Genotype × environment interactions for herbage yield of perennial ryegrass sward plots in Ireland

Perennial ryegrass (Lolium perenne L.) is by far the most widely sown grass species in Ireland. Genotype × environment (G × E) interactions are a frequent occurrence in herbage yield evaluations. The objectives were to determine (i) the nature and relative magnitudes of the pertinent G × E interaction variance components for dry matter yield of perennial ryegrass sward plots in Ireland and (ii) the optimal allocation of replicates, locations and years in a testing programme. Sixteen perennial ryegrass cultivars were sown at six locations throughout Ireland between 2000 and 2004. Plots from each sowing were harvested for 2 consecutive years under a simulated mixed grazing and conservation management programme. The largest component of the G × E variance was generally genotype × location × year emphasizing the need for evaluation of genotypes across locations and years to adequately characterize genotypes for differences in yield. Relative differences among genotypes from year to year and location to location were due mainly to changes in genotype rankings. Weather was estimated to have a greater effect on annual variation in herbage yield than age of stand. The optimum allocation of resources for a testing programme was estimated at four replicates per location, and either two locations and 3 sowing years or three locations and 2 sowing years with 2 harvest years for each sowing year. The most appropriate option depends on the relative importance of time vs. financial resources.     

南非红麻产量基因型与环境互作的效应分析

本实验分析了9个红麻品种在南非地区的产量稳定性。结果显示，在南非纳塔尔地区，红麻产量的基因型和环境相互作用显著。在不同的参试地区和年份中，红麻鲜重，鲜茎产量以及干茎产量均为极显著差异。灌溉条件下各产量指标明显高于干旱地区。本实验还应用了3个不同的参数和方案。评估了这9个品种的稳定性。结果表明，综合三个参数，EI Salvador是在不同环境条件下具有丰产潜力的品种。     

南非红麻产量基因型与环境互作的效应分析

本实验分析了9个红麻品种在南非地区的产量稳定性.结果显示,在南非纳塔尔地区,红麻产量的基因型和环境相互作用显著.在不同的参试地区和年份中,红麻鲜重,鲜茎产量以及干茎产量均为极显著差异.灌溉条件下各产量指标明显高于干旱地区.本实验还应用了3个不同的参数和方案,评估了这9个品种的稳定性.结果表明,综合三个参数,EI Salvador是在不同环境条件下具有丰产潜力的品种.     

Association mapping of grain quality and flowering time in elite japonica rice germplasm

Grain quality traits play an important role in the economic prosperity of commercial rice markets. The objective of our research was to identify candidate molecular markers associated with three grain quality and flowering traits in a collection of elite rice japonica inbred lines evaluated in five U.S. states. Candidate marker effects were associated with the traits mapped within regions reported from previous QTL analyses while several new allelic interactions were also detected. Common markers for each trait were observed across two or more locations, and two-way interactions unique to a single location were also found. Significant genotype × location interactions were detected while broad-sense heritability estimates were low for all characters. All but one selected marker effect was associated with a reduction in apparent amylose content. A reduction in heading date at three locations was observed with one marker as a main effect or as a component of two-way interactions that mapped ∼ 5 cM from the Hd3a flowering locus. The majority of selected effects for head rice were associated with modest to substantial increases in value. Marker loci and their interactions identified in this study highlighted targeted regions for future association studies and marker-assisted breeding efforts of grain quality traits.     

东北三省大豆蛋白质、油分含量的地点、年份效应分析

选用5个品质性状有差异的东北春大豆品种在东北地区11个试验点种植,进行大豆品质生态研究,所得结果如下:东北三省大豆蛋白质含量、油分含量、蛋白质油分总含量均存在年份、地点、品种、年份×地点、年份×品种、品种×地点、年份×品种×地点互作效应.对于蛋白质含量、油分含量来说品种效应最大,所以在东北三省范围内提高蛋白质含量、油分含量以品种改良为最理想途径.从各项互作效应检测的变异系数大小来看,均表现油分含量变异系数＞蛋白质含量变异系数＞蛋白质油分总含量变异系数.即油分含量对环境影响最敏感,其次为蛋白质含量,最后是蛋白质油分总含量.由于各项互作效应的存在,使得东北三省范围内大豆品质表现更为复杂.在进行大豆优质生产时应对品种、地点、地区的气候条件年际间变化特点等综合考虑.     

