Yellow lupin (Lupinus luteus) tolerates waterlogging better than narrow-leafed lupin (L-angustifolius) - I. Shoot and root growth in a controlled environment

We studied the adaptation of narrow-leafed lupin (Lupinus angustifolius) an d yellow lupin (L. luteus) to waterlogging because yellow lupin may have po tential as a new legume crop for coarse-textured, acidic, waterlogging-pron e areas in Western Australia. In a controlled environment, plants were wate rlogged for 14 days at 28 or 56 days after sowing (DAS). Plants were more sensitive when waterlogged from 56 to 70 DAS than from 28 to 42 DAS, root growth was more sensitive than shoot growth, and leaf expan sion was more sensitive than leaf dry weight accumulation. Waterlogging red uced the growth of narrow-leafed lupin (60-81%) more than that of yellow lu pin (25-56%) and the response was more pronounced 2 weeks after waterloggin g ceased than at the end of waterlogging. Waterlogging arrested net root gr owth in narrow-leafed lupin but not in yellow lupin, so that after 2 weeks of recovery the root dry weight of yellow lupin was the same as that of the control plants but in narrow-leafed lupin it was 62% less than the corresp onding control plants. Both species produced equal amounts of hypocotyl roo t when waterlogged from 28 to 42 DAS but yellow lupin produced much greater amounts than narrow-leafed lupin when waterlogged from 56 to 70 DAS.