|EPHRATH, JHONATHAN - Ben Gurion University Of Negev|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2010
Publication Date: 11/11/2010
Citation: Ephrath, J., Baker, J.T., Mcmichael, B.L., Burke, J.J., Gitz, D.C., Lascano, R.J. 2010. Sand abrasion injury and plant survival in cotton seedlings of different ages[abstract]. 3rd International Conference on Deserts, Drylands, and Desertification. November 8-11, 2011, Sede Boqer, Israel.
Technical Abstract: Millions of hectares of crops are exposed to wind-blown soil abrasion injury each year and in many instances the damage is severe enough to require replanting. Little attention has been given to plant physiological or morphological factors that may lend resistance to, or enhance recovery from, wind-blown soil abrasion injury to the plant. Several studies in Texas on cotton seedlings (Gossypium hirsutum L.), has shown that shoot growth efficiency is increased following sand abrasion injury compared with that of untreated controls. We conclude that this increased shoot growth efficiency was either the result of remobilization of previously stored assimilates in the roots to the damaged shoots and/or an increase in photosynthetic efficiency of newly formed leaves on previously damaged plants. Our overall hypothesis is that cotton seedlings with greater root-to-shoot biomass ratio (R/S), prior to soil abrasion injury, should be better able to withstand and recover from abrasion injury compared with cotton seedlings with lower R/S ratio. In a study conducted in a greenhouse during 2009 and 2010, we utilized the Texas wind tunnel to expose cotton seedlings of different ages to wind velocities of 15.2 m s-1 with sand abrasive flux density of 0.42 g cm-1 width per second for six treatment durations ranging from 0 (control) 5, 10, 20 30 to 40 minutes and mechanical pruning to remove all leaves using scissors with no wind. Cotton seedling ages were defined by the number of mainstem nodes, varying from 0 (only cotyledons) to 8 nodes. Cotton relative growth rate was expressed based on growing degree days rather than chronological time. To test for photosynthetic upregulation of new leaves formed on previously damaged nodes, photosynthesis vs. substomatal CO2 (A/Ci) curves were generated with a portable photosynthesis system. Growth analysis (Relative Growth Rates, Net Assimilation Rates and Leaf Area Ratios) as well as biomass increments of the whole plant (including the roots) were calculated at two periods, 2 and 4 weeks after the wind-blown treatments.