Influence of the cultivar,environment and management on the grain yield and bread-making quality in winter wheat

The genotype, environment and their interaction play an important role in the grain yielding and grain quality attributes. The main aim of this study was to determine the contributions of the genotype, environment and their interaction to the variation in bread-making traits. The data that were used for the analyses performed in this study were obtained from 3 locations in Poland from post-registration multi-environment trials with winter wheat in 2009 and 2010. The experimental factors were the cultivar (7 cultivars) and the crop management level (low input and high input). In the multi-environment trials, 17 traits were investigated that characterize grain, flour and dough quality. Most of the traits were affected much more strongly by environmental factors (i.e., year and location) than by genotype. The variance components revealed an especially strong effect of the year on the baking score, loaf volume and water absorption, as well a strong effect of the location on dough development and protein content. The obtained results demonstrate that the grain quality as measured by the parameters based on the protein content and quality may be substantially improved by crop management practices, especially by N fertilization level.     

Some estimates of genotype × environment interactions in potato variety tests

Five cultivars were studied for 3 years to estimate the genotype × environment interactions. Plant height was studied at four locations. The tuber characters, yield, type, number, and specific gravity were studied at three locations. There were no significant clone × location or clone × year interactions. The clone × year × location interaction was significant for plant height and tuber yield. The clone × replication in year and location interaction was significant for all characters studied. The theoretical variance of a clonal mean was used to determine the most efficient allocation of plots. The largest reduction in standard error of the mean was obtained by increasing locations. Comparisons of standard errors of differences in percentages of the observed mean were also made to estimate precision obtained with specific testing procedures.     

籼型杂交晚稻农艺性状及综合性状的分析

 以1991 年和1992 年籼型杂交水稻区域试验的中稻迟熟组的数据为资料，采用朱军等提出的方法分析产量、生育期、米质和抗逆性等性状的基因型×环境互作，以及单一性状和综合性状的稳定性表现。方差分析的结果表明，大多数性状存在年份×地点的互作，一些性状存在较大的基因型×地点互作和基因型×年份的互作。对籽粒产量和综合性状的组合间比较表明，广优4号、汕优63、Ⅱ优62-16、W6154/特三矮和汕A/CDR22五个组合的产量较高。汕优63、W6154/特三矮和马协优63三个组合的综合性状的表现较好。对不同地区选育的品种产量和综合性状进行了线性比较。此外还分析了各组合产量和综合性状对环境指数的反应敏感程度和稳定性表现。     

啤酒大麦品种的蛋白质含量和环境变异研究

大麦是兼食用、饲用、酿造于一体的作物 ,蛋白质含量是各种用途大麦的重要品质性状。本研究在我国南方冬大麦区设置 8个试点 ,测定分析了 10个大麦品种在各试点种植两年的蛋白质含量。结果表明 ,蛋白质含量在品种间、地区间以及年度间均存在着显著差异 ,两年平均 ,浙农大 6号和盐引一号分别为蛋白质含量最高和最低的品种 ,泰安和杭州是蛋白质含量最高和最低的试点。年度间和品种与地区及品种与年份之间的互作均达极显著水平。     

Effect of Genotype,Environment and Their Interaction on Quality Parameters of Wheat Breeding Lines of Diverse Grain Hardness

Abstract

Understanding the contribution of genotype, environment and genotype-by-environment interaction to wheat grain quality facilitates the selection for quality in breeding programs. Stability of grain quality characteristics is an important requirement in the baking industry. We assessed 24 winter wheat genotypes with different grain hardness in multienvironment trials at four locations and two levels of fertilization in each location. Grain samples were analyzed for hardness, protein and starch content, and wet gluten content, Zeleny sedimentation value, alveograph parameter (W) and hectoliter weight. All parameters were evaluated on whole grains using the near infrared transmittance technique. Differences between hard and soft genotypes appeared to be significant, apart from grain hardness, for protein content, Zeleny test and alveograph parameter. Genotype was found to have a major influence only on grain hardness; for protein content, wet gluten and Zeleny sedimentation value environment prevailed the influence of genotype, and for starch content, alveograph W parameter and hectoliter weight both sources of variation had similar importance. Genotype-by-environment interaction was of smaller size relative to genotype and environment in terms of all the studied quality parameters. Stable genotypes predominate the breeding lines studied. Response of unstable genotypes to environmental conditions was nonlinear in most cases.     

