MASI.AMMI computes the Modified AMMI Stability Index (MASI) (Ajay et al. 2018) from a modified formula of AMMI Stability Index (ASI) (Jambhulkar et al. 2014; Jambhulkar et al. 2015; Jambhulkar et al. 2017) . Unlike ASI, MASI calculates stability value considering all significant interaction principal components (IPCs) in the AMMI model. Using MASI, the Simultaneous Selection Index for Yield and Stability (SSI) is also calculated according to the argument ssi.method.

MASI.AMMI(model, n, alpha = 0.05, ssi.method = c("farshadfar", "rao"), a = 1)

Arguments

model

The AMMI model (An object of class AMMI generated by AMMI).

n

The number of principal components to be considered for computation. The default value is the number of significant IPCs.

alpha

Type I error probability (Significance level) to be considered to identify the number of significant IPCs.

ssi.method

The method for the computation of simultaneous selection index. Either "farshadfar" or "rao" (See SSI).

a

The ratio of the weights given to the stability components for computation of SSI when method = "rao" (See SSI).

Value

A data frame with the following columns:

MASI

The MASI values.

SSI

The computed values of simultaneous selection index for yield and stability.

rMASI

The ranks of MASI values.

rY

The ranks of the mean yield of genotypes.

means

The mean yield of the genotypes.

The names of the genotypes are indicated as the row names of the data frame.

Details

The Modified AMMI Stability Index (\(MASI\)) (Ajay et al. 2018) is computed as follows:

\[MASI = \sqrt{ \sum_{n=1}^{N'} PC_{n}^{2} \times \theta_{n}^{2}}\]

Where, \(PC_{n}\) are the scores of \(n\)th IPC; and \(\theta_{n}\) is the percentage sum of squares explained by the \(n\)th principal component interaction effect.

References

Ajay BC, Aravind J, Abdul Fiyaz R, Bera SK, Kumar N, Gangadhar K, Kona P (2018). “Modified AMMI Stability Index (MASI) for stability analysis.” ICAR-DGR Newsletter, 18, 4--5.

Jambhulkar NN, Bose LK, Pande K, Singh ON (2015). “Genotype by environment interaction and stability analysis in rice genotypes.” Ecology, Environment and Conservation, 21(3), 1427--1430.

Jambhulkar NN, Bose LK, Singh ON (2014). “AMMI stability index for stability analysis.” In Mohapatra T (ed.), CRRI Newsletter, January-March 2014, volume 35(1), 15. Central Rice Research Institute, Cuttack, Orissa.

Jambhulkar NN, Rath NC, Bose LK, Subudhi HN, Biswajit M, Lipi D, Meher J (2017). “Stability analysis for grain yield in rice in demonstrations conducted during rabi season in India.” Oryza, 54(2), 236--240.

See also

Examples

library(agricolae)
data(plrv)

# AMMI model
model <- with(plrv, AMMI(Locality, Genotype, Rep, Yield, console = FALSE))

# ANOVA
model$ANOVA
#> Analysis of Variance Table
#> 
#> Response: Y
#>            Df Sum Sq Mean Sq  F value    Pr(>F)    
#> ENV         5 122284 24456.9 257.0382  9.08e-12 ***
#> REP(ENV)   12   1142    95.1   2.5694  0.002889 ** 
#> GEN        27  17533   649.4  17.5359 < 2.2e-16 ***
#> ENV:GEN   135  23762   176.0   4.7531 < 2.2e-16 ***
#> Residuals 324  11998    37.0                       
#> ---
#> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

# IPC F test
model$analysis
#>     percent  acum Df     Sum.Sq   Mean.Sq F.value   Pr.F
#> PC1    56.3  56.3 31 13368.5954 431.24501   11.65 0.0000
#> PC2    27.1  83.3 29  6427.5799 221.64069    5.99 0.0000
#> PC3     9.4  92.7 27  2241.9398  83.03481    2.24 0.0005
#> PC4     4.3  97.1 25  1027.5785  41.10314    1.11 0.3286
#> PC5     2.9 100.0 23   696.1012  30.26527    0.82 0.7059

