Search

The sugar beet crop has always been attacked by various pests and diseases. Rhizomania viral disease, which has spread in different regions of sugar beet cultivation, has become a disease of prime importance for the crop in the last three decades. Resistant cultivar usage is the only reliable way to manage rhizomania disease. In order to identify promising genotypes, eleven sugar beet genotypes with natural infection to rhizomania, in a company with three controls, were assessed in a Randomized Complete Block Design (RCBD) with four replications. The experiment was conducted in six research stations of Karaj, Khoy, Kermanshah, Mashhad, Miandoab, and Shiraz for two cropping seasons (2020 and 2021). Based on the rhizomania score, all genotypes had acceptable resistance to the disease. The Additive Main Effects and Multiplicative Interaction (AMMI) stability analysis illustrated that the first five principal components were significant and specified 88.8% of the total genotype by environment interaction variance. Gen-7, Gen-10, Gen-11, and Gen-2 were selected as stable genotypes based on the AMMI model. Genotype plus Genotype by Environment Interaction (GGE) biplot results also confirmed the superiority of Gen-10 and Gen-11 regarding sugar yield and stability in disease-infected environments. According to the results of the Multi-Trait Stability Index (MTSI), genotypes Gen-4, Gen-1, Gen-2, and Gen-11 were identified as stable genotypes under rhizomania-infected conditions. By applying different stability measurement methods, in addition to identifying the genotypes' adaptation to different environments, accurate decisions for future breeding or cultivar registration can be achieved. [ABSTRACT FROM AUTHOR]

Climate change-induced hazards, such as drought, threaten forest resilience, particularly in vulnerable regions such as the Mediterranean Basin. Maritime pine (Pinus pinaster Aiton), a model species in Western Europe, plays a crucial role in the Mediterranean forest due to its genetic diversity and ecological plasticity. This study characterizes transcriptional profiles of scion and rootstock stems of four P. pinaster graft combinations grown under well-watered conditions. Our grafting scheme combined drought-sensitive and drought-tolerant genotypes for scions (GAL1056: drought-sensitive scion; and Oria6: drought-tolerant scion) and rootstocks (R1S: drought-sensitive rootstock; and R18T: drought-tolerant rootstock). Transcriptomic analysis revealed expression patterns shaped by genotype provenance and graft combination. The accumulation of differentially expressed genes (DEGs) encoding proteins, involved in defense mechanisms and pathogen recognition, was higher in drought-sensitive scion stems and also increased when grafted onto drought-sensitive rootstocks. DEGs involved in drought tolerance mechanisms were identified in drought-tolerant genotypes as well as in drought-sensitive scions grafted onto drought-tolerant rootstocks, suggesting their establishment prior to drought. These mechanisms were associated with ABA metabolism and signaling. They were also involved in the activation of the ROS-scavenging pathways, which included the regulation of flavonoid and terpenoid metabolisms. Our results reveal DEGs potentially associated with the conifer response to drought and point out differences in drought tolerance strategies. These findings suggest genetic trade-offs between pine growth and defense, which could be relevant in selecting more drought-tolerant Pinus pinaster trees. [ABSTRACT FROM AUTHOR]

The Multitrait Genotype Ideotype Distance Index (MGIDI) is a strong and adaptable technique for choosing superior genotypes of diverse crops based on numerous attributes. It is a multivariate selection indicator that incorporates different characteristic information into a single value and ranks genotypes based on their distance from an ideal genotype. Breeders can use variable selection criteria including weighting traits and assessing genetic strengths and weaknesses. It organizes attributes into components and chooses optimal genotypes based on many traits using principal component analysis. This review covered the available information regarding the background, applications, prospects, and limitations of MGIDI for crop improvement and breeding in this research. We discussed the significant discoveries and consequences of several studies that used MGIDI to enhance the productivity, excellence, and flexibility of numerous crops, such as bush yam, barley, cassava, cucumber, guar, lentil, maize, rice, bean, soybean, wheat, etc. Additionally, we talked about some of the potential applications of MGIDI for breeding and crop improvement, such as tolerance to salinity, stability analysis, tolerance to waterlogging, mechanism of drought response, performance in agronomy and tuber quality, nutritional value and productivity, adaptability, increased yield, early maturity, and stress resistance etc. Following the upward trend, MGIDI can be considered as a valuable index technique for selection of crop genotypes that can address food security, climate change, and nutritional quality problems worldwide. We expect that this study will spark more research and use of MGIDI in different crops characteristics, contributing to the improvement of plant breeding science.

Extremes in temperature resulting from global warming significantly threaten agriculture worldwide. Obtaining reliable information about the unique response of cultivars to changing environmental conditions can help employ precision practices for better plant physiology and growth. Researches on the effect of high temperatures on vines have generally focused on characteristics such as phenology, growth, yield, and fruit composition. Experimental knowledge about the effects of high temperatures on vine physiology largely remains insufficient. In this study, physiological responses of three different grapevine genotypes ['Michelle Palieri', 'Black Magic' and the rootstock 41 B (Vinifera × Berlandieri)] to three different temperature conditions were established using glasshouses and open vineyard. The conditions were (I) optimum temperature (OT, maintaining a day time average of 25±2°C), (II) low temperature (LT, maintaining a day time average of 17±2°C), and (III) high temperature (maintaining a day time average of 33±2°C) during the study period. OT and HT conditions were established by using two different climate controlled glasshouses while LT occurrednaturally under the temperate zone condition of open vineyard. The highest gs values were always determined under OT condition, while the gs values were far below the literature at LT and HT conditions for all genotypes. Leaf temperature consistently increased with the increase in environmental temperature across the grapevines. The soil temperature around the efficient root zone was as high as 29.7°C, around the upper threshold level of the optimum photosynthesis for grapevines, while the soil temperatures for other conditions were in recommended levels. The general findings revealed that the different temperature conditions directly affected the physiology of the grapevines with adverse effects of high or low temperatures outside the optimum levels. 41 B showed higher sensitivities to changing temperatures than those of V. vinifera cultivars. Differential responses of the genotypes revealed the importance of the use concrete and more stress tolerable cultivar to cope with the constrains of the climate change on viticulture. [ABSTRACT FROM AUTHOR]

