title: Bread wheat progenitors:Aegilops tauschii(DD genome) andTriticum dicoccoides(AABB genome) reveal differential antioxidative response under water stress.
abstract: Antioxidant enzymes are known to play a significant role in scavenging reactive oxygen species and maintaining cellular homeostasis. Activity of four antioxidant enzymes viz., superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) was examined in the flag leaves of nineAegilops tauschiiand threeTriticum dicoccoidesaccessions along with two bread wheat cultivars under irrigated and rain-fed conditions. These accessions were shortlisted from a larger set on the basis of field performance for a set of morpho-physiological traits. At anthesis, significant differences were observed in enzyme activities in two environments. A 45% elevation in average GR activity was observed under rain-fed conditions. Genotypic variation was evident within each environment as well as in terms of response to stress environment.Aegilops tauschiiaccession 3769 (86% increase in SOD, 41% in CAT, 72% in APX, 48% in GR activity) and acc. 14096 (37% increase in SOD, 32% CAT, 25% APX, 42% GR) showed up-regulation in the activity of all the four studied antioxidant enzymes.Aegilops tauschiiaccessions-9809, 14189 and 14113 also seemed to have strong induction mechanism as elevated activity of at least three enzymes was observed in them under rain-fed conditions.T. dicoccoides, on the other hand, maintained active antioxidative machinery under irrigated condition with relatively lower induction under stress. A significant positive correlation (r = 0.760) was identified between change in the activity of CAT and GR under stress. Changes in plant height, spike length and grain weight were recorded under stress and non-stress conditions on the basis of which a cumulative tolerance index was deduced and accessions were ranked for drought tolerance. Overall,Ae. tauschiiaccession 3769, 14096, 14113 (DD-genome) andT. dicoccoidesaccession 7054 (AABB-genome) may be used as donors to combine beneficial stress adaptive traits of all the three sub-genomes into a synthetic hexaploid for improving wheat for water stress conditions.
authors.affiliation: Department of Biochemistry, Punjab Agricultural University, Ludhiana, India.
authors.forename: Yadhu
authors.initials: Y
authors.lastname: Suneja
authors.affiliation: Department of Biochemistry, Punjab Agricultural University, Ludhiana, India.
authors.forename: Anil Kumar
authors.initials: AK
authors.lastname: Gupta
authors.affiliation: Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, India.
authors.forename: Navtej Singh
authors.initials: NS
authors.lastname: Bains
keywords: Antioxidant enzymes; Reactive oxygen species; Water deficit stress; Wild wheats