EVALUATION ON CRACK RESISTANCE OF WATERMELON (CITRULLUS LANATUS)

Abstract

Anti-cracking watermelon genotypes were found in breeding practices which can be used as resources resistant to fruit cracking. Whereas watermelon crack of indicators and evaluation criteria have not yet established, and some good crack resistance genes has not been well used. Therefore, a group of tests was carried out for establishing methods of evaluation of watermelon fruit cracking, in general greenhouse and open field conditions. Resistance to fruit cracking in the 11 gene-types watermelon was evaluated. The grades, symptom characters and evaluation criteria in watermelon fruit cracking were also developed. The relationship between the cracking index and significant of fruit cut crack, pressure of fruit cracking, time of vacuum-immersion crack is analyzed. The results show that the variance of resistance indices were significant in opening field (F=5.78 ** ) and protected field (F=10.72 ** ). The correlation coefficients of crack resistance indices in both conditions were significant (r=0.918 ** ). Pressure method, vacuum-immersion method, the fruit cut cracking method have basically the same results with field observations, so the they can be use for evaluating watermelon fruit cracking. Cluster analysis of different crack resistance of watermelon and accurate classification can be used as an assistant way to screening crack resistance watermelon germplasm.