Male Sterile Lines Research Articles

Development and Trait-Based Molecular Characterization of Thermosensitive Genic Male-Sterile Rice (Oryza sativa L.) Lines at Texas A&M AgriLife Research

This study aimed to develop and genetically characterize thermosensitive genic male-sterility (TGMS) lines for use in hybrid rice (Oryza sativa L.) breeding. Male-sterile F2 to F4 generation lines were screened during the high-temperature summer season, and ratoon crops of selected male-sterile rows were harvested for pure seed. Sixty-six F5 TGMS lines were genotyped using DNA markers controlling 16 traits from the LSU80 QA/QC Rice PlexSeq SNP Panel. Ten TGMS lines with desirable traits that included semidwarf, glabrous, non-aromatic, long-grain, narrow brown leaf spot resistance, and blast resistance genes were selected for further genotypic characterization using markers for low chalkiness (chalk5), wide compatibility (S5-n), cold tolerance (qSCT-11 and qCST-12), and anaerobic germination (AG1 and AG2). TGMS lines TIL21051S and TIL21052S possess favorable alleles for each of the genes evaluated in this study and are desirable parents for two-line hybrid breeding in the southeast United States. TIL21044S, TIL21095S, TIL21060S, and TIL21066S each contain three blast resistance genes and have potential as parental lines. TIL21014S-2, TIL21015S, and TIL21016S-1 include the fgr allele for aroma and can also be used as parental lines for aromatic two-line hybrids.

The miR3367-lncRNA67-GhCYP724B module regulates male sterility by modulating brassinosteroid biosynthesis and interacting with Aorf27 in Gossypium hirsutum.

Cytoplasmic male sterile (CMS) lines play a crucial role in utilization of heterosis in crop plants. However, the mechanism underlying the manipulation of male sterility in cotton by long non-coding RNA (lncRNA) and brassinosteroids (BRs) remains elusive. Here, using an integrative approach combining lncRNA transcriptomic profiles with virus-induced gene silencing experiments, we identify a flower bud-specific lncRNA in the maintainer line 2074B, lncRNA67, negatively modulating with male sterility in upland cotton (Gossypium hirsutum). lncRNA67 positively regulates cytochrome P274B (GhCYP724B), which acted as an eTM (endogenous target mimic) for miR3367. The suppression of GhCYP724B induced symptoms of BR deficiency and male semi-sterility in upland cotton as well as in tobacco, which resulted from a reduction in the endogenous BR contents. GhCYP724B regulates BRs synthesis by interacting with GhDIM and GhCYP90B, two BRs biosynthesis proteins. Additionally, GhCYP724B suppressed a unique chimeric open reading frame (Aorf27) in 2074A mitochondrial genome. Ectopic expression of Aorf27 in yeast inhibited cellular growth, and over expression of Aorf27 in tobacco showed male sterility. Overall, the results proved that the miR3367-lncRNA67-GhCYP724B module positively regulates male sterility by modulating BRs biosynthesis. The findings uncovered the function of lncRNA67-GhCYP724B in male sterility, providing a new mechanism for understanding male sterility in upland cotton.

Analysis of Rfo-Mediated Network in Regulating Fertility Restoration in Brassica oleracea.

Ogura cytoplasmic male sterility (CMS) lines play a crucial role in the utilization of heterosis. However, valuable traits, such as disease resistance genes from Ogura CMS hybrids, are challenging to incorporate for germplasm innovation, particularly in cabbage and broccoli. To date, the Rfo-mediated network regulating fertility restoration remains largely unexplored. In this study, we conducted a transcriptomic analysis of broccoli flower buds from Ogura CMS SFB45 and its Rfo-transgenic fertility restoration line, pRfo, at different stages of pollen development. Gene Ontology (GO) terms such as "pollen exine formation", "flavonoid metabolic and biosynthetic processes", and "pollen wall assembly", along with Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways including "flavonoid biosynthesis", "MAPK signaling pathway-plant", and "ABC transporters", were significantly enriched. We identified five differentially expressed genes (DEGs) involved in tapetum-mediated callose metabolism, thirty-four DEGs related to tapetum-mediated pollen wall formation, three DEGs regulating tapetum programmed cell death (PCD), five MPKs encoding DEGs, and twelve DEGs associated with oxidative phosphorylation. Additionally, yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays demonstrated that RFO directly interacts with ORF138 at the protein level. These findings provide valuable insights into the fertility recovery mechanisms regulated by Rfo in broccoli and offer important clues for breeders aiming to enhance Ogura CMS hybrids in Brassica oleracea.

