Validating field regeneration capacity for selected accessions of Gossypium hirsutum using callus induction and regeneration capacity

Background Gossypium hirsutum undergoes rapid clonal propagation to regenerate a mature plant through tissue culture.However,the correlation between cotton leaf regeneration,callus induction,and regeneration ability was still obscure.In this research,cotton leaf regeneration level for 21 accessions in the field(new leaves)was observed after the first harvest,and a comparison between field regeneration level and callus induction with its regeneration capacity(new shoots and roots)for the same 21 accessions was carried out.Agronomic traits,including plant height,leaf area,fresh leaf weight,dry leaf weight,the number of flowers and bolls,and biochemical(proline content)and physiological(chlorophyll and carotenoid content)traits during the flowering stage of 21 upland cotton accessions,were investigated.Result A significant correlation between physiological parameters and callus induction was discovered.Callus induction and regeneration capacity of roots and shoots for hypocotyl,cotyledons,and shoot tip tissues were used to validate field leaf regeneration level after the first harvest.CCRI 24 showed significant leaf regeneration in the field and callus induction capacity through callus induction and regeneration.Conclusion We found a substantial relationship between field regeneration capability and callus induction with its regeneration capacity for the hypocotyl,cotyledons,and shoot tip.The results showed that ZS061,Lumian 378,Jimian 863,and ZS065 have the highest moisture retention capacity,while CCRI 24,Liaoyang Duomaomian,and Beizhe Gongshemian have the lowest moisture retention capacity.CCRI 24 has the highest leaf regeneration capacity in the field,while Beizhe Gongshemian has the lowest leaf regeneration capacity.All our result provides a clue for checking the regeneration capacity through leaf regeneration level in the field.

Genetics of biochemical attributes regulating morpho-physiology of upland cotton under high temperature conditions

Background Cotton is a strategically important fibre crop for global textile industry.It profoundly impacts several countries’industrial and agricultural sectors.Sustainable cotton production is continuously threatened by the unpre-dictable changes in climate,specifically high temperatures.Breeding heat-tolerant,high-yielding cotton cultivars with wide adaptability to be grown in the regions with rising temperatures is one of the primary objectives of modern cotton breeding programmes.Therefore,the main objective of the current study is to figure out the effective breed-ing approach to imparting heat tolerance as well as the judicious utilization of commercially significant and stress-tolerant attributes in cotton breeding.Initially,the two most notable heat-susceptible(FH-115 and NIAB Kiran)and tolerant(IUB-13 and GH-Mubarak)cotton cultivars were spotted to develop filial and backcross populations to accom-plish the preceding study objectives.The heat tolerant cultivars were screened on the basis of various morphological(seed cotton yield per plant,ginning turnout percentage),physiological(pollen viability,cell membrane thermostabil-ity)and biochemical(peroxidase activity,proline content,hydrogen peroxide content)parameters.Results The results clearly exhibited that heat stress consequently had a detrimental impact on every studied plant trait,as revealed by the ability of crossing and their backcross populations to tolerate high temperatures.However,when considering overall yield,biochemical,and physiological traits,the IUB-13×FH-115 cross went over particularly well at both normal and high temperature conditions.Moreover,overall seed cotton yield per plant exhibited a posi-tive correlation with both pollen viability and antioxidant levels(POD activity and proline content).Conclusions Selection from segregation population and criteria involving pollen viability and antioxidant levels concluded to be an effective strategy for the screening of heat-tolerant cotton germplasms.Therefore,understanding acquired from this study can assist breeders identifying traits that should be prioritized in order to develop climate resilient cotton cultivars.

Genome-wide identification and expression profiling of photosystem II(PsbX)gene family in upland cotton(Gossypium hirsutum L.)

