Yield Stability Analysis Research Articles

Analysis of Genotype-Environment Interaction and Yield Stability of Introduced Upland Rice in the Groundnut Basin Agroclimatic Zone of Senegal

Identification of highly performing varieties under Senegalese environment is crucial to sustain rice production. Genotype-environment interaction and stability performance on the grain yield of ten upland rice genotypes were investigated across 11 environments in Senegal during the rainy seasons of 2016 and 2017 to identify adapted varieties. The experiment was conducted using a randomized complete block design with three replications at each environment. Data on grain yield were recorded and analyzed using the additive main effects and multiplicative interaction (AMMI) model. The combined analysis of variance revealed that the grain yield was significantly affected by environment (67.9%), followed by genotype × environment (G × E) interaction (23.6%) and genotype (8.5%). The first two principal component axes were highly significant with 37.5 and 26% of the total observed G × E interaction variation, respectively. GGE biplot grouped the environments into four potential megaenvironments. Based on the yield stability index parameter and ranking GGE biplot, NERICA 8 and ART3-7-L9P8-1-B-B-1 were stable and high-yielding varieties compared to the local check NERICA 6. These varieties should be proposed for cultivation in order to sustain the rice production in the southern part of the groundnut basin of Senegal and used as parental lines in rice breeding program for grain yield improvement.

Stability analysis for quality, yield and yield attributing traits in heritage rice landrace Zag (Red Rice) of Kashmir Himalayas

Eighteen red rice collections from different sites of the Kashmir Himalayas valley were evaluated during kharif - 2017, 2018 and 2019 for stability performance for yield along with its related traits and cooking quality traits. The genotype effect had a significant mean square for all traits except panicle length based on analysis of variance. The genotype×environment interaction showed a significant difference for some of the studied traits, which included kernel elongation ratio, grain yield, number of panicles, 1000 seed weight, kernel length before cooking and kernel length after cooking. When the environment + (G × E) interaction is divided into environment (linear), G x E (linear) and congruent deviation, the mean square by environment (linear) shows that all attributes are taken into consideration. These results showed a significant difference between the environments that can have a great impact on the expression of the studied traits. Similarly, G x E (linear) was observed to be significant for all traits except 50% flowering days, plant height and maturity days, which means that the genotype behaviour of these traits is environmentally predictable and indicates that this is the function of the components of the linear environment. Mean squares due to pooled deviation (nonlinearity) were significant for all traits except 1000 grain weight and kernel breadth before cooking, suggesting that nonlinear composition is important for characteristics that contribute to the total G×E interaction. Thus, the genotypes differ significantly in terms of stability to the environment for such traits. C-5 has a low average for flowering days up to 50% and ripening days relative to the population mean, the row also has a uniform regression coefficient and the least deviation from the regression of yield showing consistent behaviour of the stream over the years. Likewise, C14 has a uniform regression coefficient and the least deviation from the regression for yield as well as a low mean for days up to 50% flowering and days until ripening, showed suitability of the line for consistent yield and early maturity.

