Effect Of IAA On Physiological Characteristics And N、P Absorption And Utilization In Rice Seedling

The auxin (auxins), also known as indole acetic acid (indole-3-acetic acid, IAA), isthe first discovery of a plant hormone. Auxin as a growth regulator can promote cropgrowth and develpoment, increase production, and improve quality, which are benefit toto the improvement of economic efficiency. Moreover, it are widely used because of itswide range of applications, and prominent effect. In this study, hydroponic experimentwas conducted to study the effects of the exogenous auxin on rice roots, shoot growth,chlorophyll content and N、P in the rice seedling stage. The aim is to explore theoptimal concentration to promote growth and photosynthesis of rice seeing, and providea theoretical basis for the rational application of IAA and cultivate strong seedling inagricultural production. The main results of this study are as follows:(1) The root growth and chlorophyll content in rice seedling was no significantdifference when treated with different concentrations of IAA from1d to5d. Whentreated for10d, root length of rice for the treatment of1μM IAA increased by41.1%(p<0.05), while plant height, root and shoot weights were not significantly affected; rootweight for the treatments of10μM,25μM and100μM IAA increased by39.1%,25.9%and17.8%(p <0.05), respectively; plant heights and shoot weights reduced significantlyfrom a rate of16.0%to20.7%, and from20.0%to36.7%with increasing IAAconcentration from25μM to100μM IAA, respectively, as compared with CK. As aresult, the ratios of root to shoot increased with IAA concentration increases. Whentreated for10d, contents of chlorophyll a, b and total chlorophyll for treatments with IAA(1μM-75μM) increased by more than30%(p <0.05) compared withthe CK.(2) After1-10μM IAA pretreatment of rice seeding transferred to the low-Nenvironment, the growth characteristics of rice root and shoot was considerable, evenincreased comparative to that normal N treatment. Root weight of10μM IAA treated-rice was increased11.1%. Moreover, N and P absorption in10μM treated-rice wereincreased. Compared with normal N treatment, N content in the shoot was increased by3.8%, and P content in shoot and root were significantly increased by10.7%and12.8%respectively.To sum up, applying1-10μM IAA in rice seedling stage can promote rice growthand increase chlorophyll content, which is beneficial to promote photosynthesisefficiency and cultivate strong seedling. Rice seeds by1-10μM IAA pre cultivationtransferred to low nitrogen stress environment, can promote the absorption of N and Pabsorption, and the rice seedling growth was considerable comparative to that normal Ntreatment.