Influence of Drought Environment on the Genetic Characteristics and Nature of Gene Action for Different Genotypes of Grain Sorghum (Sorghum bicolor)

Physiological differences among sorghum (Sorghum bicolor L. Moench) genotypes under high temperature stress

Selecting sorghum genotypes with higher grain yield and nutritional quality is essential to tackle food insecurity and malnutrition in arid and semi-arid areas. Therefore, this study aimed to determine the genetic diversity, trait association and genotype by yield by trait (GYT) analysis and to select superior sorghum genotypes. One hundred and ten sorghum genotypes were evaluated at three locations in Tigray during the 2018 and 2019 growing seasons using alpha lattice design. Traits such as grain yield, protein content, ash content, starch content, zinc content, iron content, calcium content and magnesium content were profiled. Results showed that wide range and highly significant (p < 0.001) genotype mean performance in each environment as well as combined environments. Several highly performing genotypes were distinguished for each trait studied that could be exploited as breeding parents or direct use. This study further detected highly significant variation (p < 0.001) among the test genotypes for all the traits studied in individual environments and across environments suggesting the presence of sufficient genetic diversity for selection. The high broad-sense heritability (H2 > 0.9) in all individual environments and moderate to high (H2 > 0.0.41 < 0.82) in pooled environments recorded in the present study assured the possibility of effective selection among the genotypes. Besides, strong positive and negative associations were detected between some of the traits in individual and across environments. The significant positive association between traits indicates that both the traits can be improved concurrently through direct selection. Using the GYT analysis, we suggest ten promising sorghum genotypes for direct use or breeding programs in arid and semi-arid areas in general and in Tigray in particular.

Increasing CO2 concentration ([CO2]) is thought to induce climate change and thereby increase air temperatures and the risk of drought stress, the latter impairing crop growth. The objective of this study was to investigate the effects of elevated [CO2] and drought stress on root growth of one maize genotype (Zea mays cv. Simao) and two sorghum genotypes (Sorghum bicolor cv. Bulldozer and Sorghum bicolor × Sorghum sudanense cv. Inka) under the cool moderate climate of Central Europe. It was hypothesized that root growth stimulation due to elevated [CO2] compensates for a reduced root growth under drought stress. Therefore, we established an experiment within a free‐air carbon dioxide enrichment system (FACE) in 2010 and 2011. Sorghum and maize genotypes were grown under ambient [CO2] (385 ppm CO2) and elevated [CO2] (600 ppm CO2) and in combination with restricted and sufficient water supply. Elevated [CO2] decreased root length density (RLD) in the upper soil layers for all genotypes, but increased it in deeper layers. Higher [CO2] enhanced specific root length (SRL) of “Simao” and “Bulldozer,” however, did not affect that of “Inka.” “Simao” achieved a higher SRL than the sorghum genotypes, indicating an efficient investment in root dry matter. Although elevated [CO2] affected the root growth, no interaction with the water treatment and, consequently, no compensatory effect of elevated [CO2] could be identified.

The effect of water deficit was compared between drought‐tolerant (P954035) and drought‐susceptible (P721N) sorghum (Sorghum bicolor [L.] Moench) genotypes. Gas analysis and leaf water potential (ΨW) measurements indicated clear phenotypic differences between the genotypes in response to water deficit. Both genotypes experienced declines in ΨW, net assimilation rate (A), transpiration rate (E) and stomatal conductance (gs) during stress. P954035, however, dried more slowly and maintained higher values for A, E and gs relative to P721N. In vivo labeling studies and immunoblot analysis using an anti‐dehydrin antibody identified a protein of Mr 21 000 which was induced by water deficit and accumulated to similar levels in both genotypes. The observed molecular changes were essentially identical in both genotypes but differed only in the timing of expression. A sorghum dehydrin cDNA, dhnl, was isolated which encodes a hydrophilic protein of approximately 16.3 kDa with a predicted pl of 10.48. The deduced polypeptide sequence contains two lysine‐rich elements (KKGIMDKIKEKLPG) and shares extensive homology with other dehydrins. DHN 1 mRNA was induced by water deficit in seedlings of both drought‐tolerant and drought‐susceptible sorghum genotypes. Water deficit also induced changes in gene expression in mature preflowering sorghum plants. The anti‐dehydrin antibody detected a protein that accumulated in leaves and roots of stressed plants. The level of DHN 1 mRNA increased in the same tissues, but the abundance of this transcript was much higher in leaves and roots of mature plants than in seedlings.

