Effects of drought stress on physiological indicators and biomass of Rosa laevigata seedlings / 中草药

ABSTRACT

Objective: To determine the effects of different drought stress levels on the physiological indexes and biomass changes of the seedlings of Rosa laevigata, and to provide theoretical basis for the future drought diagnosis and rational irrigation of R. laevigata. Methods: The content of malondialdehyde (MDA), proline (Pro), photosynthetic pigments and biomass indices in leaves of R. laevigata, under different drought stress were determined by setting up six soil water content levels of 100%, 90%, 80%, 70%, 60%, and 50% respectively. Results: With the increase of the degree of drought stress, the content of malondialdehyde and proline in the leaves of R. laevigata was significantly increased only under serious drought (W5, 60% of the field water content) and severe drought (W6, 50% of the field water content). Except for the ratio of Car/(Chla + Chlb), photosynthetic pigment content peaked in light to moderate drought (W3, field moisture content 80%). Plant height was decreased significantly at W6, and the stem increased to its maximum at W3. The fresh and dry weights of roots, stems and leaves also reached their maximum at W3. Conclusion: The resistance of R. laevigata to drought stress was strong, and the plant growth reached the best state under mild and moderate drought (W3, 80% of the field water capacity), which was most conducive to the formation of dry matter accumulation and yield. However, the field water holding capacity should not be less than 60%, otherwise stress will occur, and the biological yield will also decline significantly.