Comparison of drought tolerance of banana genotypes
Banana is an importment international economical crop, but drought is the most significant environmental stress in banana intrustry. Previous studies on banana drought tolerance evaluated just a few indicators, such as malondialdehyde (MDA) and plasma membrane permeability (PMP), with little or no systematic morphological and physiological information. We examined the morphological and anatomical structure characters of nine genotypes among 28 banana varieties from the variety resource nursery of China academy of topical agricultural sciences, and combined physiological markers (PMP and MDA) with morphological data. Leaf thickness, upper leaf epidermis and cutin thickness, palisade tissue thickness, spongy tissue thickness, lower leaf epidermis and cutin thickness, cell tense ratio (CTR), PMP and MDA content were significantly different among these varieties. Banana varieties were divided into three groups by cluster analysis based on a CTR index or a MDA content index, and the varieties were divided into two groups by cluster analysis based on the PMP index. Based on discriminant functions, the original classification was confirmed, and the result of discriminant classification was 100% correct. Three discrimination models with superior distinguishing abilities were established.