Combined Analysis Of Variance Research Articles

Investigation of Combining Ability and Heterosis in Sorghum [Sorghum bicolor (L) Moench] Genotypes under Moisture Stress Areas

The most important prerequisite in sorghum crop improvement is the identification of suitable parents that can combine well and produce superior hybrids. However, a narrow genetic base, lack of potential hybrids and lack of information on the genetic components are the most important limiting factors for sorghum yield improvement. Therefore, the experiment was conducted to estimate the combining abilities and heterosis for yield and agronomic traits. A total of 42 sorghum genotypes were evaluated using an alpha lattice experimental design with two replications at Mieso and Kobo during the cropping season of 2019. Combined analysis of variance revealed highly significant differences due to genotypes for days to flowering, plant height, days to maturity, effective productive tillers, panicle exersion, panicle length, panicle width, panicle yield, grain yield and thousand seed weight traits. Based on general combining ability analysis, inbred lines P-9505 and P-9534 were identified as the best general combiners for both days to flowering and plant height traits; whereas inbred lines P-9501 and B5 were identified as the best general combiners for stay green traits. The hybrid crosses P-9534 x Melkam, B6 x ICRS-14 and MARC3 x Melkam were identified as the best specific combiners for grain yield, while the hybrid TX-623 x ICRS-14 was the best specific combiner for days to flowering, days to maturity, panicle length, panicle width and thousand-seed weight. The estimates of general and specific combining ability revealed the preponderance of non-additive gene action since the ratio of general combining ability to specific combining ability was less than unity for all the traits under study except for plant height. The maximum grain yield was obtained from the hybrids P-9534 x Melkam (6.32 tha-1), followed by the hybrids B6 x ICRS-14 (5.92 tha-1), TX-623 x ICRS-14 (5.88 tha-1), P9511 x Melkam (5.78 tha-1) and P-850341 x ICRS-14 (5.57 tha-1). Among the hybrids, B6 x ICRS-14 exhibited (112.41%) yield advantage over the mid parents, hybrid TX-623 x ICRS-14 exhibited (68.71%) yield advantage over the better parent, whereas P-9534 x Melkam exhibited (30.71%) yield advantage over the standard check for grain yield. Finally, based on the mean yield performance, heterosis response and combining ability estimates for grain yield and its components, the hybrid crosses P-9534 x Melkam, B6 x ICRS-14, TX-623 x ICRS-14, MARC3 x Melkam, MARC3 x ICRS-14, P9511 x Melkam and P-850341xICRS-14 were found to be the most promising and potential hybrids that could be exploited commercially after critical evaluation for their superiority and yield stability across locations over the years.

Preliminary Exploration of Variations in Measures of Pharyngeal Area During Nonswallowing Tasks.

Age- and disease-related changes in oropharyngeal anatomy and physiology may be identified through quantitative videofluoroscopic measures of pharyngeal area and dynamics. Pixel-based measures of nonconstricted pharyngeal area (PhAR) are typically taken during oral bolus hold tasks or on postswallow rest frames. A recent study in 87 healthy adults reported mean postswallow PhAR of 62%(C2-4)2, (range: 25%-135%), and significantly larger PhAR in males. The fact that measures were taken after initial bolus swallows without controlling for the presence of subsequent clearing swallows was identified as a potential source of variation. A subset of study participants had completed a protocol including additional static nonswallowing tasks, enabling us to explore variability across those tasks, taking sex differences into account. Videofluoroscopy still shots were analyzed for 20 healthy adults (10 males, 10 females, Mage = 26 years) in head-neutral position, chin-down and chin-up positions, a sustained /a/ vowel vocalization, and oral bolus hold tasks (1-cc, 5-cc). Trained raters used ImageJ software to measure PhAR in %(C2-4)2 units. Measures were compared to previously reported mean postswallow PhAR for the same participants: (a) explorations of sex differences; (b) pairwise linear mixed-model analyses of variance (ANOVAs) of PhAR for each nonswallowing task versus postswallow measures, controlling for sex; and (c) a combined mixed-model ANOVA to confirm comparability of the subset of tasks showing no significant differences from postswallow measures in Step 2. Overall, PhAR measures were significantly larger in male participants; however, most pairwise task comparisons did not differ by sex. No significant differences from postswallow measures were seen for 5-cc bolus hold, chin-down and chin-up postures, and the second (but not the first) of two repeated head neutral still shots. PhAR during a 5-cc bolus hold was most similar to postswallow measures: mean ± standard deviation of 51 ± 13%(C2-4)2 in females and 64 ± 16%(C2-4)2 in males. PhAR is larger in men than in women. Oral bolus hold tasks with a 5-cc liquid bolus yield similar measures to those obtained from postswallow rest frames.

