Sweet Sorghum Cultivars Research Articles

Unveiling the Genomic Symphony: Identification Cultivar-Specific Genes and Enhanced Insights on Sweet Sorghum Genomes Through Comprehensive superTranscriptomic Analysis.

Sorghum (Sorghum bicolor (L.) Moench) is a multipurpose crop grown for food, fodder, and bioenergy production. Its cultivated varieties, along with their wild counterparts, contribute to the core genetic pool. Despite the availability of several re-sequenced sorghum genomes, a variable portion of sorghum genomes is not reported during reference genome assembly and annotation. The present analysis used 223 publicly available RNA-seq datasets from seven sweet sorghum cultivars to construct superTranscriptome. This approach yielded 45,864 Representative Transcript Assemblies (RTAs) that showcased intriguing Presence/Absence Variation (PAV) across 15 published sorghum genomes. We found 301 superTranscripts were exclusive to sweet sorghum, including 58 de novo genes encoded core and linker histones, zinc finger domains, glucosyl transferases, cellulose synthase, etc. The superTranscriptome added 2,802 new protein-coding genes to the Sweet Sorghum Reference Genome (SSRG), of which 559 code for different transcription factors (TFs). Our analysis revealed that MULE-like transposases were abundant in the sweet sorghum genome and could play a hidden role in the evolution of sweet sorghum. We observed large deletions in the D locus and terminal deletions in four other NAC encoding loci in the SSRG compared to its wild progenitor (353) suggesting non-functional NAC genes contributed to trait development in sweet sorghum. Moreover, superTranscript-based methods for Differential Exon Usage (DEU) and Differential Gene Expression (DGE) analyses were more accurate than those based on the SSRG. This study demonstrates that the superTranscriptome can enhance our understanding of fundamental sorghum mechanisms, improve genome annotations, and potentially even replace the reference genome.

Physiological, Metabolome and Gene Expression Analyses Reveal the Accumulation and Biosynthesis Pathways of Soluble Sugars and Amino Acids in Sweet Sorghum under Osmotic Stresses.

Water scarcity is a major environmental constraint on plant growth in arid regions. Soluble sugars and amino acids are essential osmolytes for plants to cope with osmotic stresses. Sweet sorghum is an important bioenergy crop and forage with strong adaptabilities to adverse environments; however, the accumulation pattern and biosynthesis basis of soluble sugars and amino acids in this species under osmotic stresses remain elusive. Here, we investigated the physiological responses of a sweet sorghum cultivar to PEG-induced osmotic stresses, analyzed differentially accumulated soluble sugars and amino acids after 20% PEG treatment using metabolome profiling, and identified key genes involved in the biosynthesis pathways of soluble sugars and amino acids using transcriptome sequencing. The results showed that the growth and photosynthesis of sweet sorghum seedlings were significantly inhibited by more than 20% PEG. After PEG treatments, the leaf osmotic adjustment ability was strengthened, while the contents of major inorganic osmolytes, including K+ and NO3-, remained stable. After 20% PEG treatment, a total of 119 and 188 differentially accumulated metabolites were identified in the stems and leaves, respectively, and the accumulations of soluble sugars such as raffinose, trehalose, glucose, sucrose, and melibiose, as well as amino acids such as proline, leucine, valine, serine, and arginine were significantly increased, suggesting that these metabolites should play key roles in osmotic adjustment of sweet sorghum. The transcriptome sequencing identified 1711 and 4978 DEGs in the stems, as well as 2061 and 6596 DEGs in the leaves after 20% PEG treatment for 6 and 48 h, respectively, among which the expressions of genes involved in biosynthesis pathways of sucrose (such as SUS1, SUS2, etc.), trehalose (including TPS6), raffinose (such as RAFS2 and GOLS2, etc.), proline (such as P5CS2 and P5CR), leucine and valine (including BCAT2), and arginine (such as ASS and ASL) were significantly upregulated. These genes should be responsible for the large accumulation of soluble sugars and amino acids under osmotic stresses. This study deepens our understanding of the important roles of individual soluble sugars and amino acids in the adaptation of sweet sorghum to water scarcity.

