Mechanisms of Differential Manganese Uptake Efficiency in Winter Cereals at Generative Phase

Abstract

Plant species as well as cultivars of the same species differ in their Mn efficiency. This paper studied the differential Mn efficiency in relation to Mn dynamics in the rhizosphere and root shoot relations of one durum wheat (cultivar PDW 291), four bread wheat varieties (cv. PBW 509, PBW 636, DBW 17 and PBW 550) and one triticale (cv. TL 2908). The six cultivars were grown in pots under two Mn treatments: (i) 0 mg Mn kg−1 soil (i.e. soil with 1.54 mg kg−1 of DTPA-extractable Mn) and (ii) 50 mg Mn kg−1 soil. Plants were harvested at tillering and 45 days post tillering to record root length (RL), shoot dry weight (SDW), Mn uptake and soil parameters. Under Mn deficiency conditions, PBW 550 produced 47 % of its maximum RL and 58 % of its maximum SDW, whereas PDW 291 produced only 13 and 35 %, respectively. PBW 550 and PDW 291 showed highest and lowest RL/SDW ratio, root surface area and Mn uptake, respectively. Greater Mn concentration difference between bulk soil and root surface in PBW 550 and TL 2908 resulted into 1.4 times higher Mn influx as compared to durum cultivar. It seemed triticale cv. has adaptations to low nutrient availability as indicated by its lowest relative shoot growth rate and highest relative root growth rate.