生物合成、苯丙烷生物合成、光合作用-天线蛋白等通路较为活跃.通过富集分析筛选CK vs T和CK vs M中与倍性相关的DEGs发现,多倍体在应激反应(62.46％和54.84％)、逆境反应(57.42％和53.85％)、细胞(70.16％和66.22％)、代谢(72.73％和66.14％)、生物活性物质和抗性(60.33％和63.37％)、光合(58.06％和63.16％)等方面的差异基因大都是上调表达,这可能是导致多倍体优势的关键因子.Nr注释信息CK vs M中共获得27个与抗性相关的基因(19个上调,8个下调),11个与光合相关的基因(9个上调,2个下调).对不同倍性草棉与光合相关的27个DEGs进行聚类分析发现,18个(66.67％)基因在四倍体中表达丰度最高.对3组间共同表达的205个DEGs进行Nr注释和表达情况分析发现,有30个基因都表现为上调表达,且在四倍体中表达量最高,7个基因都表现为下调表达,且在四倍体中表达量最低,这37个基因可能是受DNA剂量影响或是与植株倍性相关的基因.研究结果进一步表明多倍体植株在抗性、生长势、新陈代谢以及光合速率方面均优于二倍体.

Nitrogen (N) fertilizer application is essential for crop-plant growth and development. Identifying genetic loci associated with N-use efficiency (NUE) could increase wheat yields and reduce environmental pollution caused by overfertilization. We subjected a panel of 389 wheat accessions to N and chlorate (a nitrate analog) treatments to identify quantitative trait loci (QTL) controlling NUE-associated traits at the wheat seedling stage. Genotyping the panel with a 660K single-nucleotide polymorphism (SNP) array, we identified 397 SNPs associated with N-sensitivity index and chlorate inhibition rate. These SNPs were merged into 49 QTL, of which eight were multi-environment stable QTL and 27 were located near previously reported QTL. A set of 135 candidate genes near the 49 QTL included TaBOX (F-box family protein) and TaERF (ethylene-responsive transcription factor). A Tabox mutant was more sensitive to low-N stress than the wild-type plant. We developed two functional markers for Hap 1, the favorable allele of TaBOX.

[目的]稀有冷诱导2(RCI2)基因,又称为质膜蛋白3(PMP3)基因,编码一类小分子量的跨膜蛋白质,在植物生长发育和非生物胁迫应答中发挥重要调控作用.本文旨在研究棉花中RCI2基因的特征与表达模式,为进一步了解该基因在棉花中的功能提供理论支持.[方法]本文通过生物信息学方法,对陆地棉、海岛棉、亚洲棉和雷蒙德氏棉4个棉种中RCI2家族基因特征、亚细胞定位、系统进化、启动子顺式元件和非生物胁迫应答模式进行系统分析.[结果]分别从陆地棉、海岛棉、亚洲棉和雷蒙德氏棉基因组中分别筛选到12、12、8、8个RCI2基因,该基因编码的蛋白质仅含有PMP3(PF01679)一个高度保守的结构域.通过进化分析,将棉花中RCI2基因分为3类.顺式作用元件分析结果表明,陆地棉RCI2家族基因的启动子中含有较多的激素响应、胁迫响应和生长发育相关的元件,其中激素响应和胁迫响应的元件数目较多.陆地棉中12个RCI2基因在不同组织器官中表达方式不同,在低温、高温、盐和PEG胁迫下的表达模式也不同.[结论]本研究明确了RCI2基因在棉花基因组中的数量和理化性质,并对该家族的进化和表达特征进行了分析,为进一步研究RCI2基因的作用机理提供了参考,为研究棉花应对非生物胁迫的分子机制提供新的方向.

棉花远缘杂交是种质创新和新品种选育的重要途径.以实验室前期合成的陆地棉与野生斯特提棉远缘杂种为材料,对其进行形态学、细胞遗传学及SSR分子标记鉴定.形态学分别从植株、叶片和花三方面进行了双亲和杂种的分析比较,结果表明杂种植株高于双亲,叶片大于双亲,表现出显著的杂种优势;叶色与父本相近,为翠绿色,杂种花基部花斑与父本相近,为深红色;细胞遗传学上对杂种进行了花粉母细胞减数分裂观察,结果表明不育杂种F1在减数分裂过程中出现许多异常行为,其中二分体占24.00％,三分体占10.40％,四分体占40.60％,多分体占25.00％.在四分体中,正常四分体占72.91％,异常占27.09％,以至于最后形成很多异常花粉粒,所占比例为24.00％,正常花粉粒占76.00％,这是杂种不育的主要原因;最后通过SSR分子标记鉴定结果表明,杂种F1不仅扩增出双亲的互补带,还扩增出双亲没有的特异性条带,遗传成分比例分别为:父本占7.69％,母本占34.62％,双亲的互补带占23.07％,特异性新带占34.62％,既表明在杂交过程中发生了基因重组,也从分子水平证实了该杂种是陆地棉和斯特提棉的真杂种,同时为棉花遗传育种和种质创新提供了有价值的材料.

