Abstract:

To understand inheritance of pollen fertility in progenies of indica-japonica hybrid rice, the present study tested pollen fertility of 47 indica-japonica F₁ and tracked that in progenies of a representative hybrid, IR36/Kamairazu (KM). The 47 hybrids had an averaged pollen fertility of (79.9±31.2)%, and 68% of them showed partial pollen sterility by their fertility lower than 90%. The pollen fertility of IR36/KM F₁ was 79.5%, its derived F₂ plants have a higher averaged fertility as (91.0±15.7)% (Fig.1). A plant A4-3, which was from F₂ population and have pollen fertility of 98.3%, showed averaged fertility of (95.9±11.1)% in its derived F₃ population including 81 plants. While, a plant A4-6, which has pollen fertility of 61%, showed a significant lower averaged fertility of (74.3±35.2)% in its derived population including 51 plants (Fig.1). Two plants which were in F₃ population derived from A4-3 and have pollen fertility of 99.2% and 99.5%, derived populations of fertility as (93.0±7.4)% and (94.9±3.5)%, respectively. While, two plants, both of which have pollen fertility of 69.2%, derived populations of fertility as (88.5±22.1)% and (89.8±6.7)% (Table 1). The results implied that, pollen fertility of IR36/KM was controlled by multigene, and showed conform to the allelic interaction model. In the F₂, two F₃ and four F₄ populations, there were no significant correlation between pollen fertility and spikelet fertilized rate in populations which have higher averaged pollen fertility, while, showed significant correlation in populations which have lower averaged pollen fertility (Table 2).

Key words: Rice, Indica-japonica hybrid, Pollen fertility, Inheritance