Influence of paclobutrazol on mineral element content of rice seedlings

Abstract

Rice seedlings (Oryza sativa cv. Te Qin No. 1) were hydroponically grown in Espino's solution containing various levels of paclobutrazol introduced into the solution at the three-leaf stage. After the 15th day of treatment, several mineral elements were determined to evaluate the effect of paclobutazol on mineral uptake.In the root, paclobutrazol increased the concentration (on a dry weight basis) of N, P, K, and Cu, decreased Ca and Fe, and did not affect Mg. In the shoot, paclobutrazol enhanced N, P, Ca, and Cu concentration, but decreased Mg, and did not influence K And Fe. In the whole seedling, P, Ca, and Cu concentrations were increased, but N, K, Mg, and Fe were not changed.The total content of mineral elements (on per plant basis) in the shoot and whole seedlings was decreased by paclobutrazol treatment. Fe in the root also decreased.Based on the results mentioned above, paclobutrazol, in general, does not increase the total content of mineral elements in the plant; however, if element concentrations are expressed on a dry weight basis, they show an increase. This is probably due to paclobutrazol inhibition of plant growth. INTRODUCTIONThe influence of plant growth retardants on plant growth and physiology are relatively well understood but their effects on mineral nutrition is still unclear. Chlormequat increased concentration of a majority of mineral elements in different parts of wheat, and soybean (4) matthiola incana and althaea rosea (5).Faclobutrazol significandy increased the concentration of 11 kinds of mineral elements in leaves of apple seedlings in water culture (10), but the change in

Influência do etil-trinexapac no acúmulo, na distribuição de nitrogênio (15N) e na massa de grãos de arroz de terras altas

“…Na China, o efeito do paclobutrazol constatado foi o aumento na concentração de P, Ca e Cu na planta inteira de arroz; no entanto, a quantidade acumulada de todos os elementos determinados na planta inteira diminuiu. Esses resultados podem estar associados à inibição do crescimento da planta promovida pelo paclobutrazol (Pan et al, 1991). Os efeitos dos reguladores vegetais têm sido inconsistentes: em algumas situações, verifica-se aumento de produtividade; em outras, redução.…”