Genetic Diversity and Performance Evaluation of Durum Wheat ( Triticum durum Desf.) Genotypes for Grain Yield and Rust Resistance in the Wolaita Zone, Southern Ethiopia

Lack of improved varieties and soil fertility degradation are among the major factors that limit durum wheat (Triticum turgidum L.) production in Ethiopia. The objectives of this study were to determine the response of durum wheat cultivars (i) to nitrogen, phosphorus, sulphur, and boron (NPSB) fertilizer blend; (ii) rust infection; and (iii) partial budget analysis using NPSB fertilizer blend. A 2-location experiment was conducted in 2021 in South Ethiopia to evaluate the response of 4 durum wheat genotypes to blended NPSB fertilizer rates in a randomized complete block design in a 4 × 4 factorial arrangement. The results showed significant (P<0.05) differences due to genotypes (G), rate of NPSB fertilizer (F), and location (E) for all the parameters. The effects due to the G × F × E interaction were significant (P<0.05) for the number of total tillers, number of productive tillers, and grain yield (GY). A significant (P<0.05) G × E interaction was observed for the majority of parameters except days to 50% heading and plant height. Durum wheat genotype S3-213037 produced the highest grain yield of 3689.3 kg·ha−1 when NPSB fertilizer was applied at a rate of 225 kg·ha−1 at Adekoysha. Moreover, partial budget analysis indicated that genotype S3-213037 accrued a maximum benefit of 112,986.50 birr·ha−1 and the highest marginal rate of return of 1356.4% when NPSB fertilizer was applied at a rate of 225 kg·ha−1. Therefore, this study indicated that the application of an NPSB fertilizer rate of 225 kg·ha−1 could be used in the production of durum wheat in the East African region with similar agroecologies to the study area.

Durum and bread wheat are well adapted to the Mediterranean Basin. Twenty-three genotypes of each species were grown to evaluate the intra- and inter-genetic diversity based on omega (ω), gamma (γ) and alpha (α)-gliadin profiles. To achieve this purpose, the endosperm storage proteins (both gliadins and glutenins) were extracted from wheat grains and electrophoresed on sodium dodecyl sulfate (SDS)-polyacrylamide gels. The results of SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) revealed nine polymorphic loci out of 16 loci with durum wheat genotypes and nine polymorphic loci out of 18 loci with bead wheat genotypes. The polymorphisms revealed by the SDS-PAGE were 56% and 50% in durum and bread wheat genotypes, respectively. Using the cluster analysis, the durum wheat genotypes were clustered into five groups, while the bread wheat genotypes were grouped into six clusters using un-weighed pair group mean analyses based on ω, γ, and α-gliadins profiles. The 46 durum and bread wheat genotypes were grouped into seven clusters based on the combined ω, γ, and α-gliadins profiles revealed by the SDS-PAGE. The in silico analysis determined the intra-genetic diversity between bread and durum wheat based on the sequences of ω, γ, and α-gliadins. The alignment of ω-gliadin revealed the highest polymorphism (52.1%) between bread and durum wheat, meanwhile, the alignment of γ and α-gliadins revealed very low polymorphism 6.6% and 15.4%, respectively. According to computational studies, all gliadins contain a lot of glutamine and proline residues. The analysis revealed that the bread wheat possessed ω and γ -gliadins with a lower content of proline and a higher content of glutamine than durum wheat. In contrast, durum wheat possessed α-gliadin with a lower content of proline and a higher content of glutamine than bread wheat. In conclusion, the SDS-PAGE, in silico and computational analyses are effective tools to determine the intra- and inter-genetic diversity in tetraploid and hexaploid wheat genotypes based on ω, γ, and α-gliadins profiles.