Salinity stress represents an increasing issue for agriculture and has a great negative impact on plant growth and crop production. The selection of genotypes able to tolerate salt stress could be a suitable solution to overcome the problem. In this context, in vitro cultures can represent a tool for identifying the NaCl tolerant genotypes and quickly producing large populations of them. The possibility of exerting selection for tolerance to NaCl by using encapsulation technology was investigated in two genotypes of fig: 'Houmairi' and 'Palazzo'. The effects of five concentrations of NaCl (0, 50, 100, 150 and 200 mM) added to the artificial endosperm were tested on the conversion of synthetic seeds and on the growth of derived shoots/plantlets. Moreover, proline (Pro) and malondialdehyde (MDA), the enzymatic activities of catalase (CAT), guaiacol peroxidase (POD), and EL (Electrolytic Leakage), as well as the chlorophyll content, flavanols, anthocyanins, and Nitrogen Balance Index (NBI) were determined on shoots/plantlet. The obtained results clearly showed that 'Houmairi' and 'Palazzo' could tolerate salt stress, although a strong difference was found depending on each specific physiological pathway. Indeed, 'Houmairi' was revealed to be more tolerant than 'Palazzo', with different response mechanisms to salt stress. The use of encapsulated vitro-derived explants proved to be a useful method to validate the selection of genotypes tolerant to salinity stress. Further investigation in the field must validate and confirm the legitimacy of the approach. [ABSTRACT FROM AUTHOR]

Abstract The objective of this work was to identify the most adapted and stable genotypes for dry mass and seed yield using the genotype plus environment interaction (GGE) biplot technique. The experiment was conducted in the municipality of Frederico Westphalen, in the state of Rio Grande do Sul, Brazil, in 2018, 2019, 2020, and 2021, using five lines and two cultivars of black oat, in a randomized complete block experimental design, with three replicates. The adaptability and stability of the genotypes, as well as their behavior in the environments, were evaluated using the GGE biplot. The seed yield of black oat genotypes is highly influenced by the environmental conditions over the four studied cultivation years. The UFSMFW 2-07 genotype stands out, but shows instability. The UFSMFW 2-07 and 'UPFA 21-Moreninha' genotypes show adaptability in specific years. Mega environments are formed for the dry mass trait in 2018 and 2021 and seed yield in 2018, 2020, and 2021, whereas, 2019 is considered the year for genotype discrimination.

Climate change-induced hazards, such as drought, threaten forest resilience, particularly in vulnerable regions such as the Mediterranean Basin. Maritime pine (Pinus pinaster Aiton), a model species in Western Europe, plays a crucial role in the Mediterranean forest due to its genetic diversity and ecological plasticity. This study characterizes transcriptional profiles of scion and rootstock stems of four P. pinaster graft combinations grown under well-watered conditions. Our grafting scheme combined drought-sensitive and drought-tolerant genotypes for scions (GAL1056: drought-sensitive scion; and Oria6: drought-tolerant scion) and rootstocks (R1S: drought-sensitive rootstock; and R18T: drought-tolerant rootstock). Transcriptomic analysis revealed expression patterns shaped by genotype provenance and graft combination. The accumulation of differentially expressed genes (DEGs) encoding proteins, involved in defense mechanisms and pathogen recognition, was higher in drought-sensitive scion stems and also increased when grafted onto drought-sensitive rootstocks. DEGs involved in drought tolerance mechanisms were identified in drought-tolerant genotypes as well as in drought-sensitive scions grafted onto drought-tolerant rootstocks, suggesting their establishment prior to drought. These mechanisms were associated with ABA metabolism and signaling. They were also involved in the activation of the ROS-scavenging pathways, which included the regulation of flavonoid and terpenoid metabolisms. Our results reveal DEGs potentially associated with the conifer response to drought and point out differences in drought tolerance strategies. These findings suggest genetic trade-offs between pine growth and defense, which could be relevant in selecting more drought-tolerant Pinus pinaster trees.

BACKGROUND: Most plant breeding and agricultural practices are based on selecting genotypes for yield. However, this is inadequate to screen crop varieties for specific attributes, such as drought tolerance. In this study, we quantified the response of oat (Avena sativa L.) plant physiological and morphological traits to drought stress and selected some key traits to establish a genotype by yield*trait (GYT)‐based method for ranking 30 oat genotypes. The effectiveness of this method was also evaluated under drought conditions. RESULTS: Water‐deficit treatment significantly reduced leaf chlorophyll, root morphological traits, groat yield and associated components, such as mean grain weight. We observed that the genotypes 'JUSTICE' and 'BOLINA' had the smallest and largest yield loss, respectively, after exposure to drought stress, but showed opposite trends in the biomass allocation of roots and grains. This indicated that drought tolerance was highly dependent on the distribution of photoassimilates. Our results also illustrated that the GYT method is a trade‐off approach and more effective in selecting oat ideotypes under drought conditions than the yield‐related index method because it combines yield, yield stability, and related agronomic traits in the calculation process. CONCLUSION: Drought‐tolerant genotypes had more biomass allocated to roots and grains with higher chlorophyll content and better root structure, e.g. longer root lengths than drought‐sensitive lines. By integrating yield and yield‐related traits, the GYT approach is more practical than traditional single‐trait selection methods when assessing drought tolerance. © 2023 His Majesty the King in Right of Canada. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Reproduced with the permission of the Minister of Agriculture and Agri‐Food Canada. [ABSTRACT FROM AUTHOR]

Data analysis using the General linear model assumes the factors to be fixed effects, and the BLUE method, which is based on their mean performance, is appropriate to select the best performing genotypes. The linear mixed model incorporates fixed and random effects that are very important to compare a genotype's performance through BLUP. The purpose of this study was to identify the best performing genotypes that provided a high grain yield using a mixed model, compare the mean performance of genotypes on grain yield using BLUP and BLUE, and determine the impact of drought on sorghum production in Ethiopia. The experiment used water availability as a treatment, and each replication within the treatment levels used a lattice square design for data collection. The design consisted of 14 × 14 square experimental units (plots) comprising 196 genotypes, where each row of the square was represented as a block receiving 14 genotypes. The phenotypic characteristics were measured for the study. The statistical methods used for the study were ANOVA and the linear mixed model to identify the best performing genotypes of sorghum. The study found that sorghum production was influenced by drought, which restricted sorghum growth due to a shortage of water. The implementation of irrigation increased the grain yield from 2.48 to 3.17 t/ha, indicating that the difference in grain yield between treatments (with and without irrigation) was 0.69 t/ha. The study compared the general linear model and linear mixed model, and the investigation revealed that the mixed model was more accurate than the general linear model. The linear mixed model selected the best performing genotypes in grain yield with better accuracy. It is recommended to use the linear mixed model to select the best performing genotypes in grain yield. [ABSTRACT FROM AUTHOR]

