Studies On Photosynthetic Characteristics, Cutting Propagation And Response Under Stresses Of Pseudo Drought For Peperomia Obtusifolia ‘Variegata’

Differences of the Photosynthetic characteristics among three potted plants, that are, Peperomia obtusifolia, P.obtusifolia ‘Variegata’, P. obtusifolia ‘Albo Marginata’ are compared. Effects of two leaf cutting propagation with flat and inclined method and in company with different concentration of 6-BA among Peperomia obtusifolia and P. obtusifolia ‘Variegata’ are researched. Plants characteristics and some physiological and biochemical indexes among with sub-irrigation, unilateral irrigation and conventional irrigation on P. obtusifolia ‘Variegata’ are compared. These results are shown as below.1. The leaf chlorophyll content of P. obtusifolia ‘Variegata’ is almost half of P. obtusifolia, so, indexes such as leaf net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular carbon dioxide concentration of P. obtusifolia ‘Variegata’ is lower respectively than of P. obtusifolia. The suitable light intensity of P. obtusifolia ‘Variegata’ is about 1600 μmol?m -2 s -1, while of P. obtusifolia is about 800 μmol?m -2 s -1.2. The sprout of flat leaf cutting is faster than of inclined leaf cutting. There is no difference of finally sprouting rate among two cutting method, the effect of sprout in company with different concentration is not obvious.3. Most leaf color are atavistic green, few leaf color are all white or combination of green and yellow in sprouts with leaf cutting. The color of seedlings is determined by the sprouting area because of it’s a kind of chimera, only the plaque leaf can be retention by shoot cutting.4. The plan growth maybe promote by sub-irrigation than by conventional irrigation(contrast), while the internode spacing is obviously increased by unilateral irrigation than by contrast. There are most roots numbers coming from sub-irrigation, and followed by unilateral irrigation, mean that root growth maybe promote by pseudo-drought stress. The water content of plant can be increased, while dry matter weight and root-to-crown ratio is both decreased by pseudo-drought stress.5. Both leaf MDA content and enzyme activity of POD by sub-irrigation are higher than by contrast, while these indexes by unilateral irrigation are lower than by contrast. The plasma membrane permeability by sub-irrigation is lower than by contrast, but by unilateral irrigation. It is suggested that the response with unilateral irrigation maybe similar with real drought stress, while the response with sub-irrigation maybe not same as real drought stress.