A summary describing all plant architecture, flower, fruit, and yield, and phenological traits for each of the thirteen Phaseolus sp. and Vigna sp. landraces in the open field and the greenhouse conditions is provided in Supporting Tables S3, S4 and S5. Main effects Kruskal–Wallis tests are summarised in Table 1, and the interactions between treatment conditions (open field and greenhouse) and species, and landrace and climatic background are summarised in Table 2.
I. Plant architecture
Plants under high temperatures and low humidity in the greenhouse exhibited significant higher overall mean rank values than field plants for stem diameter, the degree of branch orientation, composite sheet length and width, and the terminal leaflet length. The size of the angle of the base of the terminal leaflet, however, was bigger in the field (Supporting Tables S3 and Table 1). There were overall significant differences for species and landrace for all studied characters (Table 1). The Kruskal–Wallis analyses of the interactions between treatment (open field vs greenhouse conditions) and species, climatic background, and landrace were significant for all the traits (p-value < 0.001; Table 2).
Post hoc pairwise comparisons for treatment × species interaction (Table 3), found that P. vulgaris plants produced significant higher mean rank values for branch orientation angle in the greenhouse than in the field (median values: 140.00° vs 133.33°). Similarly, P. lunatus plants exhibited significant higher values in the greenhouse for composite sheet length and width and terminal leaflet width (median values: 238.28, 209.95 and 115.26 mm, respectively) than in the field (median values: 208.34, 169.27 and 93.76 mm, respectively); but the terminal leaflet length performed better in the field compared to greenhouse (medians: 62.36 and 52.02 mm). Post hoc pairwise comparisons for treatment × climatic background highlighted that cold background landraces had higher values for branch orientation angle, composite leaf length and width, and terminal leaflet length in the greenhouse than in the field. Cold background landraces produced wider terminal leaflet widths in the greenhouse while warm background landraces did it in the field (Table 3). Post hoc analysis for the treatment × landrace (Table 4) found that P. lunatus had higher mean rank values in the greenhouse than in the open field for composite sheet length (238.28 vs 208.34 mm) and width (209.95 vs 169.27 mm), and terminal leaflet length (115.26 vs 93.76 mm). P. vulgaris landrace 8 failed to grow in the field. Plant architectural traits were only affected in one P. vulgaris (8) and the P. lunatus (13) landraces. P. vulgaris landrace 1, from cold background, performed better in the field than in the greenhouse. Landrace 8, from cold background as well; however, performed better in the greenhouse than in the field, suggesting a wrong identification of its real origin.
II. Flower and fruit characteristics and yield
Greenhouse plants exhibited significant higher overall mean rank values than field plants for the total number of flowers per plant (medians: 57 vs 11 flowers), the number of pods per plant (medians: 34.5 vs 2.0 pods), the number of pods per infructescence (medians: 1.6 vs 1.4 pods), the number of grains per pod (medians: 4.2 vs 0.0 grains), the dry weight of 100 seeds (medians: 37.46 vs 0.0 g), the gross weight of seeds per plant (medians: 24.92 vs 0.0 g), the net weight of seeds per plant (medians: 24.01 vs 0.0 g), and the number of seeds (medians: 60.0 vs 0.0). On the contrary, the sheath width was larger in the field (12.48 mm) than in the greenhouse (11.01 mm; see Supporting Table S4 and Table 1). There were overall significant differences for species and landrace for all characters (Supporting Table S4 and Table 1). For the climatic background of the landraces, all characters exhibited significant differences except for the peduncle length, the number of pods per plant and the number of pods per infructescence.