Genetic Variability and Association Studies for Morpho-floral Traits in Backcross Introgression Lines of Rice (Oryza sativa L.)

Background: Wild introgressions are pivotal in enriching the genetic diversity of cultivated varieties by introducing novel alleles beneficial for crop improvement. Understanding insights into genetic variability and association studies of morphological and floral traits are crucial for enhancing hybrid seed production in rice. Methods: 290 backcross introgression lines (BC4F2) from inter-specific cross of CRMS 32B (maintainer of male sterile line as low stigma exsertion recipient parent) cv. Oryza sativa with Oryza longistaminata (wild rice as high stigma exsertion donor parent) were assessed for 12 morpho-floral traits. The experiment was laid out in randomized complete block design (RCBD) at Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, during Kharif, 2019. Result: ANOVA results showed significant differences among lines for all examined traits. The phenotypic coefficient of variation (PCV) was slightly greater than genotypic coefficient of variation (GCV) for each trait. High PCV, GCV, heritability and genetic advance as percentage of mean were observed for dual stigma exsertion percentage (DSE%) and total stigma exsertion percentage (TSE%), whereas moderate to high values of these parameters were noted for single stigma exsertion percentage (SSE%), grain yield per plant (GYPP), effective tillers per plant (ETPP) and grains per panicle (GPP) traits. Most traits showed positive skewness, except traits SFP (spikelet fertility percentage), SSE% and TSE%. Most traits recorded leptokurtic kurtosis, whereas plant height (PH), GYPP and TSE% exhibited platykurtic kurtosis. TSE% displayed a highly significant positive association with SSE% and DSE%, while GYPP showed a significant positive correlation with ETPP and GPP, presenting a promising opportunity for simultaneous selection of these traits.

Genetic Analysis of Combining Ability and Gene Action in Sunflower (Helianthus annuus L.) Hybrids through Line × Tester Design

This study was conducted to evaluate the combining ability of six cytoplasmic male sterile (CMS) lines and nine testers using the line × tester method. Biometrical data were recorded for ten agronomic traits: days to 50% flowering, days to maturity, plant height, head diameter, seed filling percentage, 100-seed weight, volume weight, hull content, oil content, and seed yield per plant. The results indicated that specific combining ability (SCA) variance was higher than general combining ability (GCA) variance for most traits, except for days to 50 percent flowering and seed filling percentage, suggesting that non-additive gene action predominantly governed the inheritance of these traits. The GCA of parents did not always align with their per se performance, indicating that GCA should be the primary criterion for selecting parents in breeding programs. Three CMS lines, CMS-103A, CMS-10A and CMS-112A, along with testers EC-75717, EC-502036, EC-279309-1 and R-271-1, were identified as good general combiners for seed yield and yield-contributing traits. Among the hybrids, CMS-243A × EC-279309-1, CMS-243A × EC-75717 and CMS-103A × EC-75717 exhibited the highest SCA effects for seed yield per plant. These findings underscore the importance of selecting superior general combiners for traits like oil content and seed yield to develop high-yielding sunflower hybrids.