The study was conducted on 25 sorghum genotypes grown in Randomized Block Design during Kharif 2015 toevaluate, categorize and classify them for fodder yield and quality traits. Correlation and path analysis studieswere conducted to determine the association among various fodder yield and its component traits, and the directand indirect contribution towards fodder yield in 25 sorghum (Sorghum bicolor L. Moench) genotypes grown atforage section in CCS Haryana Agricultural University, Hisar (Haryana, India) during Kharif, 2015. Plant heightup to the base of flag leaf was positively associated with green fodder yield (0.30), dry fodder yield(0.91),digestible dry matter(0.96), IVDMD(0.54), and negatively associated with the time of panicle emergence. Thenumber of tillers per plant was found to be positively associated with the number of leaves(0.37), crudeprotein(0.25), green fodder yield(0.26), dry fodder yield(0.30), and lignin content and negatively with stem girth.Green fodder yield was positively associated with plant height(0.30), the no. of leaves(0.27), stem girth, dryfodder yield, IVDMD, DDM and protein yield. Dry fodder yield was positively associated with GFY, plant height,stem girth, the no. of tillers, IVDMD, DDM and protein yield and negatively with panicle length visible abovesheath. Lignin was positively associated with plant height and the no. of tillers and negatively with ADF, IVDMDand stem girth. The IVDMD content was positively associated with GFY, DFY, the no. of leaves, DDM and proteinyield while, negatively with lignin. Crude protein was positively associated with the no. of leaves, stem girth, theno. of tillers, lignin, IVDMD and protein yield and negatively with ADF. The NDF was positively associated withcrude protein. The DDM was positively associated with GFY, stem girth, DFY, IVDMD and protein yield. Proteinyield was positively associated with GFY, the no. of leaves, stem girth, DFY, IVDMD, crude protein and DDM annegatively with stigma length. Therefore, these traits could be considered as the best selection criteria in sorghumbreeding programmes for the development of high yielding varieties.

Local sorghum ( Sorghum bicolor ) is a cereal crop that the people of Bahari Village, Buton Selatan Regency still cultivate as an interlude crop of corn. Local sorghum ( Sorghum bicolor ) functions as genetic material and a gene donor to improve the crop’s characters in a plant breeding program. Therefore, it is necessary to take conservation steps to maintain the availability of sorghum germplasm collections. This study aims to characterize local sorghum ( Sorghum bicolor ) from Bahari Village, Buton Selatan Regency based on morphological characters (qualitative vegetative and generative parameters) and agronomic characters. This study was an explorative study that directly identified the genotypes of local Sorghum bicolor cultivated in the field. This study reveals six genotypes of local Sorghum bicolor ; they are Labanda, Lapandewa, Lagadi, Wapinauri, Mbae, and Madea. The differences in sorghum genotypes can be more clearly identified in the generative phases, namely the symmetrical and pyramidal panicle shapes; the panicle density can be grouped into loose, slightly compact, and compact; husk colors vary from black, orange, grey, yellow, white, to red; the husk traits are categorized into short, slightly long, and very long; and the seeds are categorized round and round flat and white and brown. Meanwhile, the agronomic characters indicate that sorghum genotypes have long panicles; the weight of 100 seeds vary in categories from very low, low, to moderate; and one sorghum genotype (genotype Lagadi ) has the fastest flowering and harvest ages than the other genotypes.

&lt;p&gt;&lt;strong&gt;&lt;em&gt;Abstract&lt;/em&gt;.&nbsp; Production of sorghum seeds (Sorghum bicolor [L.] Moench.) faces&nbsp; land scarcity due to land use competition with other crops that have been cultivated by farmers since longer time ago such as soybean, peanuts, green bean, cowpea bean, and cassava. So, it have to do by using planting systems of intercropping and/or ratoon instead of monoculture.&nbsp; The problem was what sorghum genotypes that are compatible to planting system of intercropping, monoculture, and ratoon. &nbsp;The objective of this experiment was to evaluate the seed yield of various sorghum genotypes harvested from intercropping, monoculture, and ratoon planting systems.&nbsp; &lt;/strong&gt;&lt;em&gt;&lt;strong&gt;A split-plot&nbsp; experiment was conducted during March &ndash; November 2016 at the Village of Tulungagung, Sub District of Gadingrejo, Regency of Pringsewu, Lampung Province, Indonesia to reach that objective. Fifteen sorghum genotypes as subplots were placed randomly on three planting systems as main plot.&lt;/strong&gt; &lt;/em&gt;&lt;strong&gt;It was replicated three times as three blocks&lt;/strong&gt;. &lt;strong&gt;The seed yields observed were weight of thousand seeds (WTS), seed weight per plant (SWPP), seed number per plant (SNPP), and flowering day (FD). In general, the planting system did not affect significantly to seed yield, except on the flowering day. The genotypes affected significantly on weight of thousand seeds and the flowering day.&nbsp; There was an interaction effect of planting systems and genotypes showed by seed weight per plant and flowering day. &lt;/strong&gt;&lt;/p&gt;

