Caryopsis Germination in Different Methodologies of Energy-sugarcane Crossing (Saccharum officinarum L.)

Aims: To compare and evaluate the germination index of caryopsis obtained by means of different crossing methods and to determine the quantitative of seeds to be used to compose the base population for selection among families by the Simplified Selection System (SSS) method.

Study Design: The experiment was conducted under a completely randomized design.

Place and Duration of Study: Devaneio Station of Sugarcane Flowering and Crossing and Experimental Sugarcane Station of Carpina, between February 2018 and December 2018.

Methodology: 27 crosses were performed, being eight biparental, ten polycrossing and nine self-fertilized. Germination tests were carried out in the greenhouse. From each crossing, four samples were sown with 0.5g caryopsis. The number of germinated caryopsis per box, five and thirty days after sowing, was evaluated to estimate the percentage of germination (% G).

Results: In the first evaluation, the C27 crossing (53.73%) presented the highest average. The caryopsis obtained by self-fertilization (12.82%) presented the highest germination average, followed by the polycrossing (10.88%) and the biparental crosses (9.99%). In the second evaluation, it was found that the crosses C8 (76.74%), C27 (61.02%), C3 (53.99%) and C13 (49.65%) presented with averages high. The highest percentage of germination was verified by the biparental method (31.10%), followed by the self-fertilizations (21.35%) and the polycrossing (20.43%).

Conclusion: Only crosses that show high germination are recommended for the composition of the families that will be evaluated through the Simplified System of Selection; caryopsis obtained through self-fertilization germinate rapidly compared to the methods of the polycrossing and biparental with respect to crosses between selected energy-sugarcane parents; biparental crosses between selected energy-sugarcane parents tend to have higher fertility of caryopsis than those obtained by means of polycrossing or self-fertilization; the families C1, C3, C8, C13, C26 and C27 can be used to compose the base populations in the SSS.