GROWTH AND YIELD OF SWEET POTATO (Ipomoea batatas L.) MONOCROPS VERSUS INTERCROPS IN THE SEMI-ARID KATUMANI, KENYA

<p><strong>Background</strong>: Sweet potato producers in Kenya practice either sole cropping of or relay cropping and rarely do intercropping which aims at maximizing on time and space. <strong>Objective.</strong> To assess the relative performance of sweet potato under various cropping systems. <strong>Methodology:</strong> This study was conducted in Katumani, Kenya for two seasons; 2018/2019 and 2019/2020. The treatments comprised of sole cropping of Kabode, sole cropping of Bungoma, Kabode + common bean, Bungoma + common bean, and sole cropping of common beans (<em>Mwezi mbili</em>) were laid out in a randomized complete block design (RCBD) in 3 replications. Monocropped sweet potato and beans served as the control treatment. Weather data, leaf area, leaf area index, vine length, and percent canopy cover were collected throughout the cropping period. The data were analysed by a two-way ANOVA at 0.05% significance level followed by a Pearson’s correlation analysis on the extent to which length of vines, percent canopy cover, leaf area index, and weather parameters; ETo, aridity index, and rainfall influenced the attained tuber yields.<strong> Results:</strong> Intercropping significantly (p < 0.05) reduced sweet potato yields of Kabode and Bungoma varieties by 19.3% and 44%, respectively. Monocropped Kabode yielded 31.4 t ha<sup>-1</sup>, significantly (p< 0.05) higher than monocropped Bungoma with 23.9 t ha<sup>-1 </sup>whereas their common bean intercrops yielded 26.2 t ha<sup>-1 </sup>and 18.1 t ha<sup>-1</sup>,respectively.<strong> </strong>Correlation analysis showed that rainfall, ETo, LAI, vine length, and percent canopy cover negatively affected tuber yields. <strong>Implication:</strong> Land equivalent ratio revealed that intercropping sweet potato varieties with common beans was biologically efficient and that the percentage of the land saved averagely ranged from 8% to 33%. More studies should be conducted to determine the extent of sweet potato allelopathy on companion crops and nutrient use under intercropping systems. <strong>Conclusion:</strong> Yield stability analysis showed that orange-fleshed Kabode was the most stable variety across seasons to be grown in Katumani.</p>

WAASB‐based stability analysis and simultaneous selection for grain yield and early maturity in soybean

AbstractSoybean [Glycine max (L.) Merr.] is the leading Indian oilseed crop grown under rainfed conditions. Meticulous understanding of genotype × environment interaction patterns is essential to develop superior and widely adaptable soybean varieties. In the current study, 32 soybean genotypes were evaluated at eight locations for two consecutive years. Additive main effect and multiplicative interaction ANOVA revealed that only 41.6% of variance was explained by the first two interaction principal component axes (IPCAs), leaving 58.4% to the remaining 13 IPCs. The weighted average of absolute scores (WAASB) stability index, a best linear unbiased prediction–based mixed model that takes in to account all the IPCAs, has been used in stability analysis. SL1171 (WAASB score, 4.09) was found to be highly stable among the genotypes under study, with grain yield (2,050.87 kg ha−1) lower than the grand mean (2,082.50 kg ha−1). A superiority index that allows weighting between mean performance and stability (WAASBY) was used to select stable and high yielding genotypes. MACS 1620 (WAASBY score, 74.47) was found to be high yielding (2,476.05 kg ha−1) and widely adaptable. A simultaneous selection index (i.e., multi‐trait stability index [MTSI]) has been used for selecting early‐maturing and high‐yielding genotypes. DSb 33 was found to have the lowest MTSI (0.001) and can be used as a parent for breeding for early maturity and higher yield. The 100‐seed weight was found to be positively correlated with grain yield and can be used in direct selection for grain yield. Through genotypic cluster analysis, NRC 146 was found to be more divergent, with the highest mean 100 seed weight (16.39 g), and therefore can be used as a parent for breeding solely for grain yield.

Genotype x Environment interaction and stability analysis for leaf yield of mulberry (Morus alba L.) under alkali affected soils

The objective of this study was to determine the stability analysis and genotype x environment interaction of alkali tolerant mulberry genotypes at different alkali soils (untreated/unreclaimed, reclaimed with inorganic/organic amendment) on leaf yield to understand their adaptation. Five alkali tolerant mulberry genotypes along with two improved genotypes and one ruling local check were evaluated in an alkali hotspot. The large variation in mean leaf yield/microplot, regression coefficient (bi) and deviation from regression (Sdi2) indicates the different responses of genotypes to soil reclaimed with amendments. Average two year leaf yield/microplot, maximum of 18.240 kg was produced by the AR-12 followed by the AR-14, AR-29, AR-08, V1, AR-10 and S-34. Genotypes AR-12 and AR-14 showed high leaf yield (AR-12: 18.240 kg, AR-14: 16.15 kg), the low deviation from regression (Sdi2) (AR-12: -0.04, AR-14: 0.03) and their regression coefficient values (bi) were close to unity (AR-12: 1.41, AR-14: 1.34) and could be classified as stable genotypes. Key wordsGenotype x Environment Interaction, Stability analysis, Leaf Yield, Morus alba. &nbsp