Exploitation of heterosis in chilli using genetic male sterile lines for red fruit yield with special reference to high rainfall conditions

High-quality red/dry chilli for spice, pharmaceutical and medicinal purposes is a major goal in chilli breeding. The male sterile lines have greater potential for the exploitation of heterosis in chilli to achieve this objective. Genetic male sterile lines with special traits like destalking and ability to withstand high rainfall were involved in heterosis breeding to identify hybrids for commercial and industrial purposes. Forty F1 hybrids were developed by crossing 4 diverse GMS lines with 10 testers using Line × Tester mating design to estimate heterosis, combing ability and gene action. The experiment involving 14 parents and 40 F1s, along with standard variety ‘CH-27’ was laid out in α-lattice square design in three replications during summer 2020 and 2021. The GMS lines MS 9-2 and MS 26-1 along with testers DPCh 10, VVG, DPCh 40 and Him Palam Mirch-2 showed significant GCA for marketable red/dry fruit yield and majority of their component traits. Ten F1 hybrids were identified with superiority for fruit yield based on mean performance, significant heterosis and SCA effects, providing an opportunity to utilize them in value-added products and dried spice purposes viz., MS 9-2 × HPM-2, MS 11-2 × DPCh 40, MS 9-2 × DPCh 40 and MS 9-2 × DPCh 101 with erect fruiting habit and that of MS 9-2 × DPCh 10, MS 26-1 × DPCh 10, MS 9-2 × PBC 535, MS 26-1 × VVG, MS 29-2 × DPCh 10 and MS 26-1 × DPCh 22- C with pendent fruits. The non-additive gene action was predominant in the expression of fruit yield, total red fruits/plant, oleoresin and capsanthin. A significant positive correlation among SCA, economic heterosis and per se performance is an indicative to identify superior hybrids. Multi-location testing of these hybrids shall pave way to exploit them commercially by making them available to the farmers.

Disruption of Energy Metabolism and Reactive Oxygen Species Homeostasis in Honglian Type-Cytoplasmic Male Sterility (HL-CMS) Rice Pollen

Honglian type-cytoplasmic male sterility (HL-CMS) is caused by the inter-communication between the nucleus and mitochondria. However, the mechanisms by which sterility genes regulate metabolic alterations and changes in mitochondrial morphology in the pollen of HL-CMS remains unclear. In this study, we compared the morphological differences between the pollen of the male sterile line YA and the near-isogenic line NIL-Rf6 using hematoxylin and eosin staining as well as 4ʹ,6-diamidino- 2-phenylindole (DAPI) staining. HL-CMS is characterized by gametophytic sterility, where the aborted pollen grains are empty and the tapetal layer remains intact. Transmission electron microscopy was employed to observe mitochondrial morphological changes at the microspore stage, revealing that significant mitochondrial alternations, characterized by the formation of 'large spherical mitochondria', occurred at the binucleate stage in the YA line. Additionally, metabolomics analysis revealed decreased levels of metabolites associated with the carbohydrate and flavonoid pathways. Notably, the decrease in flavonoids was found to contribute to an elevation in reactive oxygen species (ROS) levels. Therefore, we propose a model in which rice fertility is modulated by the levels of pollen carbohydrates and flavonoid metabolites, with impaired mitochondrial energy production and reduced flavonoid biosynthesis being the main causes of ROS accumulation and pollen abortion in rice.

Genetic Diversity Analysis of Monogerm Cytoplasmic Male Sterile and Maintainer Lines of Sugar Beet

Genetic Diversity Analysis of Monogerm Cytoplasmic Male Sterile and Maintainer Lines of Sugar Beet

Improvement of Quality and Disease Resistance for a Heavy-Panicle Hybrid Restorer Line, R600, in Rice (Oryza sativa L.) by Gene Pyramiding Breeding.

The utilization of heavy-panicle hybrid rice exemplifies the successful integration of architectural enhancement and heterosis, which has been widely adopted in the southwest rice-producing area of China. Iterative improvement in disease resistance and grain quality of heavy-panicle hybrid rice varieties is crucial to promote their sustainable utilization. Here, we performed a molecular design breeding strategy to introgress beneficial alleles of broad-spectrum disease resistance and grain quality into a heavy-panicle hybrid backbone restorer line Shuhui 600 (R600). We successfully developed introgression lines through marker-assisted selection to pyramid major genes (Wxb + ALKA-GC + Pigm + Xa23) derived from three parents (Huanghuazhan, I135, I488), which significantly enhance grain quality and confer resistance to rice blast and bacterial blight (BB). The improved parental R600 line (iR600) exhibited superior grain quality and elevated disease resistance while maintaining the heavy-panicle architecture and high-yield capacity of R600. Moreover, the iR600 was crossed with male sterility line 608A to obtain a new heavy-panicle hybrid rice variety with excellent eating and cooking quality (ECQ) and high yield potential. This study presents an effective breeding strategy for rice breeders to expedite the improvement of grain quality and disease resistance in heavy-panicle hybrid rice.