# Mean yield and IPC scores
model$biplot
#>         type    Yield         PC1          PC2         PC3         PC4
#> 102.18   GEN 26.31947 -1.50828851  1.258765244 -0.19220309  0.48738861
#> 104.22   GEN 31.28887  0.32517729 -1.297024517 -0.63695749 -0.44159957
#> 121.31   GEN 30.10174  0.95604605  1.143461054 -1.28777348  2.22246913
#> 141.28   GEN 39.75624  2.11153737  0.817810467  1.45527701  0.25257620
#> 157.26   GEN 36.95181  1.05139017  2.461179974 -1.97208942 -1.96538800
#> 163.9    GEN 21.41747 -2.12407441 -0.284381234 -0.21791137 -0.50743629
#> 221.19   GEN 22.98480 -0.84981828  0.347983673 -0.82400783 -0.11451944
#> 233.11   GEN 28.66655  0.07554203 -1.046497338  1.04040485  0.22868362
#> 235.6    GEN 38.63477  1.20102029 -2.816581184  0.80975361  1.02013062
#> 241.2    GEN 26.34039 -0.79948495  0.220768053 -0.98538801  0.30004421
#> 255.7    GEN 30.58975 -1.49543817 -1.186549449  0.92552519 -0.32009239
#> 314.12   GEN 28.17335  1.39335380 -0.332786322 -0.73226877  0.05987348
#> 317.6    GEN 35.32583  1.05170769  0.002555823 -0.81561907  0.58180433
#> 319.20   GEN 38.75767  3.08338144  1.995946966  0.87971668 -1.11908943
#> 320.16   GEN 26.34808 -1.55737097  0.732314249 -0.41432567  1.32097009
#> 342.15   GEN 26.01336 -1.35880873 -0.741980068  0.87480105 -1.12013125
#> 346.2    GEN 23.84175 -2.48453928 -0.397045286  1.07091711 -0.90974484
#> 351.26   GEN 36.11581  1.22670345  1.537183139  1.79835728 -0.03516368
#> 364.21   GEN 34.05974  0.27328985 -0.447941156  0.03139543  0.77920500
#> 402.7    GEN 27.47748 -0.12907269 -0.080086669  0.01934016 -0.36085862
#> 405.2    GEN 28.98663 -1.90936369  0.309047963  0.57682642  0.51163370
#> 406.12   GEN 32.68323  0.90781100 -1.733433781 -0.24223050 -0.38596144
#> 427.7    GEN 36.19020  0.42791957 -0.723190970 -0.85381724 -0.53089914
#> 450.3    GEN 36.19602  1.38026196  1.279525147  0.16025163  0.61270137
#> 506.2    GEN 33.26623 -0.33054261 -0.302588536 -1.58471588 -0.04659416
#> Canchan  GEN 27.00126  1.47802905  0.380553178  1.67423900  0.07718375
#> Desiree  GEN 16.15569 -3.64968796  1.720025405  0.43761089  0.04648011
#> Unica    GEN 39.10400  1.25331924 -2.817033826 -0.99510845 -0.64366599
#> Ayac     ENV 23.70254 -2.29611851  0.966037760  1.95959116  2.75548057
#> Hyo-02   ENV 45.73082  3.85283195 -5.093371615  1.16967118 -0.08985538
#> LM-02    ENV 34.64462 -1.14575146 -0.881093222 -4.56547274  0.55159099
#> LM-03    ENV 53.83493  5.34625518  4.265275487 -0.14143931 -0.11714533
#> SR-02    ENV 14.95128 -2.58678337  0.660309540  0.89096920 -3.25055305
#> SR-03    ENV 11.15328 -3.17043379  0.082842050  0.68668051  0.15048221
#>                 PC5
#> 102.18  -0.04364115
#> 104.22   0.95312506
#> 121.31  -1.30661916
#> 141.28  -0.25996142
#> 157.26  -0.59719268
#> 163.9    0.18563390
#> 221.19  -0.57504816
#> 233.11   0.65754266
#> 235.6   -0.40273415
#> 241.2    0.07555258
#> 255.7   -0.46344763
#> 314.12   0.54406154
#> 317.6    0.39627052
#> 319.20   0.29657050
#> 320.16   2.29506737
#> 342.15  -0.10776433
#> 346.2   -0.12738693
#> 351.26   0.30191335
#> 364.21  -0.95811256
#> 402.7   -0.28473777
#> 405.2   -0.34397623
#> 406.12  -0.49796296
#> 427.7    1.00677993
#> 450.3   -0.34325251
#> 506.2    0.87807441
#> Canchan  0.49381313
#> Desiree -0.86767477
#> Unica   -0.90489253
#> Ayac     1.67177210
#> Hyo-02   0.01540152
#> LM-02    0.52350416
#> LM-03   -0.40285728
#> SR-02    1.37283488
#> SR-03   -3.18065538

