Sexual Hybrids of Azolla filiculoides with A. microphylla uri icon

abstract

  • Sexual hybrids of Azolla microphylla with A. filiculoides were reported p reviously. The reciprocal cross-A. filiculoides with A. microphylla was made. Among 114 crosses, eventually 9 populations survived. Hybridization was confirmed by the isozyme patterns and monoclonal antibody specific to cyano-symbiont of A. filiculoides. One of them (IRRI Accession No. FI 1064) was found to be non-hybrid. Five strains (FI 1066-1070) grew poorly and were pale green at the initial stage of the sporophyte growth with symbiotic cyanobacteria inside and outside leaf cavities. Cyano-symbionts eventually entered in the leaf cavities, or lost (FI 1070). Three strains (FI 1062, FI 1063, FI 1065) grew apparently normally, but two of them were devoid of cyano-symbionts (FI 1062, 1063). Strain FI 1065 grew as good as both parents at 26/18-degrees-C, but strains FI 1066-1069 produced 50% less biomass than both the parents. Their acetylene reduction activity was 20% less than the parents, resulting in the higher N contents than the parents. At 37/29-degrees-C, all the hybrids produced less biomass than heat-sensitive female parent. Particularly strains FI 1066-1069 died in a 2-3 week period at this high temperature. Combined N could not repair poor growth. The hybrids with A. filiculorides as a female parent exhibited higher sensitivity to high temperature than the hybrids with 4. microphylla as a female parent.

publication date

  • 1993
  • 1993
  • 1993