Locally adapted landraces are the major barley varieties welcomed in the desert climate regions of Iran. These germplasms have potentials in terms of yield and drought tolerance which makes their evaluation worthwhile. To this end, fifty barley landraces along with six check varieties (Nosrat, Yoused, Nimroz, Goharan, Mehr and Khatam) were evaluated under well-watered and drought conditions during 2019–2020 and 2020–2021 growing seasons. The data were analyzed by GT (genotype by trait) biplot and GYT (Genotype by yield*trait) biplot method. Additionally, drought stress tolerant and susceptibility indices, including TOL, SSI, YSI, HM, GMP, MP and STI, were calculated and utilized in the GYT biplot which denominated as GYSI (Genotype by yield*stress index) biplot in this paper. Referring to ATC view and SI ranking of GYT data, 27 genotypes under well-watered and 27 genotypes under drought stress were selected which all were above average with the positive SI values. Likewise, 25 above average drought-tolerant genotypes were identified based on GYSI methodology. Based on the results, plant height and YSI were defined as ideal trait and stress index in combination with grain yield to identify superior genotypes, respectively. Overall, our study determined 12 genotypes which meet all the criteria to achieve high yield and drought tolerance. It could be concluded that combination of GT, GYT and GYSI methodologies led us to simultaneous selection of high-yielding and drought-tolerant genotypes accurately among locally adapted barley landraces of Iran. [ABSTRACT FROM AUTHOR]

Sorghum is the most popular crop in arid and semi-arid areas, especially in Sub-Saharan African countries. Genotype effects, environmental and the interaction of genotype by environmental factors have an influence on phenotypic traits. The aim of the study is to identify the relationship between grain yield and other yield-related traits and select the genotypes which perform better in grain yield as well as to examine the association between the uncorrelated phenotypic traits and grain yield via mixed model. The data was generated using a lattice square design. Principal component analysis was used to generate uncorrelated variables for the mixed model. The study revealed that there was a difference in grain yield due to the treatment and there was a pairwise relationship among the phenotypic variables. 77.12% of the total variance of the original phenotypic variables was explained by the first three principal components and decided to use PCAs as input variables for the mixed model. All PCs had significant effects on grain yield as well as grain yield variability due to random effects associated with genotypes, genotype interaction by treatment, and replication within the treatment. The variability of grain yield due to genotype effect was explained about 45.73%, the variation of grain yield due to the interaction of genotype by the treatment was also explained about 39.06% and 1.55% of the variation of grain was explained by replication within treatment. The best performer genotypes recommended for mass production were G40 (Genotype 40), G186 (Genotype 186) and G196 (Genotype 196) without any constraint of environment. The genotypes recommended for mass production under irrigation conditions were G40 (Genotype 40), G62 (Genotype 62) and G192 (Genotype 192). G26 (Genotype 26), G55 (Genotype 55) and G49 (Genotype 49) were the genotypes recommended for mass production under stress conditions. Overall, the study recommends using a mixed model to fit the grain yield, and future work will focus on to evaluate the performance of genotypes under different environments and years of production.

Salinity stress represents an increasing issue for agriculture and has a great negative impact on plant growth and crop production. The selection of genotypes able to tolerate salt stress could be a suitable solution to overcome the problem. In this context, in vitro cultures can represent a tool for identifying the NaCl tolerant genotypes and quickly producing large populations of them. The possibility of exerting selection for tolerance to NaCl by using encapsulation technology was investigated in two genotypes of fig: ‘Houmairi’ and ‘Palazzo’. The effects of five concentrations of NaCl (0, 50, 100, 150 and 200 mM) added to the artificial endosperm were tested on the conversion of synthetic seeds and on the growth of derived shoots/plantlets. Moreover, proline (Pro) and malondialdehyde (MDA), the enzymatic activities of catalase (CAT), guaiacol peroxidase (POD), and EL (Electrolytic Leakage), as well as the chlorophyll content, flavanols, anthocyanins, and Nitrogen Balance Index (NBI) were determined on shoots/plantlet. The obtained results clearly showed that ‘Houmairi’ and ‘Palazzo’ could tolerate salt stress, although a strong difference was found depending on each specific physiological pathway. Indeed, ‘Houmairi’ was revealed to be more tolerant than ‘Palazzo’, with different response mechanisms to salt stress. The use of encapsulated vitro-derived explants proved to be a useful method to validate the selection of genotypes tolerant to salinity stress. Further investigation in the field must validate and confirm the legitimacy of the approach.

In the present study, using the BLUP-GGE approach, southern-type (ST) Populus deltoides genotypes were analyzed and evaluated, and variations in growth traits, seedling height (H), and ground diameter (GD) were studied in various climatic regions, which could facilitate the increase of the breeding range of ST. The test materials were 119 one-year-old ST genotypes, and the test sites were Ningyang (NY) and Hainan (HN). A linear mixed-effects model was constructed, and the BLUP values of H and GD were obtained using the linear unbiased prediction (BLUP) method. GGE-Biplots were generated. The H variation was greater than the GD variation. The effects of environment, block, and genotype–environment interaction (G×E) were highly significant. The goodness of fit of the GGE-Biplots obtained by extracting the BLUP values was >95%. According to the GGE-biplot results, the performance of each genotype varied considerably. The genotype No. 13 had the highest average GD and the highest average H. In NY, the genotypes No. 93 and 115 had the highest H and GD, and in HN, the genotype No. 9 had the highest H and GD. ST had a better second-year survival rate in NY than in HN. The hybridization of tropical Populus deltoides can be performed using the No. 13 and 117 genotypes, which grow rapidly and have high yields. [ABSTRACT FROM AUTHOR]

