Genotype Trait  Value
1       Biomass 1.28
1       Biomass 1.07
1       Biomass 1.97
1       TLength 1070.7
1       TLength 875.14
1       TLength 1547.93

PROC MIXED DATA=multi56 covtest cl;
WHERE trait IN ("Biomass","TLength")
CLASS genotype trait;
MODEL value=trait;
RANDOM trait/SUBJECT=genotype TYPE=un;
/* The RANDOM statement tells SAS to estimate the 2 x 2
among genotype variance component matrix for the two traits
listed in the where statement */
RUN;

Covariance Parameter Estimates
Cov Parm    Subject Estimate    Standard Error  Z Value Pr Z    Alpha   Low Upper
UN(1,1) Genotype    0   .   .   .   .   .   .
UN(2,1) Genotype    50450   19630   2.57    0.0102  0.05    11975   88924
UN(2,2) Genotype    316010  90306   3.50    0.0002  0.05    193511  606860
Residual        55618   3437.23 16.18   <.0001  0.05    49451   63021

PROC MIXED DATA=multi56 covtest cl NOBOUND ;

Iteration History
Iteration   Evaluations -2 Res Log Like Criterion
0            1                  10109.62259781

WARNING: Stopped because of infinite likelihood.

Covariance Parameter Values
At Last Iteration
Cov Parm    Subject    Estimate
UN(1,1)    genotype   -34470
UN(2,1)    genotype    249.06
UN(2,2)    genotype    188855
Residual               83814

NOTE: 125 observations are not included because of missing values.
WARNING: Stopped because of infinite likelihood.