ASSESSMENT OF THE GENETIC DIVERSITY OF NEW SUGARCANE HYBRIDS USING PRINCIPAL COMPONENT AND CLUSTER ANALYSES

Abstract

With a cultivated area of approximately 800 thousand hectares distributed in 15 states, sugarcane (Saccharum spp.) is one of the main crops in Mexico. Despite its socioeconomic importance, the genetic base of this crop has been reduced in recent decades, making the production system vulnerable to both biotic and abiotic stresses. For this reason, the Colegio de Postgraduados Campus Córdoba initiated a varietal selection program in 2009. In this study, morphological and agronomic attributes of 20 advanced hybrids were analyzed during the 2020-2021 and 2021-2022 growing seasons to determine genetic variability based on principal component analysis (PCA) and cluster analysis. Commercial cultivars widely planted in the area of influence of the Córdoba Campus (CP 72-2086, Mex 79-431, Mex 69-290 and Mex 05-204) were used as reference samples. In terms of agronomic indicators, most of the new hybrids showed higher averages than the commercial control cultivars. The hybrids COLPOSCCMex 09-50 and COLPOSCCMex 09-66 showed better germination capacity. The average height of the tallest milling stems was presented by the hybrids COLPOSCCMex 09-341 (318.1 cm) and COLPOSCCMex 09-93 (311.85 cm). The hybrid COLPOSCCMex 09-289 showed outstanding values for five variables: diameter (36.43 mm), °Brix (21.89 %), stem height (149.33 cm), leaf width (5.36 cm) and number of leaves (11.15). Morphological characterization was carried out according to 54 descriptors, combining categorical and continuous traits that were easy to observe, with a high degree of differentiation and low environmental influence. Principal component and cluster analyses showed the distribution of hybrids into five groups. These results show promising sugarcane lines with high yields, which can contribute to genetic diversity in agroecological zones where they can be adapted.