Fig. 1.Changes in (A) Soil Water Content Expressed As% of Field Capacity (FC), Measured

Fig. 1.Changes in (a) soil water content expressed as% of field capacity (FC), measured just before daily rewatering in the well-watered (WW) treatment;(b) predawn leaf water potential (MPa), and (c) leaf stomatal conductance (mmol m-2 s-1) in the WW treatment(solid symbols) and the water-stressed (WS, open symbols) treatment after water was withheld for 13 days and then re-watered (RW, indicated by the arrow) in accessions SC-2 (circles) and SC-4(squares). Each mean is accompanied by a bar representing the mean ±s.e. (n=4) when larger than the symbol.

Fig.2. The average number of mature pods, aborted pods or aborted flowers that formed from tagged open flowers on the main raceme and the two uppermost side branches during the 13-day water-stressed (WS) or well-watered (WW) treatments in ten Brassica accessions. Each flower was tagged as it opened to track the result of pod development at each flower node. Flowers that failed to develop a pod (at least 5 mm) 2 to 3 days after opening were defined as “aborted flowers”, pods that failed to develop mature seeds were defined as “aborted pods”, while “mature pods”containedwell developedmature seeds at harvest.

Fig.3.Changes inthe percentage flower abortion as the soil water content decreased in the water stress treatment, for accessions SC-2 (●) and SC-4 (○).Each mean is accompanied by a bar representing the mean ±s.e. (n=4) when larger than the symbol.

Fig. 4.Relative silique length (a) and relative beak length (b) ofpods formed on the main raceme and the two uppermost side branches during the 13-day water-stressed (WS) treatment in ten Brassica accessions, expressed as a percentage of the well-watered (WW) treatment. Each mean is accompanied by a bar representing one s.e. above themean (n=4).

Fig. 5.Effect of reduction in soil water content (% field capacity) during 13 days of water-stressed (WS) treatment on the leaf-to-airtemperature difference (LTD) (●) and bud-to-air temperature difference (BTD) (○) in three representative Brassica accessions: (a) SC-1, (b) PI-3, and (c) PI-5. Leaf and bud temperatures began to increase significantly after SWC dropped to certain values (varied among accessions) which were defined as the “threshold SWC” and indicated by arrows. Each mean is accompanied by a bar representing the mean ±s.e. (n=4)when larger than the symbol. See Supplementary Fig S3 for all the 10 accessions.

Fig. 6. Leaf-to-air (a) and bud-to-air (b) temperature differences during the 13-day treatment period among 10 Brassica accessions. Values are for the average across the 13 days in the well-watered (WW) and water-stressed (WS) treatments, and the interpolated value at soil water content equal to 20% field capacity (FC). Each meanis accompanied by a bar representing one s.e below the mean (n=4).