# G*E matrix (deviations from mean)
array(model$genXenv, dim(model$genXenv), dimnames(model$genXenv))
#>          ENV
#> GEN              Ayac      Hyo-02       LM-02       LM-03        SR-02
#>   102.18    5.5726162 -12.4918224   1.7425251  -2.7070438   2.91734869
#>   104.22   -2.8712076   7.1684102   3.9336218  -4.0358373   0.47881580
#>   121.31    0.3255230  -3.8666836   4.3182811  10.4366135 -11.88343843
#>   141.28   -0.9451837   5.6454825  -9.7806639  14.6463104  -4.80337115
#>   157.26  -10.3149711 -10.6241677   4.2336365  16.8683612   2.71710210
#>   163.9     3.0874931  -6.9416721   3.4963790 -12.5533271   7.01688164
#>   221.19   -0.6041752  -6.0090018   4.0648518  -2.6974743   1.27671246
#>   233.11    2.5837535   6.8277609  -3.4440645  -4.4985717   0.19989490
#>   235.6    -1.7541523  19.8225025  -2.2394463  -5.6643239  -8.11400542
#>   241.2     1.0710975  -5.3831118   5.4253097  -3.2588271   0.46433086
#>   255.7     2.4443155   1.3860497  -1.8857757 -12.9626594   4.31373929
#>   314.12   -3.8812099   6.2098482   2.3577759   5.9071782  -3.92419060
#>   317.6    -1.7450319   3.0388540   3.0448064   5.5211634  -4.79271565
#>   319.20   -6.0155949   2.8477540  -9.7697504  24.8850017  -1.82949467
#>   320.16   10.9481796 -10.2982108   4.9608280  -6.2233088   2.99984918
#>   342.15    0.8508002  -0.3338618  -2.4575390 -10.3783871   7.29753151
#>   346.2     4.7000495  -6.2178087  -2.2612391 -14.9700672   9.90123888
#>   351.26    2.6002030  -0.9918665 -10.8315931  12.7429121  -0.02713985
#>   364.21   -0.4533734   3.2864208  -0.1335527  -0.1592533  -4.82292664
#>   402.7    -1.2134573  -0.0387229  -0.2179557  -0.8774011   1.08032472
#>   405.2     6.6477681  -8.3071271  -0.6159895  -8.8927189   3.52179705
#>   406.12   -6.1296667  12.0703469   1.1195092  -2.2601009  -3.13776595
#>   427.7    -3.1340922   4.3967072   4.2792028  -1.0194744   0.76266844
#>   450.3    -0.5047010  -1.0720791  -3.2821761  12.8806007  -5.04562407
#>   506.2    -1.2991912  -1.5682154   8.3142802  -3.1819279   0.60021498
#>   Canchan   1.2929442   5.7152780  -9.3713622   9.0803035  -1.65332869
#>   Desiree   9.5767845 -22.3280421   0.2396387 -11.8935722   9.62433886
#>   Unica   -10.8355195  18.0569790   4.7604622  -4.7341684  -5.13878822
#>          ENV
#> GEN             SR-03
#>   102.18    4.9663762
#>   104.22   -4.6738028
#>   121.31    0.6697043
#>   141.28   -4.7625741
#>   157.26   -2.8799609
#>   163.9     5.8942454
#>   221.19    3.9690870
#>   233.11   -1.6687730
#>   235.6    -2.0505746
#>   241.2     1.6812008
#>   255.7     6.7043306
#>   314.12   -6.6694018
#>   317.6    -5.0670763
#>   319.20  -10.1179157
#>   320.16   -2.3873373
#>   342.15    5.0214562
#>   346.2     8.8478267
#>   351.26   -3.4925156
#>   364.21    2.2826853
#>   402.7     1.2672123
#>   405.2     7.6462704
#>   406.12   -1.6623226
#>   427.7    -5.2850119
#>   450.3    -2.9760204
#>   506.2    -2.8651608
#>   Canchan  -5.0638348
#>   Desiree  14.7808522
#>   Unica    -2.1089651