Yield Stability Analysis of Durum Wheat Genotypes Using AMMI Method

چکیده اهداف:این تحقیق به منظور بررسی اثر متقابل ژنوتیپ در محیط و شناسایی ژنوتیپ های پایدار گندم دوروم در مناطق معتدل ایران اجرا گردید. مواد و روش ها: تعداد 19 ژنوتیپ انتخابی از آزمایشات مقایسه عملکرد گندم دوروم در اقلیم معتدل کشور به همراه یک رقم شاهد گندم نان در چهار منطقه شامل کرج، کرمانشاه، نیشابورو خرم آباد در قالب طرح بلوک های کامل تصادفی با 3 تکرار و طی دو سال زراعی مورد ارزیابی قرار گرفت. برای عملکرد دانه، داده­ها مورد تجزیه واریانس مرکب قرارگرفت. همچنین برای شناسایی ژنوتیپ هایی که در کنار پتانسیل عملکرد دانه بالا از پایداری عملکرد و سازگاری عمومی بالایی برخوردار باشند، تجزیه پایداری با استفاده از روش چند متغیره امی انجام گردید. یافته ها: براساس دو مولفه اصلی اول و دوم تجزیه پایداری چند متغیره AMMI ژنوتیپ های شماره 5، 11، 13، 15 و 20 و براساس آماره پایداری ASV ژنوتیپ های شماره 5، 7، 16 و 19 از پایداری بیشتری برخوردار بودند. ژنوتیپ های شماره 5 ، 16 و 19 بترتیب با میانگین عملکرد 497/7، 326/7 و 551/7 تن در هکتار هم عملکرد بالایی داشتند و هم از پایداری عملکرد بالایی برخوردار بودند. این ژنوتیپ­ها از نظر خصوصیات زراعی نیز وضعیت مطلوبی داشتند . نتیجه گیری: با در نظر گرفتن عملکرد دانه و پایداری عملکرد، ژنوتیپ های شماره 5 ، 16 و 19 بعنوان ژنوتیپ های برتر انتخاب شدند. هرکدام از این ژنوتیپ­ها که در شرایط زارعین نیز برتری خود را نشان دهد بعنوان رقم جدید برای مناطق معتدل کشور معرفی خواهد شد.

Genotype × Environment Interaction and Stability Analysis for Root Yield in Sweet Potato [Ipomoea batatas (L.) Lam

Sweet potato breeding in Africa, more especially in Nigeria, has mainly focused on improving productivity on farmers' fields and on fresh root consumption. In order to target the breeding program, the study was conducted to estimate the magnitude of genotype × environment interaction (G × E) and to select stable and high yielding sweet potato genotypes for fresh root yield and root Cylas severity in two locations, and to identify the most discriminating and representative test environments in Nigeria. The 41 genotypes were evaluated across two diverse environments using a randomized complete block design (RCBD) with three replications. Data were collected on total number of roots per plant, number and weight of marketable roots per plant, fresh root yield, and root Cylas severity. The data were subjected to analysis of variance using the Generalized Linear Model procedure of SAS 9.2 where genotype was treated as a fixed factor and replication treated as a random variable. Stability analysis was conducted using Genotype and Genotype x Environment Interaction (GGE) bi-plot. Environment, genotype, and G × E interaction variances were highly significant (p < 0.01) among the assessed agronomic traits. Moreover, the analysis of variance revealed highly significant (p < 0.01) differences among genotypes, environments, and G × E interaction effects for all the studied traits. The GGE biplot analyses identified three promising genotypes—G13, G11, and G14—that possess both high mean root yield and high stability, closest to the ideal genotype for root performance and consistency of performance across environments. This study provides valuable information that could be utilized in a breeding program to ameliorate local clones of sweet potato in Nigeria.

