A comparative study of the pericarp of litchi cultivars susceptible and resistant to fruit cracking

SummaryTime-course changes of fruit cracking percentage, mechanical properties of pericarp and contents of cell wall components in litchi pericarp were studied by comparing two litchi cultivars differing in cracking susceptibility. Mechanical strength of the pericarp of crack-resistant cv. Huaizhi was greater than that of cracking-susceptible cv. Nuomici. The resistance of `Huaizhi' was also reflected in higher threshold cracking turgor as well as in higher pericarp tensile strength and extensibility. Correspondingly higher contents of calcium and structural components viz. cellulose, hemicellulose and insoluble pectin were found in the pericarp cell walls of `Huaizhi', which might have materially contributed to its higher pericarp strength and thus cracking resistance as compared with `Nuomici'.