# With default n (N') and default ssi.method (farshadfar)
MASI.AMMI(model)
#>               MASI SSI rMASI rY    means
#> 102.18  0.91530136  43    20 23 26.31947
#> 104.22  0.40081051  19     6 13 31.28887
#> 121.31  0.63276765  25    10 15 30.10174
#> 141.28  1.21699070  26    25  1 39.75624
#> 157.26  0.91082968  24    19  5 36.95181
#> 163.9   1.19850969  51    24 27 21.41747
#> 221.19  0.49376604  34     8 26 22.98480
#> 233.11  0.30298956  21     4 17 28.66655
#> 235.6   1.02255689  25    21  4 38.63477
#> 241.2   0.46342001  29     7 22 26.34039
#> 255.7   0.90543659  32    18 14 30.58975
#> 314.12  0.79261972  30    12 18 28.17335
#> 317.6   0.59705480  18     9  9 35.32583
#> 319.20  1.82014106  30    27  3 38.75767
#> 320.16  0.89982225  38    17 21 26.34808
#> 342.15  0.79525659  37    13 24 26.01336
#> 346.2   1.40653491  51    26 25 23.84175
#> 351.26  0.82406788  22    14  8 36.11581
#> 364.21  0.19600590  12     2 10 34.05974
#> 402.7   0.07586154  20     1 19 27.47748
#> 405.2   1.07959190  39    23 16 28.98663
#> 406.12  0.69456043  23    11 12 32.68323
#> 427.7   0.32076990  12     5  7 36.19020
#> 450.3   0.85107482  21    15  6 36.19602
#> 506.2   0.25208300  14     3 11 33.26623
#> Canchan 0.85313814  36    16 20 27.00126
#> Desiree 2.10738319  56    28 28 16.15569
#> Unica   1.04376808  24    22  2 39.10400

# With n = 4 and default ssi.method (farshadfar)
MASI.AMMI(model, n = 4)
#>               MASI SSI rMASI rY    means
#> 102.18  0.91554126  43    20 23 26.31947
#> 104.22  0.40126006  19     6 13 31.28887
#> 121.31  0.63994359  25    10 15 30.10174
#> 141.28  1.21703916  26    25  1 39.75624
#> 157.26  0.91474200  24    19  5 36.95181
#> 163.9   1.19870830  51    24 27 21.41747
#> 221.19  0.49379060  34     8 26 22.98480
#> 233.11  0.30314909  21     4 17 28.66655
#> 235.6   1.02349733  25    21  4 38.63477
#> 241.2   0.46359958  29     7 22 26.34039
#> 255.7   0.90554120  32    18 14 30.58975
#> 314.12  0.79262390  30    12 18 28.17335
#> 317.6   0.59757871  18     9  9 35.32583
#> 319.20  1.82077706  30    27  3 38.75767
#> 320.16  0.90161328  38    17 21 26.34808
#> 342.15  0.79671385  37    13 24 26.01336
#> 346.2   1.40707881  51    26 25 23.84175
#> 351.26  0.82406927  22    14  8 36.11581
#> 364.21  0.19884907  12     2 10 34.05974
#> 402.7   0.07743222  20     1 19 27.47748
#> 405.2   1.07981604  39    23 16 28.98663
#> 406.12  0.69475868  23    11 12 32.68323
#> 427.7   0.32158122  12     5  7 36.19020
#> 450.3   0.85148251  21    15  6 36.19602
#> 506.2   0.25209096  14     3 11 33.26623
#> Canchan 0.85314460  36    16 20 27.00126
#> Desiree 2.10738414  56    28 28 16.15569
#> Unica   1.04413498  24    22  2 39.10400