水稻区域试验点对品种判别能力估计方法的研究

 提出利用AMMI 模型中达显著水平的主成分轴上环境分量作为水稻区试点对品种判别能力的估算依据, 并设计了估算参数D j 。试验表明, D j 值小的试点, 其与基因型互作效应弱, 包含较少的互作信息。以浙江省早籼稻区域试验15 个区试点为例, 剔除D j 值最小的4 个试点后, 交互作用值仅损失10. 12%。     

Genotype x environment interactions and optimum resource allocation for sugarcane yield trials in Swaziland

To account for genotype x environment (G x E) interactions, sugarcane varieties are tested in multi-environment trials (METs) across multiple crop-years and seasons (early vs. late) under fully irrigated conditions in Swaziland. This study aimed to quantify the main sources of variation relevant to the MET network, identify mega-environments, evaluate adaptability of imported sugarcane varieties, and optimize resource use within the testing network. Nine varieties (eight imported Mauritian and one South African variety) were tested at two sites (Mhlume – M and Simunye – S), harvested early (E) and late (L) in the season across five crop-years in replicated (8) Latin square designs. A linear mixed model analysis of cane yield (tons of cane per ha; TCH), sucrose content (SUC%), sucrose yield (tons of sugar per ha; TSH), and fiber content (FIB%) showed that variety x season interactions were highly significant (P < 0.001) and larger than variety x site interactions for most traits. Genotype + genotype x environment (GGE) biplots revealed clustering of environments into two mega-environments by season rather than by site. Two Mauritian varieties were superior in each of the early and late mega-environments. Broad-sense heritability (H²) for all traits was larger than 0.79, with the highest value observed for FIB% (0.89). Resource optimization analysis, using variance components, suggested that future testing be conducted at a single site, across two seasons, with replicate numbers >5, and harvested across approximately five crop-years. Strong variety x season interactions should be exploited more aggressively in irrigated sugarcane selection programs.     

Selection for individual traits in the early generations of a potato breeding program dedicated to producing cultivars with tubers having long shape and russet skin

Early generation selection in a potato breeding program involves visual assessment of economic worth based on appearance. Efficiency could be improved by using individual characteristics with defined selection behavior. This study was done to define the selectability of visible traits used for selection in the early generations of potato breeding. Twenty-seven traits were evaluated through three clonal generations using two hundred clones, twenty from each of ten crosses, taken from a population created to produce cultivars with long tuber shape and russet skin. Genotype × environment interactions, heritabilities, correlation coefficients among generations and locations, and rejection pattern analysis were used to quantify the consistency of expression for each trait. The chosen traits showed a wide range of heritabilities and consistency of expression. Traits were divided into three categories: those amenable to positive selection, those appropriate for negative selection, and those which should be ignored. The study showed positive selection to be possible for degree of skin russetting, and the incidence and severity of skin defects. It showed negative selection to be appropriate for incidence of second growth, growth cracks, tuber malformations, tuber curvature, pointed ends, the incidence and severity of russet patchiness, eye depth, tuber shape, yield, tuber number, average tuber weight, and flatness. To a lesser extent, negative selection could be used to reduce eyebrow prominence, degree of eye covering, and prominence of internodes. Traits too inconsistent for use in selection in early generations included uniformity of skin russetting, uniformity of tuber shape, and uniformity of tuber size. Severity ratings for second growth, growth cracks, tuber malformations, tuber curvature, and pointed ends were inconsistent and should not be used in lieu of incidence scores for the same traits.     

