Table 2: The mean squares (MS) and degrees of freedom (df) of treatments and residuals for genotype (G), heat (H), drought (D), and their interactions for 11 phenomic traits and 3 agronomic traits as measured on 12 Brassica genotypes from 1 to 7 days after treatments (DAT) during anthesis. The statistical significance of main effects and interactions is shown as 0.01 < p < 0.05 ( ) and p < 0.01 ( ). “ns” and “NA” indicate “not significant” and “not applicable,” respectively.

TraitDATSource of variationResiduals
df =11df =1df =1df =11df =11df =1df =11dfMS

(i) Six in-cabinet rapid phenotyping traits

PRI10.0040 0.0006 nsnsnsnsns960.0001
30.0028 0.0007 nsnsnsnsns960.0001
50.1000 nsns0.1093 nsnsns960.0049
7nsns0.0005 nsnsnsns960.0001

Qy10.0260 0.0060 nsnsnsnsns960.0010
30.0419 nsnsnsnsnsns960.0007
50.0318 ns0.0069 nsnsnsns960.0008
70.0409 0.0156 0.0330 nsns0.0336 ns960.0014

T11ns71.700 nsnsnsnsns965.6368
3118.452 89.508 nsnsnsnsns963.3334
5122.400 67.800 97.300 nsns86.500 ns965.3684
7123.480 ns193.590 nsns61.460 ns964.7786

T21132.360 462.590 nsnsnsnsns965.9198
3179.160 264.880 96.86 nsns42.140 ns965.1332
5284.740 ns599.43 nsns255.470 ns968.1280
7203.710 31.920 1187.95 nsns219.530 ns966.3080

T31207.403 169.743 nsnsnsnsns966.7461
3ns33.046 55.406 nsns29.348 ns964.6506
5101.137 ns209.639 nsns51.073 100.395 964.9548
7nsns418.200 nsns55.600 ns965.2742

LC1447132 nsnsnsnsnsns967670.82
3440562 ns211692 nsns91991 ns964992.83
5263299 28906 539613 nsns63756 ns965936.44
7ns18381 651370 nsnsnsns963676.20

(ii) Three photosynthetic traits derived from A/Ci curve

Vcmax138159 201158 2100 35625 17665 nsNA12293.98
3ns191108 nsnsnsnsNA122407.81
7ns17042 39130 nsns17887 NA121018.22

ETR116189 2031 ns4424 nsnsNA12114.25
38118 2337 nsnsnsnsNA12285.85
7ns10776 23629 nsns7068 NA12886.04

TPU1117.500 nsnsnsnsnsNA121.9685
353.700 16.300 nsnsnsnsNA121.5817
7153.900 ns96.100 ns125.300 nsNA123.6774

(iii) Two plant growth imaging-derived phenotyping traits

VolWP3463877 ns19157 ns31012 nsns961245.17
7261725 30020 267973 ns126866 nsns961461.15

VolF3102.935 nsns20.590 ns3.112 ns960.5380
7241.570 18.740 65.870 34.950 54.320 5.680 ns961.1831

(iv) Three agronomic traits

FW7101256 116824 1238679 6001 41512 10410 5545 481883.69

SYAt harvest12.789 14.719 4.490 nsnsnsNA120.9399

SWAt harvest0.0198 0.0101 nsnsnsnsNA120.0015

G×H: Genotype by Heat interaction; G×D: Genotype by Drought interaction; H×D: Heat by Drought interaction; G×H×D: Genotype by Heat by Drought interaction. The phenomic traits include (i) six in-cabinet rapid phenotyping traits: photochemical reflectance index (PRI), photosystem II quantum yield (Qy), leaf conductance (LC), and the temperature differences between (a) bud and ambient environment (T1), (b) leaf and ambient environment (T2), and (c) bud and leaf (T3); (ii) three photosynthetic traits derived from A/Ci curves: maximum carboxylation rate allowed by Rubisco (Vcmax), photosynthetic electron transport rate (ETR) and the rate of triose phosphate use (TPU); and (iii) two plant growth imaging derived phenotyping traits: whole plant volume (VolWP) and flower volume (VolF). The agronomic traits include fresh weight (FW) of the whole plant at DAT7, and seed yield (SY) and 100-seed weight (SW) of each plant at maturity.