Background Photosystem II(PSII)constitutes an intricate assembly of protein pigments,featuring extrinsic and intrinsic polypeptides within the photosynthetic membrane.The low-molecular-weight transmembrane protein PsbX has been identified in PSII,which is associated with the oxygen-evolving complex.The expression of PsbX gene protein is regulated by light.PsbX’s central role involves the regulation of PSII,facilitating the binding of quinone molecules to the Qb(PsbA)site,and it additionally plays a crucial role in optimizing the efficiency of photosynthesis.Despite these insights,a comprehensive understanding of the PsbX gene’s functions has remained elusive.Results In this study,we identified ten PsbX genes in Gossypium hirsutum L.The phylogenetic analysis results showed that 40 genes from nine species were classified into one clade.The resulting sequence logos exhibited substantial conservation across the N and C terminals at multiple sites among all Gossypium species.Furthermore,the ortholo-gous/paralogous,Ka/Ks ratio revealed that cotton PsbX genes subjected to positive as well as purifying selection pressure might lead to limited divergence,which resulted in the whole genome and segmental duplication.The expression patterns of GhPsbX genes exhibited variations across specific tissues,as indicated by the analysis.Moreover,the expression of GhPsbX genes could potentially be regulated in response to salt,intense light,and drought stresses.Therefore,GhPsbX genes may play a significant role in the modulation of photosynthesis under adverse abiotic conditions.Conclusion We examined the structure and function of PsbX gene family very first by using comparative genom-ics and systems biology approaches in cotton.It seems that PsbX gene family plays a vital role during the growth and development of cotton under stress conditions.Collectively,the results of this study provide basic information to unveil the molecular and physiological function of PsbX genes of cotton plants.

GhWDL3 is involved in the formation and development of fiber cell morphology in upland cotton(Gossypium hirsutum L.)

Background Cotton fiber is a model tissue for studying microtubule-associated proteins(MAPs).The Xklp2(TPX2)proteins that belong to the novel MAPs member mainly participate in the formation and development of microtubule(MT).However,there is a lack of studies concerning the systematic characterization of the TPX2 genes family in cotton.Therefore,the identification and portrayal of G.hirsutum TPX2 genes can provide key targets for molecular manipula-tion in the breeding of cotton fiber improvement.Result In this study,TPX2 family genes were classified into two distinct subclasses TPXLs and MAP genes WAVE DAMP-ENED2-LIKE(WDLs)and quite conservative in quantity.GhWDL3 was significantly up-regulated in 15 days post anthe-sis fibers of ZRI-015(an upland cotton with longer and stronger fiber).GhWDL3 promotes all stem hairs to become straight when overexpressed in Arabidopsis,which may indirectly regulate cotton fiber cell morphology during fiber development.Virus induced gene silencing(VIGS)results showed that GhWDL3 inhibited fiber cell elongation at fiber development periods through regulating the expression of cell wall related genes.Conclusion These results reveal that GhWDL3 regulated cotton fiber cell elongation and provide crucial information for the further investigation in the regulatory mechanisms/networks of cotton fiber length.

棉花品种MH410433的选育及配套栽培技术

MH410433于2021年通过河北省农作物品种审定委员会审定。在河北省冀中南植棉区,其生育期122 d,植株塔形,叶片中等偏大,铃卵圆形,吐絮肥畅,纤维品质达到河北省审定Ⅲ型棉花品种标准,早熟不早衰,抗枯萎病,耐黄萎病。主要介绍了MH410433的选育过程、生物学特性、产量表现、纤维品质及栽培技术要点。