Relationships Among Antioxidant Activity, Total Phenolic Content and Specific Gravity in Several Potato (Solanum tuberosum L.) Cultivars Grown in Different Environments

Environmental conditions influence crop productivity and quality, making breeding for improvement of a particular trait challenging. Similarly, relationships among traits may make trait improvement difficult, especially if selection for high levels of one trait results in low levels of the other(s). Therefore, understanding the influence of environment and relationships among traits is necessary in trait selection and crop improvement. The objective of this study was to investigate the variability and correlations among antioxidant activity (AOA), total phenolic content (TP), and specific gravity (SPG) in potato cultivars and advanced breeding selections. This research included investigation of genotype x environment (GxE), using four cultivars (Atlantic, Red LaSoda, Russet Norkotah, and Yukon Gold) grown for 3 years (2005, 2006, and 2007) in nine states (CA, ID, MI, MN, NJ, NC, OR, TX, and WI), and two broader genotype studies using 15 advanced breeding selections grown in Texas in 2005 and 60 advanced selections and five cultivars grown in Texas in 2009. Two methods, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), were used to evaluate AOA, and total phenolic (TP) content was determined using the Folin-Ciocalteau method. Significant effects of cultivar, year, location and their interactions on AOA, TP, and SPG were observed, as well as significant trait differences among cultivars within and between locations. The correlations between AOA and TP were significantly positive, while between AOA and SPG, and between TP and SPG were weak and negative in the GxE study. Correlations between AOA and SPG, and between TP and SPG in the two genotype studies were not significant. The weak relationships observed in the GxE study between AOA and SPG, and between TP and SPG may have been due to the small sample size and/or the cultivar Atlantic consistently exhibiting the lowest values of AOA and TP, and highest SPG in all locations. Results from the genotype studies suggest that breeding for high AOA and TP to increase the nutritional value of potato cultivars can be done without compromising tuber quality in terms of specific gravity.     

Yield Stability of Aromatic Upland Rice with High Yielding Ability in Indonesia

Abstract

Aromatic rice variety, Mentikwangi, was crossed with high-yielding upland rice variety, Poso, and the pedigree was selected to obtain lines with high yielding and aromatic characters. The objectives of the research were to study the yield stability of aromatic upland genotypes across different locations and to select aromatic upland rice genotypes having wide adaptability, and or specific location adaptability. Yield stability of genotypes was estimated by using regression lines proposed by Finlay and Wilkinson. Some genotypes showed high yield stability and wide adaptability in different locations, and others showed good adaptability to a specific location. The lines having high yield stability and wide adaptability were G10 (405 g m-²), G19 (400 g m-²), G39 (418 g m-²), and G136 (411 g m-²), which may be considered as candidates of new aromatic upland rice cultivars. Situpatenggang had specific adaptability at the fertile locations; and Poso and G13 at the infertile locations. Genotype x location interactions for the yield and its components performance were observed.     

Genotype × environment interaction for zinc and iron concentration of wheat grain in eastern Gangetic plains of India

Zinc and iron are important micronutrients for human health for which widespread deficiency occurs in many regions of the world including South Asia. Breeding efforts for enriching wheat grains with more zinc and iron are in progress in India, Pakistan and CIMMYT (International Maize and Wheat Improvement Centre). Further knowledge on genotype × environment interaction of these nutrients in the grain is expected to contribute to better understand the magnitude of this interaction and the potential identification of more stable genotypes for this trait. Elite lines from CIMMYT were evaluated in a multilocation trial in the eastern Gangetic plains (EGP) of India to determine genotype × environment (GE) interactions for agronomic and nutrient traits. Agronomic (yield and days to heading) data were available for 14 environments, while zinc and iron concentration of grains for 10 environments. Soil and meteorological data of each of the locations were also used. GE was significant for all the four traits. Locations showed contrasting response to grain iron and zinc. Compared to iron, zinc showed greater variation across locations. Maximum temperature was the major determinant for the four traits. Zinc content in 30–60 cm soil depth was also a significant determinant for grain zinc as well as iron concentration. The results suggest that the GE was substantial for grain iron and zinc and established varieties of eastern Gangetic plains India are not inferior to the CIMMYT germplasm tested. Hence, greater efforts taking care of GE interactions are needed to breed iron and zinc rich wheat lines.     

