Ecophysiological analysis of drought and salinity stress of quinoa (Chenopodium quinoaWilld.)

We assessed the relative influence of drought or salinity stress with similar soil water potentials on growth, plant water relations, and photosynthesis rate of Chenopodium quinoa Willd., as well as the suitability of common techniques used in stress physiology studies. Our results from greenhouse pot experiments showed that salt stress induced better absolute and relative growth rates, and that the plant developed adaptation mechanisms to drought through high water use efficiency and high root shoot ratios. The stomatal resistance and the leaf water potential increased with an increased stress level. Variable to maximal chlorophyll fluorescence (Fv/Fm) and quenching analysis (qP and qN) showed that dehydrated plants are less protected from photoinhibition. The dynamic diffusion porometer is of limited use in leaves with salt glands.