Genotype by Environment Interaction Using AMMI, GGE Biplot and Multivariate Analysis of Nepalese Aromatic Rice Landraces

Aromatic group of rice comprises fine, medium, long and extra-long grain that has rich in agro-biodiversity, carries historical and cultural significance in Nepalese society. The objective was to identify stable, high-yielding aromatic rice landraces for Nepal Thirty aromatic rice landraces including two released varieties as standard checks were evaluated at three locations during 2020 and 2021. The experiment was laid out in a Randomized Complete Block Design with three replications. The combined analysis of variance indicated differences among genotypes and genotype-environment interactions for grain yield. The additive main effects and multiplicative interaction (AMMI) analysis revealed that genotypic effects for 69%, genotype × environment interaction effects for 28% and environmental effects accounted for 3% of the total sum of squares. Similarly, GGE biplot analysis showed that the principal components (PC1 and PC2) accounted for 53% and 47% of the GGE sum of squares, respectively. Based on AMMI1, AMMI2 biplots, and GGE biplots, the genotypes Samba Masuli Sub-1 and Sugandhit Dhan-1 were identified as the high yielding and stable fine and aromatic rice landraces. Other promising genotypes are Damari Dhan, Tilki, Hiupuri, Kalo Basmati, Gouriya, and Brahmamusi Dhan. Specifically, Samba Masuli Sub-1 demonstrated the highest grain yield performance at the NRRP, Hardinath, while Sunaulo Sugandha and Balamsari Dhan excelled in the Tarahara and Khajura environments, respectively. In PCA analysis, four PCs showed significant eigen value >1.0 contributing more than 84% of total variance. Biplot analysis reflected that 1000 grain weight, panicle length, heading and maturity days, and grain yield showed greater variation among the landraces. The results provide a robust basis for the further evaluation and verification of this findings in advance stage trials. The superior and outstanding landraces with higher yields and aroma are potential future varieties that can be either use directly as varieties after selection or utilize in future breeding programs for the development of new aromatic rice varieties.

Study on gene action, combining ability and heterosis for different traits in Indian mustard (Brassica juncea L. Cxern & Coss)

Abstract Combining ability and heterosis was investigated in mustard hybrids obtained from 7 × 7 half diallel cross. Twenty one F1s along with seven parents were evaluated in Randomized Complete Block Design. The combined analysis of variance revealed very significant differences among the parents for all morphological variables with the exception of secondary branches and siliqua length, indicating wide diversity among the parental material used in the present study. Significant GCA and SCA variance indicated additive and non-additive gene action across all the characters. The SCA variance components were larger than the GCA variance components for most traits indicating the prevalence of non-additive gene effects. Jawahar mustard × PM-30, showed a significantly positive SCA and better parent heterosis for seed yield per plant whereas five hybrids (Kranti × PM-30, Gujarat Mustard-3 × Pusa Mahak, Jawahar Mustard × PM-30, Jawahar Mustard × Pusa Mahak and PM-30 × Pusa Mahak) exhibited significant positive SCA effect for number of siliqua/ plant. Jawahar Mustard × PM-30, Varuna×Jawahar Mustard, Gujarat Mustard-3 × PM-30, exhibited highly significant heterosis over the mid-parent. Keywords: Brassica juncea, GCA, SCA, gene action, Heterosis