The Kruskal–Wallis analyses of the treatment × species, treatment × climatic background (except for sheath length) and treatment × landrace interactions were significant for all the traits (Table 2). Post hoc pairwise comparisons for treatment × species interaction found that P. vulgaris, V. unguiculata and P. lunatus produced higher mean rank values in the greenhouse than in the field (Table 3) for: the number of pods per plant (median values: 31.0, 20.5 and 96.0, respectively vs 3.5, 0.0 and 47.5 pods), the gross weight of seeds per plant (medians: 24.04, 17.11 and 251.90 vs 0.00, 0.00 and 112.12 g, respectively), the net weight of seeds per plant (medians: 22.32, 15.25 and 238.78 vs 0.00, 0.00 and 104.80 g, respectively), and the total number of seeds (medians: 36.5,93.5 and 205 vs 0.0, 0.0 and 93.5 seeds, respectively). The sheath width was significantly higher in the field than in the greenhouse (medians: 12.8 and 11.4 mm, respectively), and the scar length mean ranks were higher in the greenhouse than in the field only for P. vulgaris. Then, P. vulgaris and V. unguiculata, produced higher mean rank values for the following characters in the greenhouse than in the field (Table 3) for the number of flowers per plant (medians: 48.0 and 28.0 vs 11 and 7.5 flowers, respectively) and the number of grains per pod (medians: 4.2 and 10.0 vs 0.0 grains, respectively). Similarly, P. vulgaris and P. lunatus exhibited higher mean rank values in the greenhouse than in the field for the weight of 100 seeds (medians: 40.51 and 116.39 vs 0.00 and 109.43 g, respectively).
In the treatment × climatic background, post hoc pairwise comparisons (Table 3) found significant higher mean rank values in landraces from cold background growing in the field than in the greenhouse for chalice length. Warm background landraces produced higher mean rank values in the greenhouse for the number of flowers per plant, the number of pods per plant and infructescence, the number of grains per pod, the 100 seeds weight, the gross and net weight of seeds per plant and the number of seeds. The commercial cultivar exhibited higher median peduncle length in the field than in the greenhouse, and higher median values in the greenhouse than in the field for the number of flowers per plant, the 100 seeds weight, the gross and net weight of seeds per plant and the number of seeds.
In the treatment × landrace, post hoc analysis (Table 4) found that the number of flowers per plant was significantly higher in P. vulgaris landraces 2, 4, 5, 8 and 9, and in V. unguiculata 10. Analogously, more pods per plant were produced in the greenhouse for P. vulgaris landraces 2, 4, 5 and 8, and in V. unguiculata 10. The total number of seeds produced in the greenhouse was higher than in the field for P. vulgaris landraces 2, 4, 5, 6 and 8, both V. unguiculata 10 and 11, and P. lunatus 13. P. vulgaris 3 produced higher mean rank values for the 100 seeds weight in the greenhouse than in the field. P. vulgaris landraces 5 and 6 (both from warm background), however, failed to produce enough flowers, pods, or seeds. Landrace 1, from cold background, failed to prosper in the greenhouse, and landrace 8 did not grow in the field. Otherwise, all other significant values highlighted the positive effects of warmer conditions compared to the field acting on flower, fruit, and yield characteristics (Table 4).
III. Phenology
The treatment had significant overall effects for all the studied characters except for the emergence of hypocotyl, the full flowering when the 50% of the flowers are open, and the 50% of pods ripe (Supporting Tables S5 and Table 1; Fig. 1). Moreover, growing in the open field under colder and more humid conditions than in the greenhouse, delayed the development of the characters except for the finishing of the flowering, which was delayed in the greenhouse (medians: 144 and 123 days, respectively), and the time when pods are fully ripe (medians: 169 and 146 days, respectively). All the three species showed significant differences in mean ranks for all their phenological characters except for the first side shoot visible, while for landrace, there were significant differences for all the characters (Table 1). However, the climatic background of the landrace had no effects on the first side shoot visible, the full flowering and the end of flowering.
Phenological stages in chronological order. (A) Development of the 13 landraces in the open field treatment; (B) development of the 13 landraces in the greenhouse.