Determining the most stable potato hybrid using AMMI yield stability analysis method

Genotype-environment interaction (GEI) is very important for breeders. It is considered a complicated issue in breeding programs to obtain stable and high-yielding genotypes to release new genotypes. This study was conducted to achieve a stable high-yielding genotype that is adaptive to climatic conditions of potato-producing regions in Iran. A total of 20 potato breeding lines along with five commercial varieties (Savalan, Agria, Caesar, Luta and Satina) were evaluated in a randomized complete block design with three replicates in the Agricultural Research and Natural Resources Stations of five location (Ardabil, Razavi Khorasan, Karaj, Isfahan and Hamadan) in Iran, for two years (2016 and 2017). Combined ANOVA of yield data for studied genotypes and environments indicates significant differences among potato genotypes, environments, and GE interaction was significant. Thus, the AMMI method and its parameters were used to analyze yield stability. The results indicated that only four interaction principal components were significant (P<0.01), which accounted for 81.2% of the GEI sum of squares. Based on type 1 parameters (SIPC1, FA1, Za1, Dz1, EV1, and Da1), genotypes G7, G10, G14, G20 and G24 were identified as to be stable. Moreover, according to the results of type 2, 3 and 4 parameters, genotypes G2, G6, G7, G14, G15 and G20, as well as cultivars Agria (G24) and Luta (G23), were found to be stable. Genotypes G6, G7, G14, G15, G20, and G24 were stable according to the ASV parameter, and genotypes G6 and G7 were stable based on the MASV parameter. Amongst the stable genotypes identified by the AMMI parameters, while genotype G6 was high-yielding, G14 and G24 (Agria) were moderate-yielding.

Potencial productivo de variedades experimentales de sorgo blanco para el sur de Tamaulipas

En México el cultivo de sorgo ocupa el tercer lugar en superficie sembrada después del maíz y frijol. Tamaulipas es el principal estado productor de sorgo, donde se siembra en promedio 895 mil hectáreas y se producen dos millones 383 mil toneladas anuales; sin embargo, esta zona presenta el problema de dependencia de semilla para siembra importada y cara. El objetivo del presente trabajo fue determinar el potencial productivo y estabilidad, de un grupo de variedades experimentales derivadas de la cruza de RB-Paloma x Fortuna. Método: Se evaluaron 14 variedades experimentales, durante los años 2013 a 2017, en tres ambientes de riego y uno de secano. Los testigos fueron las variedades comerciales que les dieron origen a las variedades experimentales: RB-Paloma y Fortuna. El sitio de evaluación fue la estación Cuauhtémoc, Altamira, Tamaulipas, perteneciente al INIFAP. Se aplicó el diseño experimental bloques completos al azar con tres repeticiones. El modelo GGE biplot se usó para el análisis de estabilidad fenotípica para rendimiento de grano. Resultados: En los cuatro ambientes de evaluación la variedad experimental 196-2 presentó un rendimiento de grano promedio (p≤0,05) de 3,533 kg ha-1, similar al de RB-Paloma (2,955 kg ha-1) y superior al de Fortuna (2,494 kg ha-1) en 41.7 %. Además, esta variedad fue más precoz a la floración (74.1 días) que Fortuna (84.3 días) Los parámetros de estabilidad indicaron que 196-2 presentó alto rendimiento medio de grano, estabilidad y mejor respuesta en los ambientes. Las variedades experimentales 197-2 y 206-1 presentaron un buen rendimiento medio de grano y estabilidad, además de un rendimiento de biomasa fresca (p≤0,05) de 27,822 y 27,914 kg ha-1 respectivamente, similar al de Fortuna (28,541 kg ha-1) y superior al de RB-Paloma (18,419 kg ha-1) en 55 %; además, fueron más precoces a la floración (77 y 75.3 días, respectivamente) que Fortuna. La variedad 197-2 fue más tolerante a enfermedades foliares que RB-Paloma. Discusión o Conclusión: Las variedades experimentales 196-2, 197-2 y 206-1 presentaron características agronómicas sobresalientes para la región sur de Tamaulipas.