In-Depth Understanding of Cytoplasmic Male Sterility by Metabolomics in Spring Stem Mustard (Brassica juncea var. tumida Tsen et Lee)

Male sterility (MS) caused by aborted pollen is a vital germplasm resource. In this study, metabolomic, transcriptomic, and proteomic analyses were performed to investigate the molecular regulatory mechanism of cytoplasmic male sterility (CMS) in the flower buds of the male sterile line 09-05A and its maintainer line, 09-05B, of Brassica juncea. Our metabolomic analysis revealed that 41 metabolites involved in pollen development and male fertility formation were differentially accumulated between 09-05A and 09-05B at the bi-nucleate stage of B. juncea. Integrated omics indicated that the expression of key genes and proteins in the amino acid and phenylpropanoid metabolic pathways was remarkably downregulated in the flower buds of 09-05A. Furthermore, the abnormal expression of key transcription factor (TF) genes related to tapetum development and pollen wall formation may affect pollen development in the 09-05A CMS line. The results indicated that the downregulated expression level of critical genes and proteins in amino acid metabolism; phenylpropanoid synthesis; and TF genes, such as shikimate kinase, phenylalanine ammonia-lyase, and MYB103, may have led to impaired tapetum and pollen wall development, thereby causing pollen abortion in 09-05A. This study provides new insights into the metabolic and molecular regulatory mechanisms underlying the formation of CMS in B. juncea and lays a foundation for detailed studies on the identity and characteristics of MS-related genes.

Multi-Omics analysis reveals the important role of indole-3-acetic acid homeostasis in male fertility of cotton

Auxin (Indole-3-acetic acid, IAA) is essential for anther development and male fertility, but little is known about its homeostasis in developing anthers due to its complex and diverse synthesis pathways. Here, we employed transcriptomic, targeted metabolomic, and amino acid analyses on a wild type (WT) cotton (Gossypium hirsutum) line SD98–6 and its nearly-isogenic male sterile (MS) line SD98–6A, to delve into the relationship between IAA and anther fertility. In WT anthers, IAA homeostasis was achieved mainly through self-synthesis, conjugate hydrolysis, and polar transport, and accumulation of IAA exhibited an inverted "U" pattern with the highest content observed at the tetrad stage. In MS anthers, no IAA accumulation was observed after the meiosis stage and the IAA content remained constantly low, mainly due to reduction of the substrates (phenylalanine and tryptophan) for IAA synthesis, and significantly decreased expression of the genes involved in IAA synthesis. Meanwhile, carbohydrate metabolism pathways directly contributing to IAA synthesis and synthesis of amino acids were malfunctional in MS anthers based on the expression profile of the metabolic genes and content measurement. These results provide valuable insights into the IAA homeostasis in cotton anthers and imply that genes related to IAA homeostasis are potential targets for development of IAA-sensitive male sterile cotton lines.

HSP70 and APX1 play important roles in cotton male fertility by mediating ROS homeostasis

Male sterility is used in the production of hybrid seeds and can improve the breeding efficiency of cotton hybrids. Reactive oxygen species is closely associated with the tapetum and pollen development, but their relationship in cotton male fertility remains unclear. In this study, we comprehensively compared the cytology and proteome of the anthers from an Upland cotton (Gossypium hirsutum) material, Shida 98 (WT), and its nearly-isogenic male sterile line Shida 98A (MS). Cytology indicated delayed PCD in the tapetum and defects in microspores in MS anthers. And further studies revealed disruption of ROS homeostasis. Proteomic analysis identified proteins with differential abundance mainly being related to redox homeostasis, protein folding, and apoptotic signaling pathways. GhAPX1 interacted with GhHSP70 and played a crucial role in the development of cotton anthers. Exogenous application of HSP70 inhibitor increased H2O2 content and decreased the activity of APX1 and pollen viability. The GhAPX1 mutants generated by CRISPR/Cas9-mediated gene editing exhibited premature degradation of the tapetum, significant decrease in pollen viability, and significant increase in H2O2 content. Altogether, our results imply HSP70 and APX1 being the key players jointly regulating male fertility by mediating ROS homeostasis. These results provide insights into the proteins associated with male fertility.

