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

General and specific combining abilities for chlorophyll fluorescence param eters in leaves of seven sugarcane lines widely used as parents in China we re estimated from seedlings of the 12 crosses mated in an incomplete dialle l cross-design and of two reciprocal crosses. Results indicated that potent ial quantum yield of PSII, measured as F-v/F-m, was highly inherited and de pended on nonadditive gene effects, however, the inheritances of the photos ynthetic activities estimated by Rfd and the pool size of the electron acce pters on the reducing side of PSII as measured by T-1/2 depended on additiv e gene effects. Heritability of T-1/2 was less than that of the other fluor escence parameters. The high general combining ability of YN73-204, CP67-41 2 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.