Supplemental data

Additional supporting information is available in the online version of this article.

Supplementary Table S1. List of greengram genotypes used for screening on the basis of total root exudation and biomass under low-P (2 µM) and sufficient (100 µM) levels.

Supplementary Table S2. Analysis of variance for total biomass and 14C exudation of forty-four greengram genotypes grown at low (2 µM) and sufficient (100 µM) levels of P. Fifteen days old seedlings were exposed to 14CO2 and sampling of root exudate was done at 24, 48 and 96 h.

Supplementary Table S3. Analysis of variance for carboxylic acid concentration in root exudate and root apices, growth attributes and P uptake of selected seven genotypes in response to low (2 µM) and sufficient (100 µM) P levels.

Table S1. List of greengram genotypes used for screening on the basis of total root exudation and biomass under low (2 µM) and sufficient (100 µM) P levels

S. No. / Genotype / S. No. / Genotype
1 / PS-10 / 23 / SM-9-266
2 / Asha / 24 / SM-9-269
3 / SM-9-117 / 25 / SM-9-263
4 / SM-9-265 / 26 / SM-9-164
5 / SM-9-202 / 27 / PUSA-9531
6 / SM-9-262 / 28 / PUSA-671
7 / PUSA-9532 / 29 / PDM-54
8 / KM-7-211 / 30 / SM-9-206
9 / ML-818 / 31 / SM-9-201
10 / SM-149 / 32 / KM-7-134
11 / MH-1K-27 / 33 / PUSA BAISAKHI
12 / 11/395 SMALL / 34 / T-44
13 / M-1319 BLACK / 35 / PUSA-9072
14 / P-831 / 36 / HUM-1
15 / SM-9-267 / 37 / COGG-912
16 / SM-9-204 / 38 / PDM-91-269
17 / SM-9-157 / 39 / PUSA-871
18 / PUSA 105 / 40 / PUSA-9971
19 / SML-970 / 41 / NIMB-101
20 / PANT MUNG-9 / 42 / RMG-991
21 / PUSA-532 / 43 / PDM-139
22 / MH-96-1 / 44 / SM-9-257

Table S2 Analysis of variance for total biomass and 14C exudation of forty-four greengram genotypes grown at low (2 µM) and sufficient (100 µM) levels of phosphorus.

Fifteen days old seedlings were exposed to 14CO2 and exudate sampling was done after 24, 48 and 96 h

Traits / Sources of variability / CD at P <0.05 / CD at P <0.01
P / G / P x G / P / G / P x G / P / G / P x G
Total biomass / ** / ** / ** / 2.11 / 9.90 / 14.01 / 2.79 / 13.07 / 18.49
14C exudation 24 h / ** / ** / ** / 20.11 / 94.31 / 133.38 / 26.54 / 124.47 / 176.02
14C exudation 48 h / ** / ** / ** / 20.32 / 95.32 / 134.81 / 26.82 / 125.79 / 177.90
14C exudation 96 h / ** / ** / ** / 21.61 / 101.36 / 143.35 / 28.52 / 133.77 / 189.18

Significant effects are indicated for phosphorus (P) and genotype (G) treatments, and their interaction (P x G); ** significant at P <0.01; CD – critical difference

Table S3. Analysis of variance for carboxylic acid concentration in root exudate and root apices, growth attributes and P uptake of selected seven greengram genotypes in response to low (2 µM) and sufficient (100 µM) P levels.

Traits / Sources of variability / CD at P <0.05 / CD at P <0.01
P / G / P x G / P / G / P x G / P / G / P x G
Root dry wt / ns / ** / ** / 4.589 / 8.587 / 12.144 / 6.192 / 11.585 / 16.383
Shoot dry wt / ns / ** / ** / 5.747 / 10.752 / 15.205 / 7.753 / 14.505 / 20.514
Total biomass / ns / ** / ** / 8.993 / 16.825 / 23.795 / 12.134 / 22.699 / 32.103
Root-to-shoot ratio / ns / ** / * / 0.030 / 0.057 / 0.080 / 0.040 / 0.076 / 0.108
Root P concentration / ** / ** / * / 0.109 / 0.204 / 0.288 / 0.147 / 0.275 / 0.389
Shoot P concentration / ** / ** / ** / 0.132 / 0.247 / 0.349 / 0.178 / 0.334 / 0.472
Total P uptake / ** / ** / ** / 0.033 / 0.061 / 0.087 / 0.044 / 0.083 / 0.117
Oxalic acid (internal) / ** / ** / ** / 2.274 / 4.255 / 6.018 / 3.157 / 5.906 / 8.352
Maleic acid (internal) / ** / ** / ** / 0.007 / 0.013 / 0.018 / 0.010 / 0.018 / 0.025
Succinic acid (internal) / ** / ** / ** / 3.326 / 6.222 / 8.799 / 4.616 / 8.635 / 12.212
Lactic acid (internal) / ** / ** / * / 2.822 / 5.279 / 7.467 / 3.917 / 7.328 / 10.363
Oxalic acid (exudate) / ** / ** / ** / 0.949 / 1.776 / 2.512 / 1.318 / 2.465 / 3.487
Citric acid (exudate) / ** / ** / ** / 0.438 / 0.819 / 1.158 / 0.607 / 1.136 / 1.607
Lactic acid (exudate) / ns / ** / ** / 0.143 / 0.267 / 0.377 / 0.198 / 0.370 / 0.524

Significant effects are indicated for phosphorus (P) and genotype (G) treatments, and their interaction (P x G); ns - no significant difference; * P <0.05; ** P <0.01; CD – critical difference