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To replace explosive nitrate-based chemicals in MS medium, this study developed a new, safer, and more cost-effective method using fertilizer-grade calcium ammonium nitrate and ammonium sulfate. This approach replaces ammonium nitrate and potassium nitrate, ensuring both safety and cost efficiency for sugarcane propagation. Six local sugarcane varieties—Zhongtang1 (ZT1), Zhongtang3 (ZT3), Zhongtang6 (ZT6), Guitang42 (GT42), Guitang44 (GT44), and Guiliu 07150 (GT07150)—were used. In the control group (Ck), nitrate ions (NO3−) were 39.28 mM, and ammonium ions (NH4+) were 20.49 mM, with a 2:1 ratio. In the treatment groups, the concentrations of nitrate ions (NO3−) and ammonium ions (NH4+) included treatment 1 (19.69 mM NO3− and 10.3 mM NH4+), treatment 2 (29.54 mM and 15.44 mM), treatment 3 (39.38 mM and 20.59 mM), treatment 4 (49.225 mM and 25.74 mM), treatment 5 (59.07 mM and 30.89 mM), and treatment 6 (68.915 mM and 36.03 mM), respectively, all with the same 2:1 ratio. Fifty bottles per treatment, with three replicates, were used for each sugarcane plantlets treatment. After five subcultures, the optimal ratio was determined by assessing morphological and physiological parameters, nitrogen levels, and SOD enzyme activity. The results indicated that treatment 3 (39.38 mM and 20.59 mM) and treatment 4 (49.225 mM and 25.74 mM) had the best morphological and physiological indicators. The optimal doses of calcium ammonium nitrate and ammonium sulfate were found in treatments 3 and 4, as well as in the control, with no significant difference among them. However, treatment 3, due to its lower dose, was more cost effective. To improve cost efficiency in practical production, it is recommended to use the lower concentration ratio of treatment 3 for plant tissue culture plantlets.

Environmental stresses are the main constraints on agricultural productivity and food security worldwide. This issue is worsened by abrupt and severe changes in global climate. The formation of sugarcane yield and the accumulation of sucrose are significantly influenced by biotic and abiotic stresses. Understanding the biochemical, physiological, and environmental phenomena associated with these stresses is essential to increase crop production. This review explores the effect of environmental factors on sucrose content and sugarcane yield and highlights the negative effects of insufficient water supply, temperature fluctuations, insect pests, and diseases. This article also explains the mechanism of reactive oxygen species (ROS), the role of different metabolites under environmental stresses, and highlights the function of environmental stress-related resistance genes in sugarcane. This review further discusses sugarcane crop improvement approaches, with a focus on endophytic mechanism and consortium endophyte application in sugarcane plants. Endophytes are vital in plant defense; they produce bioactive molecules that act as biocontrol agents to enhance plant immune systems and modify environmental responses through interaction with plants. This review provides an overview of internal mechanisms to enhance sugarcane plant growth and environmental resistance and offers new ideas for improving sugarcane plant fitness and crop productivity.

We investigated the locations of 5S and 45S rDNA in Gossypium diploid A, B, D, E, F, G genomes and tetraploid genome (AD) using multi-probe fluorescent in situ hybridization (FISH) for evolution analysis in Gossypium genus. The rDNA numbers and sizes, and synteny relationships between 5S and 45S were revealed using 5S and 45S as double-probe for all species, and the rDNA-bearing chromosomes were identified for A, D and AD genomes with one more probe that is single-chromosome-specific BAC clone from G. hirsutum (A1D1). Two to four 45S and one 5S loci were found in diploid-species except two 5S loci in G. incanum (E4), the same as that in tetraploid species. The 45S on the 7th and 9th chromosomes and the 5S on the 9th chromosomes seemed to be conserved in A, D and AD genomes. In the species of B, E, F and G genomes, the rDNA numbers, sizes, and synteny relationships were first reported in this paper. The rDNA pattern agrees with previously reported phylogenetic history with some disagreements. Combined with the whole-genome sequencing data from G. raimondii (D5) and the conserved cotton karyotype, it is suggested that the expansion, decrease and transposition of rDNA other than chromosome rearrangements might occur during the Gossypium evolution.