以亚洲棉为母本,野生种拟似棉为父本进行远缘杂交,人工辅助授粉合成杂种F1,验证F1杂种的真实性,以期进一步加倍成异源四倍体新种质.采用重复授粉和赤霉素保铃等措施提高杂交结铃率,对F1进行形态学及SSR分子标记鉴定.结果表明,F1杂种有典型的合子后生殖隔离现象,植株培养过程中伴随有杂种致死,F1杂种幼苗叶型大部分介于双亲之间且整体偏向于父本拟似棉;SSR分子标记结果显示杂种F1不仅扩增出双亲的互补带,还出现了双亲没有的新带;经过统计分析发现杂种F1中总的遗传成分比例母本占45.91％,父本占40.98％,新出现的组合带占13.11％.从分子水平证明了杂种的真实性,同时伴随的杂交过程也发生了AD基因组互作及遗传重组.

棉属具有丰富的种质资源,将抗病性从野生棉转移到陆地棉中,以此提高陆地棉抗病性是一条理想的育种途经.本研究通过陆地棉和C组野生澳洲棉远缘杂交获得杂种F1,对其进行染色体加倍,将加倍的异源六倍体再与B组野生绿顶棉杂交,产生陆地棉、澳洲棉、绿顶棉的异源四倍体杂种.异源四倍体杂种继承了亲本的部分性状,同时也产生了如蔓生等特异性状;该杂种减数分裂后期染色体不能均等分离,四分体时期有多分体和微核出现;SSR结果发现,该杂种不仅具有三个亲本的特征条带,并且产生了新的重组成分.本研究不仅为该异源四倍体杂种不育提供了直接原因,也为进一步探讨有效的育性恢复方法及棉花新种质创制提供了依据,同时为利用野生棉资源控制棉花黄萎病育种探索培育了中间材料.

Cotton is a significant economic crop that plays an indispensable role in many domains. Gossypium hirsutum L. is the most important fiber crop worldwide and contributes to more than 95% of global cotton production. Identifying stable quantitative trait locus (QTLs) controlling fiber quality and yield related traits are necessary prerequisites for marker-assisted selection (MAS). A genetic linkage map was constructed with 312 simple sequence repeat (SSR) loci and 35 linkage groups using JoinMap 4.0; the map spanned 1 929.9 cM, with an average interval between two markers of 6.19 cM, and covered approximately 43.37% of the cotton genome. A total of 74 QTLs controlling fiber quality and 41 QTLs controlling yield-related traits were identified in 4 segregating generations. These QTLs were distributed across 20 chromosomes and collectively explained 1.01%~27.80% of the observed phenotypic variations. In particular, 35 stable QTLs could be identified in multiple generations, 25 common QTLs were consistent with those in previous studies, and 15 QTL clusters were found in 11 chromosome segments. These studies provide a theoretical basis for improving cotton yield and fiber quality for molecular marker-assisted selection.

陆地棉(Gossypium hirsutum)是世界上重要的栽培棉种,野生斯特提棉(G.sturtianum)含有陆地棉所缺乏的许多优质基因.本研究通过陆地棉和斯特提棉的远缘杂交和染色体加倍,获得了自交可育的后代植株,对其进行流式细胞倍性检测和花粉母细胞减数分裂观察,筛选出2株染色体组完整的异源六倍体植株.统计鉴定表明,六倍体和亲本及三倍体比较,叶形介于双亲之间,叶面积增大,保卫细胞中叶绿体数明显增多;远缘杂种与亲本在花的表型性状方面差异明显,六倍体的花粉粒直径大于亲本和三倍体;六倍体棉纤维为白色,长度小于母本陆地棉,父本斯特提棉的种子腺体延缓发育性状在异源六倍体中得到表达.这些结果证明通过远缘杂交和加倍成功获得了陆地棉与斯特提棉间可育的异源六倍体新种质,为棉花遗传育种研究提供了有价值的材料.

This study was aimed to obtain autotetraploid cotton plants w hich could steadily produce cotton bolls through the induction of diploid grass cotton plants .The study is of significance for cotton germplasm innovation and further distant hybrid genetic breeding .[M ethods] The diploid cotton G .herbaceum L .was induced by improved meristem technique to obtain the tetraploid plants .The morphological ,flow cytometric ,and cytogenetic characteristics of mutants were analyzed and compared to that of wild type.[Results ] Morphological study indicated that mutant plants displayed a significant difference ( P＜ 0. 05 ) from parent plants with stronger grow th vigor , shorter stem length ,darker green and thicker leaves w hich became shrunken to some extent .The diameter of stem w as getting big‐ger than that of wild type.The result of flow cytometric analysis show ed the peak value of mutants and wild type at 400 and 200 respectively w hich indicated that DNA content of mutants w as two times of the wild type .Cytogenetic re‐sults revealed 52 chromosomes in mutant plants and 26 in wild type w hich demonstrated the successful induction of cotton polyploid.Significant differences between the mutant and the wild type strains were also observed in stomatal density and guard cell length .The stomatal density of the mutant strain was 25. 29% lower than that of the wild type strain ,and the number of guard cell of the mutant strain was increased by 32. 86% .[Conclusions] In our study autote‐traploid plants were successfully obtained and the physiological characteristics were investigated .The results provided new valuable materials for the cotton innovation and cotton genetics and breeding studies .