Durum wheat production and grain quality in Ethiopia are below the global average, primarily due to the limited availability of high‐yielding and industrial‐quality varieties. Assessing genetic variability is essential for breeding high‐yielding cultivars. This study evaluated 45 advanced durum wheat lines (Triticum turgidum L. var. durum) at the Ethiopian Institute of Agricultural Research, Pawe Agricultural Research Center (Kossober sub‐station) during the 2020/2021 cropping season using an alpha lattice design with two replications. Fourteen quantitative traits were analyzed, including 13 yield‐related traits and one grain quality trait (protein content [PC]). Significant genetic variability was observed among the genotypes, with the highest phenotypic coefficients of variation (PCV) and genotypic coefficients of variation (GCV) recorded for grain yield (GY), number of effective tillers plant−1 (ETN), and harvest index (HI). Additionally, GY, ETN, HI, and number of kernel spike−1(KPS) exhibited high broad‐sense heritability (H2b) and genetic advance as a percentage of the mean (GAM), indicating strong genetic control and potential for selection. In contrast, PC showed moderate heritability and low genetic advance, suggesting limited selection efficiency for grain quality improvement. Additive gene effects predominantly influenced ETN, KPS, GY, and HI, making phenotypic selection effective for these traits. GY exhibited strong positive genotypic and phenotypic correlations with HI, number of spikelet spike−1 (SPS), KPS, grain filling period (GFP), and days to maturity (DSM). However, number of non‐effective tiller plant−1 (NNT) showed the highest negative correlation with GY. Genotypically, KPS and GFP had the strongest positive direct effects on GY, while at the phenotypic level, SPS and HI were the most influential. Conversely, DSM, NNT, and plant height (PH) had negative direct effects on GY at both levels. The observed genetic variability and trait associations provide valuable insights for designing selection and hybridization strategies in durum wheat breeding. Selecting genotypes based on traits with strong positive correlations and direct effects on GY is recommended to enhance yield potential.

The main objective of this study was to evaluate 21 durum wheat genotypes for grain yield and agronomic traits under rain fed condition in three districts of Axum Agricultural Research Center, namely Hatsebo, Tahtay-Maichew and Ahferom during 2014 cropping season. Completely randomized block design with three replications was conducted for each location. The result of analysis of variance indicated that there was a significant difference among the genotypes for all the traits except harvest index. Thus, considerable variation was recorded among durum wheat genotypes. However, the effect of location on grain yield was non-significant. Among the genotypes, the highest grain yield was obtained from genotype 34thIDONMD/134/off2011 (2.39 t ha-1) across all environments. High value of genotypic coefficient of variation (GCV) was calculated for panicle length, biomass yield, grain yield and harvest index both at Hatsebo and Tahtay-Maichew. However, at Ahferom, medium GCV was observed for these traits, which might be due to terminal moisture stress during the cropping season. High genotypic coefficient of variation, heritability and genetic advance as percent of mean were found in panicle length, biomass yield, grain yield and harvest index at Hatsebo and Tahtay-Maichew. This indicated that these characters could be useful basis of selection. The association of grin yield was positive and significant with harvest index (0.67), days to maturity (0.25), days to heading (0.22) and biomass yield (0.2), however the association between biomass yield and harvest index was negative (-0.54). Key words: Durum wheat, genetic variation, heritability, quantitative traits.

Micronutrients deficiency stress is one of the most important dangers for increasing the yield and good production of crops in the world. In order to evaluate genetic diversity of nineteen durum wheat (Triticum turgidum var durum) genotypes to identify the most zinc-deficient stress resistant genotypes and also finding the best stress tolerance indices, an experiment was carried out in the University of Maragheh, Iran during cropping season of 2014 by using a factorial design in the randomized complete block design (RCBD) with three replications. The experiment was done zinc deficient stress (non-Zn application; -Zn) and normal soil application (5 mg Zn/kg soil + foliar application with 0.44 g Zn/liter water at stem elongation and grain filling stages; +Zn) conditions. Results indicated that Zn conditions as well as, wheat genotypes differed significantly for all studied agro-morphological traits in both normal and Zn deficient stress conditions. Our findings indicated that Zn-deficient stress significantly decreased the spike length (SL), peduncle length (PedL), penultimate length (PenL), plant height (PH), spike weight (SW), peduncle weight (PedW), penultimate weight (PenW), biological yield (BY), grain yield (GY), harvest index (HI), number of grains per spike (NGS), number of fertile spikelet per spike (FS) and 1000 grains weight (TGW) by 14, 10.6, 10.4, 12.5, 25.3, 26.2, 27.9, 27.5, 29.4, 5.0, 25.5, 17.7 and 5.4%, respectively. Among durum wheat genotypes, ‘G2’ had the highest and also ‘G10’ and ‘G19’ had the lowest SW, PedW, BY and FS, respectively; while the highest and the shortest GY and NGS was observed in ‘G17’ (0.763 g/plant and 23.2 grain) and ‘G10’ and ‘G19’ (0.372 and 367 g/plant and 8.9 and 9.5 grain) genotypes, respectively. This indicating the presence of variability, which can be exploited through selection for further breeding programs. According to results of stress tolerance indices, ‘G17’, ‘G16’ and ‘G3’ genotypes have higher GY and STI index than other genotypes in two Zn conditions and identified as suitable genotypes for production in Zn deficient stress condition. Key words: Agro-morphological traits; Breeding; Calcareous soil; Durum wheat; Genetic variability; Zinc deficit.