陆地棉种质资源表型性状综合评价

【目的】鉴定分析陆地棉种质的纤维品质、产量和早熟等性状,筛选综合评价指标,建立可靠的综合评价模型,为陆地棉品种选育提供理论支撑。【方法】以来源广泛的630份陆地棉种质为材料,在中国3个主要植棉区的8个环境下,对17个表型性状进行鉴定,使用R包“lme4”对表型性状数据进行最佳线性无偏估计(best linear unbiased prediction,BLUP),并用于后续分析。综合运用相关分析、主成分分析、隶属函数法、聚类分析和逐步回归等方法对陆地棉种质进行综合评价。【结果】陆地棉种质群体具有较高的遗传多样性,不同性状的多样性指数为1.961-2.084,并且存在明显的区域特异性。该群体的铃数、伸长率、纺纱均匀性指数和短绒率具有较大变异,纤维长度、纤维强度和生育期性状的变异较小。相关分析表明,多数性状间存在显著或极显著相关性,部分纤维品质性状之间存在极强相关性。通过主成分分析,将17个性状转换为6个独立的综合指标,其贡献率为5.860%-31.044%,累积贡献率达到82.642%。主成分分析可以很好地将该陆地棉群体的纤维品质性状、产量性状和农艺性状进行分类。利用隶属函数法计算表型综合值(F值),17个性状的表型值与F值均显著相关。发现F值高的材料(均值为0.668)的产量性状(铃数、单铃重、衣分和子指)和纤维品质性状(纤维长度、纤维整齐度、纤维强度、纺纱均匀性指数、短绒率和马克隆值)显著优于F值低的材料(均值为0.396),并且具有植株较高和生育期较长的特点。通过逐步回归建立了8个性状(铃数、吐絮期、单铃重、开花期、衣分、株高、果枝始节和纺纱均匀性指数)作为自变量的回归方程。基于F值进行系统聚类,将630份陆地棉种质划分为4类,第Ⅰ类为纤维品质优质型,包含118份材料;第Ⅱ类丰产型包含250份材料;第Ⅲ类为早熟型,包含51份材料;第Ⅳ类材料的表型介于第Ⅱ类和第Ⅲ类之间。最终筛选出23份纤维品质优良材料和135份高产材料,可提供育种和生产应用。【结论】陆地棉表型性状存在地理来源特异性;采用多元统计分析方法综合评价陆地棉种质是可行的;630份陆地棉种质可被分划为4种类型(优质型、丰产型、早熟型和其他型)。

基于主成分分析和隶属函数的棉花种子萌发期耐涝性鉴定评价

参照棉花耐渍涝性鉴定技术标准,在棉花种子萌发期模拟淹水胁迫,采用主成分分析、隶属函数法及聚类分析方法,分析了涝渍胁迫处理对6份陆地棉材料出苗率、株高、主根长、子叶叶绿素含量(SPAD值)、幼苗鲜物质质量、幼苗干物质质量的影响。结果表明:幼苗鲜物质质量、株高、主根长、出苗率、幼苗干物质质量和SPAD值可以作为棉花萌发期耐涝性鉴定的指标;6份参试材料的耐涝性强弱顺序依次为402、晋棉36、冀丰908、宛棉3号、苏棉9号、TM-1,其中402和晋棉36为耐涝性较强的材料。相关研究方法可为批量鉴定和评价棉花种质资源的耐涝性提供依据。