Stability analysis of dry matter and seed yield of cowpea [Vigna unguiculata (L.) walp.] genotypes in humid and lowland areas of southwestern Ethiopia

Cowpea is a multi-purpose legume interested in dealing with genotype and genotype-by-environment interaction which has a significant impact on the success of breeding method. Twelve cowpea genotypes were examined across three experimental sites in Southwest Ethiopia through the cropping seasons in 2020 and 2021. A randomized complete block design (RCBD) with three replications for each location was applied to complete the trials, and the dry mater and seed yields were recorded and analyzed using AMMI and GGE biplot models. Dry matter yield (DMY) was significantly influenced by genotype (35.51 %), environment (34.25 %), and genotype by environment (G × E) interface (24.82 %), according to the combined analysis of variance. On the other hand, seed yield (SY) was highly influenced by the environment (39.93 %), genotype-environment (G × E) (19.08 %), and genotype (11.88 %). For both dry matter and seed yield, the investigated genotypes were divided into four mega-environments using AMMI and GGE biplot. The initial mega-environment contain E6, the subsequent contain E3 and E5, the third one has E1 and E2, and the final mega-environment hold E4 for dry matter and E3, E4, and E6, E5, as well as E1, and E2 for seed yield. The GGE biplot revealed that the three vertex genotypes for dry matter yield, G6, G7, and G10 whereas, six vertexes for seed yield G2, G6, G8, G7, G11, and G10, scored higher yield in corresponding environment, while the AMMI model showed G4, G6, G9, and G10 were comparably stable and high yielders for DMY and G4, G5, and G9 were for SY, whereas G6 and G7 had the highest SY but were unstable genotypes. Based on the AEC line, genotypes represented by G4, and G9 were relatively stable and high yielders for both DMY and SY. The selected genotypes could be suggested for variety development in the region.

Characterization of genetic diversity in Eragrostis tef (zucc.) Trotter through microsatellite and morphological markers

Eragrostis tef (Zucc.) Trotter is Ethiopia's most significantly important grain crop; however, its productivity is quite low (1.7 tons per hectare) due to a variety of issues, including the poor yield potential of varieties produced thus far. To achieve future production improvements in tef, comprehensive study of the crop's genetic variability and variety, utilizing both genetic and morphological markers, necessary. The study was designed to assess the genetic diversity of 64 tef genotypes utilizing 10 Simple Sequence Repeats (SSRs) markers. This investigation took place at the Agricultural Biotechnology Research Center in Holeta, Ethiopia. Field phenotypic diversity evaluation was conducted at two distinct locations: Debre Zeit and Worabe, applied a simple lattice design during 2020/21 season. Molecular analysis of variance demonstrated a substantial proportion of variation among individuals (46 %), followed closely variation among individuals (43 %), with the least variation observed within population (11 %). Concurrently, analysis of morphological data, encompassing twenty phenotypic characteristics, revealed significant variation (P ≤ 0.01) among almost all the tested genotypes for recorded parameters, as indicated by combined analysis of variance across sites. These findings underscore the high diversity among the studied genotypes, suggesting a considerable potential for crop improvement through direct selection and intra-specific hybridization strategies. From the perspectives of both conservation and utilization of tef genetic materials, there is a pressing need for more extensive and systematic molecular level research. Promoting field trials and genotype-by-environment interaction research is crucial. These efforts will enhance our understanding of tef genetic and contribute to its effective conservation and utilization.