# With default n (N') and ssi.method = "rao"
MASI.AMMI(model, ssi.method = "rao")
#>               MASI       SSI rMASI rY    means
#> 102.18  0.91530136 1.3969172    20 23 26.31947
#> 104.22  0.40081051 2.2505076     6 13 31.28887
#> 121.31  0.63276765 1.7607970    10 15 30.10174
#> 141.28  1.21699070 1.7014749    25  1 39.75624
#> 157.26  0.91082968 1.7462362    19  5 36.95181
#> 163.9   1.19850969 1.1097764    24 27 21.41747
#> 221.19  0.49376604 1.7481314     8 26 22.98480
#> 233.11  0.30298956 2.5622159     4 17 28.66655
#> 235.6   1.02255689 1.7419553    21  4 38.63477
#> 241.2   0.46342001 1.9229400     7 22 26.34039
#> 255.7   0.90543659 1.5420219    18 14 30.58975
#> 314.12  0.79261972 1.5407527    12 18 28.17335
#> 317.6   0.59705480 1.9777463     9  9 35.32583
#> 319.20  1.82014106 1.5346430    27  3 38.75767
#> 320.16  0.89982225 1.4071180    17 21 26.34808
#> 342.15  0.79525659 1.4682620    13 24 26.01336
#> 346.2   1.40653491 1.1279691    26 25 23.84175
#> 351.26  0.82406788 1.7759790    14  8 36.11581
#> 364.21  0.19600590 3.6263979     2 10 34.05974
#> 402.7   0.07586154 7.3962265     1 19 27.47748
#> 405.2   1.07959190 1.4018946    23 16 28.98663
#> 406.12  0.69456043 1.7756352    11 12 32.68323
#> 427.7   0.32076990 2.7173148     5  7 36.19020
#> 450.3   0.85107482 1.7596054    15  6 36.19602
#> 506.2   0.25208300 3.0408597     3 11 33.26623
#> Canchan 0.85313814 1.4584033    16 20 27.00126
#> Desiree 2.10738319 0.7607639    28 28 16.15569
#> Unica   1.04376808 1.7474547    22  2 39.10400

# Changing the ratio of weights for Rao's SSI
MASI.AMMI(model, ssi.method = "rao", a = 0.43)
#>               MASI       SSI rMASI rY    means
#> 102.18  0.91530136 1.0898268    20 23 26.31947
#> 104.22  0.40081051 1.5492279     6 13 31.28887
#> 121.31  0.63276765 1.3165893    10 15 30.10174
#> 141.28  1.21699070 1.4705116    25  1 39.75624
#> 157.26  0.91082968 1.4376382    19  5 36.95181
#> 163.9   1.19850969 0.8752516    24 27 21.41747
#> 221.19  0.49376604 1.1788734     8 26 22.98480
#> 233.11  0.30298956 1.6345262     4 17 28.66655
#> 235.6   1.02255689 1.4670755    21  4 38.63477
#> 241.2   0.46342001 1.3164054     7 22 26.34039
#> 255.7   0.90543659 1.2315857    18 14 30.58975
#> 314.12  0.79261972 1.1861309    12 18 28.17335
#> 317.6   0.59705480 1.5069682     9  9 35.32583
#> 319.20  1.82014106 1.3802152    27  3 38.75767
#> 320.16  0.89982225 1.0947449    17 21 26.34808
#> 342.15  0.79525659 1.1148160    13 24 26.01336
#> 346.2   1.40653491 0.9281302    26 25 23.84175
#> 351.26  0.82406788 1.4348902    14  8 36.11581
#> 364.21  0.19600590 2.1923580     2 10 34.05974
#> 402.7   0.07586154 3.6910517     1 19 27.47748
#> 405.2   1.07959190 1.1415367    23 16 28.98663
#> 406.12  0.69456043 1.3709472    11 12 32.68323
#> 427.7   0.32076990 1.8410472     5  7 36.19020
#> 450.3   0.85107482 1.4293404    15  6 36.19602
#> 506.2   0.25208300 1.9258290     3 11 33.26623
#> Canchan 0.85313814 1.1289370    16 20 27.00126
#> Desiree 2.10738319 0.6273850    28 28 16.15569
#> Unica   1.04376808 1.4781609    22  2 39.10400

# ASI.AMMI same as MASI.AMMI with n = 2

a <- ASI.AMMI(model)
b <- MASI.AMMI(model, n = 2)

identical(a$ASI, b$MASI)
#> [1] TRUE