Root growth, malonyldialdehyde content and antioxidant enzyme activities in response to low phosphorus supply in rice (Oryza sativa L.) genotypes

摘要

Six genotypes of rice viz., lET 20710, lET 20894, lET 20716, MTU 1010, lET 20744 and Swarna, were examined in sand culture with two P levels in modified Hoagland solution (Low phosphorus-LP ; 1.6 pM and Normal phosphorus-NP : 200 mM). Physiological and biochemical parameters of root and leaves were evaluated in response to P supply. Root length was significantly higher while root volume and diy weight were lower in plants with LP. Among rice genotypes viz., lET 20710, Swarna and lET 20716 exhibited higher length of roots with less reduction in root volume and dry weight and higher root : shoot ratio indicative of adaptation to low P conditions. These genotypes had higher levels of antioxidant enzyme activities (SOD, POD and CAT) and lower MDA content in leaves and roots under low P conditions indicative of less oxidative injury. In contrast, lET 20744 and lET 20894 genotypes with LP supply exhibited reduction in root traits, higher levels of MDA content and reduced antioxidant enzyme activities.