Evaluation of Alternative Break Crops in Rotation with Bread Wheat (triticum aestivum l.) in South-Eastern Ethiopia

Crop rotation could be a possible intervention to resolve multifaceted problems of monoculture. In recent years, there is a concern about soil depletion caused by intensive farming. In crop rotation legume crops, which capture atmospheric nitrogen and “fix” it into forms available to plants will increase soil fertility. Faba bean (Vicia faba L.), rapeseed (Brassica napus L.), oat (Avena sativum L.) and vicia (Vicia dasycarpa Ten.) forage mixture were considered as a break/precursor crops. The result showed that most profitable cropping sequence was faba bean grown in a 3 year cycle with 2 crops of wheat (Amanuel et al., 1994). Thus, searching for promising and alternative break crops for wheat based rotation could increase productivity and maximize profit. Adaptaion trial around Bekoji showed that sweet lupine seems an option in tolerating acidity where faba bean is found susceptible. Thus, the objectives of this study was to evaluate alternative break crops on yield and yield components of the succeeding wheat and soil fertility maintenance in the rotation scheme. Thus, this study was executed for three consecutive years from 2017- 2019 main cropping seasons at Kulumsa, Bekoji and Asasa Arsi zone, South-Eastern Ethiopia to evaluate advantage of alternative break crops on yield and yield components of the succeeding wheat and its effect on soil fertility maintenance in the rotation scheme. The experiment was laid out in randomized block design with five replications. The treatment include: wheat-sweet lupine-wheat-wheatwheat in year one (2017), sweet lupine-wheat-wheat faba bean-Ethiopian mustard in year two (2018) and wheat-wheat-wheat-wheat-wheat in the third year (2019). These leguminous crops have improved physico-chemical properties of soil. Plant nutrients of soil on which legumes were grown were increased. This improvement of soil properties by leguminous crops has resulted in higher yield of wheat than plots on which wheat was grown after wheat. Although non-significant, the third year Bekoji and Asasa combined analysis of variance revealed that the highest wheat grain yield (4197kg/ha) was obtained at sweet lupine-wheat-wheat followed by wheat-faba bean-wheat (4003kg/ha). However, plant height was significantly (P<0.05) affected by rotational crops effect. The tallest plant height of wheat (105.0cm) was recoded from wheat-Ethioian mustard-wheat treatment. From this study, sweet lupine-wheat-wheat followed by wheat-faba bean-wheat with proper agronomic packages could be forwarded as a temporary recommendation in Asasa, Bokoji and Kulumsa areas and in areas with similar agro ecologies.

Effect of harvesting time on root yield and nutritional composition of orange-fleshed sweet potato [Ipomoea batatas (L.) Lam] varieties in East Hararghe

In eastern Ethiopia, sweet potato is a vital food and nutrition security crop; moreover, orange-fleshed sweet potato (OFSP) varieties are rich in beta-carotene content and have the potential to alleviate chronic Vitamin A malnutrition in the region. However, the unavailability of adaptable varieties and lack of information on production and post-harvest handling practices have limited its production and utilization in eastern Ethiopia. The research was conducted to identify the proper harvesting stage of OFSP varieties for optimum yield and nutritional compositions at Rare and Babile research stations of Haramaya University during the main rainy season of 2022. Three varieties (Alamura, Kabode, and Bakule) and four harvesting periods (120, 150, 180, and 210 days after planting (DAP) in factorial combinations were evaluated in randomized complete block design with three replications. Data were collected for growth, yield, and physicochemical composition-related parameters. Combined analysis of variance revealed the interaction effect of harvesting time and varieties had a significant (p < 0.05) effect on yield, yield-related parameters, and physicochemical components. Alamura variety produced comparable above-ground biomass (28.99 t ha−1) and the highest marketable root yield of 36.40 t ha−1 at 150 DAP, with dry matter content of 33.01 and 30.58 % at 150 and 120 DAP, respectively. Harvesting Alamura at 150 DAP also had the highest ꞵ-carotene, zinc, and iron contents of 11809 μg/100 g, 3.79, and 14.47 mg/100 g, respectively. It was concluded that growing the Alamura variety and harvesting at 150 DAP was better for obtaining higher root yield with good nutritional compositions in the study area.