Stigma and Glume Characteristics Synergistically Determine the Stigma Exsertion Rate in Thermo-Photo-Sensitive Genic Male Sterile Wheat.

Wheat hybrids have been widely demonstrated to have remarkable heterosis or hybrid vigor in increasing yield potential and stability since the 1960s. Two-line hybrid wheat can achieve higher yields than local varieties, especially in marginal environments. However, the commercial application of hybrid wheat is hindered by higher seed costs, primarily due to lower yields in hybrid seed production. Stigma exsertion has been verified as a decisive factor in increasing rice's hybrid seed yield, but more investigation is needed in hybrid wheat breeding and production. In this study, four thermo-photo-sensitive genic male sterile lines, including K41S, K64S, K66S, and K68S, with different stigma exsertion rates (SERs) were used to compare the differences in floral architecture relative to stigma exsertion over two growing seasons. The results revealed that the K41S and K64S exhibited a relatively higher SER at 21.87% and 22.81%, respectively. No exserted stigma was observed in K66S, and K68S had an SER of only 0.82%. This study found that the stigma length, glume width and the length-width ratio of the glume were significantly correlated with the SER, with correlation coefficients of 0.46, -0.46 and 0.60, respectively. Other stigma features such as the branch angle, stretch width and hairbrush length, as well as the glume length, also had a weakly positive correlation with SER (r = 0.09-0.27). For K41S and K64S, the SER was significantly affected by the differences in the stigma branch angle and stigma stretch width among florets. A cross-pollination survey showed that the out-crossing ability of florets with an exserted stigma was about three times as high as that of florets with a non-exserted stigma. As a result, the stigma-exserted florets that accounted for 21.87% and 22.81% of the total florets in K41S and K64S produced 46.80% and 48.53% of the total cross-pollinated seeds in both sterile lines. These findings suggest that a longer stigma combined with a slender glume appears to be the essential floral feature of stigma exsertion in sterile wheat lines. It is expected that breeding and utilizing sterile lines with a higher SER would be a promising solution to cost-effective hybrid wheat seed production.

Morphological and cytological assessments reveal pollen degradation causes pollen abortion in cotton cytoplasmic male sterility lines

BackgroundUnderstanding the mechanism of male sterility is crucial for producing hybrid seeds and developing sterile germplasm resources. However, only a few cytoplasmic male sterility (CMS) lines of cotton have been produced due to several challenges, like inadequate variation of agronomic traits, incomplete sterility, weak resilience of restorer lines, and difficulty in combining strong dominance. Therefore, the morphological and cytological identification of CMS in cotton will facilitate hybrid breeding.ResultsTwo F2 segregating populations of cotton were constructed from cytoplasmic male sterile lines (HaA and 01A, maternal) and restorer lines (HaR and 26R, paternal). Genetic analysis of these populations revealed a segregation ratio of 3:1 for fertile to sterile plants. Phenotypic analysis indicated no significant differences in traits of flower bud development between sterile and fertile plants. However, sterile plants exhibited smaller floral organs, shortened filament lengths, and anther atrophy on the flowering day in comparison with the fertile plants. When performed scanning electron microscopy (SEM), the two F2 populations revealed morphological variations in the anther epidermis. Cellular analysis showed no significant differences in pollen development before pollen maturation. Interestingly, between the pollen maturation and flowering stages, the tapetum layer of sterile plants degenerated prematurely, resulting in abnormal pollen grains and gradual pollen degradation.ConclusionThe results of this study suggest that fertility-restoring genes are controlled by a single dominant gene. Sterile plants exhibit distinctive floral morphology, which is characterized by stamen atrophy and abnormal anthers. Pollen abortion occurs between pollen maturity and flowering, indicating that premature tapetum degradation may be the primary cause of pollen abortion. Overall, our study provides a theoretical basis for utilizing CMS in hybrid breeding and in-depth investigation of the dominant configuration of cotton hybrid combinations, mechanisms of sterility, and the role of sterile and restorer genes.