Sorghum bicolor L. Stalk Stiffness Is Marginally Affected by Time of Day under Field Conditions

This study sought to better understand how time of day (ToD) or turgor pressure might affect the flexural stiffness of sweet sorghum stalks and potentially regulate stalk lodging resistance. Stalk flexural stiffness measured across a 48 h period in 2019 showed a significant diurnal association with leaf water potential and stalk flexural stiffness. While the correlation between stalk flexural stiffness and this proxy for internal turgor status was statistically significant, it only accounted for roughly 2% of the overall variance in stiffness. Given that turgor status is a dynamic rather than fixed physiological variable like the cellular structure, these data suggest that internal turgor plays a small yet significant role in influencing the flexural stiffness of fully mature stalks prior to a stalk lodging event. The association was assessed at earlier developmental stages across three distinct cultivars and found not to be significant. Panicle weight and stalk basal weight, but not stalk Brix or water content, were found to be better predictors of stalk flexural stiffness than either ToD or turgor status. Observation across three cultivars and four distinct developmental stages ranging from the vegetative to the hard-dough stages suggests that stalk flexural stiffness changes significantly as a function of time. However, neither ToD nor turgor status appear to meaningfully contribute to observed variations in stalk flexural stiffness in either individual stalks or across larger populations. As turgor status was not found to meaningfully influence stalk strength or flexural stiffness at any developmental time point examined in any of the three sweet sorghum cultivars under study, turgor pressure likely offers only inconsequential contributions to the biomechanics underlying sweet sorghum stalk lodging resistance.

Optimizing Bioethanol (C2H5OH) Yield of Sweet Sorghum Varieties in a Semi-Arid Environment: The Impact of Deheading and Deficit Irrigation

Bioethanol production offers promise in mitigating environmental impacts from ethanol consumption despite water scarcity. This study endeavors to evaluate the nuanced influence of different deheading times (45 days before harvest, 21 days before harvest, and no deheading) along with varying water regimes on select sweet sorghum cultivars (Honey, Willy, MN1500, and Atlas), focusing on yield traits, theoretical ethanol production, and water productivity. Findings underscore the substantial impact of cultivation practices on bioethanol yield. A water deficit ranging from 30% to 70% resulted in a discernible reduction in stalk yields of 17.86% to 18.54% and in sugar yields of 0.2 to 0.31 Mg ha−1, accompanied by a corresponding decline in theoretical ethanol yield of 120.9 to 180.9 L ha−1. Additionally, notable enhancements in Brix and sugar content of 16.32% to 18.42% and 16.81% to 19.03%, respectively, were observed across both seasons. Of particular significance, the Honey variety, subjected to a 30% water deficit and deheading at 21 days before harvest, demonstrated exceptional growth and yield characteristics. These empirical insights furnish valuable guidance for optimizing sweet sorghum cultivation practices, thereby augmenting sustainable bioethanol production and propelling forward the frontier of renewable energy technologies towards a more environmentally sustainable future.

Effects of harvest height and time on hay yield and quality of some sweet sorghum and sorghum Sudangrass hybrid varieties.

This experiment was conducted in the Research and Application Field of Canakkale Onsekiz Mart University, Faculty of Agriculture, during the 2020 and 2021 summer period. The objective of this experiment was to determine the effects of different harvesting heights on forage yields and crude ash, fat, protein, and carbon and nitrogen content of leaves and stalks of sweet sorghum (SS) and sorghum sudangrass hybrid (SSH) cultivars. Nutri Honey and Nutrima varieties of SSH and the M81-E and Topper-76 varieties of SS were used in this study. The experiment was conducted using the randomized complete block design with four replications. The main plots each included two early and late varieties of SS and SSH cultivars, while the subplots were used to test different harvesting heights (30, 60, 90, 120, 150 cm) and physiological parameters of each crop. The results of this study showed that dry forage yields increased with plant growth, with the amount of forage produced at the end of the growth cycle increasing 172.2% compared to the early growth stages. Carbon (C) content of leaves decreased by 6.5%, nitrogen (N) by 46%, crude protein (CP) by 54%, crude fat (CF) by 34%, while crude ash (CA) content increased by 6% due to the increase in plant height harvest. At the same time, in parallel with the increase in plant height at harvest, the nitrogen content of the stems of the plants decreased by 87%, crude protein by 65%, crude ash by 33% and crude fat by 41%, while the carbon content increased by 4%. As plant height at harvest increased, hay yield increased but nutrient contents of the hay decreased. However, the Nutrima, Nutri Honey and M81-E sorghum cultivars, harvested three times at heights of 90 to 120 cm, are recommended for the highest yield.