Genetic analysis was carried out in 55 genotypes (10 parents and 45 F1s) through diallel mating design excluding reciprocals in bread wheat. Analysis of variance showed appreciable variability among the breeding material for almost all the traits under study. The highest value of phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) was found for flag leaf area (PCV=18.82, GCV=17.74), biological yield (PCV=12.98, GCV=11.70), grain yield (PCV=11.90, GCV=10.39) and harvest index (PCV=10.39, GCV=10.05). Highest heritability with highest genetic advance was estimated for flag leaf area (h2=52.24, GA=34.64), biological yield (h2=15.04, GA=21.71), harvest index (h2=18.19, GA=20.01), peduncle length (h2=31.72, GA=15.96) and spikelets per spike (h2=34.92, GA=12.96), therefore selection will be effective based on these traits. Grain yield was found significantly correlated (at <1% level of significance) with productive tillers (gr=0.3283**, pr=0.4347**), spike length (gr=0.1959**, pr=0.2203**), spikelets per spike (gr=0.4342**, pr=0.3813**), grains per spike (gr=0.7188**, pr=0.4918**), biological yield (gr=0.6101**, pr=0.6616**), harvest index (gr=0.3518**, pr=0.3227**) and thousand grain weight (gr=0.5232**, pr=0.3673**). Similarly path coefficient analysis estimates for biological yield (g=1.0524, p=1.0554), harvesting index (g=0.8862, p=0.8291), thousand grain weight (g=0.0588, p=0.0269), grains per spike (g=0.0496, p=0.0074), spike length (g=0.0209, p=0.0289), days to maturity (g=0.0142, p=0.0127), productive tillers (g=0.0186, p=0.0147), peduncle length (g=0.0123, p=0.0157), days to 50% flowering (g=0.0093, p=0.0072) and plant height (g=0.0042, p=0.0020) showed high positive direct effects on grain yield indicating that due importance should be given to these traits during selection for high yield.

