Cucumber leaf necrosis caused by radiation with abrupt increase of far-red component

Plants exhibit morphological plasticity in response to changes the proportion of far-red radiation (FR). However, little is known about a sudden increase FR component. Cucumber seedlings were acclimatized without (FR-) for 1 - 5 d after germination, and then transferred containing (FR+) at levels similar those natural sunlight. Other FR- or FR+, which was maintained continuously. The damaged cotyledons first true leaf, especially when changed from FR+ days 3 4 germination. Necrosis leaves may have resulted inhibition water flow leaf xylem, because wilting decreased stomatal conductance observed simultaneously with necrosis. treatment groups that showed most frequent damage two peaks cotyledon elongation. This suggests had been easily by promotion expansion caused FR+.