An integrative analysis of yield stability for a GWAS in a small soybean breeding population

AbstractDrought stress is one of the most important factors limiting soybean [Glycine max (L.) Merr.] productivity and reducing yield stability. Soybean breeders need phenotypic and genotypic tools to improve drought stress tolerance, but most of available strategies are expensive and unaffordable for small‐scale public breeding programs. In this study, elite germplasm of a locally adapted breeding population was used to estimate a yield stability index as an indicator of drought response. In order to associate yield stability of analyzed genotypes to drought response, water deficit scenarios related to the crop cycle group were defined. Four groups of genotypes were identified in relation to yield stability: two groups showed stables yield (without interaction with water deficit scenarios), and two groups showed unstable yield (with crossover interaction with water deficit scenarios). This phenotypic information was used to identify genomic regions and candidate genes associated with yield stability index. A new method for the definition of a quantitative trait loci (QTL) region was developed based on the probability of marker pairwise of belonging to four linkage disequilibrium (LD) categories. Seven QTL were found and their implication on drought tolerance was further supported by linkage to previously reported QTL for water use efficiency trait.

Genotypic × Environment Interaction and Stability Analysis for Yield and Yield Attributes in Taramira (Eruca sativa Mill.)

Aims: To identify the stable genotypes across the different environments for yield and its attributing traits.&#x0D; Study Design: Field experimental design was applied.&#x0D; Place and Duration of Study: The experiment was conducted at Research Farm, SKN College of Agriculture, S.K.N. Agriculture University, Jobner (Rajasthan), India in different environments during rabi 2018-19.&#x0D; Methodology: An experiment was conducted on thirty genotypes of taramira (Eruca Sativa Mill.) in three environments created by three dates of sowing during rabi 2018-2019 in randomized block design with three replications to estimate genotypic × environment interaction and stability parameters for various yield and yield attributing traits. The stability analysis was carried out according to Eberhart and Russell model.&#x0D; Results: The highest yielding genotypes were RTM-1351, RTM-1810, RTM-1315 and RTM-314. Genotypes RTM-314, RTM-1800, RTM-1810 and RTM-1815 were found relatively stable for seed yield per plant. Genotypes RTM-1795, RTM-1798 and RTM-1799 had below average stability for seed yield per plant and suitable for better environmental conditions. Genotypes RTM-1791, RTM-1815 and RTM-1351 were showed above average stability for seed yield per plant and suitable for poor environmental condition. Further, these genotypes can be utilized in the development of stable cultivar taramira.&#x0D; Conclusion: Pooled analysis of variance indicated significant differences among environments and genotypes. Genotypes RTM-314, RTM-1800, RTM-1805 and RTM-1810 were found most stable for most of the characters, which can be grown in wide range of environments (all three dates of sowing).

Assessment of stability performance and G X E interaction for yield and its attributing characters in bread wheat (Triticum aestivum L.)

The present study was undertaken to identify the stable genotypes for grain yield and yields related components with desirable performance under different environmental conditions taking forty wheat genotypes and were evaluated for two years (2017-19) with different dates of sowing. Pooled analysis of variance showed highly significant variations for genotypes, environments and genotypes x environments (G X E). Stability analysis for grain yield revealed that the genotypes LOK-1, NI-5439 and HUW-468 has a high mean value and non-significant regression coefficient (bi) and non-significant deviation from regression and found more stable across the four environments. Therefore the above mentioned genotypes were found most stable for grain yield and can be incorporated as breeding stocks in any future breeding programs aiming to produce high yielding lines of bread wheat.