The Kruskal–Wallis analyses of the treatment × species, treatment × climatic background and treatment × landrace were significant for all traits (Table 2). Post hoc analysis for treatment × species (Table 3) found that V. unguiculata developed the first phenological traits (P08–P12) faster than P. vulgaris and P. lunatus. However, V. unguiculata was the slowest species producing the flowering period (median: 121–169 days; P. vulgaris 71–116 days; P. lunatus 107–169 days), and produced more seeds per pod (9 seeds) than P. vulgaris (3.6 seeds) or P. lunatus (2.1 seeds), for other yield related traits produced lower values than the Phaseolus sp. The presence of the first shoot visible had higher mean rank values (appearance of the character delayed in time) in the field than in the greenhouse for all the species. In P. vulgaris, all significant comparisons confirmed that field conditions delayed the development of such traits, except for the fully ripe pods, which was delayed in the greenhouse for P. vulgaris and V. unguiculata (medians: 156.0 and 189.0 vs 136.5 and 149.0 days, respectively). In addition, P. lunatus produced nine or more leaves unfolded later in the field than in the greenhouse (medians: 60 vs 51 days).
Post hoc analysis for the treatment × climatic background (Table 3), found significant differences in mean rank values for the development of nine or more leaves unfolded, the first side shoot visible, the first flower buds visible and enlarged, and the first petals visible independently of the background origin of the landraces, which happened later in the field than in the greenhouse. In landraces from cold or warm background, the third true leaf developed later in the field compared to greenhouse but the fully ripe pods developed later in the greenhouse (Table 3). In warm background landraces, the flowering finishing was delayed in the greenhouse but the presence of first pods visible and the occurrence of 10% of pods ripe was delayed in the field.
Post hoc analysis for the treatment × landrace (Table 4) found that the number of pods per plant exhibited significant higher values in the field than in the greenhouse for P. vulgaris landraces 1, 4, 6, 7 and 9, P. lunatus 13 and both V. unguiculatus 10 and 11. P. vulgaris landrace 2 finished the flowering and the fully ripe pods later in the greenhouse than in the field; and landrace 8 failed to grow under field conditions. The development of nine or more leaves for P. vulgaris landraces 3, 7 and 9 and P. lunatus, and the end of flowering for P. vulgaris landraces 1, 3, 4 and 7 were delayed in the field. Other significant differences in character expression had higher values in the field (Table 4).
IV. Climate resilience landrace index and clustering
Across all landraces, the following morphological and reproductive characters were the strongly affected by changing the environmental conditions of the plants (when three or more landraces exhibited significant changes in the expression of the character): the number of flowers per plant, the number of pods per plant, the number grains per pod, the grain length, width and thickness, the scar length, the 100 seeds weight, the gross and net weight of seeds/plant and the number of seeds. Phenologically, the most affected traits were: cotyledons completely unfolded, two full leaves unfolded, the unfolding of nine or more leaves, the emergence of the first shoot, first flower buds visible and enlarged, first petals visible, the end of flowering and the pods fully ripe.
The climate resilience landrace index (CRLI, Table 4) found that P. vulgaris landrace 8 (0.688) was highly susceptible, and landraces 1 (0.396) and 6 (0.250) and V. unguiculata landrace 11 (0.354) were very susceptible to changes in their environmental conditions. P. vulgaris landrace 12 and the commercial variety 9 were the most resilient to environmental conditions (0.000 and 0.063, respectively). When using this index for species, P. vulgaris was the most susceptible (0.479) and P. lunatus the most resilient (0.146) to treatment. Warm background landraces were more prone to accumulate significant differences in their traits (0.404) compared to cold background (0.298) or the commercial cultivar (0.234).
The clustering of the mean ranks for the 48 characters expressed by the 12 landraces in both treatments produced a heatmap (Fig. 2) that identified the groups of morphological and phenological characters based on the components of the PCA, thus highlighting the differences induced by the treatment. All phenological characters were grouped in two clusters.
Heatmap of the studied landraces based on the mean rank values for all morphological and phenological characters. Hierarchical clustering of the heatmap for all the studied characters (columns) in the 13 landraces (rows). Columns are clustered using Euclidean distance and complete linkage. Then, we stablished seven groups of characters after the results of the PCA and the parallel analysis that suggested seven factors.
Source: Ecology - nature.com