Feed Quality of Sweet Sorghum Grains

Sweet sorghum crop produces grains at its ear-head which can be utilised as food and feed, produces stalks for the production of syrup, bio-ethanol, bio-diesel, bagasse and green foliage for use as organic fertiliser and excellent animal fodder. Approximately 4000 sweet sorghum cultivars are spread over the globe, providing a broad and varied genetic foundation for the development of highly productive, region-specific cultivars. A study was conducted to assess the grains of selected 10 different sweet sorghum varieties for the feed quality characters. For this aim, ADF, NDF, ADL, DMD, DMI, TDN, RFV, DE and ME values of sweet sorghum grains were determined. As a result of the study, crude ash, CP, ADF, NDF, ADL, DMD, DMI, RFV, TDN, DE and ME values were determined as 0.19-3.74%; 9.03-11.05%; 10.0-24.6%; 24.3-38.0%; 1.07-9.13%; 69.69-81.09%; 3.16-4.94%; 170.5-309.5%; 63.85-74.84%; 3.25-3.74 MJ/kg and 9.85-11.78 Mcal/kg, respectively. Variety "Smith" stands out with its ADF, NDF and ADL characteristics. Gülşeker, USDA-Taiwan and Erdurmuş varieties were significant in terms of CP. Ulusoy variety stands out with DMI, TDN, RFV, DE and ME.

Evaluation of Bioethanol Yield Potential of Different Sweet Sorghum Cultivars Grown as a Second Crop Under Eastern Mediterranean Conditions

Sweet sorghum has a high potential for bioethanol production due to its high fermentable sugar content and biomass yield. This research was carried out to evaluate bioethanol yield potential of six sweet sorghum cultivars (ICSV 93046, ICSV 700, Black Amber, White African, Gülşeker, and Red’s Red) during summer growing season of 2022 under eastern Mediterranean conditions. Cultivars were significantly differed for brix degree, green herbage yield, juice yield, and juice ethanol yields in the study. ICSV 93046 produced the significantly highest fresh stem yield (58811 kg/ha), juice yield (16105 kg/ha), and juice ethanol yield (1194 L/ha) and followed by ICSV 700. On the other hand, the significantly lowest brix degree (10.5 ◦ Bx) and juice ethanol yield (322 L/ha) were achieved by Gülşeker. These results suggested that ICSV 93046 was the most suitable cultivar to be grown as a second crop for bioethanol production under eastern Mediterranean conditions.

Effects of Different Harvesting Practices on Forage Yield and Quality Characteristics in some Sweet Sorghum Cultivars

Effects of Different Harvesting Practices on Forage Yield and Quality Characteristics in some Sweet Sorghum Cultivars

Screening of Selected Cultivars of Sweet Sorghum for Phytochemicals and In vitro Evaluation of Their Antihyperglycemic and Cytotoxic Activity

Background: Sorghum, a wonder millet, is well known for its beneficial phytochemical profiles. In comparative terms, juice from sweet sorghum has better commercial potential as syrup in several food-based applications. Various sweet sorghum differs in their profile of various phytochemicals, which can impact the commercial potential of sweet sorghum juice. Methods: Our previous works on cultivars developed at ICAR-IIMR were screened for phytochemical, sugar and mineral profile. To give a holistic view of the phytochemical profile of sweet sorghum varieties, the present study is attempted to evaluate the total phenolic and flavonoid content, antihyperglycaemic and cytotoxic profile of the components present in the varieties CSV19SS, SSV84, SSV74. The phytochemical footprint of sweet sorghum juice was studied through HRLCMS. Results: The results showed ethyl acetate extract of SSV84 having potential antihyperglycemic effects with an IC50 of 22.156 ± 0.9 µg/ml (α-glucosidase) and 0.070 ± 0.02 mg/ml (α-amylase) with a comparatively higher phenolic (232.6 ± 1 mg GAE/g) and flavonoid (138.18 ± 0.9 mg QE/g) content. The chloroform extract of SSV 84 showed a higher cytotoxic effect at an IC50 of 165.502 ± 7 µg/ml (HeLa cells) and 237.895 ± 15 µg/ml (Hep G2 cells). HRLCMS profile of SSV 84 showed the presence of long-chain fatty acids in hexane extract. Anthraquinones, carotenoids, xanthophylls, cinnamic acid and derivatives, and isoflavones were present in chloroform extract, while Ethyl acetate extract was rich in phenolic acids and also consisted of coumarins, quinones, alkaloids, and terpenoids. Conclusion: The high cytotoxic and antihyperglycemic activities of extracts can be attributed to the presence of these phytochemicals.