Understanding drought tolerance status in sorghum (Sorghum bicolor) is very important for the development of sorghum varieties suitable for sub-optimal, drought prone areas in Indonesia. We estimated drought tolerance status of 20 Indonesian sorghum genotypes by observing their leaf water potential under glasshouse condition. Research design was randomized complete block design with 20 sorghum genotypes, 2 water treatments (control and water stress), and 2 replicates. The control plants were irrigated under field capacity, while the water stress treated plants were sown under field capacity followed by drought treatment without watering for one month. Sorghum seeds were cultivated in soil medium containing top soil, organic fertilizer and sand (50:20:30) in four 1x1.2x1 m3 containers. Seeds were sown in soil media pre-treated with tap water under field capacity. Leaf water potential was observed one month after planting by using WP 4 Dew Point. Plant growth performances, including plant height and leaf width were observed. Leaf water potential observation of the 20 sorghum genotypes showed that 2 sorghums genotypes, KLR and KS, had leaf water potential of -2.43 Mpa and - 2.455 Mpa respectively, which were categorized as tolerance to water stress. Four sorghum genotypes, Buleleng Empok, UPCA, Kawali and WHP, had leaf water potential of -3.7275 MPa, -3.7650, - 3.7700 and - 3.7950 Mpa respectively, were classified to be very sensitive to drought stress. The rest of the sorghum genotypes were classified as medium tolerance with leaf water potential between - 2.5200 Mpa and 3.6550 Mpa. Although it is a preliminary results and needs to be combined with field experimental data, the results obtained was an important step in determining sorghum genotypes which was best suited to be cultivated in drought prone areas and also to identify sorghum genotypes suitable to be used as drought tolerant trait donor.

Sorghum (Sorghum bicolor (L.) Moench) is an important essential cereal crop in Ethiopia. Conversely, its productivity is low due to numerous biotic and abiotic factors. There are diverse and dynamic environmental conditions which needs detail and continue study on genotypes by environment interaction (GEI) to develop stable genotypes. The objective of this study was to determine the magnitude of GEI for grain yield of forty two sorghum genotypes and to identify stable and high yielding genotypes across locations. The experiments were laid out at three locations for two growing seasons using alpha lattice design with three replications. The plot size 5 m x 0.75 m x 2 rows (7.5 m&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;) and distance between block, replication, and plot was 1m, 1.5m, and 0.75m, respectively. Phonologic, agronomic, diseases and grain yield data were collected but only grain yield was used for stability analysis. The ANOVA revealed highly significant variation (p &amp;lt;0.01) among sorghum genotypes across locations and seasons. Mean grain yield of genotypes ranged from 1.29 to 3.69 with mean grain yield of 2.36, while environment range from 1.18 to 3.63 t/ha. The genotype G1 showed good performance across all test sites which range 5&amp;lt;sup&amp;gt;th&amp;lt;/sup&amp;gt; at E1,3&amp;lt;sup&amp;gt;rd&amp;lt;/sup&amp;gt; at E3 and E4, 15&amp;lt;sup&amp;gt;th&amp;lt;/sup&amp;gt; and 7&amp;lt;sup&amp;gt;th&amp;lt;/sup&amp;gt; at E5 and E6 and maximum grain yield was harvested from E3. Yield data were also analyzed using the GGE (that is, G, genotype +GEI, genotypes-by- environment interaction) bi-plot method. The first two principal components (PC1 and PC2) were used to create a 2- dimensional GGE bi-plot and explained 59.67 and 13.48 % of GGE sum of squares, respectively. GGE bi- plot identified G16, G4, and G1 high yielders and stable and G34 and G25 was the lowest yielding and least stable across locations. On the other hand, the environment E6, E4 and E1 were the most suitable to select desirable genotypes.