In temperate and subtropical climates, Populus deltoides is an important poplar species. To analyze the stability, adaptability, and high yield of P. deltoides hybrid genotypes in East China, 38 P. deltoides genotypes were screened at three experimental sites in Shandong Province, and the coefficients of variation and genetic characteristics of 5-year growth were examined using BLUP-GGE. Results showed that all coefficients of variance were higher for diameter at breast height (DBH) than for tree height at all sites; the repeatability and heritability of tree height were greater than those of DBH at all sites. The fitting degree of tree height and DBH was 93.72% and 92.22%, respectively. The optimum genotype varied by location and grouping, of which Shanxian County divisions are the most powerful and representative of the three sites. The growth of 5-year-old P. deltoides was highly varied because of hereditary factors. Shanxian County is the more appropriate site for growth of P. deltoides in the tested sites in East China. In East China, genotypes 16, 5, 21, and 7 are regarded as superior. The genotypes 8, 26, and 36 are better for the site Rizhao; 16, 5, and 21 for site Shanxian; and 22, 21, and 5 for site Boxing. [ABSTRACT FROM AUTHOR]

ABSTRACT The objective of this work was to assess the breeding influences in different agronomic and physiological traits in Brazilian soybean cultivars, released between 1965 and 2011, to identify traits associated with modern cultivars. A total of 29 cultivars were evaluated in two locations in the 2016/17 crop season. Genotype selection based on agronomic and physiological traits was determined using GYT (Grain Yield*Trait) methodology, which uses the Superiority Index to rank genotypes by mean of all traits. Grain Yield is combined with other target traits and shows the strengths and weaknesses of each genotype. Soybean breeding improved desirable traits during the 46 years of evaluation. Superiority index can be a powerful tool for breeders to obtain high genetic gains in the future. The cultivars DMario 58i, TMG 7161RR and TMG 7262 RR stand out as the best cultivars but present different sets of desirable traits. The traits grain yield, harvest index, number of pods per plant, reproductive-vegetative ratio, photosynthetic rate and transpiration rate are core traits which can be evaluated in soybean breeding programs.

Background. Wheat is a staple food crop and easily accessible to the population, so the biofortification of wheat grains is substantial to mitigate malnutrition. Objective. To evidence and select wheat genotypes based on nutritional multi-characters of grains based on genetic parameters. Methodology. Experiments were carried out in the 2019 agricultural season in five wheat areas of the state of Rio Grande do Sul, in two sowing seasons, in the municipalities of Cachoeira do Sul, Cruz Alta, Santo Augusto, São Gabriel and Vacaria. The experimental design was randomized blocks, organized in a factorial scheme with 10 cultivation environments (5 sites by two sowing dates) and 30 genotypes, with three replications. To carry out the selection of genotypes, the WAASB, AMMI, GGE and BLUP methodologies were applied. Results. In terms of lipids and fibers, three mega environments were formed, highlighting the genotypes BRS 327, CD 1550, Ametista, CD 1303 and BRS 331, respectively. For mineral material, there was the formation of two mega environments and the genotypes that stood out were Quartz and Tbio Toruk, while for carbohydrate there was the formation of a mega environment and the genotype that stood out was CD 1550. The Tbio Mestre and LG Prisma genotypes were the ideal genotypes, with high performance in the Cachoeira do Sul environment – Sowing 2nd fortnight. Tbio Iguaçú expressed high levels of lipids in Santo Augusto – Seeding 1st fortnight, São Gabriel – Seeding 2nd fortnight and Vacaria – Seeding 2nd fortnight. ORS 1405 and Tbio Iguaçú expressed high levels of carbohydrates in the Vacaria - Seeding 2nd fortnight environment. Heritabilities without interaction effects were high, which characterizes high genotypic additive variance. Implications. The current results indicate that there is genetic variability, making it possible to select genotypes with greater expression of nutrients in the grains. Conclusion. The TBio Mestre, CD 1440, LG Prisma and Marfim genotypes expressed greater performance and stability of the evaluated traits.

Wild-growing Cornelian cherries (Cornus mas L., Cornaceae) are well-known native fruits in Greece since ancient times that are still consumed locally nowadays. Modern research has highlighted the value of Cornelian cherries as functional food with exceptional health benefits on account of the fruits' biochemical profile. However, apart from local consumption directly from wild growing individuals, Greek native C. mas populations have not yet been investigated or sustainably utilized. A multifaceted evaluation was conducted herein including authorized collection-documentation, taxonomic identification, and molecular authentication (DNA barcoding), asexual propagation via cuttings and phytochemical evaluation (multiple antioxidant profiling) of neglected and underutilized Greek native C. mas germplasm sources. Successive botanical expeditions resulted in the collection of 18 samples of genotypes from distant C. mas populations across different natural habitats in Greece, most of which were DNA fingerprinted for the first time. Asexual propagation trials revealed high variability in rooting frequencies among Greek genotypes with low (<25%), average (25–50%), and adequate propagation potential (>50%) using external indole-3-butyric acid (IBA) hormone application on soft- or hard-wood cuttings. The comparative phytochemical evaluation of the studied Greek genotypes showed significant potential in terms of antioxidant activity (>80% radical scavenging activity in 13 genotypes), but with variable phenolic content (47.58–355.46 mg GAE/100 g), flavonoid content (0.15–0.86 mg CE/100 g), and vitamin C content (1–59 mg AAE/100 g). The collected material is currently maintained under ex situ conservation for long-term monitoring coupled with ongoing pilot cultivation trials. The pivotal data create for the first time a framework for the sustainable utilization of Greek native C. mas germplasm as a superfood with significant agronomic potential. [ABSTRACT FROM AUTHOR]

Abstract The objective of this work was to evaluate the bioactive compounds and foliar anatomy of yerba mate (Ilex paraguariensis) morphotypes. The antioxidant capacity, total phenolic compounds, methylxanthines, and caffeoylquinic acids were determined from the aqueous extract of leaves of the following yerba mate morphotypes: “sassafras”, dark green, dull green, gray, and “peludinha”. Light microscopy and scanning electron microscopy were used to observe the anatomical differentiations. The dark-green morphotype showed the highest contents of caffeine (20.4 mg g-1), differing significantly only from the “peludinha” morphotype (8.8 mg g-1). All morphotypes showed similar and high antioxidant activity (886.0 and 588.1 μmol Trolox equivalent antioxidant activity per gram of sample for ABTS and DPPH, respectively), as well as high total phenolic compounds content (73.9 mg gallic acid equivalent per gram of sample). Although the anatomy of the leaf mesophyll is similar, the wax deposition and cuticle striation configuration on the adaxial surface differ between all five morphotypes.