The characteristic analysis of TaTDF1 reveals its function related to male sterility in wheat (Triticum aestivum L.)

BackgroundThe male sterile lines are an important foundation for heterosis utilization in wheat (Triticum aestivum L.). Thereinto, pollen development is one of the indispensable processes of wheat reproductive development, and its fertility plays an important role in wheat heterosis utilization, and are usually influencing by genes. However, these key genes and their regulatory networks during pollen abortion are poorly understood in wheat.ResultsDEFECTIVE IN TAPETAL DEVELOPMENT AND FUNCTION 1 (TDF1) is a member of the R2R3-MYB family and has been shown to be essential for early tapetal layer development and pollen grain fertility in rice (Oryza sativa L.) and Arabidopsis thaliana. In order to clarify the function of TDF1 in wheat anthers development, we used OsTDF1 gene as a reference sequence and homologous cloned wheat TaTDF1 gene. TaTDF1 is localized in the nucleus. The average bolting time of Arabidopsis thaliana overexpressed strain (TaTDF1-OE) was 33 d, and its anther could be colored normally by Alexander staining solution, showing red. The dominant Mosaic suppression silence-line (TaTDF1-EAR) was blue-green in color, and the anthers were shrimpy and thin. The TaTDF1 interacting protein (TaMAP65) was confirmed using Yeast Two-Hybrid Assay (Y2H) and Bimolecular-Fluorescence Complementation (BiFC) experiments. The results showed that downregulated expression of TaTDF1 and TaMAP65 could cause anthers to be smaller and shrunken, leading to pollen abortion in TaTDF1 wheat plants induced by virus-induced gene-silencing technology. The expression pattern of TaTDF1 was influenced by TaMAP65.ConclusionsThus, systematically revealing the regulatory mechanism of wheat TaTDF1 during anther and pollen grain development may provide new information on the molecular mechanism of pollen abortion in wheat.

Overexpression of sesame O-acetylserine(thiol)lyase induces male sterility by delaying tapetum programmed cell death

Male sterile lines are key resources for hybrid seed production and for ensuring high varietal purity. However, the genes and mechanisms underlying sesame male sterility remain largely unknown. Hence, this study identified an O-acetylserine(thiol)lyase gene SiOASTL1 and functionally characterized its roles in inducing defective anther development. Spatiotemporal expression analysis revealed that SiOASTL1 is significantly (2.7 fold) up-regulated in sterile sesame anthers at the microspore stage compared with fertile ones. Sequence and phylogenetic analyses showed that SiOASTL1 is homologous to Arabidopsis OAS-TL plastid isoforms. We thus overexpressed SiOASTL1 in Arabidopsis to unravel its regulatory roles. Cytological observation revealed that SiOASTL1 overexpression transformed transgenic plants into male sterile lines arising at the microspore development stage. SiOASTL1 overexpression decreased cysteine biosynthesis and down-regulated the expression of the sporopollenin synthesis-related genes, including AtTKPR1, AtTKPR2, AtPKSA, and AtPKSB in transgenic Arabidopsis. Consequently, the tapetum programmed cell death (PCD) was delayed, resulting in the formation of defective pollen grains with irregular walls and empty cytoplasm. Our findings prove that the induction of SiOASTL1 expression disrupts pollen development and contributes to sesame male sterility. Moreover, these results suggest that genetic manipulation of SiOASTL1 expression may facilitate the development of new hybrid varieties in sesame and other crops.

