Physiological responses of quinoa (Chenopodium quinoa Willd.) to drought and waterlogging stresses. Dry matter partitioning

GONZÁLEZ, JUAN ANTONIO; GALLARDO, MIRIAM; HILAL, MIRNA; ROSA, MARIANA; PRADO, FERNANDO

Botanical Studies

Academia Sinica

Lugar: Taiwan; Año: 2009 vol. 50 p. 35 - 42

1817-406X

Quinoa (Chenopodium quinoa Willd.) plants respond differently to drought and waterlogging. Plant and root dry weight (DW) was lower in both drought and waterlogging stresses than in well-watered condition, but the lowest values were obtained under waterlogging. However, root weight ratio (RWR: root dry weight per unit plant dry weight) did not show significant changes in all treatments. Leaf area (LA) and specific leaf area (SLA) were higher in drought than in waterlogging, but there was no significant difference between drought and control treatments. Conversely, specific leaf weight (SLW) and relative water content (RWC) were higher under waterlogging than in drought plants. However, between control and waterlogging conditions there was no significant difference in RWC value. In addition, the number of leaves and height of plants remained unchanged in all treatments. The lowest content of total chlorophyll, chlorophyll a and chlorophyll b was observed in waterlogging condition, whereas between control and drought treatments there were no significant differences. Chlorophyll a/b ratio remained unchanged in all treatments. Leaf nitrogen content, expressed per unit of leaf dry weight (Nm), was lower in control plants, whereas it remained unchanged under drought and waterlogging conditions. However, when it was expressed per unit of leaf area (Na) the highest value was observed under waterlogging condition. In addition, soluble protein content was also higher in waterlogging treatment than in control and drought conditions. Proline content was higher under drought than in control and waterlogging conditions; however, there was no significant difference between  control and waterlogging treatments. Between control and drought treatments there were no differences in starch, sucrose and fructose contents. Glucose and total soluble sugars contents were higher under drought than in well-watered condition. However, the highest amounts of soluble sugars and starch were found in waterlogging stress. Relationships between soil water surplus and quinoa growth are discussed.