亚洲棉短纤维发育相关长链非编码RNA的鉴定及表达

【目的】长链非编码RNA(long non-coding RNAs,lncRNAs)是一类无蛋白质编码能力,但参与许多重要生命活动调控过程的长度大于200 nt的RNA。通过对亚洲棉无短纤维突变体(GA0149)和野生型(GA0146)纤维发育早期的转录组数据进行分析,挖掘调控短纤维发育的lncRNA,并明确其调控网络,为进一步解析棉花纤维发育机制奠定基础。【方法】选择GA0146和GA01492个材料在开花后当天(0 DPA)及花后3 d(3 DPA)、5 d(5 DPA)和8 d(8 DPA)的胚珠和纤维为材料进行转录组测序。鉴定lncRNA并预测其调控的靶基因;通过mRNA和lncRNA的差异表达分析,比较2个材料在不同纤维发育时期的差异。进一步利用KOBAS软件预测对差异lncRNA的靶基因进行富集分析并预测其参与的生物过程;最后通过实时荧光定量(RT-qPCR)技术对25个差异表达的lncRNA转录组数据进行验证。【结果】共鉴定获得15339个lncRNA,其中11595个lncRNA位于基因间区,包括2428个反义lncRNA、350个内含子lncRNA及966个正义lncRNA。共有1932个差异表达lncRNA(DE-lncRNA),它们所对应的8134个靶基因中,有788个为差异表达基因(DE-mRNA)。KEGG代谢通路富集分析表明,DE-mRNA主要参与植物激素信号转导(plant hormone signal transduction)和内质网中蛋白质加工过程(protein processing in endoplasmic reticulum)。共表达调控网络分析显示,表达量差异比较显著的lncRNA(MSTRG.454250.3)和其所调控的靶基因表达趋势一致,仅在野生型(GA0146)短纤维发育早期胚珠中特异表达;而lncRNA(MSTRG.454261.4)与其调控的靶基因表达趋势相反,在突变体(GA0149)中的表达量显著高于野生型。RT-qPCR结果证实了转录组数据的真实性。【结论】鉴定了26个与亚洲棉短纤维发育相关的lncRNA,其通过调控植物激素信号转导途径相关的吲哚乙酸合成酶基因(Ga03G2421)和生长素响应蛋白基因(Ga05G1344)的表达而影响短纤维的发育。

天然彩色棉品种棕234的选育及栽培技术要点

对天然彩色棉品种棕234的选育过程进行了介绍,并概括了该品种的产量、品质、抗病性等性状及相关配套高产栽培技术要点。

Review of oxidative stress and antioxidative defense mechanisms in Gossypium hirsutum L.in response to extreme abiotic conditions

Oxidative stress occurs when crop plants are exposed to extreme abiotic conditions that lead to the excessive production and accumulation of reactive oxygen species(ROS).Those extreme abiotic conditions or stresses include drought,high temperature,heavy metals,salinity,and ultraviolet radiation,and they cause yield and quality losses in crops.ROS are highly reactive species found in nature that can attack plant organelles,metabolites,and molecules by interrupting various metabolic pathways until cell death occurs.Plants have evolved defense mechanisms for the production of antioxidants to detoxify the ROS and to protect the plant against oxidative damage.Modern researches in crop plants revealed that low levels of ROS act as a signal which induces tolerance to environmental extremes by altering the expression of defensive genes.In this review,we summarized the processes involved in ROS production in response to several types of abiotic stress in cotton plants.Furthermore,we discussed the achievements in the understanding and improving oxidative stress tolerance in cotton in recent years.Researches related to plant oxidative stresses have shown excellent potential for the development of stress-tolerant crops.

Heritability and correlation analysis of morphological and yield traits in genetically modified cotton

Background:Cotton is known for fiber extraction and it is grown in tropical and sub-tropical areas of the world due to having hot weather.Cotton crop has a significant role in GDP of Pakistan.Therefore,the two-years research was conducted to estimate heritability and association among various yield contributing parameters of cotton,i.e.,plant height,number of bolls per plant,number of sympodial branches per plant,seed cotton yield,boll weight,seed index,ginning outturn(GOT),fiber length,fiber strength,and fiber fineness.Results:Association analysis revealed that seed cotton yield had a significant positive correlation with plant height,number of bolls per plant,number of sympodial branches per plant,GOT,staple length and fiber strength.Staple length and fiber strength were negatively linked with each other.Estimates of heritability were high for all of the traits except the number of sympodial branches per plant and boll weight.Conclusion:The parent IUB-222 was found to be the best for plant height,the number of bolls per plant,boll weight,GOT,seed cotton yield,and seed index.The genotypes namely,NIAB-414 and VH-367 were identified as the best parents for fiber length,strength,and fineness.Among the crosses NIAB-414×IUB-222 was the best for the number of bolls per plant,seed index,seed cotton yield and fiber fineness,whereas,the cross of NIAB-414×CIM-632 was good for plant height.The combination of A555×CIM-632 was the best for the number of sympodial branches per plant,boll weight,fiber length,and strength,and VH-367×CIM-632 proved the best for GOT.