Environmental stresses are the main constraints on agricultural productivity and food security worldwide. This issue is worsened by abrupt and severe changes in global climate. The formation of sugarcane yield and the accumulation of sucrose are significantly influenced by biotic and abiotic stresses. Understanding the biochemical, physiological, and environmental phenomena associated with these stresses is essential to increase crop production. This review explores the effect of environmental factors on sucrose content and sugarcane yield and highlights the negative effects of insufficient water supply, temperature fluctuations, insect pests, and diseases. This article also explains the mechanism of reactive oxygen species (ROS), the role of different metabolites under environmental stresses, and highlights the function of environmental stress-related resistance genes in sugarcane. This review further discusses sugarcane crop improvement approaches, with a focus on endophytic mechanism and consortium endophyte application in sugarcane plants. Endophytes are vital in plant defense; they produce bioactive molecules that act as biocontrol agents to enhance plant immune systems and modify environmental responses through interaction with plants. This review provides an overview of internal mechanisms to enhance sugarcane plant growth and environmental resistance and offers new ideas for improving sugarcane plant fitness and crop productivity. [ABSTRACT FROM AUTHOR]

[Objectives] Sugarcane is the most significant sugar cash crop in the tropical and subtropical regions of China. However, it is notable for its narrow genetic basis, limited trait improvement, weak adaptability of varieties, and poor planting efficiency. In order to accelerate the process of sugarcane variety replacement and expand the basis of genetic variation, interspecific hybridization and multiple mutagen-esis are the most effective methods for obtaining new sugarcane varieties. The evaluation and identification of phenotypic traits of germplasm represents a significant analytical method. The "Zhongtang" series of sugarcane varieties is distinguished by its high yield and high sugar content. New sugarcane germplasms with excellent agronomic and quality traits can be identified and developed as breeding parents and new breeding lines through comprehensive evaluation of the existing germplasm. [Methods] A total of 181 new lines were selected through genetic origin and orientation, and evaluated and appraised for growth, yield, and economic characteristics. The data on 6 important agronomic and quality traits, including tillering, initial plant height, plant height, stem diameter, number of effective stems, and brix at maturity, were used to discover superior lines. These traits were evaluated during the two production seasons of the participant lines. [Results] A comprehensive evaluation of seedling growth traits and economic traits at maturity of the experimental lines identified 30 excellent new germ-plasms of sugarcane. Among the selected lines, 1501 and 1701 exhibited superior agronomic and quality traits, rendering them suitable as parental lines for sugarcane breeding or breeding as new varieties. [Conclusions] The exemplary results obtained in this study provide a solid foundation for the improvement of sugarcane germplasm, with the goal of enhancing quality and efficiency. These findings are of great scientific and practical significance to the study of sugarcane yield and sugar-related genes, as well as the exploration of the evaluation and utilization of sugarcane germplasm resources. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to investigate the mutagenic effects of space radiation mutagenesis on sugarcane hybrid seeds. [Methods] Sugarcane hybrid spikes were subjected to space radiation mutagenesis treatment to identify the effects on the germination, seedling growth and plant growth and development of sugarcane hybrid seeds. [ Results] The space radiation treatment had a great impact on the germination and growth of sugarcane hybrid seeds, especially on the germination of sugarcane seeds. The germination number per gram of seeds increased significantly, and die survival rate of seedlings increased significantly. The effect on die growth status was relatively small. The average number of tillers decreased slightly, the percentage of available stems increased, and the plants became higher, which resulted in a greater effect on sugarcane yield. Sugarcane sucrose was increased. The seed germination and late growth status indicated that space radiation promoted the germination and growth of sugarcane hybrid seeds. [ Conclusions] This study provides a basis for the space radiation mutagenesis breeding of sugarcane hybrid seeds and the promotion of sugarcane breeding process. [ABSTRACT FROM AUTHOR]