Data analysis using the General linear model assumes the factors to be fixed effects, and the BLUE method, which is based on their mean performance, is appropriate to select the best performing genotypes. The linear mixed model incorporates fixed and random effects that are very important to compare a genotype’s performance through BLUP. The purpose of this study was to identify the best performing genotypes that provided a high grain yield using a mixed model, compare the mean performance of genotypes on grain yield using BLUP and BLUE, and determine the impact of drought on sorghum production in Ethiopia. The experiment used water availability as a treatment, and each replication within the treatment levels used a lattice square design for data collection. The design consisted of 14 × 14 square experimental units (plots) comprising 196 genotypes, where each row of the square was represented as a block receiving 14 genotypes. The phenotypic characteristics were measured for the study. The statistical methods used for the study were ANOVA and the linear mixed model to identify the best performing genotypes of sorghum. The study found that sorghum production was influenced by drought, which restricted sorghum growth due to a shortage of water. The implementation of irrigation increased the grain yield from 2.48 to 3.17 t/ha, indicating that the difference in grain yield between treatments (with and without irrigation) was 0.69 t/ha. The study compared the general linear model and linear mixed model, and the investigation revealed that the mixed model was more accurate than the general linear model. The linear mixed model selected the best performing genotypes in grain yield with better accuracy. It is recommended to use the linear mixed model to select the best performing genotypes in grain yield.

In the present study, using the BLUP-GGE approach, southern-type (ST) Populus deltoides genotypes were analyzed and evaluated, and variations in growth traits, seedling height (H), and ground diameter (GD) were studied in various climatic regions, which could facilitate the increase of the breeding range of ST. The test materials were 119 one-year-old ST genotypes, and the test sites were Ningyang (NY) and Hainan (HN). A linear mixed-effects model was constructed, and the BLUP values of H and GD were obtained using the linear unbiased prediction (BLUP) method. GGE-Biplots were generated. The H variation was greater than the GD variation. The effects of environment, block, and genotype–environment interaction (G×E) were highly significant. The goodness of fit of the GGE-Biplots obtained by extracting the BLUP values was >95%. According to the GGE-biplot results, the performance of each genotype varied considerably. The genotype No. 13 had the highest average GD and the highest average H. In NY, the genotypes No. 93 and 115 had the highest H and GD, and in HN, the genotype No. 9 had the highest H and GD. ST had a better second-year survival rate in NY than in HN. The hybridization of tropical Populus deltoides can be performed using the No. 13 and 117 genotypes, which grow rapidly and have high yields.

In temperate and subtropical climates, Populus deltoides is an important poplar species. To analyze the stability, adaptability, and high yield of P. deltoides hybrid genotypes in East China, 38 P. deltoides genotypes were screened at three experimental sites in Shandong Province, and the coefficients of variation and genetic characteristics of 5-year growth were examined using BLUP-GGE. Results showed that all coefficients of variance were higher for diameter at breast height (DBH) than for tree height at all sites; the repeatability and heritability of tree height were greater than those of DBH at all sites. The fitting degree of tree height and DBH was 93.72% and 92.22%, respectively. The optimum genotype varied by location and grouping, of which Shanxian County divisions are the most powerful and representative of the three sites. The growth of 5-year-old P. deltoides was highly varied because of hereditary factors. Shanxian County is the more appropriate site for growth of P. deltoides in the tested sites in East China. In East China, genotypes 16, 5, 21, and 7 are regarded as superior. The genotypes 8, 26, and 36 are better for the site Rizhao; 16, 5, and 21 for site Shanxian; and 22, 21, and 5 for site Boxing.

The objective of this work was to assess the breeding influences in different agronomic and physiological traits in Brazilian soybean cultivars, released between 1965 and 2011, to identify traits associated with modern cultivars. A total of 29 cultivars were evaluated in two locations in the 2016/17 crop season. Genotype selection based on agronomic and physiological traits was determined using GYT (Grain Yield*Trait) methodology, which uses the Superiority Index to rank genotypes by mean of all traits. Grain Yield is combined with other target traits and shows the strengths and weaknesses of each genotype. Soybean breeding improved desirable traits during the 46 years of evaluation. Superiority index can be a powerful tool for breeders to obtain high genetic gains in the future. The cultivars DMario 58i, TMG 7161RR and TMG 7262 RR stand out as the best cultivars but present different sets of desirable traits. The traits grain yield, harvest index, number of pods per plant, reproductive-vegetative ratio, photosynthetic rate and transpiration rate are core traits which can be evaluated in soybean breeding programs. [ABSTRACT FROM AUTHOR]

Poplar is a commercially globalized tree species that provides energy and economic and ecological support. To evaluate the twelve hybrid Populus euramericana genotypes developed in China, a total of six locations were selected for the current study, comprising four climatic types and three kinds of soil. The objective of this study was to characterize the early stages of Populus euramericana growth and to test the locations; to identify good genotypes for stable and high yield; and to offer practical experience and technical assistance for further breeding of Populus euramericana. The main research methods included the statistical description of tree heights and diameter at breast height (DBH), the establishment of a mixed effect model to analyze the genotype and environmental interaction effect (G × E), the use of best linear unbiased prediction (BLUP) values as GGE biplots to achieve visual screening, and the calculation of genetic parameters. Results show that the genotype effect (G), the environmental effect (E), and the G × E interaction is significant; the BLUP value has a strong correspondence with the observed value; the goodness of fit of all biplots can explain more than 85% of the variation; the broad-sense heritability of tree height and DBH is 0.13 and 0.3, respectively; and the type-B correlation is 0.36 and 0.65. In addition, G5, G7, G4, and G9 are excellent genotypes with high yield and stability; using the tree height and DBH of these four genotypes can achieve genetic gains of 3.35% and 0.81%. The conclusions of this study are as follows: the rank-change and scale-effect interactions were distinct; G, E, and G × E all had a significant effect on the growth of poplar trees during their early stage; G4, G5, G7, and G9 genotypes have favorable development characteristics; and N146 is an excellent source of paternal genetics.