Dry Leaf Biomass Stability of Stevia (Stevia rebaudiana) Clones over Different Environments

In order to identify stable high-yielding stevia (Stevia rebaudiana) genotypes, a multi-environment testing was conducted over four different growing environments. The experiments were conducted in a randomized block design, with three replications during 2019 and 2020. The combined analysis of variance showed significant variation for genotype, environment, and G×E interaction for all studied traits. The highest mean performance for all the traits revealed that Hoshiarpur has favorable conditions for stevia cultivation, and CSIR-IHBT-ST-1801 followed by CSIR-IHBT-ST-G12 were the best performers over all the locations. The Eberhart and Russell model-based stability parameters demonstrated that CSIR-IHBT-ST-1801 was a stable performer for dry leaf biomass, and that was also further confirmed by GGE biplot analysis. Primary shoots were major contributors to the dry leaf biomass, as indicated by the substantial positive leaf biomass contribution shown by Pearson's correlation coefficients. As a result, primary shoots might be utilized as selection criteria to increase the dry leaf biomass. The CSIR-IHBT-ST-1801 could be used as a stable high-yielding variety for the targeted regions and also, can be used for further stevia breeding programs.

On‐farm foliar application of a humic biostimulant increases the yield of rice

AbstractBiostimulants play a crucial role in enhancing crop yields while promoting sustainability and environmental responsibility. Evaluating the efficacy of biostimulants on‐farm requires rigorous, multiyear trials conducted across various locations and with different cultivars. This study was conducted in Uruguay from 2015 to 2023 to assess the impact of a single application of a humic biostimulant (HB) during the R3 phenological stage on irrigated rice (Oryza sativa L.). The study encompassed 103 farms situated in diverse cropping zones, each characterized by distinct cultivars, soil qualities, radiation, and temperature conditions across the East and North regions. Results revealed that the HB treatment elicited an average yield increase of 7.4% across all sites. Notably, 93% (97) of the trials exhibited a positive yield response, with an average increase of 8.5%, while only six trials (all in the eastern zone) showed a negative response to the HB treatment. A combined analysis of variance indicated that the biostimulant's effect did not significantly differ between production zones, years, or rice cultivars when negative responses were excluded. Furthermore, relationships with environmental variables were nonsignificant, underscoring the positive effect of the biostimulant regardless of location. These findings hold significant implications for Uruguay's rice sector, that is, integrating HBs into standard management practices could substantially boost irrigated rice yields in rice‐producing areas.

Assessing drought tolerance in advance wheat genotypes using stress tolerance indices

Wheat, an important crop of Nepal, is significantly affected by drought, leading to severe yield losses. Thus, an experiment was conducted to assess effect of drought on wheat traits and to identify drought resilient genotypes comparing stress tolerance indices. Altogether seventy-two genotypes including checks were evaluated under drought and non-stress condition in an alpha-lattice design with two replications at the research block of National Rice Research Program, Hardinath, Nepal during winter of 2019/20. Analysis of variance revealed significant genotypic differences (p&lt;0.01) in traits such as days to heading, anthesis, and maturity, plant height, flag leaf area, spike length, grains per spike, 1000-grain weight, and grain yield under both conditions. The combined analysis of variance showed that genotype, environment, and their interaction significantly influenced most traits. The environment was the dominant factor, accounting for 86.2% of the variation in grain yield, followed by genotype (9.5%) and genotype-environment interaction (4.3%). Among the nine quantitative traits assessed, grain yield was most severely affected due to drought, experiencing a substantial reduction of 63%. To assess drought tolerance, six indices (TOL, SSI, MP, GMP, HMP, and STI) were calculated based on grain yield data. Most indices identified genotypes NL1373, NL1308, NL1407, BL4868, and BL4947 as highly drought-tolerant. Among the indices, MP, STI, and GMP were the most reliable for measuring stress tolerance due to their strong positive correlation with yield under both conditions. These identified genotypes are promising candidates for breeding programs aimed at developing drought-resilient wheat varieties, thereby enhancing food security in drought-affected regions.

