Analyses for inheritance and combining ability of photochemical activities measured by chlorophyll fluorescence in the segregating generation of sugarcane

General and specific combining abilities for chlorophyll fluorescence parameters in leaves of seven sugarcane lines widely used as parents in China were estimated from seedlings of the 12 crosses mated in an incomplete diallel cross-design and of two reciprocal crosses. Results indicated that potential quantum yield of PSII, measured as F-v/F-m, was highly inherited and depended on nonadditive gene effects, however, the inheritances of the photosynthetic activities estimated by Rfd and the pool size of the electron accepters on the reducing side of PSII as measured by T-1/2 depended on additive gene effects. Heritability of T-1/2 was less than that of the other fluorescence parameters. The high general combining ability of YN73-204, CP67-412 as female parents and Ya73-512, Ya71-374 as male parents identified those lines as parents with high photosynthetic efficiency. The performances of F-1 progenies derived from YN73-204 x Ya73-512 and CP67-412 x Ya73-512 were the most desired cross-combinations for high photosynthetic efficiency. (C) 2000 Elsevier Science B.V. All rights reserved.