Pollen genotype selection for genes expressed in both the haploid and diploid phases of the plant life cycle can lead to correlated responses detectable in the sporophyte. Here, Impact of pollen selection for heat tolerance was assessed in segregating population of maize. Two subsets of F1 were made among which one was self-fertilized with heat treated pollen grains while other set by normal pollen where no such selection was made that resulted in two F2 populations TF2 and CF2, respectively. The TF2 population recorded significantly higher mean values for pollen per anther (4646.78 ± 176.70) than that for control F2 population (3321.89 ± 164.91). In addition, the test F2 population recorded significantly higher seed yield per plant (2.02 ± 0.72 g) than that of test F2 population (1.38 ± 0.08 g) under heat stress. These two populations were also evaluated under normal condition to verify whether the TF2 population showed heat tolerance improvement has any impact on yield attributes. The result showed non-negative impact of pollen selection on performance of TF2 under normal condition. Thus, pollen selection could be used to selectively improve the trait of interest. The segregation analysis of SSR markers followed the expected Mendelian distribution in CF2 population whereas a significant deviation in allelic frequency was observed in TF2 population. These results clearly evidence that the gametophytic selection for heat tolerance in F1 generation had positive effect towards increasing the resistant alleles in F2 population of maize. [ABSTRACT FROM AUTHOR]

The article presents information on Persian walnut (Juglans regia L.) cultivars of Iran including Persia, Caspian, Chaldoran and Alvand. Topics discussed include the walnut breeding program which started in 1984 through the selection of native germplasm, the selection of some superior genotypes and phenological and pomological traits of the selected cultivars.

Given its high biomass and plasticity, Arundo donax L. is a promising ligno-cellulosic crop for cultivation in marginal lands in temperate climates. In order to test for adaptation to salinity, growth parameters of several A. donax clones were evaluated under two salt regimes in hydroponics. Mild NaCl stress (50 mM NaCl, 5.6 mS cm−1 EC, for 10 days) failed to discriminate between ecotypes, while a more severe NaCl treatment (150 mM, 18.8 mS cm−1 EC, for 21 days) enabled the identification of ecotypes maintaining plant growth under high salinity. Among several biometric parameters, 4th leaf width, and shoot and root DW consistently highlighted differences between ecotypes. Gas-exchange parameters also responded to severe NaCl treatment, while the photosystem efficiency was good, regardless of treatment. The results confirm that A. donax can be considered moderately tolerant to NaCl stress, with variation between ecotypes. Our screening protocol identified ecotypes with higher biomass production under severe NaCl treatment and can be useful for preliminary evaluation of NaCl tolerant clones for increasing productivity under salinity. The detected inter-ecotype variability could also be investigated to identify suitable clones for different environments. [ABSTRACT FROM AUTHOR]

Sulfur (S) deficiency can negatively affect seed yield and nitrogen (N) use efficiency of winter oilseed rape. In this study, it was tested whether genotypic variation in sulfur-related plant traits exists and how this is related to agronomic performance of oilseed rape accessions at low and high N availability in the field. A range of highly diverse oilseed rape accessions was grown in short-term hydroponic experiments under N-limiting conditions. Accessions showed high variation in S uptake and S distribution within shoots, and particularly in leaf S concentration, malate:sulfate ratio and glucosinolate concentration, while variation in N-related plant traits was less pronounced. Accessions could be classified into four groups by cluster analysis using the measured plant traits in hydroponics. The same grouping of the accessions could also be achieved by using only the leaf S parameters. Apart from the variation in hydroponic experiments, groups also differed in agronomic parameters in the field. Within glucosinolate-containing accessions those characterized by high S uptake and S distribution in hydroponics showed superior yield both at low and high N supply. Low-glucosinolate (00) accessions with high S uptake in hydroponics had higher seed S concentrations than other 00-accessions in field experiments. It was concluded that assessing S-related plant traits under controlled conditions in an early growth stage is effective for identifying genotypes with superior S utilization. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ceres is the property of Revista Ceres and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sorghum is the most popular crop in arid and semi-arid areas, especially in Sub-Saharan African countries. Genotype effects, environmental and the interaction of genotype by environmental factors have an influence on phenotypic traits. The aim of the study is to identify the relationship between grain yield and other yield-related traits and select the genotypes which perform better in grain yield as well as to examine the association between the uncorrelated phenotypic traits and grain yield via mixed model. The data was generated using a lattice square design. Principal component analysis was used to generate uncorrelated variables for the mixed model. The study revealed that there was a difference in grain yield due to the treatment and there was a pairwise relationship among the phenotypic variables. 77.12% of the total variance of the original phenotypic variables was explained by the first three principal components and decided to use PCAs as input variables for the mixed model. All PCs had significant effects on grain yield as well as grain yield variability due to random effects associated with genotypes, genotype interaction by treatment, and replication within the treatment. The variability of grain yield due to genotype effect was explained about 45.73%, the variation of grain yield due to the interaction of genotype by the treatment was also explained about 39.06% and 1.55% of the variation of grain was explained by replication within treatment. The best performer genotypes recommended for mass production were G40 (Genotype 40), G186 (Genotype 186) and G196 (Genotype 196) without any constraint of environment. The genotypes recommended for mass production under irrigation conditions were G40 (Genotype 40), G62 (Genotype 62) and G192 (Genotype 192). G26 (Genotype 26), G55 (Genotype 55) and G49 (Genotype 49) were the genotypes recommended for mass production under stress conditions. Overall, the study recommends using a mixed model to fit the grain yield, and future work will focus on to evaluate the performance of genotypes under different environments and years of production., Competing Interests: We have no known competing financial interest or personal relationships., (© 2023 The Authors.)