Yield stability analysis of orange - Fleshed sweet potato in Indonesia using AMMI and GGE biplot

Orange-Fleshed Sweet Potato (OFSP) is an important crop in Indonesia. Yield potential and genotypic adaptability are important factors in varietal development. The purpose of this study was to estimate the stability of yield and to select the best OFSP genotypes across three agroecosystems in West Java, Indonesia. The field trials used were augmented design with 50 F1 Orange-Fleshed Sweet Potato (OFSP) genotypes as treatment, and seven check varieties as controls. The experiments were conducted in three different agroecosystems in West Java (Sumedang, Bandung, and Karawang). Selection was based on physical characteristics of sweet potato tuber, yield and stability across three environments. Data analysis of the yield characters, yield component, and tuber quality were performed by combined variance analysis. Selected genotypes were analyzed for stability yield using the parametric, non-parametric, Additive Main effects and Multiplicative Interaction (AMMI), AMMI Stability Value (ASV), and Genotype and Genotype by Environment (GGE) biplot models. Results identified the top best ten F1 genotypes namely F1-38 (G1), F1-69 (G2), F1-71 (G3), F1-77 (G4), F1-127 (G5), F1-128 (G6), F1-135 (G7), F1-159 (G8), F1-191 (G9), and F1-226 (G10). Location showed a significant effect on yield. Genotypes F1-069, F1-077, F1-226, F1-038, and F1-128 have the lowest ASR based on non-parametric and parametric stability models and there were identified as the most stable. AMMI analysis identified F1-128, F1-135, F1-038, and F1-069 as the most stable genotypes. F1-38 (G1), F1-69 (G2), F1-128 (G6) were found to be the most stable genotypes based on ASV analysis, while GGE biplot identified F1-38 (G1) and F1-69 (G2) genotypes as the stable genotypes. Other genotypes were considered to as location-specific. Based on AMMI, ASV, and GGE Biplot models, F1-038, and F1-069 were identified as stable genotypes. They produced higher yields than other genotypes. Therefore, the F1-038 and F1-069 genotypes can be potentially recommended as superior varieties for West Java, Indonesia.

Genetic Divergence and GGE Bi-plot Analysis of Multi-environment Trial Data of Barley (Hordeum vulgare L.) to Identify “Ideal” Genotype

The present research revealed the study of genetic divergence and genotype (G) main effect and genotype by the environment (GE) interaction (G × GE) bi-plot analysis for multi-environmental trial data using yield data of three years. Since, genotypes were planted in 2017 in two dates like early and lates own condition hence, there was very slight differences in their yield so both the environments come together as compared to third environment (2018) which for from the two locations of year 2017. The objective of this study was to determine the effects of genotype, environment and their interaction on grain yield and to identify stable barley genotypes. The field experiment comprising of 69 barley genotypes laid out in a Randomized Block Design with three replications during Rabi 2016-2017. The extent of genetic variability, association between yield and yield components, frequency distribution of 25 top best genotypes in response to yield in three different environments, yield stability analysis and genetic diversity was studied. For stability analysis yield data of current year for one location and yield data of two locations/environments of previous year have been used. Field observations were recorded on six important characters days to 50% flowering, days to maturity, effective tillers per plant, plant height with awn, plant height without awn and 1000 grain weight (g). The result of bi-plot analysis using yield data of three years revealed that AXIS1 explained 57.6 per cent variation while AXIS2 was explained 31.07 per cent variation. Since, genotypes were planted in 2017 in two dates like early and late sown condition hence, there was very slight differences in their yield so both the environments come together (Figure1) as compared to third environment (2018) which for from the two locations of year 2017. Our result indicate that line G69 recommended as most stable genotype for yield potential and stability whereas lines G9, G55, G67 and G68 were consider as superior genotypes.