Background The study aimed to assess six recently developed rice varieties: BRRI dhan84, BRRI dhan89, BRRI dhan92, BRRI dhan99, BRRI dhan100, and BRRI dhan102 of Bangladesh. The primary objectives were to assess genetic variability and key genetic parameters for selected qualitative and quantitative traits, identify, and prioritize promising traits for targeted improvement in rice breeding programs aimed at enhancing quality, productivity, and adaptability in Bangladesh's agriculture. The experiment was conducted using a completely randomized design with three replications. A total of 22 qualitative and quantitative traits were assessed across six varieties. Additionally, the study assessed genetic variability, genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), heritability (h 2 b), genetic advance (GA), and genetic advance as a percentage of the mean (GA%) across multiple traits. Results The ANOVA results indicated that the mean squares were very highly significant for most traits among the six rice varieties studied. Grains per panicle exhibited the highest genotypic and phenotypic variances, recorded at 579.88 and 742.85, respectively, while chlorophyll a at 45 days after transplanting showed the lowest values, both recorded at 0.05. Zinc content demonstrated the highest genotypic and phenotypic coefficients of variation (GCV and PCV), recorded at 37.13% and 37.95%, respectively, whereas carbohydrate content showed the lowest, with GCV and PCV values of 2.98% and 3.35%, respectively. Traits such as iron content with 99.84%, amylose content with 98.47%, protein content with 96.54%, zinc content with 95.73%, and thousand‐grain weight with 94.29% exhibited minimal environmental influence due to their high heritability estimates (>60%). GA was highest for grains per panicle, with a value of 43.83, followed by filled grains per panicle with 29.15, and zinc content with 12.63. In contrast, the lowest GA was recorded for chlorophyll a at 70 days after transplanting, with a value of 0.29, followed by chlorophyll a at 45 days with 0.43, and chlorophyll b at 70 days with 0.68. High heritability along with high GA as a percentage of the mean (GA%) was observed for several key traits, including iron, protein, and zinc content; thousand‐grain weight; chlorophyll a at 45 days after transplanting; total chlorophyll at 45 and 70 days after transplanting; grain, straw, and biological yield; number of grains and filled grains per panicle; and number of productive tillers per hill. These traits are likely governed by additive gene action, indicating strong potential for improvement through simple selection methods. In contrast, traits such as amylose content, harvest index, and panicle length exhibited high heritability with moderate GA%, suggesting the involvement of both additive and non‐additive gene effects. Carbohydrate content showed high heritability but low GA%, implying a predominance of nonadditive gene action and the need for improvement through combination breeding strategies. Conclusion These findings highlight the genetic potential of newly developed rice varieties and provide valuable guidance for breeding programs aimed at enhancing yield, nutritional quality, and adaptability in rice breeding for Bangladesh's agriculture.

A study was conducted to evaluate ten bread wheat genotypes along with their 45 F₁ hybrids (excluding reciprocals), laid out in a randomized block design with three replications during the Rabi season of 2022–2023 at the Student’s Instructional Farm, C.S. Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh. The primary aim was to assess the extent of genetic variability and key selection parameters for improving grain yield and associated quality traits. The analysis encompassed fourteen traits, including days to fifty percent heading, days to maturity, plant height, chlorophyll content, productive tillers per plant, spike length, spikelets per spike, grains per spike, grain weight per spike, 1000-grain weight, biological yield, harvest index, protein content, and grain yield per plant. Among parents, days to maturity showed the widest range of variation (117.33 to 137.67 days), whereas plant height exhibited the greatest variability among F₁ hybrids (85.97 to 120.53 cm). Across all traits, phenotypic coefficient of variation (PCV) exceeded the genotypic coefficient of variation (GCV), suggesting a notable environmental influence. Grain yield per plant showed the highest values for both PCV and GCV among hybrids. Heritability estimates were generally high across all traits in the F₁ generation, with yield of grain and total plant dry matter per plant showing the most substantial genetic gain, highlighting their potential for effective selection in future breeding programs.

Relationships between flag leaf carbon isotope discrimination and several morpho-physiological traits in durum wheat genotypes under Mediterranean conditions

Information on the extent of genetic variability and heritability as well as correlation among agronomically important traits is a requirement to design a suitable plant breeding method. The present research was conducted at Sinana, Southeastern Ethiopia during the 2009 main crop growing season. The experimental material consisted of 16 durum wheat genotypes tested in a randomized complete block design with three replications. Twelve agronomic traits were included in the investigation. Highly significant differences were revealed among durum wheat genotypes for all traits studied, suggesting the possibility of improving durum wheat for these traits. Plant height and number of kernels per spike showed the highest phenotypic and genotypic coefficients of variations and genetic advance, whereas, days to maturity and test weight had the lowest values. Plant height exhibited highest heritability value of 98.3% while number of spikelets per spike showed minimum value of 36.4%. The genotypic correlations estimated showed positive association of grain yield with days for heading (r=0.50), harvest index (r=0.69) and kernels number per spike (r=0.81). Harvest index (1.13) and biomass (0.81) exhibited the highest positive and significant direct effect on grain yield. Hence, these traits could be considered as suitable selection criteria for the development of high yielding durum wheat varieties. Key words: Correlation coefficient, durum wheat, genetic advance, heritability, path coefficient.

