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Nicholas A. George, Mark Shankle, Jeff Main, Kenneth V. Pecota, Consuelo Arellano, and G. Craig Yencho

, Department of Primary Industries and Fisheries, Brisbane, Queensland, Australia Collins, W.W. Wilson, L.G. Arrendell, S. Dickey, L.F. 1987 Genotype × environment interactions in sweet-potato yield and quality factors J. Amer. Soc. Hort. Sci. 112 579 583

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José López Medina, Patrick P. Moore, Carl H. Shanks Jr., Fernando Flores Gil, and Craig K. Chandler

Genotype × environment interaction for resistance to the twospotted spider mite (Tetranychus urticae Koch) of eleven clones of Fragaria L. sp. (strawberries) grown in six environments throughout the United States was examined using two multivariate analysis techniques, principal coordinate analysis (PCA) and additive main effect and multiplicative interaction (AMMI). Both techniques provided useful and interesting ways of investigating genotype × environment interaction. PCA analysis indicated that clones X-11 and E-15 were stable across both low and high environments for the number of spider mites per leaflet. The initial AMMI analysis showed that the main effects of genotype, environment, and their first-order interaction were highly significant, with genotype × environment interaction due mainly to cultivar `Totem' and environment FL94. A second AMMI analysis, which excluded `Totem' and FL94, showed that the main effects of the remaining genotypes, environments, and genotype × environment interaction were also highly significant. AMMI biplot analysis revealed that FL93 and GH93 were unstable environments, but with opposite interaction patterns; and GCL-8 and WSU2198 were unstable genotypes with similar interactions that were opposite those of WSU 2202.

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V.W. Poysa, R. Garton, W.H. Courtney, J.G. Metcalf, and J. Muehmer

Abstract

Improved methods of breeding, selection, and testing for yield can be developed with information on the magnitude and nature of genotype–environment interactions. Cultivar trials of processing tomatoes (Lycopersicon esculentum Mill.) grown in Ontario for 2 years at 5 locations each year were studied for genotype–environment interactions. Cultivars were evaluated for phenotypic stability and desirability using regression coefficients, mean square deviations from linear regression, and t test comparisons of genotype means with environment means. Genotype-environment interactions were significant for yield of marketable fruit each year and in a combined analysis across years. Regression analysis indicated that low-yielding genotypes had above-average yield stability across environments, while several high-yielding genotypes were unstable. Several cultivars were found to be desirable because they had a high mean yield and did not have lower yields than the test mean in any of the 5 environments. Regression analysis alone could result in misleading conclusions about the performance of high-yielding tomato genotypes. Large genotype-environment interaction variances relative to genotype variances were detected. The interaction variance components involving year were large relative to the genotype-location interaction variance, indicating the need for multiyear evaluation and selection for stability even when breeding for a limited geographic region.

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Dilip R. Panthee, Chunxue Cao, Spencer J. Debenport, Gustavo R. Rodríguez, Joanne A. Labate, Larry D. Robertson, Andrew P. Breksa III, Esther van der Knaap, and Brian B. McSpadden Gardener

Genotype × environment interaction for quality traits in durum wheat cultivars adapted to different environments Afr. J. Biotechnol. 9 3054 3062 USDA-NASS 2008 Agricultural statistics. U.S. Department of Agtriculture, National Agricultural Statistics

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Solveig J. Hanson and Irwin L. Goldman

genetic control and genotype × environment interactions associated with geosmin concentration and TDS in table beet, to facilitate breeding for desired table beet flavor. The earthy flavor in table beet is conferred by geosmin ( trans -1,10-dimethyl- trans

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Kathleen G. Haynes, Beverly A. Clevidence, David Rao, Bryan T. Vinyard, and J. Marion White

Genotype × environment interactions for specific gravity in diploid potatoes Crop Sci. 35 977 981 Institute of Medicine 2000 Dietary reference intakes for vitamin C, vitamin E, selenium, and carotenoids National Academy Press

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T. E. Thompson, E. F. Young Jr., W. O. McIlrath, H. D. Petersen, and G. S. Sibbett

Abstract

Results are presented for performance of pecan [Carya illinoinensis (Wangenh.) C. Koch] clones at six established National Pecan Advanced Clone Testing System (NPACTS) sites for 16 nut quality factors from 1980 through 1985. Total nut weight and percent kernel were significantly greater at Tulare, Calif. than at any other location, with ≈80% of the clones averaging 6.5 g/nut or more and ≈90% averaging at least 54.5% kernel. Nut weight was smallest at El Paso, Texas. Daily mean temperatures during nut expansion may be a major factor determining nut weight response. Low nut density was characteristic of more clones at Baton Rouge, La. than at any other location. Kernel color was lightest at El Paso and darkest at Baton Rouge, with darker color appearing to be related to high field moisture conditions before harvest. Nut weight was not related to kernel percentage, color, or percent kernel covered with fuzz (packing material); thus, large nuts are not necessarily of lower quality and can be selected in an effective breeding program. Amount of nut “packing material” retained in the sutures of kernel halves after shelling was generally not related to other traits, except that material retained in ventral grooves increased with nut and kernel weight. Depth and width of dorsal grooves were not related to retention of packing material and can be disregarded in future pecan nut evaluation systems. Many other expected character relationships were verified and the overall NPACTS nut evaluation system will be revised based on these results.

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Wanda W. Collins, L. George Wilson, Susan Arrendell, and Lynn F. Dickey

Abstract

Genotype (G) x environment (E) interactions were measured in sweet potatoes (Ipomoea batatas L.) for yield (seven genotypes, six locations, 3 years) and selected quality factors (nine genotypes, six locations, 2 years). Yield of all grades of roots and all quality factors tested were affected significantly by genotype, environment, and G × E interactions. Quality factors were less affected by G × E interactions than yield factors. Broad-sense heritability estimates ranged from 75% to 92% for yield factors and 94% to 99% for quality factors. Estimates of variances of clonal means with varying years, locations, and replications suggest that 2 years, four locations, and four replications would provide reliable test data for yield and quality factors.

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V.R. Bachireddy, R. Payne Jr, K.L. Chin, and M.S. Kang

The analysis of variance of a data set made up of 30 sweet corn (Zea mays L.) hybrids evaluated over 5 years for marketable ears (dozens per hectare) indicated a significant genotype (hybrid) × year (GY) interaction. Three selection methods were compared: 1) a conventional method based on mean yield alone (YA), 2) Kang's ranksum (KRS) method, and 3) Kang's modified rank-sum (KMR) method. The number of hybrids selected on the basis of YA, KRS, and KMR was 13. The KRS selected the lowest number of unstable hybrids (three) compared with the YA and KMR, which selected eight and six unstable hybrids, respectively. The mean yields of the selected hybrids were 3034 dozen/ha for YA, 2945 dozen/ha for KRS, and 3019 dozen/ha for KMR. The mean yield of KRS-selected hybrids and KMR-selected hybrids was <2.9% and 0.5%, respectively, than that of YA-based selections. This yield reduction was regarded as insignificant considering the farmer would be able to choose more consistently performing hybrids on the basis of KRS than on the basis of KMR or YA. Heterogeneity due to environmental index is the mean of all genotypes in the jth year and X is the overall mean) was significant and was removed from the GY interaction. The removal of heterogeneity revealed that hybrids 77-2269, 116-Kandy Korn-EH, Golden Queen, 141-Sundance, Merit, and Stowell Evergreen were unstable because of a linear effect of the environmental index, and that hybrids 76-2681 and 806F-Truckers showed stable performance due to a linear effect of the environmental index.