Grain Yield Stability Analysis of Some Durum Wheat (Triticum durum Desf.) Genotypes Growing under Sub-humid Conditions

Background: Assessment of yield stability of durum wheat growing under different environments has been an important issue for wheat breeder. More Information about phenotypic stability is useful for the selection of adapted and stable genotypes which are suitable for wider range of planting.Methods: To calculate the parametric and non-parametric index, we use the program STABILITYSOFT. The aim of this study is the selection of adapted and stable genotypes based on the use of parametric and non-parametric index.Result: The graphic distribution of the genotypes tested based on the relationship between the mean grain yield and regression coefficient (bi), proved that the suitable genotypes for the tested conditions are Bidi17, Wahbi and Gta dur. The values of deviation from regression (S²di) classified the genotype Waha, as the most desirable genotypes. The Association between Wricke’s ecovalence (Wi²) indice and the grain yield proved that the best genotype for growing under these conditions are Bidi17, Wahbi and Gta dur. In addition, the non-parametric index confirmed the results which are registered by the selection based on the parametric index. Thus, the genotypes Bidi17 and Wahbi are the most stable genotypes. The classification based on the use of the principal component analysis classified the genotypes Wahbi and Bidi17 in dynamic stability group with highest grain yield. Therefore, genotypes with b values close to 1 (Wahbi, b = 0.95 and Bidi17, b = 0.98) are preferred since it is indicative of wide adaptation (dynamic stability), provided their mean yield is over the general mean. Overall, the uses of the parametric and non-parametric index are very suitable tools to select adapted and stable genotypes under sub-humid conditions.

Stability Analysis for Yield and Its Component Characters in Blackgram [Vigna mungo (L.) Hepper

Background: Blackgram [Vigna mungo (L.) Hepper] is an important pulse crop occupying a unique position in Indian agriculture. Blackgram provides a major share of the protein requirement of the vegetarian population of the country. The crop is resistant to adverse climatic conditions and improves the soil fertility by fixing atmospheric nitrogen in the soil. Phenotypically stable genotypes are of great importance because the environmental conditions vary from season to season and year to year. Stable performance of blackgram genotypes across contrasting environments is essential for the successful selection of stable and high yielding varieties. Methods: A total of seven genotypes of blackgram were evaluated one season (Rabi - 2019) in three environments to study the G x E interaction for three traits.Result: Based on the stability analysis of Eberhart and Russell model, two genotypes viz., MDU 1 and NRIB 002 were found to be stable across the environments for seed yield. These genotypes had high seed yield with a unity regression coefficient and deviation from regression equal to zero.

Regional multi-environment analysis of corn productivity and yield stability as impacted by hybrid maturity

Abstract Corn (Zea mays L.) hybrid maturity selection can help maximize productivity, yield stability, and optimize the use of available resources such as water, solar radiation, and nutrients. We explored yield differences by hybrid maturity with long term data from corn hybrid performance tests conducted between 2005 and 2017 in three U.S. states with variable area under irrigation: Arkansas (AR; 50 environments, 100% irrigated), Nebraska (NE; 22 environments, 59% irrigated), and Kentucky (KY; 54 environments, all rainfed). Stability-analysis techniques and probability functions were used to test the effect of Corn Relative Maturity (CRM) on yield and yield stability. Average yields increased per unit increase in CRM group by 51 kg ha−1 CRM−1 in AR and 122 kg ha−1 CRM−1 in NE. Thus, hybrids maturity recommendations to maximize yield were the latest CRM groups included in Corn Performance Tests in AR and NE (CRM 118−120 and 115−118, respectively). In contrast, the yield response to CRM group showed a quadratic relationship in KY, and selecting CRM groups later than 109–114 would reduce yield stability and likely delay harvest without providing a significant yield advantage. Full-season hybrids in AR and NE also showed the greatest responsiveness to environments of increasing average productivity, unlike in KY where all CRM groups showed similar responses. Different results observed across the three states may be partially attributed to different percentage of irrigated sites, with the implication that optimum hybrid maturity recommendations may need to be redefined depending on water availability.