Sweet Sorghum as a Potential Fallow Crop in Sugarcane Farming for Biomethane Production in Queensland, Australia

Biogas from lignocellulosic feedstock is a promising energy source for decentralized renewable electricity, heat, and/or vehicle fuel generation. However, the selection of a suitable energy crop should be based on several factors such as biomass yields and characteristics or biogas yields and economic returns if used in biorefineries. Furthermore, the food-to-fuel conflict for the use of a specific energy crop must be mitigated through smart cropping techniques. In this study, the potential use of sweet sorghum as an energy crop grown during the fallow periods of sugarcane cultivation was evaluated. Nine sweet sorghum cultivars were grown on sandy loam soil during September 2020 in North Queensland, Australia. The overall results showed that the crop maturity had a profound influence on chemical composition and biomass yields. Further, the total insoluble and soluble sugar yields varied among the tested cultivars and were dependent on plant height and chemical composition. The biomass yields ranged from 46.9 to 82.3 tonnes/hectare (t/ha) in terms of the wet weight (w/w) of the tested cultivars, with the SE-81 cultivar registering the highest biomass yield per hectare. The gross energy production was determined based on the chemical composition and methane yields. Biochemical methane potential (BMP) studies in batch experiments at 37 °C showed that methane yields of 175 to 227.91 NmL CH4/gVSadded were obtained from the tested cultivars. The maximum methane yield of 227.91 NmL CH4/gVSadded was obtained for cultivar SE-35. However, SE-81 produced the highest methane yields on a per hectare basis (3059.18 Nm3 CH4/ha). This is equivalent to a gross energy value of 761.74 MWh/year or compressed biomethane (BioCNG) as a vehicle fuel sufficient for 95 passenger cars travelling at 10,000 km per annum. Overall, this study demonstrated that sweet sorghum is a potential energy crop for biogas production that could be cultivated during the fallow period of sugarcane cultivation in Queensland.

Maximizing Total Sugar Recovery from Low Severity Pretreatment-Hydrolysis of Sweet Sorghum Bagasse Through Cultivar Selection and Process Optimization

The nature of a sweet sorghum cultivar influences the recovery of sugars from the bagasse during pretreatment. The sugars recovered are used in applications for conversion to high-value products such as alcohols, organic acids, and other fuels and chemicals. The severity of the pretreatment used plays a crucial role in the yield and quality of the sugars that can be recovered. Therefore, a strategic approach was taken to lower the severity of the pretreatment process to a combined severity factor (CSF) value of 0.48, whilst maintaining a high level of total-sugar recovery (i.e. 68% (w/w) and higher). This was achieved by screening 23 sweet sorghum cultivars for high-performance characteristics at low-severity conditions and optimizing the pretreatment process conditions. The pretreatment conditions included time, temperature, and acid concentration ranges of 5 to 60 min, 150 to 210 oC, and 0.00–0.96% (w/w) H2SO4, respectively. Cultivar AP6 was identified as the best performer, producing the highest total sugar yield of 78.17%. A reduction in total by-product formation from 4.79 to 2.79 g/100 g biomass was also observed. Three preferred cultivars selected for pilot scale pretreatment using steam explosion resulted in maximum total sugar recoveries that exceeded 80% (w/w). Cultivar selection provides an opportunity to utilize sweet sorghum bagasse that will liberate sugars at desired yields while reducing the generation of by-products by implementing low severity pretreatments.