This research sought to develop high-yielding and stable sorghum genotypes by comprehensively evaluating Genotype Environment Interaction (GEI). Fifteen sorghum genotypes were assessed across three locations over three years in a randomized complete block design with three replications. Significant genetic variation was observed among genotypes for all evaluated traits, indicating substantial potential for genetic improvement. Environmental factors profoundly influenced genotype performance, and GEI significantly impacted key traits such as Days to Heading, Days to Maturity, and Thousand Seed Weight, particularly Days to Heading, suggesting the presence of distinct mega-environments. The average grain yield across all locations was 4.14 t ha-1. ETSC 300,552 (G1) recorded the highest yield. The observed substantial yield variations across environments and strong GEI confirmed the critical need for multi-environment testing in cultivar development. AMMI analysis revealed highly significant main effects for genotype, environment, and their interaction on sorghum grain yield, underscoring considerable genetic differences and varied performance across environments. The first two interaction principal component axes accounted for 49.6% of the total GEI variation. The Environment contributed a dominant 27% of the total sum of squares, compared to only 10% from genotype, highlighting the influence of environmental factors on sorghum grain yield. The “which-won-where” polygon view from GGE biplot analysis effectively elucidated genotype-environment relationships, explaining 59.39% of the total variation and identifying three distinct mega-environments. Within the first mega-environment (E3, E8, E7), G1, G5, G7, and G14 performed best, with G1 identified as the winning genotype. Analysis of grain yield alongside 16 stability parameters identified G1 and G7 as the most stable genotypes. Specifically, G1 combined high grain yield with superior stability (low variance and deviation), while the $$\:{{\uptheta\:}}_{\left(\text{i}\right)}$$ parameter proved to be an excellent indicator of both performance and consistency. Finally, based on its consistently superior performance, high stability, and positive farmer evaluation, G1 was officially approved by the Ethiopian variety releasing committee for national release.

A field experiment was conducted in agricultural research station which is located at Al-Qurna district, 75 km north of Basrah governorate during the autumn season 2018. The aim was to study the effect of agricultural sulfur (0, 3, 6 and 9 t S.ha-1) on growth and yield of three sorghum genotypes (Inkath, Rabeh and Kafier2). The experiment was conducted as randomized complete block design in a factorial arrangement with three replications. The results showed that there were significant differences among the genotypes. The genotype kafier2 gave the highest average of plant height of 171.5 cm while the genotype inkath gave the highest weight of 1000 seed (25.59 gm), grain yield (3.97 t.ha-1). Genotype rabeh produced highest average of leaf area index and number of grain head of 3.10 and 1994.41 grain.head-1 respectively. The agricultural sulfur showed significant effect on most studied traits of sorghum (plant height, leaf area index, grain head, weight of 1000 grains and grain yield). The addition of agricultural suffer up to 9 t. ha-1 increased grain yield and produced 5.80 t.ha-1. The interaction of genotypes and agricultural sulfur showed a significant effect on some traits of growth and grain yield. The genotype inkath supplied with 9 t.ha-1 of agricultural sulfur resulted in highest grain yield of 5.80 t.ha-1, while the genotype rabeh supplied with 6 t.ha-1 of agricultural sulfur gave the highest average of leaf area index (3.54) and number of grains head (2106.33 grain.head-1).

Lack of cereal nutritional water productivity (NWP) information disadvantages linkages of nutrition to water–food nexus as staple food crops in Sub-Saharan Africa (SSA). This study determined the suitability of sorghum (Sorghum bicolor L. Moench) genotypes to alleviate protein, Zn and Fe deficiency under water-scarce dryland conditions through evaluation of NWP. Sorghum genotypes (Macia, Ujiba, PAN8816, IsiZulu) NWP was quantified from three planting seasons for various sorghum seed nutrients under dryland semi-arid conditions. Seasons by genotypes interaction highly and significantly affected NWPStarch, Ca, Cu, Fe, and significantly affected NWPMg, K, Na, P, Zn. Genotypic variations highly and significantly affected sorghum NWPProtein, Mn. Macia exhibited statistically superior NWPprotein (13.2–14.6 kg·m−3) and NWPZn (2.0–2.6 g·m−3) compared to other tested genotypes, while Macia NWPFe (2.6–2.7 g·m−3) was considerably inferior to that of Ujiba and IsiZulu landraces under increased water scarcity. Excellent overall NWPprotein, Fe and Zn under water scarcity make Macia a well-rounded genotype suitable to alleviating food and nutritional insecurity challenges in semi-arid SSA; however, landraces are viable alternatives with limited NWPprotein and Zn penalty under water-limited conditions. These results underline genotype selection as a vital tool in improving “nutrition per drop” in semi-arid regions.

