Large variation in waterlogging tolerance and recovery among the three subspecies of Trifolium subterranean L. is related to root and shoot responses

• Published in: Plant and Soil Vol. 464; no. 1/2; pp. 467 - 487
• Main Authors: Enkhbat, Gereltsetseg, Ryan, Megan H., Foster, Kevin J., Nichols, Phillip G. H., Kotula, Lukasz, Hamblin, Ann, Inukai, Yoshiaki, Erskine, William
• Format: Journal Article
• Language: English
• Published: Cham Springer Science + Business Media 01.07.2021; Springer Science and Business Media LLC; Springer International Publishing; Springer; Springer Nature B.V
• Subjects: Anthocyanins; biomass; Biomedical and Life Sciences; Chlorophyll; Clover; Conductance; Cultivars; Drainage; Ecology; Environmental aspects; Greenhouses; Growth rate; Hardiness; leaf area; leaf chlorophyll content; Leaves; Life Sciences; Nodulation; petioles; Physiological aspects; Pigmentation; Plant breeding; Plant growth; Plant Physiology; Plant Sciences; Plants; Porosity; Recovery; Regular Article; REGULAR ARTICLES; Resistance; root growth; Roots (Botany); Shoots (Botany); soil; Soil moisture; Soil Science & Conservation; Stomata; Stomatal conductance; tap roots; Trifolium subterraneum; Waterlogging; Australia; Leaf size; Root porosity; Pasture legumes; Stomatal conductance; Anthocyanin pigmentation
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-021-04959-0

Aims Tolerance to waterlogging and recovery ability was compared among the three subspecies of subterranean clover ( Trifolium subterraneum L.) to identify tolerance mechanisms, in order to guide future subclover breeding activities. Methods Three cultivars each of ssp. yanninicum , subterraneum and brachycalycinum were grown in a controlled environment glasshouse with T. michelianum as a waterlogging-tolerant control. After 28 days of growth two treatments were imposed for 35 days: free-draining (control) and waterlogged. A 21-day recovery period followed. Results After 35 days, waterlogging reduced shoot dry weight (DW) to 58–27% and root DW to 35–21% of respective controls in each subspecies. Shoot relative growth rate (RGR) of yanninicum was least affected (78–104% of control), compared to subterraneum (51–100%) and brachycalycinum (45–69%). The subterraneum cv. Denmark had a similar response to subspecies yanninicum . Shoot RGR of T. michelianum was 138% of its control. After recovery, all traits (except tap root length) recovered to control values. Up to 21 days, the main traits associated with waterlogging tolerance (shoot and root growth) were high petiole length, less petiole anthocyanin pigmentation and high leaf chlorophyll content, but by 35 days these were a high proportion of leaf biomass, high stomatal conductance and enhanced root porosity. Average root diameter and nodulation rates were unrelated to waterlogging tolerance. Conclusions Subspecies yanninicum had superior waterlogging tolerance. Priority traits for easily-assessed indicators of waterlogging tolerance are less reduction of leaf size and high stomatal conductance.