Physiological and Transcriptional Analyses Provide Insight into Maintaining Ion Homeostasis of Sweet Sorghum under Salt Stress

Sweet sorghum is an important bioenergy grass and valuable forage with a strong adaptability to saline environments. However, little is known about the mechanisms of sweet sorghum coping with ion toxicity under salt stresses. Here, we first evaluated the salt tolerance of a sweet sorghum cultivar “Lvjuren” and determined its ion accumulation traits under NaCl treatments; then, we explored key genes involved in Na+, Cl−, K+ and NO3− transport using transcriptome profiling and the qRT-PCR method. The results showed that growth and photosynthesis of sweet sorghum were unaffected by 50 and 100 mM NaCl treatments, indicative of a strong salt tolerance of this species. Under NaCl treatments, sweet sorghum could efficiently exclude Na+ from shoots and accumulate Cl− in leaf sheaths to avoid their overaccumulation in leaf blades; meanwhile, it possessed a prominent ability to sustain NO3− homeostasis in leaf blades. Transcriptome profiling identified several differentially expressed genes associated with Na+, Cl−, K+ and NO3− transport in roots, leaf sheaths and leaf blades after 200 mM NaCl treatment for 6 and 48 h. Moreover, transcriptome data and qRT-PCR results indicated that HKT1;5, CLCc and NPF7.3-1 should be key genes involved in Na+ retention in roots, Cl− accumulation in leaf sheaths and maintenance of NO3− homeostasis in leaf blades, respectively. Many TFs were also identified after NaCl treatment, which should play important regulatory roles in salt tolerance of sweet sorghum. In addition, GO analysis identified candidate genes involved in maintaining membrane stability and photosynthetic capacity under salt stresses. This work lays a preliminary foundation for clarifying the molecular basis underlying the adaptation of sweet sorghum to adverse environments.

Enhancing energy potential of sweet sorghum by biomass ash compost in the context of climate change and agroecosystem

Recycling renewable energy waste, nutrient-rich biomass ash, via composting for biofuel crop fertilization is feasible for integrating waste and crop production to close the nutrient loop and mitigate greenhouse gaseous emissions. The primary purpose of the present study was to investigate the nutrient-rich compost on energy crop production, energy yield, and carbon input to the soil via the root under two different agroclimatic conditions. Compost treatments exhibited superior biomass growth in both sweet sorghum cultivars landrace and Gulseker in both regions. The effect was more potent in the temperate region (Sakarya) due to evenly precipitation during the entire plant growth period. On the other hand, biomass ash compost treatments induced higher Brix values in a region with high solar energy and hot and dry (Bitlis). However, the maximum juice yield (2387 L ha−1) and juice ethanol yield (1583 L ha−1) were obtained from the Sakarya region with cultivar Gulseker due to its high cane yield (68.76 t ha−1). The energy yield of sweet sorghum bagasse ranged from 92 to 282 GJ ha−1, and the maximum value was obtained from compost treatment in Sakarya regions. Compost also promoted an increase in the carbon content of root tissue, and sweet sorghum can bind around 1250 kg ha−1 recalcitrant forms of carbon to the soil via root tissue. Overall results indicate beneficial effects of compost on plant growth, biomass fuel, and root carbon storage in the soil, which could help waste management and agriculture together towards biofuel production with a more circular economy.

Allelopathic Potential of Sweet Sorghum Root Exudates and Identification of the Relevant Allelochemicals

This study determined the influence of cattle manure compost, chemical fertilizers, and mulch on the growth of weeds, sugar content, and growth of sweet sorghum (Sorghum bicolor (L.) Moench). The inhibitory potential of root exudates from two sweet sorghum cultivars (A; K1151 and B; K3351) was also evaluated. Chemical fertilizers increased the plant height, stem weight, biomass production, and sugar content of sweet sorghum. The total phenolic contents in the root exudates were 22.93 mg gallic acid equivalent per g dry weight (GAE/g DW) for cultivar A and 15.66 mg GAE/g DW for cultivar B. The total flavonoid contents in the root exudates were 14.77 mg rutin equivalent per g dry weight (RE/g DW) for cultivar A and 12.44 mg RE/g DW for cultivar B. The leaf extracts contained a higher amount of total phenolics and flavonoids than that of the stem and root. The inhibitory level of the root exudates from cultivar A on the seed germination and shoot growth of lettuce was greater than for cultivar B. Six phenolic acids, including protocatechuic, p-hydroxybenzoic, syringic, sinapic, p-coumaric, and benzoic acids, were detected from root exudates, root, stem, and leaf of both cultivars. The amount of p-coumaric acid in root exudates was greater than the other plant parts; however, protocatechuic acid was only found in the root exudates. p-Coumaric and protocatechuic acids may play an important role in the allelopathy of sweet sorghum to help reduce the dependence on synthetic herbicides in agricultural practice. This study indicates that cultivation methods and fertilization are important to increase both agronomic and economic values of sweet sorghum in agricultural production.