Comparative transcriptome analysis reveals the impact of daily temperature difference on male sterility in photo-thermo-sensitive male sterile wheat

BackgroundPhoto-thermo-sensitive male sterility (PTMS), which refers to the male sterility triggered by variations in photoperiod and temperature, is a crucial element in the wheat two-line hybrid system. The development of safe production and efficient propagation for male sterile lines holds utmost importance in two-line hybrid wheat. Under the stable photoperiod condition, PTMS is mainly induced by high or low temperatures in wheat, but the effect of daily temperature difference (DTD) on the fertility conversion of PTMS lines has not been reported. Here, three BS type PTMS lines including BS108, BS138, and BS366, as well as a control wheat variety J411 were used to analyze the correlation between fertility and DTD using differentially sowing tests, photo-thermo-control experiments, and transcriptome sequencing.ResultsThe differentially sowing tests suggested that the optimal sowing time for safe seed production of the three PTMS lines was from October 5th to 25th in Dengzhou, China. Under the condition of 12 h 12 °C, the PTMS lines were greatly affected by DTD and exhibited complete male sterility at a temperature difference of 15 °C. Furthermore, under different temperature difference conditions, a total of 20,677 differentially expressed genes (DEGs) were obtained using RNA sequencing. Moreover, through weighted gene co-expression network analysis (WGCNA) and KEGG enrichment analysis, the identified DEGs had a close association with “starch and sucrose metabolism”, “phenylpropanoid biosynthesis”, “MAPK signaling pathway-plant”, “flavonoid biosynthesis”, and “cutin, and suberine and wax biosynthesis”. qRT-PCR analysis showed the expression levels of core genes related to KEGG pathways significantly decreased at a temperature difference of 15 ° C. Finally, we constructed a transcriptome mediated network of temperature difference affecting male sterility.ConclusionsThe findings provide important theoretical insights into the correlation between temperature difference and male sterility, providing guidance for the identification and selection of more secure and effective PTMS lines.

Estimation of heterosis on CGMS based pigeonpea

Thirty-five hybrids generated from seven cytoplasmic male sterile lines and five fertility restorer lines were tested for determining heterosis. All studied traits except pod length, number of seeds per pod, and leaf area showed significant variations between the parents indicating a sufficient variability amongthe parents (lines and testers). The mean sum of squares of the hybrids suggested high heterosis for studied traits except for test weight and number of branches per plant. The findings showed noteworthy and affirmative relative heterosis for eaj hybrid. Top three hybrids viz. CMS GT 1615 A × GTR 105 (28.34% and 38.97%), CMS GT 1615 A × GTR 18 (24.36% and 34.66%) and CMS GT 1615 × GTR 23 (22.23% and 32.35%) identified for seed yield and its contributing traits on the basis of standard heterosis against standard checks GTH 1 and GT 101, respectively. These can be exploited commercially for heterosis breeding in pigeonpea.

Marker assisted selection of male sterile (CMS-S) lines among short day Indian onion genotypes

Marker assisted selection of male sterile (CMS-S) lines among short day Indian onion genotypes

Genome-Wide Identification and Expression Analysis of Sucrose Transporter Gene Family in Wheat Lines under Heat Stress

Sucrose transporters (SUTs) play vital roles in phloem sucrose unloading and transportation in wheat grains. However, the genomic information regarding the SUT gene family and their expression patterns in response to heat stress in grains of male-sterile wheat (Triticum aestivum L.) lines has not been systematically studied. In this study, a thorough examination of the wheat SUT gene family was conducted, focusing on their expression patterns in male-sterile lines under heat stress conditions in grain tissues. A total of 19 SUT genes were identified, with phylogenetic analysis indicating their classification into five distinct groups. Polyploidization was identified as a substantial factor in the expansion of SUT genes, with segmental duplication being the predominant mechanism driving the evolutionary expansion of the SUT gene family in wheat. Transcriptome data indicate that the expression levels of TaSUT1 and TaSUT2 were higher than other SUT genes in grains of male-sterile lines. The TaSUT1 expression showed a gradual decreasing trend, while TaSUT2 showed a reverse trend with the process of grain filling. After heat stress, the TaSUT1 expression in grains of male-sterile lines was first significantly increased and then significantly decreased with the filling stage extension, aligning with the observed trend of sucrose levels, indicating that heat stress may decrease the grain weight by reducing sucrose unloading and transportation process in grains. These results provide a systematic analysis of the SUT gene family and lay a theoretical foundation for us to study the grain filling of male-sterile lines in response to abiotic stress.