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.

Genome wide identification and characterization of MAPK genes reveals their potential in enhancing drought and salt stress tolerance in Gossypium hirsutum

Background:The cotton crop is universally considered as protein and edible oil source besides the major contributor of natural fiber and is grown in tropical and subtropical regions around the world Unpredicted environmental stresses are becoming significant threats to sustainable cotton production,ultimately leading to a substantial irreversible economic loss.Mitogen-activated protein kinase(MAPK)is generally considered essential for recognizing environmental stresses through phosphorylating downstream signal pathways and plays a vital role in numerous biological processes.Results:We have identified 74 MAPK genes across cotton,41 from G.hirsutum,19 from G.raimondii,whereas 14 have been identified from G.arboreum.The MAPK gene-proteins have been further studied to determine their physicochemical characteristics and other essential features.In this perspective,characterization,phylogenetic relationship,chromosomal mapping,gene motif,cis-regulatory element,and subcellular localization were carried out.Based on phylogenetic analysis,the MAPK family in cotton is usually categorized as A,B,C,D,and E clade.According to the results of the phylogenic relationship,cotton has more MAPKS genes in Clade A than Clade B.The cis-elements identified were classified into five groups(hormone responsiveness,light responsiveness,stress responsiveness,cellular development,and binding site).The prevalence of such elements across the promoter region of these genes signifies their role in the growth and development of plants.Seven GHMAPK genes(GH_A07G1527,GH_D02G1138,GH_D03G0121,GH_D03G1517,GH_D05G1003,GH_D11G0040,and GH_D12G2528)were selected,and specific tissue expression and profiling were performed across drought and salt stresses.Results expressed that six genes were upregulated under drought treatment except for GH_D11G0040 which is downregulated.Whereas all the seven genes have been upregulated at various hours of salt stress treatment.Conclusions:RNA sequence and qPCR results showed that genes as differentially expressed across both vegetative and reproductive plant parts.Similarly,the qPCR analysis showed that six genes had been upregulated substantially through drought treatment while all the seven genes were upregulated across salt treatments.The results of this study showed that cotton GHMPK3 genes play an important role in improving cotton resistance to drought and salt stresses.MAPKs are thought to play a significant regulatory function in plants’responses to abiotic stresses according to various studies.MAPKs’involvement in abiotic stress signaling and innovation is a key goal for crop species research,especially in crop breeding.