Evaluation of Drought Resistance in Maize Genotypes Using Proline Accumulation as an Index
Kasetsart University, Chatuchak, Bangkok 10900
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A study on proline accumulation as a drought resistance index in maize was conducted at the National Corn and Sorghum Research Centre, Pak Chong, Nakhon Ratchasima province during January 1989 to October 1990. The main objective was to measure proline accumulation, growth, yield and yield components under various water regimes for evaluation of drought resistance in maize genotypes. The results indicated that under the soil moisture of 25% AWC, all studied maize genotypes accumulated high concentration of proline even though there were differences among genotypes. They were classified into three groups; high, medium, and low contents of praline. The measured proline contents were correlated with the values of consumptive water use and stem fresh weight at 21 days of age.
Two maize genotypes or cultivars from each group of proline accumulation were grown in the field under four water stress regimes. The result revealed that water stress caused grain yield reduction with a pronounced effect when stress occurred during the stages 3-6 weeks and 9-12 weeks after emergence. Furthermore, maize cultivars expressed different abilities of resistance to various water stress regimes. The maize cultivars that were in the high proline accumulation group gave low grain yield. The results also indicated that the leaf proline accumulation at seedling stage could be used as drought resistance index for maize genotype evaluation.
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