Buffel Grass (Pennisetum ciliare) Ecotypes Suitable for Subtropical Livestock in the North Central Region of Mexico

The objective was to determine the forage production and nutritional quality of six buffel grass ecotypes in vegetative and physiological maturity stages. The experiment was carried out at the Los Cañones Experimental Station in Zacatecas, Mexico. The ecotypes were as follows: E-42, E-45, E-66, E-72, E-S245, and the Titan variety as a control. The experiment design was a completely randomized block with three replications, and the evaluation years were from 2020 to 2022. The variables measured were as follows: plant height (PH), dry matter yield (DMY), leaf (Lf) and stem-inflorescence (St), crude protein (CP), neutral (NDF), and acid detergent fiber (ADF). Pearson’s correlation and a combined analysis of variance were performed for each growth stage. A correlation analysis showed significant relationships (p &lt; 0.05) between variables. In the vegetative stage, ecotypes E-42, E-45, and E-S45 showed accumulations of over 12% of CP, which were higher (p &lt; 0.05) than the ones for Titan. Low values of E-S245 (p &lt; 0.05) for NDF (63.44%) and ADF (44.49%) stood out among all ecotypes. In the maturity stage, Titan was surpassed by E-45 and E-S245 with CP higher than 4%. The neutral and acid fibers in E-42, E-45, and E-S245 were less than in Titan (p &lt; 0.05). Ecotypes E-42 and E-S245 are alternatives to improve feed efficiency in the dry subtropical climate of Zacatecas.

Genotype-by-environment interaction and stability analysis of grain yield of bread wheat (Triticum aestivum L.) genotypes using AMMI and GGE biplot analyses

Bread wheat is a vital staple crop worldwide; including in Ethiopia, but its production is prone to various environmental constraints and yield reduction associated with adaptation. To identify adaptable genotypes, a total of 12 bread wheat genotypes (G1 to G12) were evaluated for their genotype-environment interaction (GEI) and stability across three different environments for two years using Additive Main Effect and Multiplicative Interaction (AMMI) and genotype main effect plus genotype-by-environment interaction (GGE) biplots analysis. GEI is a common phenomenon in crop improvement and is of significant importance in genotype assessment and recommendation. According to combined analysis of variance, grain yield was considerably impacted by environments, genotypes, and GEI. AMMI and GGE biplots analysis also provided insights into the performance and stability of the genotypes across diverse environmental conditions. Among the 12 genotypes, G6 was selected by AMMI biplot analysis as adaptive and high-yielding genotype; G5 and G7 demonstrated high stability and minimal interaction with the environment, as evidenced by their IPCA1 values. G7 was identified as the most stable and high-yielding genotype. The GGE biplot's polygon view revealed that the highest grain yield was obtained from G6 in environment three (E3). E3 was selected as the ideal environment by the GGE biplot. The top three stable genotypes identified by AMMI stability value (ASV) were G5, G7, and G10, while the most stable genotype determined by Genotype Selection Index (GSI) was G7. Even though G6 was a high yielder, it was found to be unstable according to ASV and ranked third in stability according to GSI. Based on the study's findings, the GGE biplot genotype view for grain yield identified Tay genotype (G6) to be the most ideal genotype due to its high grain yield and stability in diverse environments. G7 showed similar characteristics and was also stable. These findings provide valuable insights to breeders and researchers for selecting high-yielding and stable, as well as high-yielding specifically adapted genotypes.

Genotype by environment interaction and stability study in bread wheat (Triticum aestivum L.) genotypes in Guji Zone, Southern Ethiopia

Genotype by environment interaction and stability study in bread wheat (Triticum aestivum L.) genotypes in Guji Zone, Southern Ethiopia

Drought resilience evaluation of sugarcane (Saccharum spp.) hybrids in Indian tropical and sub-tropical climates