Nitrogen is usually the most limiting nutrient for crop production and the poor recovery of applied fertilizer nitrogen by crops is of world wide concern. The differential response of sorghum (Sorghum bicolor L. Moench) genotypes to applied nitrogen suggests that differences in nitrogen uptake, translocation and accumulation in the grain exist1. This paper deals with (i) the extent of variation in sorghum for the above characters, (ii) correlations of these traits with agronomic traits such as days to flower, biomass and grain yield and, (iii) the implications of (i) and (ii) in breeding and crop management.Key wordsBiomassBreedingGenetic variationGrain yieldNitrogen uptake Sorghum bicolor Translocation index

There is a remarkable diversity among sorghum species; hence it requires a powerful marker system for genome characterisation. RAPD (randomly amplified polymorphic DNA) is a very favourable technique used to distinguish the sorghum genotypes due to its clarity and speed. We observed genetic diversity among 30 sorghum (Sorghum bicolor L. Moench) genotypes using RAPD markers. Sixteen RAPD markers produced a total of 148 bands with a mean of 9.25 fragments per loci. Out of the 148, 132 bands showed polymorphism (89.19%), and 16 bands showed monomorphism (10.81%). PIC (polymorphism information content) values were varying from 0.2035 to 0.3438 with a mean of 0.2792. Genetic distance was ranged from 0.013 (for genotype 4 and 8) to 0.807 (for genotype 10 and 27). Cluster analysis exhibited that dendrogram consists of four major groups. Results represent that genotype 1, 3, 5, 15, 6, 11, 4, 8, 26, 29, 20, 24, 14, 25, 19, 23, 2 and 13 were closely related to each other, and genotype 10 was the most diverse genotype among all the studied genotypes by making an independent cluster. The first two factors of principal component analysis (PCA) PC1 (15.06) and PC2 (10.98) had the highest contribution in variability as 10.18 and 7.42%, respectively. Thus, sorghum genotypes can be isolated from each other at the molecular level by using molecular markers.

Sorghum (Sorghum bicolor L. Moench) production in sub-Saharan Africa is seriously constrained by both biotic and abiotic stresses. Among the biotic stresses is witchweed (Striga spp.), a noxious parasitic weed causing major damage in cereal crops, such as sorghum. However, resistance through reduced germination stimulant production or altered germination stimulant composition provides a sustainable and most effective way for managing the parasitic weeds. Laboratory and glasshouse experiments were conducted using seven (7) sorghum genotypes to evaluate their resistance or tolerance the witch weed (Striga asiatica L. Kuntze). The first experiment was a laboratory agar gel assay arranged in a completely randomized design with six (6) replications to evaluate the effects of the seven (7) sorghum genotypes on the production of strigolactones by determining the percentage germination and the furthest germination distance of the Striga seeds. The second experiment was a seven (7) (sorghum genotypes)∗two (2) (Striga treatments) factorial glasshouse experiment conducted to evaluate the effects of Striga on sorghum growth, physiological and yield components of sorghum, Striga syndrome rating, and number of Striga per plant. The genotypes showed a significant (p&lt;0.05) difference in germination percentage and furthest germination of Striga seeds in the agar gel assay. Genotypes SV4, Mahube, and ICSV 111 IN showed the least germination percentage and lowest germination distance, implying that these varieties either produced low strigolactones or altered their composition. In contrast, Kuyuma, Wahi, SV2, and Macia caused high Striga seed germinations and high furthest germination distances, suggesting that these sorghum genotypes were susceptible to Striga infection. The sorghum × Striga × time interactions were significant (p&lt;0.05) on sorghum height. It was found that the heights of sorghum genotypes ICSV 111 IN and Mahube were not altered by Striga infection, but the heights of Kuyuma, Macia, SV2, SV4, and Wahi were reduced by Striga infection. The interaction of sorghum∗Striga effects was significant (p&lt;0.05) on chlorophyll fluorescence. Striga infection did not alter the chlorophyll content of ICSV 111 IN and SV4. The sorghum∗Striga interaction effects were significant (p&lt;0.05) on head index, leaf biomass, leaf index, root biomass, root index, plant biomass, and root : shoot ratio. Assessing Striga tolerance based on sorghum heights, chlorophyll content, and root : shoot ratio parameters, it could be concluded that the sorghum genotypes Mahube, ICSV 111 IN, and SV4 tolerated Striga infection, whereas Kuyuma and SV2 could be susceptible.