The phenotype variation and drought resistance appraise of transgenic Trifolium repens with PeDREB2b gene from Populus euphratica

Seven transgenic lines were selected from transgenic Trifolium repens obtained before,including W1-2, W1-3, W4-2, W13-4, W17-1, W28-2 and W33-3, while non-transgenic lines were used as control.Morphological characteristics and permanent wilting rate of plant were determined. Changes of foliage relative water content, electric conductivity and malon-dialdehyde(MDA) were measured under simulated drought stress by PEG. Results showed that: 1)leaf shape,leaf color, leaf mottling and leaf size of some transgenic T. repens lines changed obviously; 2)The drought-resistant capability of W1-3, W28-2 was strong, which had the lower permanent wilting rate and grew normally for long time; 3)With time and drought stress going on, the relative water content of plants decreased in different degree, but W1-3 and W28-2 could still maintain high level. And the relative electric conductivity and malondialdehyde content of plants had increased, but W1-3 had less change. Through comprehensive analysis, it was concluded that the drought resistant abilities of these seven transgenic lines were ranked as W1-3>W33-3>W28-2>W1-2>W13-4>W17-1>W4-2. Transgenic T. repens lines are superior to the control.