An experiment was conducted to study genetic variability in forty-nine elite slender grain rice genotypes for thirteen component characters including grain yield.The experimental materials possessed a considerable amount of variability for all the traits. Majority of the traits showed the smaller difference between phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV). Both PCV and GCV were high for grain yield (gm) (PCV:27.14%, GCV:26.27%), and fertile grains per panicles(PCV:20.61%, GCV:20.52%), indicating less effect of environment on these characters. PCV and GCV were moderate for characters like harvest index (PCV:16.99%, GCV: 14.18%), 100 seed weight (gm) (PCV:14.57%, GCV:13.82%), fertility percentage (PCV:15.72%, GCV:15.05%), flag leaf area (cm2 ) (PCV:17.83%, GCV: 17.74%) and days to 50 % flowering (PCV:11.20%, GCV:11.17%) indicating that there is considerable amount of environmental effect on such characters. Moderate to a high degree of heritability estimates were observed for the majority of the traits under study except for a number of effective tillers/plant indicating the low or negligible influence of environment in the expression of these traits and may respond to selection for their improvement. High heritability (H2 )estimates were associated with moderate to high genetic gain over mean (GAM) for days to 50% flowering (H2 : 99.35%,GAM: 19.52%), plant height (H2 :93.89%,GAM:14.01%), panicle length (H2 :94.06%,GAM:14.04%), flag leaf area(H2 : 98.93%,GAM: 31.05%), fertile grains/panicle (H2 :99.20%,GAM: 35.98%), fertility percentage (H2 :91.57%,GAM:25.34%),100 seed weight (H2 :89.90%,GAM:23.06%)and grain yield per plant (H2 :93.71%,GAM:44.76%) indicating the presence of additive gene effect and hence selection based on phenotypic performance for these traits would be effective.

The present study aimed analyze the variability, correlation, and path analysis in 97 rice landraces of Tamil Nadu for ten quantitative characters. The Phenotypic Coefficient of Variation and Genotypic Coefficient of Variation of the traits, namely total number of tillers, productive tillers per plant, and yield per plant, were high, indicating that these traits were not affected by the environment. Moderate Phenotypic coefficient of variation and Genotypic Coefficient of Variation was observed for the traits days to 50% flowering, plant height, days to maturity, and test weight, indicating that selection based on the heritable nature of the trait would be effective. High heritability coupled with high genetic advance as a percentage of mean was recorded for days to 50% flowering, plant height, the total number of tillers, productive tillers per plant, days to maturity, test weight, and plant yield. This shows that direct selection of these traits in crop improvement will be very effective because additive effects control these traits. In the association analysis, the plant height at the genotypic and phenotypic levels and test weight at the genotypic level showed a highly significant and significant positive correlation with plant yield. Path coefficient analysis shows that the total number of tillers, panicle length, decorticated grain length, and decorticated grain width had a strong positive effect on the performance of a single plant. Direct selection of characteristics such as plant height, test weight, the total number of tillers, panicle length, decorticated grain length, and decorticated grain width can increase single plant yield. Therefore, selection based on these traits for improving rice yield would be desirable.