Biomass and Dry Matter Yield Potential of Some Early Sweet Sorghum (Sorghum bicolor var. saccharatum (L.) Mohlenbr.) Genotypes

Sweet sorghum plant is a warm season annual crop. It can be used for animal feeding in the one-cut agricultural system. Sweet sorghum is grown for the purpose of fresh and dry grass and for silage production. Biomass of sweet sorghum is nutritive due to sweet sorghum stalk contains 15-20% sugar. The study aimed to determine biomass, dry matter yield and some agricultural characteristics of some early sweet sorghum genotypes. Research was carried out during the second crop-growing season of 2016 at the Eyyubiye campus of experimental area of the Harran University in Sanliurfa, Turkiye. The experiment was designed as complete randomized blocks design with four replicates. This study utilized 12 early sweet sorghum genotypes as crop material. The experiment investigated some yield characteristics such as cluster formation period, plant height, stalk diameter, stalk ratio, leaf ratio, cluster ratio, dry matter yield and biomass yield. Results showed significant differences between the genotypes for tested characteristics (P≤0.01). Cluster formation period values ranged from 54.25 to 69.00 day, plant height from 252.25 to 340.75 cm, stalk diameter from 19.15 to 25.60 mm, stalk ratio from 75.72% to 86.75%. Leaf ratio values varied between 8.83% and 15.98%, cluster ratio between 4.40% and 10.31%. Dry matter yield values were between 2918.12 and 8456.25 kg da-1, biomass yield values between 9283.5 and 18400.0 kg da-1. Findings revealed that UNLY-hybrid-4, Rox Orange, Blue Ribben, and Colman sweet sorghum cultivars gave higher values than others in terms of plant height, dry matter yield and biomass yield.

Composition and diversity of root-inhabiting bacterial microbiota in the perennial sweet sorghum cultivar at the maturing stage

Composition and diversity of root-inhabiting bacterial microbiota in the perennial sweet sorghum cultivar at the maturing stage

Root-associated fungal microbiota of the perennial sweet sorghum cultivar under field growth.

Root-associated fungal microbiota, which inhabit the rhizosphere, rhizoplane and endosphere, have a profound impact on plant growth and development. Sorghum bicolor (L.) Moench, also called broomcorn or sweet sorghum, is a multipurpose crop. The comparison between annual and perennial sweet sorghum cultivars in terms of plant growth, as well as their interactions with belowground fungal microbiota, is still poorly understood, although there has been growing interest in the mutualism between annual sweet sorghum and soil bacteria or bacterial endophytes. In this study, the perennial sweet sorghum cultivar N778 (N778 simply) and its control lines TP213 and TP60 were designed to grow under natural field conditions. Bulk soil, rhizosphere soil and sorghum roots were collected at the blooming and maturity stages, and then the fungal microbiota of those samples were characterized by high-throughput sequencing of the fungal ITS1 amplicon. Our results revealed that the alpha diversity of the fungal microbiota in rhizosphere soil and root samples was significantly different between N778 and the two control lines TP213 and TP60 at the blooming or maturity stage. Moreover, beta diversity in rhizosphere soil of N778 was distinct from those of TP213 and TP60, while beta diversity in root samples of N778 was distinct from those of TP213 but not TP60 by PCoA based on Bray-Curtis and WUF distance metrics. Furthermore, linear discriminant analysis (LDA) and multiple group comparisons revealed that OTU4372, a completely unclassified taxon but with symbiotroph mode, was enriched in sorghum roots, especially in N778 aerial roots at the blooming stage. Our results indicate that Cladosporium and Alternaria, two fungal genera in the rhizosphere soil, may also be dominant indicators of sorghum yield and protein content in addition to Fusarium at the maturity stage and imply that the perennial sweet sorghum N778 can primarily recruit dominant psychrotolerant bacterial taxa but not dominant cold-tolerant fungal taxa into its rhizosphere to support its survival below the freezing point.