Drought is an important limiting factor for cane production globally, imposing significant constraints on cultivation. In this study, we have evaluated eleven sugarcane hybrids with improved germplasm bases of S. officinarum, and S.robustum under both drought and normal conditions at tropical and sub-tropical region. Combined analysis of variance revealed highly significant effects (p &lt; 0.05) of environments, genotypes and G × E interaction for all studied traits. Severe drought stress was observed in both locations, with a reduction in cane yield and its related traits. GGE analysis under stress conditions indicated that clone 14–90 (G8), a high yielder, performed well in all eight environments. Seven stable clones, namely, 14–161 (G1), 14–111 (G5), 14–90 (G8), 14–58 (G6), 14–34 (G9), 14–124 (G11) and 14–83 (G3) exhibiting adaptive yield-enhancing traits under drought were identified along with displaying resistance to red rot. Selected clones, namely, 14–161, 14–131, 14–90 and 14–144, performed better for yield in sub-tropics, while clones 14-–161, 14–111 and 14–90 performed better in the tropics. Clone 14–90 showcased, the strong performance across all the environments and locations, emerging as the leading genotype and suggested for utilization in pre-breeding programs for both tropical and sub-tropical regions

Influence of Genotype × Environment Interaction on Yield Stability of Maize Hybrids with AMMI Model and GGE Biplot

Maize yields perform differently in different environments, so the selection of suitable genotypes in diverse environments is essential for variety selection to enable better site-specific planting. Hence, the objective of the study was to estimate the productivity of 11 maize hybrids (G) in 10 different environments (E) and select high-yield and stable varieties for adaptive cultivation in 2022 and 2023. The combined analysis of variance showed that G (4%), E (50%), and their interaction (31%) had a significant effect (p &lt; 0.01) on maize yield, with E factors contributing the most. In addition, the average yield ranged from 9398 kg/ha to 10,574 kg/ha, and ZF-2208 and DY-519 performed relatively well in both years. The AMMI model showed that the varieties DY-213, DY-605, and DY-519 had high and stable production in 2022, whereas it was ZF-2209 and LX-24 in 2023. The “W-W-W” biplot showed that DY-519 and JG-18 were the optimal varieties in 2022, and ZF-2208 and ZF-2210 were optimal in 2023. The “mean vs. stability” biplot indicated that JG-18, DY-605, and DY-213 (in 2022) and ZF-2208, LX-24, and ZF-2209 (in 2023) were the optimal varieties. Additionally, both the discrimination and representative biplot and the ranking biplot reflected that BinChuan and ShiDian (in 2022) and GengMa and YongSheng (in 2023) were the ideal test environments. In conclusion, DY-519, DY-605, ZF-2208, and LX-24 hybrids could be used for variety promotion. Moreover, BinChuan, ShiDian, GengMa, and YongSheng were the ideal test environments for selecting varieties. Therefore, the AMMI model and GGE biplot can be used to complement each other for a comprehensive evaluation of maize yield. In this way, excellent maize hybrids with high yield and stability can be selected, which could promote the selection and popularization of varieties and shorten the breeding process.

Occurrence and field evaluation of promising sugarcane genotypes for resistance to midrib red rot disease in China

AbstractSugarcane midrib red rot caused by Colletotrichum falcatum is widespread in China. Standardizing the resistance evaluation methods and screening resistant varieties against this disease is crucial. C. falcatum was determined as the causal agent of midrib red rot by isolating and identifying pathogenic fungi from diseased leaves in Guangxi, China. A field trial of 237 sugarcane genotypes was conducted for three consecutive years to investigate disease incidence and indices for three experimental sites in Guangxi. The combined analysis of variance showed that disease incidence was significantly affected by genotype, year, location and their interactions. Cluster and discriminant analysis showed that 237 sugarcane genotypes were classified into five categories, including 20 as highly resistant, 82 as resistant, 71 as moderately susceptible, 46 as susceptible and 18 as highly susceptible. This study has enhanced our understanding of sugarcane resistance to midrib red rot, selected disease‐resistant parents and laid the foundation for developing elite disease‐resistant varieties.

