Anatomical studies of chilling tolerance in sweetpotato (Ipomoea batatas L.) leaves

An experiment was conducted for leaf anatomy study of four chilling tolerant sweetpotato genotypes such as 105MS1, 108 MS2, 180MS3, 183MS4 which were selected from seventy nine lines from three major variety crosses for tolerant to chilling injury. Differences in leaf anatomy composition were found among the four genotypes tested. The genotypes 105MS1 and 108MS2 had lower stomata density on bath abaxial and adaxial leaf surfaces. However, since there were no differences in diffusive resistance and transpiration rate among the genotypes, stomata density should not have affected chilling tolerance through water loss. However, differences were found for leaf shrinkage, which indicated differences in water loss. Leaf shrinkage, stomata density, diffusive resistance and transpiration rate may interact with leaf water content and specific leaf weight with respect to water loss of the leaves under chilling conditions. It was concluded that leaf structure could have a role in chilling tolerance and was different among the four genotypes tested.