Cytological characterization of anther culture derived plants from the interspecific crosses between Oryza sativa x Oryza australinesis and Oryza sativa x Oryza brachyantha

Abstract

Anther culture is being used in cereal crop improvement both as a source of haploids and for inducing the new genetic variability. We studied the possibilities of producing the aneuploids in rice by anther culture. Anthers for callus induction were plated on semi solid media. Callus formation was observed 20 days after plating. The anthers became necrotic prior to callus formation. Tapei 309 exhibited the highest callus induction efficiency (7.8%) followed by IR31917-45-3-2 (7.7%). IR56 produced (1.45%) callus. The F1 hybrids (IR31917-45-3-2 x Oryza australiensis) and IR56 x Oryza brachyantha responded poorly for callus induction (0.033%) and (0.030%) respectively. The 879 calli of IR31917-45-3-2 regenerated into six (0.68%) green plants and 79 (8.9%) albinos. All the green plants were haploids. No green plant was produced from the 112 calli of IR56. Similarly, the calli from IR56 x O. brachyantha did not show any plant regeneration. The calli from the F1 hybrid (IR31917-45-3-2 x O. australiensis) yielded six (20.6%) green and two (6.89%) albino plants. Three of the six plants did not grow after regeneration, while the remaining three plants were used for cytological studies. One plant was aneuploid with 27 chromosomes. Genomic in situ hybridization (GISH) using biotin labeled genomic DNA unequivocally detected 14 chromosomes of O. australiensis and 13 chromosomes from IR31917-45-3-2 in this aneuploid. Similarly, in the other two plants with 24 chromosomes each, the 12 chromosomes of O. australiensis could be discriminated from the 12 chromosomes from IR56. © 2011 Academic Journals.