Estimation of standard heterosis and heterotic grouping of elite sorghum [Sorghum bicolor (L) Moench] inbred lines under moisture stress conditions

The development and selection of appropriate parents are prerequisites for sorghum hybrid variety development. The lack of a broad genetic base is the most significant constraint to sorghum crop improvement. The assignment of sorghum germplasm lines to appropriate heterotic groups is critical for increasing sorghum productivity. The experiment was conducted to determine the amount of standard heterosis and to categorize sorghum inbred lines into distinct heterotic groups. In the 2019 main cropping season, 42 sorghum genotypes were tested using an alpha-lattice design with two replications. Combined analysis of variance showed that there was a highly significant difference (p < 0.01) among the genotypes for all studied traits. The maximum grain yield was obtained from the hybrids 4x14 (6.32 tha-1), followed by the hybrids 8x15 (5.92 tha-1), 1x15 (5.88 tha-1), 13x14 (5.78 tha-1) and 6x15 (5.57 tha-1), with an average value of 5.0 tha-1. Similarly, the 4x14 hybrid exhibited a maximum grain yield with 30.71 % heterosis, which was greater than the standard check (ESH-4) for grain yield. The two heterotic (A and B) groups were identified based on their specific combining ability effects, whereas three heterotic groups were identified based on their general combining ability effects to develop superior hybrids from broad base and suitable parents. Finally, based on yield performance, heterotic response and combining ability estimates for grain yield and its components, the hybrid crosses 4x14, 8x15, 1x15, 11x14, 11x15, 13x14, and 6x15 were found to be the most promising and potential hybrids that could be exploited commercially after critical evaluation for their superiority and yield stability across locations over the years.

Identification of new stable resistant sources and assessing agro-morphological performance of sponge gourd germplasm against Tomato Leaf curl New Delhi Virus incidence.

Tomato leaf curl New Delhi virus (TolCNDV) causes yellow mosaic disease, which poses a significant biotic constraint for sponge gourd cultivation, potentially resulting in crop loss of up to 100%. In the present investigation, 50 diverse genotypes were screened for 3 years under natural epiphytotic conditions. A subset of 20 genotypes was further evaluated across four different environments. The combined analysis of variance revealed a significant genotype × environment interaction. Eight genotypes consistently exhibited high and stable resistance in the preliminary screening and multi-environment testing. Furthermore, genotype plus genotype × environment interaction biplot analysis identified DSG-29 (G-3), DSG-7 (G-2), DSG-6 (G-1), and DSGVRL-18 (G-6) as the desirable genotypes, which have stable resistance and better yield potential even under diseased conditions. The genotype by yield × trait biplot analysis and multi-trait genotype-ideotype distance index analysis further validated the potential of these genotypes for combining higher yield and other desirable traits with higher resistance levels. Additionally, resistant genotypes exhibited higher activities of defense-related enzymes as compared to susceptible genotypes. Thus, genotypes identified in our study will serve as a valuable genetic resource for carrying out future resistance breeding programs in sponge gourd against ToLCNDV.

Stability and adaptability evaluation of grain sorghum varieties using GGE biplot

In Pakistan, Sorghum can be a good domestic source of high-quality fodder and feed, because of its high protein and sugar contents. Location-specific adaptation of lines/varieties as found in the current study evidently implies that location-specific breeding needs are more importance than concentrating on wider adaptability. Another point of consideration is that it is essential to recognize location-specific cultivars over location and multi-year data for their consideration before commercial release for the sake of stability of the cultivar. This is important not only to sorghum only but also in other crops as well. The G × E interaction of six Pakistani experimental sorghum lines produced by Pedigree method and two check cultivars were evaluated for days to 50% flowering, stalk weight, grain yield and Brix value along with their stability and/or adaptability across two locations and two years, under randomized complete block (RCB) design. Three replications were used for each treatment. The combined analyses of variance of all the studied characters showed that they were affected significantly by environments (E), genotypes (G) and genotype by environment interaction (G × E) in every year except for the environment in Brix value. The ideal genotype evaluation proved that YSS-10 was the best line for the all four environments. Dera Gazi Khan is an ideal location for testing grain sorghum genotypes. The ’Which-won-where’ biplots indicated a crossover type of G × E between experimental lines YSS-10 and YSS-18 for the grain yield