Na agricultura atual, o método mais utilizado para o controle de plantas daninhas é o químico, em razão da facilidade de uso, elevada eficiência e baixa necessidade de mão de obra. No entanto, a utilização inadequada desses produtos provoca problemas ao ambiente e à saúde humana. Cresce, portanto, a busca por métodos alternativos de controle de plantas daninhas, menos demandadores de energia e menos tóxicos e agressivos ao ambiente. Este trabalho objetivou avaliar o efeito alelopático da cultura do girassol (Helianthus annuus) sobre diferentes espécies de plantas daninhas e cultivadas, em dois experimentos realizados em delineamento experimental completamente casualizado, utilizando o método da semeadura em substituição. O primeiro experimento foi realizado com quatro repetições, em esquema bifatorial. O primeiro fator foi constituído por seis espécies indicadoras: picão-preto (Bidens pilosa), corda-de-viola (Ipomoea grandifolia), caruru (Amaranthus hybridus), alface (Lactuca sativa, cultivar Aurélia), tomate (Lycopersicon esculentum, cultivar Santa Cruz), trigo (Triticum aestivum, cultivar BRS 208); e o segundo, pela presença ou não de plântulas de girassol. O segundo experimento foi composto por 24 tratamentos, representados por 23 genótipos de girassol e por uma testemunha sem girassol, utilizando-se quatro repetições. A espécie indicadora foi apenas o picão-preto. Em ambos os experimentos, no final do período de sete dias de convívio, foram avaliados o número de sementes germinadas e o comprimento radicular e da parte aérea das espécies indicadoras. Não foram observadas diferenças entre as porcentagens de germinação de quaisquer das espécies indicadoras avaliadas, em função da presença ou não das plântulas de girassol. A presença de plântulas de girassol estimulou o crescimento radicular das plântulas de tomate e trigo e inibiu o crescimento da parte aérea de picão-preto, trigo e corda-de-viola. Houve grande variabilidade de potencial alelopático entre genótipos de girassol sobre a germinação e o crescimento radicular e da parte aérea de Bidens pilosa. Os resultados demonstram que a técnica da semeadura em substituição é adequada para detectar efeitos estimulativos ou inibitórios de girassol sobre espécies indicadoras e para discriminar genótipos de girassol quanto à habilidade em inibir ou estimular plântulas de Bidens pilosa.In modern agriculture, the chemical method is the most used for weed control because it is highly efficient, easy to apply, and demands limited labor. However, the inadequate use of chemical products can lead to environmental and human health problems. Thus, there is a growing need to search for alternative weed control methods using substances which are less energy-demanding, less toxic and less aggressive to the environment. This work aimed to evaluate the allelopathic potential of sunflower (Helianthus annuus) culture on different weed and cultivated species, in two experiments conducted in a completely randomized design, using the relay seeding technique. The first experiment was carried out with four repetitions, in a bi-factorial scheme. The first factor was constituted by six indicative target species: beggarticks (Bidens spp.), common morninglory (Ipomoea grandifolia), pigweed (Amaranthus hybridus), lettuce (Lactuca sativa, cv. Aurélia), tomato (Solanum lycopersicum, cv. Santa Cruz), and wheat (Triticum aestivum, cv. BRS 208).The second factor was constituted by the presence or absence of sunflower seedlings. The relay seeding technique was applied. The second experiment was composed by 24 treatments including 23 sunflower genotypes and a control without sunflower, with four repetitions. The indicative species was only the beggarticks. In both experiments, at the end of seven coexistence days, number of germinated seeds, and root and aerial part length of the target species were evaluated. No difference was observed among the germination percentages of the indicative species evaluated in the presence or absence of the sunflower plants. The presence of the sunflower plants stimulated tomato and wheat root growth and inhibited the growth of the beggartick, wheat and common morninglory aerial parts. There was great variability of the potential allelopathic effect of the sunflower genotypes on germination and root and aerial part length of Bidens pilosa. The results show that the relay seeding technique is adapted to discriminate stimulating and inhibiting effects of sunflower among indicative species and to discriminate sunflower genotypes in their ability to inhibit or stimulate Bidens pilosa plants.

Thirty-five pummelo (Citrus grandis (L.) Osbeck) genotypes were assessed with respect to their quality parameters considered most essential with respect to horticultural aspects. Among the genotypes, significant to highly significant differences were observed in all the parameters. Different fruit physical parameters such as weight, diameter, length, volume pulp weight, pulp thickness, pulp-peel ratio and seed number varied significantly among the genotypes. Similarly, there were high level of differences among the genotypes with respect to chemical parameters of the fruits. The juice content varied from 13.64% to 43.56%, vitamin C from 17.40 to 52.70 mg/100 ml, total soluble solids from 7.73% to 11.67%, acidity from 0.76% to 1.86%, total sugars from 7.47% to 9.95% and sugar-acid ratio from 4.88 to 12.58. The present study reveals that parameters such as weight of the fruit, length of the fruit, diameter, volume, pulp weight, pulp-peel ratio, juice, TSS, acidity, ascorbic acid, total sugars and sugar-acid ratio can be considered as selection criteria for future breeding programmes in pummelo. The high level of differences with respect to various physical and chemical parameters of the fruits shows the great scope for superior genotype selection based on these particular parameters for genetic improvement programmes in near future. [ABSTRACT FROM AUTHOR]

Cyclocarya paliurus is a highly valued and multiple function tree species. Its leaves have traditionally been used as a medicine or nutraceutical tea. However, limited information is available on its genotype selection and cultivation under a wide range of environmental conditions for growth and enhanced antioxidant activities. Twelve genotypes of C. paliurus at four sites were assessed with respect to genotype, environment and their interaction on growth and flavonoid accumulation, while adaptability and stability of each genotype to varying growth environments were also examined. Results indicated that genotype and growth environment significantly affected the growth and flavonoid accumulation of C. paliurus , with environmental effects being more predominant. Interactions between genotype and environment significantly influenced flavonoid accumulation, but not in growth. Across four sites, stability in tree height growth and total flavonoid content of leaves varied among 12 genotypes of C. paliurus . Hierarchical cluster analysis based on height growth and total flavonoid content of leaves indicated the 12 genotypes were classified into four distinct groups, and three genotypes (SC-4, HF-10 and KM-5) were recommended for flavonoid production in future. Techniques used in this paper would be valuable in identifying the best choice among current and future genotype of C. paliurus for use in flavonoid production. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluated the degree of resistance of 36 clones of passion obtained through mass selection progenies of seven interspecific hybrids, to three different isolates of X. axonopodis pv. passiflorae. The progenies were obtained by crossing among a commercial cultivate Passiflora edulis "yellow passion fruit " with wild species P. caerulea, P. edulis "purple passion fruit" and P setacea. The bacterial isolates used were obtained in Rio Claro, SP, Planaltina.DF and Limeira, SP. Individual cloned were inoculated with bacterial solution in concentration with 108cfu ml-1 to 120 days of sowing. Symptoms were evaluated at 5, 10 and 15 days after inoculation, by measuring the longitudinal and transverse diameter of the lesion. Then, it was calculated the area under the lesion progress curve (AUPLC). A complete randomized block design with split plots was used, the treatments were the tested genotypes replicated in four blocks. All genotypes in each block had a three-plant plot. The bacterial isolates were inoculated in one plant of the plot, totaling three plants with different isolates. The plants of the genitors species P. caerulea (AUPLC=0.17) and P. setacea (AUPLC=14.50) presented high degree of resistance when compared to control plants BRS 'Gigante Amarelo' (AUPLC=4089.25), while hybrids genotypes presented intermediary values (AUPLC of 15.67 the 768.42), showing the importance of these wild Passiflora species as source of resistance to bacterial disease. [ABSTRACT FROM AUTHOR]