QTL mapping of agronomic and economic traits for four F_(2)populations of upland cotton

Background:Upland cotton(Gossypium hirsutum)accounts for more than 90%of the annual world cotton output because of its high yield potential.However,yield and fiber quality traits often show negative correlations.We constructed four F_(2)populations of upland cotton,using two normal lines(4133B and SGK9708)with high yield potential but moderate fiber quality and two introgression lines(Suyuan04–3 and J02–247)with superior fiber quality,and used them to investigate the genetic basis underlying complex traits such as yield and fiber quality in upland cotton.We also phenotyped eight agronomic and economic traits and mapped quantitative trait loci(QTLs).Results:Extensive phenotype variations and transgressive segregation were found across the segregation populations.We constructed four genetic maps of 585.97 centiMorgan(cM),752.45 cM,752.45 cM,and 1163.66 cM,one for each of the four F_(2)populations.Fifty QTLs were identified across the four populations(7 for plant height,27 for fiber quality and 16 for yield).The same QTLs were identified in different populations,including qBW4 and qBW2,which were linked to a common simple sequence repeat(SSR)marker,NAU1255.A QTL cluster containing eight QTLs for six different traits was characterized on linkage group 9 of the 4133B×Suyuan04–3 population.Conclusions:These findings will provide insights into the genetic basis of simultaneous improvement of yield and fiber quality in upland cotton breeding.

Genetic diversity and population structure of Gossypium arboreum L. collected in China

Background: Gossypium arboreum is a diploid species cultivated in the Old World. It possesses favorable characters that are valuable for developing superior cotton cultivars.Method: A set of 197 Gossypium arboreum accessions were genotyped using 80 genome-wide SSR markers to establish patterns of the genetic diversity and population structure. These accessions were collected from three major G. arboreum growing areas in China. A total of 255 alleles across 80 markers were identified in the genetic diversity analysis.Results: Three subgroups were found using the population structure analysis, corresponding to the Yangtze River Valley, North China, and Southwest China zones of G.arboreum growing areas in China. Average genetic distance and Polymorphic information content value of G. arboreum population were 0.34 and 0.47, respectively, indicating high genetic diversity in the G. arboreum germplasm pool. The Phylogenetic analysis results concurred with the subgroups identified by Structure analysis with a few exceptions. Variations among and within three groups were observed to be 13.61% and 86.39%, respectively.Conclusion: The information regarding genetic diversity and population structure from this study is useful for genetic and genomic analysis and systematic utilization of economically important traits in G. arboreum.

Identification and expression analysis of Tubulin gene family in upland cotton

Background:Cott on fibers are single-celled exte nsions of the seed epidermis,a model tissue for studying cytoskeleton.Tubulin genes play a critical role in synthesizing the microtubules(MT)as a core element of the cytoskeleton.However,there is a lack of studies concerning the systematic characterization of the tubulin gene family in cotton.Therefore,the identification and portrayal of G.hirsutum tubulin genes can provide key targets for molecular manipulation in cotton breeding.Result:In this study,we investigated all tubulin genes from different plant species and identified 98 tubulin genes in G.hirsutum.Phylogenetic an a lysis showed that tubulin family genes were classified into three subfamilies.The protein motifs and gene structure ofβ-tubulin genes are more conserved compared withγ-tubulin genes.Most tubulin genes are located at the proximate ends of the chromosomes.Spatiotemporal expression pattern by transcriptome and qRT-PCR analysis revealed that 12α-tubulin andβ-tubulin genes are specifically expressed during different fiber development stages.However,Gh.A03G027200,Gh.D03G 169300,and Gh.A1lG258900 had differential expression patterns at distinct stages of fiber development in varieties JO2508 and ZRI015.Conclusion:In this study,the evol ut io nary an alysis showed that the tubulin genes were divided into three clades.The genetic structures and molecular functions were highly con served in different plants.Three candidate genes,Gh.A03G027200f Gh.D03G169300,and Gh.A11G258900 may play a key role during fiber development complementing fiber length and strength.