Adaptation of rice (Oryza sativa L.) genotypes in the rainfed lowlands of Lao PDR

Genotype by environment (G×E) interactions for grain yield were investigated in 14 rice genotypes across eight rainfed lowland field environments in Lao PDR, in order to identify stable adapted cultivars for improved farmer livelihood and food security. G×E accounted for 20.3% of the total variance, with three vectors from ordination analysis accounting for 75.1% of the G×E-SS, in 6 genotype?×?6 environment groups. PCA1 indicated water-limited yield potential, PCA2 pre-flowering stress and PCA3 post-flowering stress. Genotype groups (G1–G6) differed in adaptation to these environments. G5 (VT450-2 and TSN9) were widely adapted and high-yielding. G6 (TDK11 and TDK37) were also high-yielding, topping the rankings in three environment groups, but yielded less in Phalanxay 2012 and Phalanxay 2011, where their phenology was unstable under stress. Other genotype groups showed specific adaptations, but failed to exceed yields of G5 and G6. Hence, VT450-2 and TSN9 (G5) were the preferred genotypes for rainfed lowland in southern Lao PDR, due to their high and stable grain yields. Stability in flowering time and high yield in rainfall deficit were desirable traits for improved farmer livelihood and food security.     

海南试验点不同年代玉米品种产量及农艺性状增益分析

在海南试验点分析了我国近60年有代表性的34个品种产量及农艺性状的增益。结果表明:产量、出籽率、千粒重等12个农艺性状年代间均存在极显著差异,茎倒率和秃尖长年代间存在显著差异。海南试验点不同年代(1950年至2000年)玉米品种产量每年增益为46.4kg/hm2,与北京和新疆试验点的产量增益趋势一致,只是明显低于北京试验点。海南三亚冬季的生态环境适宜对我国不同年代玉米品种的产量增益进行分析。     

Turf quality and reliability in varieties of four turfgrass species in contrasting Italian environments

Turf quality is a complex character of fundamental importance in turfgrass evaluation. It takes into account aesthetic and functional aspects, and depends on several individual components which may vary with time. The use of a synthetic and simple quality score is necessary when evaluating large numbers of varieties. The quality of 110 turfgrass varieties belonging to four species (Lolium perenne, Poa pratensis, Festuca arundinacea and F. rubra) was assessed in the second and third years of growth at three Italian locations, i.e. Lodi (Po Valley, continental climate), Perugia (central Italy, sub‐Mediterranean climate) and Foggia (southern Italy, Mediterranean climate), using a visual score ranging from 9 (outstanding turf) to 1 (very poor turf). A randomized block design with three replicates was used, with varieties of the same species being blocked to facilitate the comparison within species. On average, F. rubra had the lowest turf quality score in summer, whereas the other species had the lowest quality score in winter and the highest quality score in summer and autumn. Components of variance were large for genotype (i.e. variety) main effects in all species. A variety × location interaction was found in F. arundinacea and higher‐order interactions were also found for P. pratensis and F. rubra. Genotype × environment effects were small relative to genotypic effects in L. perenne. Variety × year interactions were small in all cases, whereas variety × location and variety × season interactions were greater. Stability of turf quality across sites, seasons and years was measured for each variety in terms of environmental variance, i.e. the variance of score values across sites, years and seasons. Mean scores and stability values of varieties were integrated into an index of reliability that estimated the lowest score value expected in 0·80 of cases. For each species, a small subset of highly reliable varieties could be identified. Implications of the results for the testing and breeding of varieties in Italy are discussed.     

Genotype–Environment Interactions of Selected Rice Lines in Direct Water-Seeded Culture

Summary

Five rice genotypes including 4 breeding lines (lines 36 and 42 from the cross of Aoinokaze//Lemont/ Hinohikari and 53 and 76 from Yumehikari//Lemont/Hinohikari) and a reference cultivar, Hinohikari, were grown under various environmental conditions (year, location, plant density and nitrogen level) to determine the genotype-environment interactions for yield, yield components and yield adaptability in water direct-seeded culture. No genotype-year interactions were found in yield or yield components, i.e., the ranking of the genotypes did not change across the years. The interactions of genotype with plant density and nitrogen level were significant only in the percentage of filled grains, indicating that the ranking of rice genotypes for yield traits except the percentage of filled grains remained constant across plant densities and nitrogen levels. There were significant differences in the ranking in grain yield of genotypes between the plants cultivated in Fukuoka and Chikushino. However, line 42 was ranked the highest at both locations. The adaptability to environmental conditions evaluated by a regression method varied with the genotype and line 42 which showed high average yield and higher yield in high-yielding conditions was selected to be suitable for direct-seeded culture.