Objective To investigate and collect sugarcane wild germplasm resources in northern Guangdong, analyze their genetic diversity, and provide excellent parental materials for sugarcane genetic breeding.

Method The germplasm resources were investigated and collected at the interval of 30 km or at the altitude drop of 100 m. The collection route and geographic information were recorded, and the underground rhizomes were excavated and preserved. Total six quantitative traits and 20 qualitative traits were measured. A comprehensive evaluation was conducted by calculating the coefficient of variation, genetic diversity index, and correlations between quantitative traits.

Result A total of 82 wild germplasm resources of sugarcane from four genera and four species were collected, including 28 samples of Saccharum spontaneum, 26 samples of Narenga porphyrocoma, 24 samples of Erianthus arundinaceus and four samples of Miscanthus sinensis. The phenotypic variation of sugarcane wild germplasm resources in northern Guangdong was rich, and the variation coefficient of quantitative traits was 10.9%−44.5%. The average variation coefficient of S. spontaneum was the largest (30.6%), followed by M. sinensis (30.3%), and the average variation coefficient of N. porphyrocoma was the smallest (28.1%). There was a very significant positive correlation between each pair of leaf length, leaf width, plant height and stalk diameter, and there was no significant correlation between brix and other traits. The Shannon-Wiener diversity index of qualitative traits was 0.000 0−1.222 7. Principal component analysis extracted two principal components from six quantitative traits, with a cumulative contribution rate of 62.312%. Cluster analysis revealed that six germplasms, including S. spontaneum accessions 2023GSM054 (cluster I) and 2023GSM246 (cluster III), N. porphyrocoma accessions 2023HBW224 (cluster I) and 2023HBW032 (cluster IV), and E. arundinaceus accessions 2023BM023 (cluster I) and 2023BM246 (cluster II), exhibited outstanding performance in yield and quality traits.

Conclusion The sugarcane wild germplasm resources collected in northern Guangdong have rich genetic diversity in phenotypic traits, and six germplasms with excellent comprehensive performance are screened out, which provide excellent gene sources for sugarcane breeding.