Evaluation of maize cultivars for drought tolerance based on physiological traits associated with cell wall plasticity
2013
Ul Hassan, Mehmood | Qayyum, Abdul | Razzaq, Abdul | Ahmad, Muhammad | Mahmood, Imran | Khan, Sami Ullah | Jenks, Matthew A.
Maize is negatively affected by many environmental factors during growth, with drought stress being one of the most common causes for reduction in maize yield worldwide. There is wide variation in stand establishment for various maize cultivars to water deficit condition, such as occur in in arid and semiarid regions of the world. An experiment was carried out to evaluate five cultivars of maize viz; EV-1097, Agaiti-2002, Sawaan-3, Islamabad Gold and EV-1098 for tolerance to water deficit based on their cell wall plasticity characteristics. The crop was sown in pots; each treatment consisted of five pots having three plants each, and each pot was watered uniformly up to soil capacity from germination to the three leaf stage as required. Then, the water supply was reduced to half soil capacity level for one week, and then to one-third capacity for the coming two weeks. After 35 days, irrigation was stopped for one week. After one week without water, the plants showed symptoms of drought stress, at which time data was recorded on leaf growth rate, chlorophyll content, leaf water potential, protein content, proline content, relative water content, specific leaf weight, and sugar content. Control plants were maintained at full soil capacity. The experiment was laid out by using completely randomized design with three replications and five treatments (cultivars). The response of the five cultivars examined under these water deficit stress treatments differed dramatically. Cultivars EV-1097 and Agaiti-2002 were amongst the best performers, showing maximum cell wall plasticity, having the highest leaf growth rate, proline, protein, sugar and relative water contents, as well as the highest specific leaf weight, leaf water potential, and chlorophyll content when compared with other cultivars. EV-1097 and Agaiti-2002 were thus the most tolerant cultivars to these water deficit treatments. The Islamabad gold and EV-1098 cultivars were the least tolerant to water stress conditions.
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