Plant functional traits involved in carbon and water acquisition are likely to be adaptive across the range of a species if the availability of these resources varies across this range and are limiting to growth or fitness. At the interspecific level, leaf economic traits associated with rapid resource capture are correlated with fast growth rates. However, relationships between leaf traits and growth are poorly understood at the intraspecific level., We examined two hypotheses: (i) leaf traits vary genotypically among Populus fremontii populations from different thermal environments; and (ii) leaf traits are related to growth rate of these P. fremontii populations. We used a common garden at the warm edge of P. fremontii distribution that included individuals transplanted from 11 provenances. Provenances varied in mean annual maximum temperature by 5·9 °C, reflecting a range of expected increases in temperature over the next 80 years., Conservative leaf traits (e.g. low specific leaf area, N content, stomatal conductance, net photosynthetic rate and high leaf water-use efficiency) were positively related to growth rates of genotypes and populations, a pattern opposite of that widely reported among species in other studies., Provenance temperature explained 75% of the variation in multivariate leaf traits with the warmest provenances having the most conservative traits and highest growth rates. Clinal genetic variation suggests that P. fremontii may be adapted to thermal environments., Leaf area-to-sapwood area ratio was positively associated with growth rate, while leaf area-based net photosynthetic rate was negatively associated with growth rate; these results suggest that hydraulic architecture was more important than leaf-level photosynthetic rate in determining growth rate., Synthesis. Our results suggest that conservative leaf traits promote rapid growth of P. fremontii genotypes in extremely hot environments. Thus, relationships between leaf economic traits among species do not necessarily apply to the range of variation among genotypes within species. The generality of this pattern should be examined for other species that will be exposed to climate warming. Moreover, our research shows that common garden provenance trials are useful for identifying genotypes best suited to a predicted warmer climate and for improving understanding of the physiological basis for adaptation to warm environments. [ABSTRACT FROM AUTHOR]

h gourd is an important vegetable especially in the Indo-China region, but also in America and Africa. It is a monotypic genus, and its genetic pool is considered little diverse, which makes breeding of good ash gourd cultivars difficult. A pool of 56 genotypes, of which 10 are released cultivars and 46 indigenous lines collected from different parts of India, was studied in a two-year experiment. Various traits are important when breeding new cultivars, so an optimum multivariate performance is studied in this germplasm, with a special focus on traits of the greatest importance, namely fruit yield per plant, flesh thickness, vine length, and number of days to female and male flowering. Such performance is studied for the best-yielding genotypes, and promising genotypes in terms of multivariate performance are selected. [ABSTRACT FROM AUTHOR]

A G × E performance (interaction, profile) plot for showing genotype-by-environment data is discussed. Three versions of such a plot are compared: the regular performance plot; the performance plot based on coded data (environment-centered performance plot), in which the environment means of a trait are subtracted from data; and the performance plot based on data standardized in environments (environment-standardized performance plot). The plots are compared for six soybean genotypes studied in eight environments. The regular performance plot best conveys information about genotype stability in a static sense, and provides more information about the environments than the two other plots. The environment-centered performance plot better presents genotype stability in a dynamic sense and adaptability. The environment-standardized performance plot poorly represents stability in both senses and adaptability. [ABSTRACT FROM AUTHOR]

Visualizing genotype-by-environment interaction in the case of several attributes, a situation that is often dealt with in plant breeding, is discussed in the paper. The parallel coordinate plot is proposed as an efficient tool for such visualization. Various applications of this type of graph are presented for across-environment and environment-wise plotting, thereby offering rich information about genotypes' performance. It is shown how one can analyze the data and report the results by means of the parallel coordinate plots. [ABSTRACT FROM AUTHOR]

Poplar is a commercially globalized tree species that provides energy and economic and ecological support. To evaluate the twelve hybrid Populus euramericana genotypes developed in China, a total of six locations were selected for the current study, comprising four climatic types and three kinds of soil. The objective of this study was to characterize the early stages of Populus euramericana growth and to test the locations; to identify good genotypes for stable and high yield; and to offer practical experience and technical assistance for further breeding of Populus euramericana. The main research methods included the statistical description of tree heights and diameter at breast height (DBH), the establishment of a mixed effect model to analyze the genotype and environmental interaction effect (G × E), the use of best linear unbiased prediction (BLUP) values as GGE biplots to achieve visual screening, and the calculation of genetic parameters. Results show that the genotype effect (G), the environmental effect (E), and the G × E interaction is significant; the BLUP value has a strong correspondence with the observed value; the goodness of fit of all biplots can explain more than 85% of the variation; the broad-sense heritability of tree height and DBH is 0.13 and 0.3, respectively; and the type-B correlation is 0.36 and 0.65. In addition, G5, G7, G4, and G9 are excellent genotypes with high yield and stability; using the tree height and DBH of these four genotypes can achieve genetic gains of 3.35% and 0.81%. The conclusions of this study are as follows: the rank-change and scale-effect interactions were distinct; G, E, and G × E all had a significant effect on the growth of poplar trees during their early stage; G4, G5, G7, and G9 genotypes have favorable development characteristics; and N146 is an excellent source of paternal genetics. [ABSTRACT FROM AUTHOR]

Total reliance on herbicides for weed control is unsustainable with the spread of herbicide resistance and the environmental need to reduce pesticide use. Strongly competitive wheat crops that have high tolerance to weed pressure and therefore maintain high yields in the presence of weeds are a low-cost option for reducing dependence on herbicides. We examined the feasibility of selecting for wheat tolerance to weeds by crossing varieties differing for traits associated with competitiveness. Competitive ability and yield potential must be treated as separate traits for selection. Current measures of crop tolerance to weed competition do not separate the two traits so that selection based on these measures is often synonymous with selection for yield potential rather than pure tolerance. We propose a new measure, termed Incremental Crop Tolerance (ICT) that reflects the incremental yield difference between genotypes associated with tolerance, over and above differences in underlying yield potential. [ABSTRACT FROM AUTHOR]