Evaluation and stability analysis of some bread wheat genotypes under heat stress

This study was conducted at Kom-Mombo Agricultural Research Station, Aswan governorate, ARC, Egypt to study the performance and stability analysis of some wheat genotypes.Twelve genotypes of bread wheat were investigated under six environments; two years (2016/2017 and 2017/2018 seasons) and three sowing dates (normal (D1), 23rd of Nov., late (D2), 13th of Dec. and very late (D3), 16th of January). The differences among years, dates and genotypes were significant (p ˂ 0.01) for heading date, plant height, 100-grain weight and grain yield. All first order interactionswere significant for most studied traits. Mean squares due to interaction between genotypes, sowing dates and years were significantly for heading date and grain yield. The early sowing outyielded late and vey late one by 17.79 and 63.50%, respectively. Delaying sowing date reduced all traits under investigated. Five genotypes were less susceptible (heat susceptibility index less than one) and less sensitive (less than one) for heat stress.The stability analysis for grain yield exhibited that the intermediate yielding genotypes (Masr 1, Masr 2, Sids 12, Sids 13, Sids 14, BAG#1 and KACHU*2)were stableand ranged in yield from 8.90 to 12.28Ard/fed.). However, the genotype Masr 1 was stable and high in grain yield. While, the highest yielding genotype; Gimmiza 11 was unstable.

Stability analysis of stem solidness, grain yield, and grain protein concentration in spring wheat

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is a major pest of wheat (Triticum aestivum L.) in the northern Great Plains, where it is a constant threat in Montana and is resurging in Alberta, Saskatchewan, and North Dakota. Adoption of solid-stemmed cultivars is an important management tool for wheat growers; however, the inconsistent pith expression first noted with the release of ‘Rescue’ has been repeatedly observed in modern cultivars such as ‘Lillian’ in Canada. Given the extensive hectares planted to solid-stemmed wheat cultivars during an outbreak, the identification of cultivars that display stable stem solidness, grain yield, and grain protein concentration across a wide range of environments where stem sawfly infestations occur is desirable. We assessed spring wheat plant responses in eight solid-stemmed and two hollow-stemmed genotypes grown across diverse environments using multiple statistical models. Study sites included southern Alberta and Saskatchewan, Montana, and North Dakota. Most models agreed that the genotypes ‘Choteau’, ‘BW925’, and ‘Mott’ consistently displayed high and stable stem solidness concomitant with high grain yield. ‘Choteau’ and ‘BW925’ also consistently met or exceeded the desired threshold of a 3.75/5 pith rating (averaged from the lower four stem internodes) for optimum resistance, whereas ‘Mott’ developed optimal pith at a specific (early) phenological stage when resistance to wheat stem sawfly infestation is critical. Exploring the stability of stem solidness identified ideal genotypes that would enhance germplasm development efforts, which exemplifies how this approach can facilitate the selection, production, and adoption of solid-stemmed wheat cultivars in regions prone to wheat stem sawfly attack.

Stability analysis of grain yield and its contributing traits in advanced mutant lines of sorghum [Sorghum bicolor (L.) Moench

In the present study, 23 sorghum genotypes comprising 17 advanced mutant lines (M5) and six check varieties were evaluated for stability parameters over four locations during rabi 2017-18. Based on the ten morphological and yield traits, pooled ANOVA showed significant differences for the quantitative traits except for seed yield per plant. Mean sum of squares due to E+ (GxE) was significant for most of the characters except for days to flowering, and 100 seed weight. Environment component showed significant values for all traits. The GxE (linear) showed non-significant interaction for most of the characters in this study except for plant height, panicle length and seed yield. J-12 and J-3 mutants had mean value more than population mean and coefficient of regression near to unity and adapted to all situations.