Water deficit poses significant environmental stress that adversely affects the growth and productivity of durum wheat. Moreover, projections of climate change suggest an increase in the frequency and severity of droughts, particularly in arid regions. Consequently, there is an urgent need to develop drought-tolerant and high-yielding genotypes to ensure sustained production and global food security in response to population growth. This study aimed to explore the genetic diversity among local and exotic durum wheat genotypes using simple sequence repeat (SSR) markers and, additionally, to explore the combining ability and agronomic performance of assessed durum wheat genotypes and their 28 F1 crosses under normal and drought stress conditions. The investigated SSRs highlighted and confirmed the high genetic variation among the evaluated parental durum wheat genotypes. These diverse eight parental genotypes were consequently used to develop 28 F1s through a diallel mating design. The parental durum genotypes and their developed 28 F1s were assessed under normal and drought stress conditions. The evaluated genotypes were analyzed for their general and specific combining abilities as well as heterosis for agronomic traits under both conditions. The local cultivar Bani-Suef-7 (P8) is maintained as an effective combiner for developing shortened genotypes and improving earliness. Moreover, the local cultivars Bani-Suef-5 (P7) and Bani-Suef-7 (P8) along with the exotic line W1520 (P6) demonstrated excellent general combining ability for improving grain yield and its components under drought stress conditions. Furthermore, valuable specific hybrid combinations, W988 × W994 (P1 × P2), W996 × W1518 (P3 × P5), W1011 × W1520 (P4 × P6), and Bani-Suef-5 × Bani-Suef-7 (P7 × P8), were identified for grain yield and its components under drought stress conditions. The assessed 36 genotypes were grouped according to tolerance indices into five clusters varying from highly drought-sensitive genotypes (group E) to highly drought-tolerant (group A). The genotypes in cluster A (two crosses) followed by thirteen crosses in cluster B displayed higher drought tolerance compared to the other crosses and their parental genotypes. Subsequently, these hybrids could be considered valuable candidates in future durum wheat breeding programs to develop desired segregants under water-deficit conditions. Strong positive relationships were observed between grain yield and number of grains per spike, plant height, and 1000-grain weight under water-deficit conditions. These results highlight the significance of these traits for indirect selection under drought stress conditions, particularly in the early stages of breeding, owing to their convenient measurability.

The classical Osborne wheat protein fractions (albumins, globulins, gliadins, and glutenins), as well as several proteins from each of the four subunits of gliadin using SDS-PAGE analyses, were determined in the grain of five bread (T. aestivum L.) and five durum wheat (T. durum Desf.) genotypes. In addition, content of tryptophan and wet gluten were analyzed. Gliadins and glutenins comprise from 58.17% to 65.27% and 56.25% to 64.48% of total proteins and as such account for both quantity and quality of the bread and durum wheat grain proteins, respectively. The ratio of gliadin/total glutenin varied from 0.49 to 1.01 and 0.57 to 1.06 among the bread and durum genotypes, respectively. According to SDS-PAGE analysis, bread wheat genotypes had a higher concentration of α + β + γ-subunits of gliadin (on average 61.54% of extractable proteins) than durum wheat (on average 55.32% of extractable proteins). However, low concentration of ω-subunit was found in both bread (0.50% to 2.53% of extractable proteins) and durum (3.65% to 6.99% of extractable proteins) wheat genotypes. On average, durum wheat contained significantly higher amounts of tryptophan and wet gluten (0.163% dry weight (d.w.) and 26.96% d.w., respectively) than bread wheat (0.147% d.w. and 24.18% d.w., respectively).

Field experiments were conducted at Regional Agricultural Research Station, Lam, Guntur, Andhra Pradesh during the rainy season 2004-2007, with ten chilli genotypes supplied by AICRP on vegetables (from different geographical sources). This was to study genetic variability, heritability and genetic advance as per cent mean for several economic characters to identify promising cultivars suitable for the Krishna-Godavari zone of Andhra Pradesh. Data were collected on eight characters, viz., plant height, plant spread and number of fruits per plant; fruit length, fruit girth, number of seeds per fruit, ripe-chilli yield and dry-chilli yield. Significant differences were observed among genotypes in respect of all the characters studied. Phenotypic Coefficient of Variation (PCV) was slightly higher than Genotypic Coefficient of Variation (GCV) for all the traits, indicating a low environmental influence on expression of these traits. High GCV and PCV were observed for ripe-chilli yield, dry-chilli yield, number of fruits per plant, number of seeds per fruit and fruit length indicating a higher magnitude of variability in these traits and, consequently, a greater scope for improvement through simple selection. Low GCV and PCV were recorded for plant height, plant spread and fruit girth suggesting a limited variability, for these traits. High heritability, coupled with high Genetic Advance as per cent mean, was observed for ripe-chilli yield, dry chilli yield, number of fruits per plant, number of seeds per fruit and fruit length, indicating the influence of additive genes. These characters-with high GCV, PCV, Heritability and Genetic Advance as per cent mean-should be considered as reliable selection criteria for crop improvement for yield and yield attributing characters in chilli.