Correlation analysis of stem hardness traits with fiber and yield-related traits in core collections of Gossypium hirsutum

Background:Stem hardness is one of the major influencing factors for plant architecture in upland cotton(Gossypium hirsutum L.).Evaluating hardness phenotypic traits is very important for the selection of elite lines for resistance to lodging in Gossypium hirsutum L.Cotton breeders are interested in using diverse genotypes to enhance fiber quality and high-yield.Few pieces of research for hardness and its relationship with fiber quality and yield were found.This study was designed to find the relationship of stem hardness traits with fiber quality and yield contributing traits of upland cotton.Results:Experiments were carried out to measure the bending,acupuncture,and compression properties of the stem from a collection of upland cotton genotypes,comprising 237 accessions.The results showed that the genotypic difference in stem hardness was highly significant among the genotypes,and the stem hardness traits(BL,BU,AL,AU,CL,and CU)have a positive association with fiber quality traits and yield-related traits.Statistical analyses of the results showed that in descriptive statistics result bending(BL,BU)has a maximum coefficient of variance,but fiber length and fiber strength have less coefficient of variance among the genotypes.Principal component analysis(PCA)trimmed quantitative characters into nine principal components.The first nine principal components(PC)with Eigenvalues>1 explained 86%of the variation among 237 accessions of cotton.Both 2017 and 2018,PCA results indicated that BL,BU,FL,FE,and LI contributed to their variability in PC1,and BU,AU,CU,FD,LP,and FWPB have shown their variability in PC2.Conclusion:We describe here the systematic study of the mechanism involved in the regulation of enhancing fiber quality and yield by stem bending strength,acupuncture,and compression properties of G.hirsutum.

A genome-wide association study of lateral root number for Asian cotton(Gossypium arboreum L.)

Background:The lateral root is one of the most important organs that constitute the root architecture system in plants.It can directly affect the contact area between plants and soil and plays an important role in plant structural support and nutrient absorption.Optimizing root architecture systems can greatly increase crop yields.This study was designed to identify the molecular markers and candidate genes associated with lateral root development in cotton and to evaluate correlations with yield and disease traits.Result:The number of lateral roots for 14-day old seedlings was recorded for 215 Gossypium arboreum accessions.A correlation analysis showed that the number of lateral roots positively correlates with the sympodial branch node and seed index traits,but negatively correlates with lint percentage.A Genome-wide association study(GWAS)identified 18 significant SNPs with 19 candidate genes associated with the lateral root number.Expression analysis identified three genes(FLA 12,WRKY29,and RBOHA)associated with lateral root development.Conclusion:GWAS an alysis identified key SNPs and candidate gen esfor lateral root number,a nd gen es of FLA 12,WRKY29,and RBOHA may play a pivotal role in lateral root development in Asian cotton.

EVALUATION OF THE INTROGRESSED LINES AND SCREENING FOR ELITE GERMPLASM IN GOSSYPIUM

In this research, 155 cotton introgressed lines from interspecific hybridization have been col- lected for the purpose of evaluating the effects of enhancement of new upland cotton germplasm by interspecific hybridization, screening for elite germ- plasm and improving cotton breeding. Through iden- tification of various agricultural traits, we found that different wild cotton species had different capacities in terms of fiber quality, disease resistance, tolerance of abiotic stress, pest resistance and so on. SSR molecular marker technology has been used to de- tect the exotic genetic elements in interspecific hy- brids, and 25 SSR specific loci that can be classified into two groups were found among 15 pairs of SSR primers. Results also showed that 8 exotic germ- plasm (Gossypium barbadense, G. arboreum and G. thurberi, etc) had genetic transmission toward upland cotton. A strategy of screening elite germplasm with exotic genes based on the molecular marker-assisted breeding techniques was suggested, and 18 lines with high-quality fiber and 4 lines with resistance to Fusanrium wilt and Verticillium wilt have been ob- tained.