The study was conducted on the individual chromosome identification in Gossypium darwinii (AdDd), G. klotzschianum (D3k), G. davidsonii (D3d), G. armourianum (D2-1) and G. aridum (D4) using a multi-probe fluorescence of in situ hybridization (FISH) system. Comparative analysis on their genetic maps with that of physical maps was made as well. The FISH probes used contained two sets of bacterial artificial chromosome (BAC) clones [one is specific to 26 individual chromosomes from A and D subgenomes of G. hirsutum (Ah and Dh) while the other is a D genome centromere- specific BAC clone 150D24], 45S and 5S rDNA clones. The results showed that all Ad chromosomes were marked with the 13 Ah chromosome-specific BAC clones, whilst all Dd, D3k, D3d, D2-1 and D4 chromosomes and chromosomal arms were identified with the 13 Dh chromosome-specific BAC clones and the D genome centromere-specific BAC. According to the homology within D subgenomes which are between A (D) genome and A (D) subgenome, the systematic nomenclature for individual chromo- some in the five species was established. The chromosomes of A (D) subgenomes in G. darwinii were named as Ad01-Ad13 (Dd01-Dd13). The chromosomes in D3k, D3d, D2-1 and D4 were named as D3k01-D3k13, D3d01-D3d13, D2-101-D2-113 and D401-D413, respectively. Based on the successful identification for individual chromosomes, 45S and 5S rDNA were located to the special chromosomes and chromosomal arms for all five species. And there appeared chromosomal collinearity from the BAC clones among different species by comparing BACs positions, which suggested that the majority of chromosome segment homology may exist between D genomes and D subgenome. Moreover, as the genetic map and physical map were integrated, the orientations of genetic maps for Dd and D genomes of diploid cotton were established. The orientations of some of chromosomes in genetic maps (Dd03, Dd04, Dd06, Dd09, Dd10 and Dd12) were found switched. The SSR marker in the middle of linkage group 04 was corrected at nearby the end of chromosome 04 by FISH. The study will be helpful to establish a theoretical basis using the wild gene bank to exploit more genes aiming for cotton breeding and will provide powerful evidences both for the evolution of Gossypium and assembling the sequences of the obtained and as well the on-going whole genome sequencing projects of cotton. [ABSTRACT FROM AUTHOR]

The experiment on individual chromosome assignments and chromosomal diversity was conducted using a multi-probe fluorescence in situ hybridization (FISH) system in D subgenome of tetraploid Gossypium barbadense (Db), G. thurberi (D1) and G. trilobum (D8), which the later two were the possible subgenome donors of tetraploid cottons. The FISH probes contained a set of bacterial artificial chromosome (BAC) clones specific to 13 individual chromosomes from D subgenome of G. hirsutum (Dh), a D genome centromere-specific BAC clone 150D24, 45S and 5S ribosomal DNA (rDNA) clones, respectively. All tested chromosome orientations were confirmed by the centromere-specific BAC probe. In D1 and D8, four 45S rDNA loci were found assigning at the end of the short arm of chromosomes 03, 07, 09 and 11, while one 5S rDNA locus was successfully marked at pericentromeric region of the short arm of chromosome 09. In Db, three 45S rDNA loci and two 5S rDNA loci were found out. Among them, two 45S rDNA loci were located at the terminal of the short arm of chromosomes Db07 and Db09, whilst one 5S rDNA locus was found situating near centromeric region of the short arm of chromosome Db09. The positions of the BAC clones specific to the 13 individual chromosomes from Dh were compared between D1, D8 and Db. The result showed the existence of chromosomal collinearity within D1 and D8, and as well between them and Db. The results will serve as a base for understanding chromosome structure of cotton and polyploidy evolution of cotton genome and will provide bio-information for assembling the sequences of finished and the on-going cotton whole genome sequencing projects. [ABSTRACT FROM AUTHOR]

A transgenic male sterile line of upland cotton was generated by the ectopic expression of the monooxygenase ( MNX) gene from Arabidopsis thaliana via Agrobacterium-mediated transformation. The bacterium harbored a plasmid pBinplus carrying a 1.25-kb MNX coding sequence together with a GUS reporter gene; the former was driven by the MS2 promoter of a male sterility gene in Arabidopsis, and the latter was under the control of CaMV 35S promoter. Twenty-seven putative transgenic plants (T0) were obtained, all of which showed GUS activity and positive signals of NPTII and MNX genes by PCR analysis, and also showed male sterility to some extent. It was further confirmed by Southern blotting that one copy of the NPTII and MNX gene was integrated in the genome of the plants which expressed male sterility to a higher degree. Northern blotting assay also demonstrated that the transgenes stably transcribed in the genome of the transgenic plants in F4 generation. The male sterile plants usually display lower plant height, shortened internodes, shrunken anthers without pollen grains or with some abortive pollen grains, and unusual leaves with deeper multi-lobes. Microscope observations on the meiosis processes of pollen mother cells (PMCs) showed that the abortion of pollen grains mainly resulted from abnormalities of meiosis such as direct degeneration of PMCs, degenerations of dyad and tetrads, amitosis, lagging chromosomes, and the multi-polar segregations of chromosomes and so on. This study indicates a method of developing novel cotton male sterile materials for potential application in agriculture and for engineering of male sterility in other important crops. [ABSTRACT FROM AUTHOR]