Potential of sweet sorghum (Sorghum bicolor L.) cultivars under different water regimes for some agronomic performances, juice yield and related traits

Continued evaluation for drought tolerance on crops with high potential is an important factor in mitigating the effects of climate change and in the long run secure enough food and alleviate world hunger. Sweet sorghum is one of the multifunctional crops which has shown potential as food, industrial and bioenergy source, thus it is important to study its potential under various conditions. A pot study was conducted in early rainy season (March-August 2020), the experiment was arranged 3 × 2 factorial in RCBD with four replications. Factor A was 3 water regimes (FC, 2/3AW and 1/3AW), factor B was two sweet sorghum cultivars [cv. Suwan Sweet Extra (Thai sweet sorghum) and SSV74 (imported from India)]. The results revealed that significant differences were not observed among water regimes in most traits i.e. plant height, stalk diameter, relative water content (RWC), stalk fresh weight and juice yield in harvesting day. This could suggest that sweet sorghum will perform well in any moisture condition, most importantly in lesser moisture environments. Significant differences were observed among sweet sorghum cultivars in several traits i.e. spad chlorophyll meter reading (SCMR), chlorophyll content, brix value, root dry weight, juice yield and R/S ration at harvesting day. Relationship among traits were also observed but the most interesting results was where we found juice yield having negative correlation to brix value (r=-0.736***) and another no correlation was observed between stalk weight and juice

Aromaticity of secondary products as the marker for sweet sorghum [Sorghum bicolor (L.) Moench] genotype and environment effects

Although data analytics and systems modeling are increasingly being utilized to interpret genotype × environment interactions in plant breeding, chemometrics is currently underutilized. Prior reports indicated correlations between redox-active polyphenols in stem juice of sweet sorghum [ Sorghum bicolor (L.) Moench] and its resistance against sugarcane aphid [ Melanaphis sacchari (Zehntner)]. However, such correlations are often confounded by the outperforming genotype (outlier in correlations) capable of accumulating several-fold higher secondary metabolites than other cultivars examined. To investigate the underlying chemical characteristics responsible for the pest resistance, this study first employed principal component analysis (PCA) as the exploratory analysis to visualize the primary factors affecting genotype and environmental (April, May, and June planting months) dependence of juice extracted from 24 sweet sorghum cultivars. Chemical parameters arising from redox reactivity were primarily responsible for distinguishing a resistant genotype. The distance of dendrogram based on the genotype-dependent electrochemistry (cyclic voltammetry) was then used as the perturbation parameter in 2D correlation analysis to understand the controlling chemical structures; both genotype and environment were controlled by the redox reactivity and aromaticity of sweet sorghum. Aromatic structures detectable by UV/visible spectrophotometry were then used to build calibrations based on machine learning. The workflow of data analytics in this study could be applied to expedite the biomarker-driven plant breeding without repeating chemical analysis of new field samples. • Redox reactivity of sorghum juice can serve as the marker for pest resistance. • 2 D correlation analysis of cyclic voltammogram revealed genotype dependency. • Machine learning allows calibration of redox reactivity without repeated analysis.

Interactions between the soil bacterial community assembly and gene regulation in salt‐sensitive and salt‐tolerant sweet sorghum cultivars

AbstractComplex bacterial communities in the rhizosphere play a crucial role in plant growth and stress tolerance. These communities vary across cultivars and external environments. However, the influences of salt stress on the structural composition of bacterial microbiome and gene expression of salt‐sensitive and salt‐tolerant sweet sorghum (Sorghum bicolor L. Moench) cultivars have not been studied sufficiently. Here, we employed a combination of 16S rRNA gene profiling and RNA‐seq analysis to characterize changes in root‐associated microbiomes and determine differentially expressed genes (DEG) in the roots of salt‐tolerant M‐81E and salt‐sensitive 'Roma' var. sweet sorghum cultivars under soil conditions with/without salinity. Results revealed that the two contrasting sweet sorghum genotypes selectively filtered and recruited distinct root microbiota in response to salt stress. M‐81E‐enriched bacterial taxa were more diverse and exhibited a higher abundance of metabolic functions than Roma‐enriched taxa. M‐81E‐associated bacterial co‐occurrence networks were more complex and harboured more positive links than Roma‐associated bacterial networks. Furthermore, nine DEG were identified as core salt‐responsive genes and were central to the salt tolerance of sweet sorghum. Correlation analysis revealed that the expression of HSP70, a molecular chaperone, is linked to the recruitment of numerous M‐81E‐enriched bacteria; their relationship needs further exploration. The study supplements the comprehension of the potential role of host–microbe interactions in the response of sweet sorghum to salt stress.